factory girl - Page 64 - Developer IT

Install Peppermint OS three on Asus EeePC

- by Kithoth

I just had a new Asus EeePC R051CX. Out of the box, the installed OS is Ubuntu 12.04 LTS, but I am trying to install Peppermint OS three (as single boot). Problem. Once on live CD (well, live USB stick...), I'm in trouble in both following situations: Try Peppermint OS Live In this case, the first thing I get is a message reading The system is running in low-graphics mode Your screen, graphics card, and input device settings could not be detected correctly. You will need to configure these yourself. I can solely press "return" to accept, then I have a list of 4 options to answer the question "What would you like to do?". But I simply can't do anything at this moment, except switching to console mode or rebooting (keyboard / mouse controls don't allow me to do anything else). Install Peppermint OS Something I really don't understand... it launches the Ubuntu Recovery Media (which was already installed when I received the device)! Also, it says in the bottom ERROR: This recovery media only functions on Ubuntu systems. All I can do is quit (that is, reboot). One last important thing that comes to my mind: this stick worked just fine on the other computers I've tried it on. I really hope someone could bring me the light, a friend of mine told me how cool this OS is for EeePCs. Don't want to give up! Thanks. Edit I finally could install Peppermint, but not by understanding why I couldn't do it the logical way. Instead, I reinstalled Ubuntu myself (erasing the factory one). Then, I could simply boot on my live USB and perform a fresh install of Peppermint. So, I still don't know how and why the mentioned problem occurred.

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Windows 7 misses keystrokes from internal keyboard after hibernation (on Acer Aspire 5820)

- by ron

I face a very strange symptom on my Acer Aspire laptop (with the factory default Win7 install and divers. Windows update running). After waking the computer from hibernation, it is a pain to type, since on average 5-10 keypresses are missing per 100 presses, using the laptop's keyboard. Steps to reproduce: 1) Power off 2) Power on, wait for system to become usable 3) Open notepad, for 5 times do hit 10x the same character. This gives a similar pattern of 50 chars total: xxxxxxxxxxyyyyyyyyyyaaaaaaaaaassssssssssdddddddddd 4) Optionally repeat. Everything is fine this far. 5) Hibernate. 6) Power on and resume. 7) Repeat steps 3)-4). This time approximately 3-5 character will be missing from each 50 characters. What I ruled out: putting to Sleep or just Locking and resuming from there does not cause problem battery / AC usage does not matter net connection does not matter running processes seem to be the same before and after hibernation key press speed doesn't really matter. For the test I use a nominal 3-5 strokes/second beat. plugging in an external USB keyboard works fine, but the built-in one still misbehaves What could be the problem? How could I diagnose if the keypresses arrive in, but get swallowed at some point? (maybe some nasty keyboard handler hook misbehaves?). Update: It seems that pushing the PowerSmart button and toggling to power saving state fixes the problem. Also, toggling it again back to the original state keeps it fixed. So this may be a fine workaround, but is not a conforming solution.

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Linux that restores itself on each reboot

- by jettero

I'm looking for methods and software to help create a variant of lubuntu that will restore itself to an install state and/or update on every boot. I'm thinking of doing things like putting the root filesystem on a squashfs and using unionfs and tmpfs to make root writable, but automagically restorable. I'm thinking of updating the squashfs with rsync. Perhaps there are other ways to approach the problem. Perhaps root needn't be writable at all. All thoughts welcome. The home dir would be writable in the usual way. The goal, if it matters, is a Linux that's simple to maintain from the home office, but that functions correctly for customers. We have some custom software that we wish for customers to be able to run trivially on equipment we provide. Ideally these devices would have a "restore to factory" function that would put it back the way we intended. If this is part of the normal boot cycle, so much the better. Why lubuntu? Personal preference for this application. It has a usable desktop, but doesn't take up much ram.

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Eee PC 1015BX ram compatibility?

- by AdrianaMX

Asus Eee PC 1015BX Operating System Windows 7 Starter, 32bit CPU AMD Fusion APU C60 1.0GHz (dual core) Processor Graphic AMD Radeon HD 6290 (256 MB Shared) Memory DDR3, 1 x SO-DIMM, 1GB I have upgraded the preloaded "Windows 7 Starter" to "Windows 7 Professional" I want to upgrade the ram, from 1gb (factory) to 4 gb. What should i buy? SODDR3, 4GB, 1066MHZ, PC3-8500, 204PIN? or SODDR3, 4GB, 1333MHZ, PC3-10666, 204PIN? I already know that Windows 7 32-bits can't handle 4gb, only 3gb (but 3gb is better than one stick of 2gb). ASUS send me this link, but i think they are wrong, (or Insufficient Information for me) http://www.kingston.com/us/memory/search/Default.aspx?DeviceType=3&Mfr=ASU&Line=Eee%20PC&Model=71404 Thank you. CPU-Z Chipset Memory Type DDR3 Memory Size 750 MBytes Memory Frequency 532.2 MHz (3:16) CAS# latency (CL) 7.0 RAS# to CAS# delay (tRCD) 7 RAS# Precharge (tRP) 7 Cycle Time (tRAS) 20 Bank Cycle Time (tRC) 27 Memory SPD NO INFO AIDA64 North bridge Properties North bridge AMD K14 IMC Supported Memory Types DDR3-800, DDR3-1066 SDRAM Memory Slots DRAM Slot #1 1 GB (DDR3 SDRAM) Integrated Graphics Controller Graphics Controller Type AMD Radeon HD 6290 (Wrestler) Graphics Controller Status Enabled Graphics Frame Buffer Size 256 MB

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Windows 7 misses keystrokes from internal keyboard after hibernation (on Acer Aspire 5820)

- by ron

I face a very strange symptom on my Acer Aspire laptop (with the factory default Win7 install and divers. Windows update running). After waking the computer from hibernation, it is a pain to type, since on average 5-10 keypresses are missing per 100 presses, using the laptop's keyboard. Steps to reproduce: 1) Power off 2) Power on, wait for system to become usable 3) Open notepad, for 5 times do hit 10x the same character. This gives a similar pattern of 50 chars total: xxxxxxxxxxyyyyyyyyyyaaaaaaaaaassssssssssdddddddddd 4) Optionally repeat. Everything is fine this far. 5) Hibernate. 6) Power on and resume. 7) Repeat steps 3)-4). This time approximately 3-5 character will be missing from each 50 characters. What I ruled out: putting to Sleep or just Locking and resuming from there does not cause problem battery / AC usage does not matter net connection does not matter running processes seem to be the same before and after hibernation key press speed doesn't really matter. For the test I use a nominal 3-5 strokes/second beat. plugging in an external USB keyboard works fine, but the built-in one still misbehaves What could be the problem? How could I diagnose if the keypresses arrive in, but get swallowed at some point? (maybe some nasty keyboard handler hook misbehaves?). Update: It seems that pushing the PowerSmart button and toggling to power saving state fixes the problem. Also, toggling it again back to the original state keeps it fixed. So this may be a fine workaround, but is not a conforming solution.

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Reduce size of MP4

- by testing

I have a MP4 file with a lengh of 22:44. Here are the details: Video: width: 720 px height: 404 px data bitrate: 1022 kBit/s overall bitrate: 1182 kBit/s fps: 24 codec: H264 - MPEG4 AVC (part 10) (avc1) Audio: bitrate: 159 kBit/s stereo sample rate: 48 kHz codec: MPEG AAC Audio (mp4a) I thought I can reduce the current filesize (about 200 MB) by reducing the width and the height (420 x 236). I tried different programs: Handbrake, Format Factory, Next Video Converter and Super. The first three didn't worked as expected: Handbrake has a bug by setting the width and the height, the next two doesn't allow the fine setting of the videosize (only presets of width and height). Super seems to be the best, but I didn't found a setting which reduces the file size. I reduced the width and the height but only got 20 MB less. Now I tried the xth setting and I still get a too high file size. I want to reduce the filesize to 100 MB or less. The ouput format should be FLV or MP4, because I need this for flowplayer. Which settings of SUPER or which program should I use to reduce the file size? Of course the video should still be viewable.

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Hibernate Exception, what wrong ? [[Exception in thread "main" org.hibernate.InvalidMappingException

- by user195970

I use netbean 6.7.1 to write "hello world" witch hibernate, but I get some errors, plz help me, thank you very much. my exception init: deps-module-jar: deps-ear-jar: deps-jar: Copying 1 file to F:\Documents and Settings\My Dropbox\DropboxNetBeanProjects\loginspring\build\web\WEB-INF\classes compile-single: run-main: Oct 25, 2009 2:44:05 AM org.hibernate.cfg.Environment <clinit> INFO: Hibernate 3.2.5 Oct 25, 2009 2:44:05 AM org.hibernate.cfg.Environment <clinit> INFO: hibernate.properties not found Oct 25, 2009 2:44:05 AM org.hibernate.cfg.Environment buildBytecodeProvider INFO: Bytecode provider name : cglib Oct 25, 2009 2:44:05 AM org.hibernate.cfg.Environment <clinit> INFO: using JDK 1.4 java.sql.Timestamp handling Oct 25, 2009 2:44:05 AM org.hibernate.cfg.Configuration configure INFO: configuring from resource: /hibernate.cfg.xml Oct 25, 2009 2:44:05 AM org.hibernate.cfg.Configuration getConfigurationInputStream INFO: Configuration resource: /hibernate.cfg.xml Oct 25, 2009 2:44:06 AM org.hibernate.cfg.Configuration addResource INFO: Reading mappings from resource : hibernate/Tbluser.hbm.xml Oct 25, 2009 2:44:06 AM org.hibernate.util.XMLHelper$ErrorLogger error SEVERE: Error parsing XML: XML InputStream(1) Document is invalid: no grammar found. Oct 25, 2009 2:44:06 AM org.hibernate.util.XMLHelper$ErrorLogger error SEVERE: Error parsing XML: XML InputStream(1) Document root element "hibernate-mapping", must match DOCTYPE root "null". Exception in thread "main" org.hibernate.InvalidMappingException: Could not parse mapping document from resource hibernate/Tbluser.hbm.xml at org.hibernate.cfg.Configuration.addResource(Configuration.java:569) at org.hibernate.cfg.Configuration.parseMappingElement(Configuration.java:1587) at org.hibernate.cfg.Configuration.parseSessionFactory(Configuration.java:1555) at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1534) at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1508) at org.hibernate.cfg.Configuration.configure(Configuration.java:1428) at org.hibernate.cfg.Configuration.configure(Configuration.java:1414) at hibernate.CreateTest.main(CreateTest.java:22) Caused by: org.hibernate.InvalidMappingException: Could not parse mapping document from invalid mapping at org.hibernate.cfg.Configuration.addInputStream(Configuration.java:502) at org.hibernate.cfg.Configuration.addResource(Configuration.java:566) ... 7 more Caused by: org.xml.sax.SAXParseException: Document is invalid: no grammar found. at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:195) at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.error(ErrorHandlerWrapper.java:131) at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:384) at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:318) at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(XMLNSDocumentScannerImpl.java:250) at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl$NSContentDriver.scanRootElementHook(XMLNSDocumentScannerImpl.java:626) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:3095) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:921) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:648) at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:140) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:510) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:807) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:737) at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:107) at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1205) at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:522) at org.dom4j.io.SAXReader.read(SAXReader.java:465) at org.hibernate.cfg.Configuration.addInputStream(Configuration.java:499) ... 8 more Java Result: 1 BUILD SUCCESSFUL (total time: 1 second) hibernate.cfg.xml <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory> <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property> <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property> <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hibernate</property> <property name="hibernate.connection.username">root</property> </session-factory> </hibernate-configuration> Tbluser.hbm.xml <?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">  <hibernate-mapping> <class name="hibernate.Tbluser" table="tbluser" catalog="hibernate"> <id name="userId" type="java.lang.Integer"> <column name="userID" /> <generator class="identity" /> </id> <property name="username" type="string"> <column name="username" length="50" /> </property> <property name="password" type="string"> <column name="password" length="50" /> </property> <property name="email" type="string"> <column name="email" length="50" /> </property> <property name="phone" type="string"> <column name="phone" length="50" /> </property> <property name="groupId" type="java.lang.Integer"> <column name="groupID" /> </property> </class> </hibernate-mapping> Tbluser.java package hibernate; // Generated Oct 25, 2009 2:37:30 AM by Hibernate Tools 3.2.1.GA /** * Tbluser generated by hbm2java */ public class Tbluser implements java.io.Serializable { private Integer userId; private String username; private String password; private String email; private String phone; private Integer groupId; public Tbluser() { } public Tbluser(String username, String password, String email, String phone, Integer groupId) { this.username = username; this.password = password; this.email = email; this.phone = phone; this.groupId = groupId; } public Integer getUserId() { return this.userId; } public void setUserId(Integer userId) { this.userId = userId; } public String getUsername() { return this.username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return this.password; } public void setPassword(String password) { this.password = password; } public String getEmail() { return this.email; } public void setEmail(String email) { this.email = email; } public String getPhone() { return this.phone; } public void setPhone(String phone) { this.phone = phone; } public Integer getGroupId() { return this.groupId; } public void setGroupId(Integer groupId) { this.groupId = groupId; } }

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org.hibernate.MappingException: Unknown entity:

- by tsegay

I tried to see all the questions on this topic but none of them helped me. And I really want to understand what is going on with my code. I have a standalone application which uses spring and Hibernate as JPA and I am trying to run the test using a single main Class My main class package edu.acct.tsegay.common; import edu.acct.tsegay.model.User; import edu.acct.tsegay.business.IUserBusinessObject; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class App { public static void main(String[] args) { try { ApplicationContext context = new ClassPathXmlApplicationContext( "Spring3AndHibernate-servlet.xml"); IUserBusinessObject userBusinessObject = (IUserBusinessObject) context .getBean("userBusiness"); User user = (User) context.getBean("user1"); user.setPassword("pass"); user.setUsername("tsegay"); System.out.println(user.getPassword()); userBusinessObject.delete(user); User user2 = new User(); user2.setUsername("habest"); user2.setPassword("pass1"); System.out.println(user2.getPassword()); /* * userBusinessObject.save(user2); * * User user3 = userBusinessObject.searchUserbyId("tsegay"); * System.out.println("Search Result: " + user3.getUsername()); */ System.out.println("Success"); } catch (Exception e) { e.printStackTrace(); } } } my application context is: <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">  <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="com.mysql.jdbc.Driver" /> <property name="url" value="jdbc:mysql://localhost:3306/test" /> <property name="username" value="test" /> <property name="password" value="password" /> </bean>  <bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean"> <property name="dataSource"> <ref bean="dataSource" /> </property> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop> <prop key="hibernate.show_sql">true</prop> </props> </property> </bean>  <bean id="userBusiness" class="edu.acct.tsegay.business.UserBusinessObject"> <property name="userDao" ref="userDao" /> </bean> <bean id="user1" class="edu.acct.tsegay.model.User"> <property name="username" value="tse" /> <property name="password" value="pass" /> </bean>  <bean id="userDao" class="edu.acct.tsegay.dao.UserDao"> <property name="sessionFactory" ref="sessionFactory" /> </bean> </beans> My User Model is: package edu.acct.tsegay.model; import java.io.Serializable; import javax.persistence.Entity; import javax.persistence.Id; import javax.persistence.Version; import org.hibernate.annotations.NaturalId; @Entity public class User implements Serializable { /** * */ private static final long serialVersionUID = 1L; private String username; private String password; private Integer VERSION; @Version public Integer getVERSION() { return VERSION; } public void setVERSION(Integer vERSION) { VERSION = vERSION; } @NaturalId public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } } My DAO is: package edu.acct.tsegay.dao; import edu.acct.tsegay.model.User; import org.hibernate.SessionFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.orm.hibernate3.HibernateTemplate; import org.springframework.stereotype.Repository; @Repository public class UserDao implements IUserDao { private SessionFactory sessionFactory; private HibernateTemplate hibernateTemplate; public SessionFactory getSessionFactory() { return sessionFactory; } @Autowired public void setSessionFactory(SessionFactory sessionFactory) { this.sessionFactory = sessionFactory; this.hibernateTemplate = new HibernateTemplate(sessionFactory); } public void save(User user) { // TODO Auto-generated method stub // getHibernateTemplate().save(user); this.hibernateTemplate.save(user); } public void delete(User user) { // TODO Auto-generated method stub this.hibernateTemplate.delete(user); } public User searchUserbyId(String username) { // TODO Auto-generated method stub return this.hibernateTemplate.get(User.class, username); } } And this my stacktrace error when i run the program: pass org.springframework.orm.hibernate3.HibernateSystemException: Unknown entity: edu.acct.tsegay.model.User; nested exception is org.hibernate.MappingException: Unknown entity: edu.acct.tsegay.model.User at org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:679) at org.springframework.orm.hibernate3.HibernateAccessor.convertHibernateAccessException(HibernateAccessor.java:412) at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:411) at org.springframework.orm.hibernate3.HibernateTemplate.executeWithNativeSession(HibernateTemplate.java:374) at org.springframework.orm.hibernate3.HibernateTemplate.delete(HibernateTemplate.java:837) at org.springframework.orm.hibernate3.HibernateTemplate.delete(HibernateTemplate.java:833) at edu.acct.tsegay.dao.UserDao.delete(UserDao.java:34) at edu.acct.tsegay.business.UserBusinessObject.delete(UserBusinessObject.java:30) at edu.acct.tsegay.common.App.main(App.java:23) Caused by: org.hibernate.MappingException: Unknown entity: edu.acct.tsegay.model.User at org.hibernate.impl.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:580) at org.hibernate.impl.SessionImpl.getEntityPersister(SessionImpl.java:1365) at org.hibernate.event.def.DefaultDeleteEventListener.onDelete(DefaultDeleteEventListener.java:100) at org.hibernate.event.def.DefaultDeleteEventListener.onDelete(DefaultDeleteEventListener.java:74) at org.hibernate.impl.SessionImpl.fireDelete(SessionImpl.java:793) at org.hibernate.impl.SessionImpl.delete(SessionImpl.java:771) at org.springframework.orm.hibernate3.HibernateTemplate$25.doInHibernate(HibernateTemplate.java:843) at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:406) ... 6 more Please let me know if you need any more of my configuration. Any help is much appreciated..

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need prefuse graph edges like arrows

- by merve

Hello, I did my homework and searched both google for a sample and a topic that is answered before on stackoverflow. But nothing has been found. My problem is ordinary edges who does not have a view like arrows. Here is what i do to hope there is forward arrows from target to destination: LabelRenderer nameLabel = new LabelRenderer("name"); nameLabel.setRoundedCorner(8, 8); DefaultRendererFactory rendererFactory = new DefaultRendererFactory(nameLabel); EdgeRenderer edgeRenderer; edgeRenderer = new EdgeRenderer(prefuse.Constants.EDGE_TYPE_LINE, prefuse.Constants.EDGE_ARROW_FORWARD); rendererFactory.setDefaultEdgeRenderer(edgeRenderer); vis.setRendererFactory(rendererFactory); Here is what i see about colour of edges, hoping these must not be transparent: int[] palette = new int[]{ColorLib.rgb(255, 180, 180), ColorLib.rgb(190, 190, 255)}; DataColorAction fill = new DataColorAction("socialnet.nodes", "gender", Constants.NOMINAL, VisualItem.FILLCOLOR, palette); ColorAction text = new ColorAction("socialnet.nodes", VisualItem.TEXTCOLOR, ColorLib.gray(0)); ColorAction edges = new ColorAction("socialnet.edges", VisualItem.STROKECOLOR, ColorLib.gray(200)); ColorAction arrow = new ColorAction("socialnet.edges", VisualItem.FILLCOLOR, ColorLib.gray(200)); ActionList colour = new ActionList(); colour.add(fill); colour.add(text); colour.add(edges); colour.add(arrow); vis.putAction("colour", colour); Thus, i wonder where am i wrong? Why my edges do not seem like arrows? Thanks for any idea. For more detail, i want to paste all of the code: /* * To change this template, choose Tools | Templates * and open the template in the editor. */ package prefusedeneme; import javax.swing.JFrame; import prefuse.data.*; import prefuse.data.io.*; import prefuse.Display; import prefuse.Visualization; import prefuse.render.*; import prefuse.util.*; import prefuse.action.assignment.*; import prefuse.Constants; import prefuse.visual.*; import prefuse.action.*; import prefuse.activity.*; import prefuse.action.layout.graph.*; import prefuse.controls.*; import prefuse.data.expression.Predicate; import prefuse.data.expression.parser.ExpressionParser; public class SocialNetworkVis { public static void main(String argv[]) { // 1. Load the data Graph graph = null; /* graph will contain the core data */ try { graph = new GraphMLReader().readGraph("socialnet.xml"); /* load the data from an XML file */ } catch (DataIOException e) { e.printStackTrace(); System.err.println("Error loading graph. Exiting..."); System.exit(1); } // 2. prepare the visualization Visualization vis = new Visualization(); /* vis is the main object that will run the visualization */ vis.add("socialnet", graph); /* add our data to the visualization */ // 3. setup the renderers and the render factory // labels for name LabelRenderer nameLabel = new LabelRenderer("name"); nameLabel.setRoundedCorner(8, 8); /* nameLabel decribes how to draw the data elements labeled as "name" */ // create the render factory DefaultRendererFactory rendererFactory = new DefaultRendererFactory(nameLabel); EdgeRenderer edgeRenderer; edgeRenderer = new EdgeRenderer(prefuse.Constants.EDGE_TYPE_LINE, prefuse.Constants.EDGE_ARROW_FORWARD); rendererFactory.setDefaultEdgeRenderer(edgeRenderer); vis.setRendererFactory(rendererFactory); // 4. process the actions // colour palette for nominal data type int[] palette = new int[]{ColorLib.rgb(255, 180, 180), ColorLib.rgb(190, 190, 255)}; /* ColorLib.rgb converts the colour values to integers */ // map data to colours in the palette DataColorAction fill = new DataColorAction("socialnet.nodes", "gender", Constants.NOMINAL, VisualItem.FILLCOLOR, palette); /* fill describes what colour to draw the graph based on a portion of the data */ // node text ColorAction text = new ColorAction("socialnet.nodes", VisualItem.TEXTCOLOR, ColorLib.gray(0)); /* text describes what colour to draw the text */ // edge ColorAction edges = new ColorAction("socialnet.edges", VisualItem.STROKECOLOR, ColorLib.gray(200)); ColorAction arrow = new ColorAction("socialnet.edges", VisualItem.FILLCOLOR, ColorLib.gray(200)); /* edge describes what colour to draw the edges */ // combine the colour assignments into an action list ActionList colour = new ActionList(); colour.add(fill); colour.add(text); colour.add(edges); colour.add(arrow); vis.putAction("colour", colour); /* add the colour actions to the visualization */ // create a separate action list for the layout ActionList layout = new ActionList(Activity.INFINITY); layout.add(new ForceDirectedLayout("socialnet")); /* use a force-directed graph layout with default parameters */ layout.add(new RepaintAction()); /* repaint after each movement of the graph nodes */ vis.putAction("layout", layout); /* add the laout actions to the visualization */ // 5. add interactive controls for visualization Display display = new Display(vis); display.setSize(700, 700); display.pan(350, 350); // pan to the middle display.addControlListener(new DragControl()); /* allow items to be dragged around */ display.addControlListener(new PanControl()); /* allow the display to be panned (moved left/right, up/down) (left-drag)*/ display.addControlListener(new ZoomControl()); /* allow the display to be zoomed (right-drag) */ // 6. launch the visualizer in a JFrame JFrame frame = new JFrame("prefuse tutorial: socialnet"); /* frame is the main window */ frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.add(display); /* add the display (which holds the visualization) to the window */ frame.pack(); frame.setVisible(true); /* start the visualization working */ vis.run("colour"); vis.run("layout"); } }

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Only error showing is null, rss feed reader not working

- by Callum

I have been following a tutorial which is showing me how to create an rssfeed reader, I come to the end of the tutorial; and the feed is not displaying in the listView. So I am looking for errors in logCat, but the only one I can find is one just saying 'null', which is not helpful at all. Can anyone spot a potential problem with the code I have written? Thanks. DirectRSS(main class): package com.example.rssapplication; import java.util.List; import android.app.ListActivity; import android.content.pm.ActivityInfo; import android.os.Bundle; import android.util.Log; import android.widget.ArrayAdapter; import android.widget.ListView; public class DirectRSS extends ListActivity{ @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.directrss); //Set to portrait, so that every time the view changes; it does not run the DB query again... setRequestedOrientation (ActivityInfo.SCREEN_ORIENTATION_PORTRAIT); try{ RssReader1 rssReader = new RssReader1("http://www.skysports.com/rss/0,20514,11661,00.xml"); ListView list = (ListView)findViewById(R.id.list); ArrayAdapter<RssItem1> adapter = new ArrayAdapter<RssItem1>(this, android.R.layout.simple_list_item_1); list.setAdapter(adapter); list.setOnItemClickListener(new ListListener1(rssReader.getItems(),this)); }catch(Exception e) { String err = (e.getMessage()==null)?"SD Card failed": e.getMessage(); Log.e("sdcard-err2:",err + " " + e.getMessage()); // Log.e("Error", e.getMessage()); Log.e("LOGCAT", "" + e.getMessage()); } } } ListListener1: package com.example.rssapplication; import java.util.List; import android.app.Activity; import android.content.Intent; import android.net.Uri; import android.view.View; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; public class ListListener1 implements OnItemClickListener{ List<RssItem1> listItems; Activity activity; public ListListener1(List<RssItem1> listItems, Activity activity) { this.listItems = listItems; this.activity = activity; } @Override public void onItemClick(AdapterView<?> parent, View view, int pos, long id) { // TODO Auto-generated method stub Intent i = new Intent(Intent.ACTION_VIEW); i.setData(Uri.parse(listItems.get(pos).getLink())); activity.startActivity(i); } } RssItem1: package com.example.rssapplication; public class RssItem1 { private String title; private String link; public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getLink() { return link; } public void setLink(String link) { this.link = link; } } RssParseHandler1: package com.example.rssapplication; import java.util.ArrayList; import java.util.List; import org.xml.sax.Attributes; import org.xml.sax.SAXException; import org.xml.sax.helpers.DefaultHandler; public class RssParseHandler1 extends DefaultHandler{ private List<RssItem1> rssItems; private RssItem1 currentItem; private boolean parsingTitle; private boolean parsingLink; public RssParseHandler1(){ rssItems = new ArrayList<RssItem1>(); } public List<RssItem1> getItems(){ return rssItems; } @Override public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException { if("item".equals(qName)){ currentItem = new RssItem1(); } else if("title".equals(qName)){ parsingTitle = true; } else if("link".equals(qName)){ parsingLink = true; } // TODO Auto-generated method stub super.startElement(uri, localName, qName, attributes); } @Override public void endElement(String uri, String localName, String qName) throws SAXException { if("item".equals(qName)){ rssItems.add(currentItem); currentItem = null; } else if("title".equals(qName)){ parsingTitle = false; } else if("link".equals(qName)){ parsingLink = false; } // TODO Auto-generated method stub super.endElement(uri, localName, qName); } @Override public void characters(char[] ch, int start, int length) throws SAXException { if(parsingTitle) { if(currentItem!=null) { currentItem.setTitle(new String(ch,start,length)); } } else if(parsingLink) { if(currentItem!=null) { currentItem.setLink(new String(ch,start,length)); parsingLink = false; } } // TODO Auto-generated method stub super.characters(ch, start, length); } } RssReader1: package com.example.rssapplication; import java.util.List; import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; public class RssReader1 { private String rssUrl; public RssReader1(String rssUrl) { this.rssUrl = rssUrl; } public List<RssItem1> getItems() throws Exception { SAXParserFactory factory = SAXParserFactory.newInstance(); SAXParser saxParser = factory.newSAXParser(); RssParseHandler1 handler = new RssParseHandler1(); saxParser.parse(rssUrl, handler); return handler.getItems(); } } Here is the logCat also: 08-25 11:13:20.803: D/AbsListView(26291): unregisterIRListener() is called 08-25 11:13:20.803: D/AbsListView(26291): unregisterIRListener() is called 08-25 11:13:20.803: D/AbsListView(26291): unregisterIRListener() is called 08-25 11:13:20.813: D/AbsListView(26291): unregisterIRListener() is called 08-25 11:13:20.813: D/AbsListView(26291): unregisterIRListener() is called 08-25 11:13:20.813: D/AbsListView(26291): unregisterIRListener() is called 08-25 11:13:20.813: W/ApplicationPackageManager(26291): getCSCPackageItemText() 08-25 11:13:20.843: D/AbsListView(26291): Get MotionRecognitionManager 08-25 11:13:20.843: E/sdcard-err2:(26291): SD Card failed null 08-25 11:13:20.843: E/LOGCAT(26291): null 08-25 11:13:20.843: D/AbsListView(26291): onVisibilityChanged() is called, visibility : 4 08-25 11:13:20.843: D/AbsListView(26291): unregisterIRListener() is called 08-25 11:13:20.873: D/AbsListView(26291): onVisibilityChanged() is called, visibility : 0 08-25 11:13:20.883: D/AbsListView(26291): unregisterIRListener() is called 08-25 11:13:20.903: D/AbsListView(26291): unregisterIRListener() is called 08-25 11:13:20.933: D/AbsListView(26291): unregisterIRListener() is called 08-25 11:13:20.963: D/AbsListView(26291): unregisterIRListener() is called 08-25 11:13:20.973: D/AbsListView(26291): unregisterIRListener() is called 08-25 11:13:21.323: D/AbsListView(26291): onVisibilityChanged() is called, visibility : 4 08-25 11:13:21.323: D/AbsListView(26291): unregisterIRListener() is called 08-25 11:13:21.323: D/AbsListView(26291): onVisibilityChanged() is called, visibility : 4 08-25 11:13:21.323: D/AbsListView(26291): unregisterIRListener() is called 08-25 11:13:21.323: D/AbsListView(26291): onVisibilityChanged() is called, visibility : 4 08-25 11:13:21.323: D/AbsListView(26291): unregisterIRListener() is called 08-25 11:13:21.323: D/AbsListView(26291): onVisibilityChanged() is called, visibility : 4 08-25 11:13:21.323: D/AbsListView(26291): unregisterIRListener() is called 08-25 11:13:21.323: D/AbsListView(26291): onVisibilityChanged() is called, visibility : 4 08-25 11:13:21.323: D/AbsListView(26291): unregisterIRListener() is called 08-25 11:13:21.333: D/AbsListView(26291): onVisibilityChanged() is called, visibility : 4 08-25 11:13:21.333: D/AbsListView(26291): unregisterIRListener() is called

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WCF Service returning 400 error: The body of the message cannot be read because it is empty

- by Josh

I have a WCF service that is causing a bit of a headache. I have tracing enabled, I have an object with a data contract being built and passed in, but I am seeing this error in the log: <TraceData> <DataItem> <TraceRecord xmlns="http://schemas.microsoft.com/2004/10/E2ETraceEvent/TraceRecord" Severity="Error"> <TraceIdentifier>http://msdn.microsoft.com/en-US/library/System.ServiceModel.Diagnostics.ThrowingException.aspx</TraceIdentifier> <Description>Throwing an exception.</Description> <AppDomain>efb0d0d7-1-129315381593520544</AppDomain> <Exception> <ExceptionType>System.ServiceModel.ProtocolException, System.ServiceModel, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</ExceptionType> <Message>There is a problem with the XML that was received from the network. See inner exception for more details.</Message> <StackTrace> at System.ServiceModel.Channels.HttpRequestContext.CreateMessage() at System.ServiceModel.Channels.HttpChannelListener.HttpContextReceived(HttpRequestContext context, Action callback) at System.ServiceModel.Activation.HostedHttpTransportManager.HttpContextReceived(HostedHttpRequestAsyncResult result) at System.ServiceModel.Activation.HostedHttpRequestAsyncResult.HandleRequest() at System.ServiceModel.Activation.HostedHttpRequestAsyncResult.BeginRequest() at System.ServiceModel.Activation.HostedHttpRequestAsyncResult.OnBeginRequest(Object state) at System.Runtime.IOThreadScheduler.ScheduledOverlapped.IOCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* nativeOverlapped) at System.Runtime.Fx.IOCompletionThunk.UnhandledExceptionFrame(UInt32 error, UInt32 bytesRead, NativeOverlapped* nativeOverlapped) at System.Threading._IOCompletionCallback.PerformIOCompletionCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* pOVERLAP) </StackTrace> <ExceptionString> System.ServiceModel.ProtocolException: There is a problem with the XML that was received from the network. See inner exception for more details. ---&gt; System.Xml.XmlException: The body of the message cannot be read because it is empty. --- End of inner exception stack trace --- </ExceptionString> <InnerException> <ExceptionType>System.Xml.XmlException, System.Xml, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</ExceptionType> <Message>The body of the message cannot be read because it is empty.</Message> <StackTrace> at System.ServiceModel.Channels.HttpRequestContext.CreateMessage() at System.ServiceModel.Channels.HttpChannelListener.HttpContextReceived(HttpRequestContext context, Action callback) at System.ServiceModel.Activation.HostedHttpTransportManager.HttpContextReceived(HostedHttpRequestAsyncResult result) at System.ServiceModel.Activation.HostedHttpRequestAsyncResult.HandleRequest() at System.ServiceModel.Activation.HostedHttpRequestAsyncResult.BeginRequest() at System.ServiceModel.Activation.HostedHttpRequestAsyncResult.OnBeginRequest(Object state) at System.Runtime.IOThreadScheduler.ScheduledOverlapped.IOCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* nativeOverlapped) at System.Runtime.Fx.IOCompletionThunk.UnhandledExceptionFrame(UInt32 error, UInt32 bytesRead, NativeOverlapped* nativeOverlapped) at System.Threading._IOCompletionCallback.PerformIOCompletionCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* pOVERLAP) </StackTrace> <ExceptionString>System.Xml.XmlException: The body of the message cannot be read because it is empty.</ExceptionString> </InnerException> </Exception> </TraceRecord> </DataItem> </TraceData> So, here is my service interface: [ServiceContract] public interface IRDCService { [OperationContract] Response<Customer> GetCustomer(CustomerRequest request); [OperationContract] Response<Customer> GetSiteCustomers(CustomerRequest request); } And here is my service instance public class RDCService : IRDCService { ICustomerService customerService; public RDCService() { //We have to locate the instance from structuremap manually because web services *REQUIRE* a default constructor customerService = ServiceLocator.Locate<ICustomerService>(); } public Response<Customer> GetCustomer(CustomerRequest request) { return customerService.GetCustomer(request); } public Response<Customer> GetSiteCustomers(CustomerRequest request) { return customerService.GetSiteCustomers(request); } } The configuration for the web service (server side) looks like this: <system.serviceModel> <diagnostics> <messageLogging logMalformedMessages="true" logMessagesAtServiceLevel="true" logMessagesAtTransportLevel="true" /> </diagnostics> <services> <service behaviorConfiguration="MySite.Web.Services.RDCServiceBehavior" name="MySite.Web.Services.RDCService"> <endpoint address="http://localhost:27433" binding="wsHttpBinding" contract="MySite.Common.Services.Web.IRDCService"> <identity> <dns value="localhost:27433" /> </identity> </endpoint> <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" /> </service> </services> <behaviors> <serviceBehaviors> <behavior name="MySite.Web.Services.RDCServiceBehavior">  <serviceMetadata httpGetEnabled="true"/>  <serviceDebug includeExceptionDetailInFaults="true"/> <dataContractSerializer maxItemsInObjectGraph="6553600" /> </behavior> </serviceBehaviors> </behaviors> </system.serviceModel> Here is what my request object looks like [DataContract] public class CustomerRequest : RequestBase { [DataMember] public int Id { get; set; } [DataMember] public int SiteId { get; set; } } And the RequestBase: [DataContract] public abstract class RequestBase : IRequest { #region IRequest Members [DataMember] public int PageSize { get; set; } [DataMember] public int PageIndex { get; set; } #endregion } And my IRequest interface public interface IRequest { int PageSize { get; set; } int PageIndex { get; set; } } And I have a wrapper class around my service calls. Here is the class. public class MyService : IMyService { IRDCService service; public MyService() { //service = new MySite.RDCService.RDCServiceClient(); EndpointAddress address = new EndpointAddress(APISettings.Default.ServiceUrl); BasicHttpBinding binding = new BasicHttpBinding(BasicHttpSecurityMode.None); binding.TransferMode = TransferMode.Streamed; binding.MaxBufferSize = 65536; binding.MaxReceivedMessageSize = 4194304; ChannelFactory<IRDCService> factory = new ChannelFactory<IRDCService>(binding, address); service = factory.CreateChannel(); } public Response<Customer> GetCustomer(CustomerRequest request) { return service.GetCustomer(request); } public Response<Customer> GetSiteCustomers(CustomerRequest request) { return service.GetSiteCustomers(request); } } and finally, the response object. [DataContract] public class Response<T> { [DataMember] public IEnumerable<T> Results { get; set; } [DataMember] public int TotalResults { get; set; } [DataMember] public int PageIndex { get; set; } [DataMember] public int PageSize { get; set; } [DataMember] public RulesException Exception { get; set; } } So, when I build my CustomerRequest object and pass it in, for some reason it's hitting the server as an empty request. Any ideas why? I've tried upping the object graph and the message size. When I debug it stops in the wrapper class with the 400 error. I'm not sure if there is a serialization error, but considering the object contract is 4 integer properties I can't imagine it causing an issue.

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Letter to Ballmer: Making Better Consumer Devices

- by andrewbrust

Last year, I wrote Steve Ballmer an email, and he was kind enough to write me back. The email contained a scan of a column I wrote praising Microsoft’s BI strategy. His reply contained three simple words: “Super nice thanks.” Well, now I’d like to write to Steve again, in an open letter format, and this time the love may be a bit tougher. But I’m still super earnest. The past two days have been eventful ones for Microsoft: The company announced the departure of company veterans Robbie Bach and J Allard and the market announced Apple is now besting Microsoft in market capitalization. Plus, announcements were made that make it plain that Ballmer will, in effect, be running Microsoft’s Entertainment & Devices division himself. With that in mind, I’d like to offer my list of a dozen things I think Microsoft’s CEO should do to improve that division’s offerings and, hopefully, its bottom line. So here goes: 1. On Windows Phone 7, Stay the Course The press is teeming with headlines and reader comments proclaiming the death-before-arrival of Windows Phone 7. That’s plain silly. You’ve got the makings of a great and unique SmartPhone platform, and you’re the only company (even considering RIM) that can offer full fidelity Exchange integration, not to mention implementing Office on the device. Let the existing team finish this puppy and ship it. And then have them pump out a few updates, over-the-air, quickly. Show them that Google Android’s not the only product that can do good, rapid dot releases. And another thing: make sure your OEMs’ devices have flawless touch screens. If they don’t, then you shouldn’t certify them for delivery to customers. Period. Oh, and kill the Kin, quietly. It was DOA, and you know it. 2. Move Media Center to the Xbox Platform Media Center is, at its core, a good product. But delivering a media distribution and DVR platform on a sophisticated PC operating system like Windows 7 just creates too many moving parts. Xbox already functions as the best Media Center extender device – it should actually be the hub as well. Media Center is mostly based on .NET code – and XNA is a .NET environment for Xbox – find a way to bridge that small gap and make Media Center a joy to work with instead of a frustration. Beating Apple TV out of this sub-market is the lowest hanging fruit on the tree (goofy pun, but it’s true). 3. Integrate Media Center with Mediaroom, or Kill the Latter You have two media products with almost identical names. One is for standalone DVRs and the other is for IPTV cable set tops with DVR capabilities. Can we merge these please? My previous request of putting Media Center on Xbox would seem to tie into this nicely, since you’ve announced plans to do that with Mediaroom already. 4. Fix the Red Ring of Death People love the Xbox, but they really don’t love sending their consoles back every 18-24 months, when they get a bunch of red lights flashing on power up. You’ve handled this defect about as gracefully as possible, but it’s been around for a long time now and it doesn’t seem to be fixed yet. You can do better. In fact, you must do better, or you insult your customers. 5. Add Blu Ray to Xbox I know, streaming movies are the future; physical media is legacy technology. So if that’s true, why did you back HD DVD so hard? You know why: for now, the film studios won’t allow a large selection of new release, HD, surround sound content be distributed on any medium other than Blu Ray or cable pay per view/on-demand. Don’t you want home theater buffs to see the Xbox as a fantastic device for their rigs? Don’t you want to put PlayStation 3 out of its misery? And if you follow my suggestions above (move Media Center to the Xbox and fix the Red Ring problem), you’d have it all sewn up. Do I think Blu Ray functionality will move a lot of units? No. Do I think that it would move more units with desperately needed influential home theater consumers? You bet. And you might sell more ZunePass subscriptions in the process. But while you’re at it, make the fan quieter, please. 6. Make More of Windows Home Server Home Server is a fantastic product. And for reasons unknown to me, it seems like you’re letting it languish. Development of the add-in ecosystem seems underfunded. WHS’ unparalleled ease of use and reliability for home PC backup (and emergency restores) goes unsung. Product cycles are slow. Support for your OEMs, who are doing great work, especially in the green space with Atom CPUs, seems lacking. You’ve married a trophy girl and you keep her cloistered at home! That’s cruel, unusual and, um, incredibly ill-advised. Make use of this ace card, and while you’re at it, give it real integration with Media Center. The integration thus far proof-of-concept quality. You should go way past that – both products will benefit immeasurably. 7. Set Up a Partner Platform for Custom Installers There’s a whole sub-industry of companies that install, integrate and configure home theater, security and connected home products. They have an industry group. They are influential in the high-end of the consumer electronics industry, and so are their customers. They love Media Center and they love Windows Home Server. But I have talked to several of them at the Consumer Electronics Show and they tell me you don’t love them. They find it very difficult to do business with Microsoft, even though they want nothing more than to sell and evangelize your platform. This is a travesty. Please fix it. Get Allison Watson and the Microsoft Partner Network on board and have her hire someone who knows how to run a channel program for consumer electronics companies. Problem solved. Markets expanded. 8. Make Your Own Hardware In other areas, I know you love your partners. I help run one, so I appreciate that. But when it came to Xbox and Zune you built them it yourself (albeit on a contract basis, which is fine). Windows Phone 7 has a chance to work as an OEM play, but it would work better if you produced the devices. At least consider building a reference device that sells alongside your OEMs’ offerings. That’s what Google did with the Nexxus One. And while that phone was not itself a big seller, it catalyzed two wonderful things : (1) a quality bar was set and (2) partners exceeded it. Before the Nexxus One, the best Android handset out there was the Motorola Droid. The Nexxus One was better, and the HTC Droid Incredible and Evo 4G are now even better than Google’s phone, which is why Verizon and Sprint decided not to carry it. Imagine if all Windows Phone 6.x devices were on par with the HTC HD2. I tend to believe you’d have a lot bigger market share than you do now. 9. Continue with Your Retail Initiative From what I hear, it sounds like it’s going well. And this goes right along with making your own hardware. When you build it, they will come. And then it makes the likes of Best Buy and Staples do better. 10. Make an Acquisition (or Two) TiVo and/or Moxi look ripe for the picking. With their ability to build stuff people love and your ability to run a business, you might just have something. But do a better job than you did when you bought Danger. Buy the ideas, not just the customers, eh? 11. Make Beautiful Stuff You’ve heard this one before, I know. But I have some head-shrinking advice on this one. You know that Apple obsesses over its industrial design. You know that appeals to consumers. But it seems you think doing so is Apple’s game exclusively and so you shouldn’t even try. Bull dinky. Come to New York and visit the Museum of Modern Art’s Architecture and Design gallery. You’ll see that lots of companies and product categories have had very high design value well before Apple existed. You can do this, and the Zune HD was a great start. Now run with that. Find those negative voices in your head that are telling you that you can’t and shut them up. For good. 12. Burst the Bubble Some of the products you’ve built seem like they were conceived in a bizarro world. That would appear to be the result of groupthink. You must do better. And there’s lots of people willing to advise you. This includes just about everyone in the Regional Director program, and probably a bunch of MVPs. Heck, I bet the guys at Engadget could help out too. Imagine if you let them see the Kin before it shipped. Talk to high-end gear consumers. Talk to Best Buy and CostCo customers too. Signing Off I hope this was of value to you. As I wrote this I kept telling myself how obvious, even trite, some of these pieces of advice were and then, because of that, doubting they’d really help. But I decided that they must not be obvious to Microsoft. Sometimes when you get wrapped up in stuff, it’s hard to clear your head. I think my head’s pretty clear here though (I’m wrapped up in other stuff), so maybe my perspective can help. If not, well, then, I guess they all can’t be super nice.

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value types in the vm

- by john.rose

value types in the vm p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} p.p2 {margin: 0.0px 0.0px 14.0px 0.0px; font: 14.0px Times} p.p3 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times} p.p4 {margin: 0.0px 0.0px 15.0px 0.0px; font: 14.0px Times} p.p5 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier} p.p6 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier; min-height: 17.0px} p.p7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p8 {margin: 0.0px 0.0px 0.0px 36.0px; text-indent: -36.0px; font: 14.0px Times; min-height: 18.0px} p.p9 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p10 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; color: #000000} li.li1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} li.li7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} span.s1 {font: 14.0px Courier} span.s2 {color: #000000} span.s3 {font: 14.0px Courier; color: #000000} ol.ol1 {list-style-type: decimal} Or, enduring values for a changing world. Introduction A value type is a data type which, generally speaking, is designed for being passed by value in and out of methods, and stored by value in data structures. The only value types which the Java language directly supports are the eight primitive types. Java indirectly and approximately supports value types, if they are implemented in terms of classes. For example, both Integer and String may be viewed as value types, especially if their usage is restricted to avoid operations appropriate to Object. In this note, we propose a definition of value types in terms of a design pattern for Java classes, accompanied by a set of usage restrictions. We also sketch the relation of such value types to tuple types (which are a JVM-level notion), and point out JVM optimizations that can apply to value types. This note is a thought experiment to extend the JVM’s performance model in support of value types. The demonstration has two phases. Initially the extension can simply use design patterns, within the current bytecode architecture, and in today’s Java language. But if the performance model is to be realized in practice, it will probably require new JVM bytecode features, changes to the Java language, or both. We will look at a few possibilities for these new features. An Axiom of Value In the context of the JVM, a value type is a data type equipped with construction, assignment, and equality operations, and a set of typed components, such that, whenever two variables of the value type produce equal corresponding values for their components, the values of the two variables cannot be distinguished by any JVM operation. Here are some corollaries: A value type is immutable, since otherwise a copy could be constructed and the original could be modified in one of its components, allowing the copies to be distinguished. Changing the component of a value type requires construction of a new value. The equals and hashCode operations are strictly component-wise. If a value type is represented by a JVM reference, that reference cannot be successfully synchronized on, and cannot be usefully compared for reference equality. A value type can be viewed in terms of what it doesn’t do. We can say that a value type omits all value-unsafe operations, which could violate the constraints on value types. These operations, which are ordinarily allowed for Java object types, are pointer equality comparison (the acmp instruction), synchronization (the monitor instructions), all the wait and notify methods of class Object, and non-trivial finalize methods. The clone method is also value-unsafe, although for value types it could be treated as the identity function. Finally, and most importantly, any side effect on an object (however visible) also counts as an value-unsafe operation. A value type may have methods, but such methods must not change the components of the value. It is reasonable and useful to define methods like toString, equals, and hashCode on value types, and also methods which are specifically valuable to users of the value type. Representations of Value Value types have two natural representations in the JVM, unboxed and boxed. An unboxed value consists of the components, as simple variables. For example, the complex number x=(1+2i), in rectangular coordinate form, may be represented in unboxed form by the following pair of variables: /*Complex x = Complex.valueOf(1.0, 2.0):*/ double x_re = 1.0, x_im = 2.0; These variables might be locals, parameters, or fields. Their association as components of a single value is not defined to the JVM. Here is a sample computation which computes the norm of the difference between two complex numbers: double distance(/*Complex x:*/ double x_re, double x_im, /*Complex y:*/ double y_re, double y_im) { /*Complex z = x.minus(y):*/ double z_re = x_re - y_re, z_im = x_im - y_im; /*return z.abs():*/ return Math.sqrt(z_re*z_re + z_im*z_im); } A boxed representation groups component values under a single object reference. The reference is to a ‘wrapper class’ that carries the component values in its fields. (A primitive type can naturally be equated with a trivial value type with just one component of that type. In that view, the wrapper class Integer can serve as a boxed representation of value type int.) The unboxed representation of complex numbers is practical for many uses, but it fails to cover several major use cases: return values, array elements, and generic APIs. The two components of a complex number cannot be directly returned from a Java function, since Java does not support multiple return values. The same story applies to array elements: Java has no ’array of structs’ feature. (Double-length arrays are a possible workaround for complex numbers, but not for value types with heterogeneous components.) By generic APIs I mean both those which use generic types, like Arrays.asList and those which have special case support for primitive types, like String.valueOf and PrintStream.println. Those APIs do not support unboxed values, and offer some problems to boxed values. Any ’real’ JVM type should have a story for returns, arrays, and API interoperability. The basic problem here is that value types fall between primitive types and object types. Value types are clearly more complex than primitive types, and object types are slightly too complicated. Objects are a little bit dangerous to use as value carriers, since object references can be compared for pointer equality, and can be synchronized on. Also, as many Java programmers have observed, there is often a performance cost to using wrapper objects, even on modern JVMs. Even so, wrapper classes are a good starting point for talking about value types. If there were a set of structural rules and restrictions which would prevent value-unsafe operations on value types, wrapper classes would provide a good notation for defining value types. This note attempts to define such rules and restrictions. Let’s Start Coding Now it is time to look at some real code. Here is a definition, written in Java, of a complex number value type. @ValueSafe public final class Complex implements java.io.Serializable { // immutable component structure: public final double re, im; private Complex(double re, double im) { this.re = re; this.im = im; } // interoperability methods: public String toString() { return "Complex("+re+","+im+")"; } public List<Double> asList() { return Arrays.asList(re, im); } public boolean equals(Complex c) { return re == c.re && im == c.im; } public boolean equals(@ValueSafe Object x) { return x instanceof Complex && equals((Complex) x); } public int hashCode() { return 31*Double.valueOf(re).hashCode() + Double.valueOf(im).hashCode(); } // factory methods: public static Complex valueOf(double re, double im) { return new Complex(re, im); } public Complex changeRe(double re2) { return valueOf(re2, im); } public Complex changeIm(double im2) { return valueOf(re, im2); } public static Complex cast(@ValueSafe Object x) { return x == null ? ZERO : (Complex) x; } // utility methods and constants: public Complex plus(Complex c) { return new Complex(re+c.re, im+c.im); } public Complex minus(Complex c) { return new Complex(re-c.re, im-c.im); } public double abs() { return Math.sqrt(re*re + im*im); } public static final Complex PI = valueOf(Math.PI, 0.0); public static final Complex ZERO = valueOf(0.0, 0.0); } This is not a minimal definition, because it includes some utility methods and other optional parts. The essential elements are as follows: The class is marked as a value type with an annotation. The class is final, because it does not make sense to create subclasses of value types. The fields of the class are all non-private and final. (I.e., the type is immutable and structurally transparent.) From the supertype Object, all public non-final methods are overridden. The constructor is private. Beyond these bare essentials, we can observe the following features in this example, which are likely to be typical of all value types: One or more factory methods are responsible for value creation, including a component-wise valueOf method. There are utility methods for complex arithmetic and instance creation, such as plus and changeIm. There are static utility constants, such as PI. The type is serializable, using the default mechanisms. There are methods for converting to and from dynamically typed references, such as asList and cast. The Rules In order to use value types properly, the programmer must avoid value-unsafe operations. A helpful Java compiler should issue errors (or at least warnings) for code which provably applies value-unsafe operations, and should issue warnings for code which might be correct but does not provably avoid value-unsafe operations. No such compilers exist today, but to simplify our account here, we will pretend that they do exist. A value-safe type is any class, interface, or type parameter marked with the @ValueSafe annotation, or any subtype of a value-safe type. If a value-safe class is marked final, it is in fact a value type. All other value-safe classes must be abstract. The non-static fields of a value class must be non-public and final, and all its constructors must be private. Under the above rules, a standard interface could be helpful to define value types like Complex. Here is an example: @ValueSafe public interface ValueType extends java.io.Serializable { // All methods listed here must get redefined. // Definitions must be value-safe, which means // they may depend on component values only. List<? extends Object> asList(); int hashCode(); boolean equals(@ValueSafe Object c); String toString(); } //@ValueSafe inherited from supertype: public final class Complex implements ValueType { … The main advantage of such a conventional interface is that (unlike an annotation) it is reified in the runtime type system. It could appear as an element type or parameter bound, for facilities which are designed to work on value types only. More broadly, it might assist the JVM to perform dynamic enforcement of the rules for value types. Besides types, the annotation @ValueSafe can mark fields, parameters, local variables, and methods. (This is redundant when the type is also value-safe, but may be useful when the type is Object or another supertype of a value type.) Working forward from these annotations, an expression E is defined as value-safe if it satisfies one or more of the following: The type of E is a value-safe type. E names a field, parameter, or local variable whose declaration is marked @ValueSafe. E is a call to a method whose declaration is marked @ValueSafe. E is an assignment to a value-safe variable, field reference, or array reference. E is a cast to a value-safe type from a value-safe expression. E is a conditional expression E0 ? E1 : E2, and both E1 and E2 are value-safe. Assignments to value-safe expressions and initializations of value-safe names must take their values from value-safe expressions. A value-safe expression may not be the subject of a value-unsafe operation. In particular, it cannot be synchronized on, nor can it be compared with the “==” operator, not even with a null or with another value-safe type. In a program where all of these rules are followed, no value-type value will be subject to a value-unsafe operation. Thus, the prime axiom of value types will be satisfied, that no two value type will be distinguishable as long as their component values are equal. More Code To illustrate these rules, here are some usage examples for Complex: Complex pi = Complex.valueOf(Math.PI, 0); Complex zero = pi.changeRe(0); //zero = pi; zero.re = 0; ValueType vtype = pi; @SuppressWarnings("value-unsafe") Object obj = pi; @ValueSafe Object obj2 = pi; obj2 = new Object(); // ok List<Complex> clist = new ArrayList<Complex>(); clist.add(pi); // (ok assuming List.add param is @ValueSafe) List<ValueType> vlist = new ArrayList<ValueType>(); vlist.add(pi); // (ok) List<Object> olist = new ArrayList<Object>(); olist.add(pi); // warning: "value-unsafe" boolean z = pi.equals(zero); boolean z1 = (pi == zero); // error: reference comparison on value type boolean z2 = (pi == null); // error: reference comparison on value type boolean z3 = (pi == obj2); // error: reference comparison on value type synchronized (pi) { } // error: synch of value, unpredictable result synchronized (obj2) { } // unpredictable result Complex qq = pi; qq = null; // possible NPE; warning: “null-unsafe" qq = (Complex) obj; // warning: “null-unsafe" qq = Complex.cast(obj); // OK @SuppressWarnings("null-unsafe") Complex empty = null; // possible NPE qq = empty; // possible NPE (null pollution) The Payoffs It follows from this that either the JVM or the java compiler can replace boxed value-type values with unboxed ones, without affecting normal computations. Fields and variables of value types can be split into their unboxed components. Non-static methods on value types can be transformed into static methods which take the components as value parameters. Some common questions arise around this point in any discussion of value types. Why burden the programmer with all these extra rules? Why not detect programs automagically and perform unboxing transparently? The answer is that it is easy to break the rules accidently unless they are agreed to by the programmer and enforced. Automatic unboxing optimizations are tantalizing but (so far) unreachable ideal. In the current state of the art, it is possible exhibit benchmarks in which automatic unboxing provides the desired effects, but it is not possible to provide a JVM with a performance model that assures the programmer when unboxing will occur. This is why I’m writing this note, to enlist help from, and provide assurances to, the programmer. Basically, I’m shooting for a good set of user-supplied “pragmas” to frame the desired optimization. Again, the important thing is that the unboxing must be done reliably, or else programmers will have no reason to work with the extra complexity of the value-safety rules. There must be a reasonably stable performance model, wherein using a value type has approximately the same performance characteristics as writing the unboxed components as separate Java variables. There are some rough corners to the present scheme. Since Java fields and array elements are initialized to null, value-type computations which incorporate uninitialized variables can produce null pointer exceptions. One workaround for this is to require such variables to be null-tested, and the result replaced with a suitable all-zero value of the value type. That is what the “cast” method does above. Generically typed APIs like List<T> will continue to manipulate boxed values always, at least until we figure out how to do reification of generic type instances. Use of such APIs will elicit warnings until their type parameters (and/or relevant members) are annotated or typed as value-safe. Retrofitting List<T> is likely to expose flaws in the present scheme, which we will need to engineer around. Here are a couple of first approaches: public interface java.util.List<@ValueSafe T> extends Collection<T> { … public interface java.util.List<T extends Object|ValueType> extends Collection<T> { … (The second approach would require disjunctive types, in which value-safety is “contagious” from the constituent types.) With more transformations, the return value types of methods can also be unboxed. This may require significant bytecode-level transformations, and would work best in the presence of a bytecode representation for multiple value groups, which I have proposed elsewhere under the title “Tuples in the VM”. But for starters, the JVM can apply this transformation under the covers, to internally compiled methods. This would give a way to express multiple return values and structured return values, which is a significant pain-point for Java programmers, especially those who work with low-level structure types favored by modern vector and graphics processors. The lack of multiple return values has a strong distorting effect on many Java APIs. Even if the JVM fails to unbox a value, there is still potential benefit to the value type. Clustered computing systems something have copy operations (serialization or something similar) which apply implicitly to command operands. When copying JVM objects, it is extremely helpful to know when an object’s identity is important or not. If an object reference is a copied operand, the system may have to create a proxy handle which points back to the original object, so that side effects are visible. Proxies must be managed carefully, and this can be expensive. On the other hand, value types are exactly those types which a JVM can “copy and forget” with no downside. Array types are crucial to bulk data interfaces. (As data sizes and rates increase, bulk data becomes more important than scalar data, so arrays are definitely accompanying us into the future of computing.) Value types are very helpful for adding structure to bulk data, so a successful value type mechanism will make it easier for us to express richer forms of bulk data. Unboxing arrays (i.e., arrays containing unboxed values) will provide better cache and memory density, and more direct data movement within clustered or heterogeneous computing systems. They require the deepest transformations, relative to today’s JVM. There is an impedance mismatch between value-type arrays and Java’s covariant array typing, so compromises will need to be struck with existing Java semantics. It is probably worth the effort, since arrays of unboxed value types are inherently more memory-efficient than standard Java arrays, which rely on dependent pointer chains. It may be sufficient to extend the “value-safe” concept to array declarations, and allow low-level transformations to change value-safe array declarations from the standard boxed form into an unboxed tuple-based form. Such value-safe arrays would not be convertible to Object[] arrays. Certain connection points, such as Arrays.copyOf and System.arraycopy might need additional input/output combinations, to allow smooth conversion between arrays with boxed and unboxed elements. Alternatively, the correct solution may have to wait until we have enough reification of generic types, and enough operator overloading, to enable an overhaul of Java arrays. Implicit Method Definitions The example of class Complex above may be unattractively complex. I believe most or all of the elements of the example class are required by the logic of value types. If this is true, a programmer who writes a value type will have to write lots of error-prone boilerplate code. On the other hand, I think nearly all of the code (except for the domain-specific parts like plus and minus) can be implicitly generated. Java has a rule for implicitly defining a class’s constructor, if no it defines no constructors explicitly. Likewise, there are rules for providing default access modifiers for interface members. Because of the highly regular structure of value types, it might be reasonable to perform similar implicit transformations on value types. Here’s an example of a “highly implicit” definition of a complex number type: public class Complex implements ValueType { // implicitly final public double re, im; // implicitly public final //implicit methods are defined elementwise from te fields: // toString, asList, equals(2), hashCode, valueOf, cast //optionally, explicit methods (plus, abs, etc.) would go here } In other words, with the right defaults, a simple value type definition can be a one-liner. The observant reader will have noticed the similarities (and suitable differences) between the explicit methods above and the corresponding methods for List<T>. Another way to abbreviate such a class would be to make an annotation the primary trigger of the functionality, and to add the interface(s) implicitly: public @ValueType class Complex { … // implicitly final, implements ValueType (But to me it seems better to communicate the “magic” via an interface, even if it is rooted in an annotation.) Implicitly Defined Value Types So far we have been working with nominal value types, which is to say that the sequence of typed components is associated with a name and additional methods that convey the intention of the programmer. A simple ordered pair of floating point numbers can be variously interpreted as (to name a few possibilities) a rectangular or polar complex number or Cartesian point. The name and the methods convey the intended meaning. But what if we need a truly simple ordered pair of floating point numbers, without any further conceptual baggage? Perhaps we are writing a method (like “divideAndRemainder”) which naturally returns a pair of numbers instead of a single number. Wrapping the pair of numbers in a nominal type (like “QuotientAndRemainder”) makes as little sense as wrapping a single return value in a nominal type (like “Quotient”). What we need here are structural value types commonly known as tuples. For the present discussion, let us assign a conventional, JVM-friendly name to tuples, roughly as follows: public class java.lang.tuple.$DD extends java.lang.tuple.Tuple { double $1, $2; } Here the component names are fixed and all the required methods are defined implicitly. The supertype is an abstract class which has suitable shared declarations. The name itself mentions a JVM-style method parameter descriptor, which may be “cracked” to determine the number and types of the component fields. The odd thing about such a tuple type (and structural types in general) is it must be instantiated lazily, in response to linkage requests from one or more classes that need it. The JVM and/or its class loaders must be prepared to spin a tuple type on demand, given a simple name reference, $xyz, where the xyz is cracked into a series of component types. (Specifics of naming and name mangling need some tasteful engineering.) Tuples also seem to demand, even more than nominal types, some support from the language. (This is probably because notations for non-nominal types work best as combinations of punctuation and type names, rather than named constructors like Function3 or Tuple2.) At a minimum, languages with tuples usually (I think) have some sort of simple bracket notation for creating tuples, and a corresponding pattern-matching syntax (or “destructuring bind”) for taking tuples apart, at least when they are parameter lists. Designing such a syntax is no simple thing, because it ought to play well with nominal value types, and also with pre-existing Java features, such as method parameter lists, implicit conversions, generic types, and reflection. That is a task for another day. Other Use Cases Besides complex numbers and simple tuples there are many use cases for value types. Many tuple-like types have natural value-type representations. These include rational numbers, point locations and pixel colors, and various kinds of dates and addresses. Other types have a variable-length ‘tail’ of internal values. The most common example of this is String, which is (mathematically) a sequence of UTF-16 character values. Similarly, bit vectors, multiple-precision numbers, and polynomials are composed of sequences of values. Such types include, in their representation, a reference to a variable-sized data structure (often an array) which (somehow) represents the sequence of values. The value type may also include ’header’ information. Variable-sized values often have a length distribution which favors short lengths. In that case, the design of the value type can make the first few values in the sequence be direct ’header’ fields of the value type. In the common case where the header is enough to represent the whole value, the tail can be a shared null value, or even just a null reference. Note that the tail need not be an immutable object, as long as the header type encapsulates it well enough. This is the case with String, where the tail is a mutable (but never mutated) character array. Field types and their order must be a globally visible part of the API. The structure of the value type must be transparent enough to have a globally consistent unboxed representation, so that all callers and callees agree about the type and order of components that appear as parameters, return types, and array elements. This is a trade-off between efficiency and encapsulation, which is forced on us when we remove an indirection enjoyed by boxed representations. A JVM-only transformation would not care about such visibility, but a bytecode transformation would need to take care that (say) the components of complex numbers would not get swapped after a redefinition of Complex and a partial recompile. Perhaps constant pool references to value types need to declare the field order as assumed by each API user. This brings up the delicate status of private fields in a value type. It must always be possible to load, store, and copy value types as coordinated groups, and the JVM performs those movements by moving individual scalar values between locals and stack. If a component field is not public, what is to prevent hostile code from plucking it out of the tuple using a rogue aload or astore instruction? Nothing but the verifier, so we may need to give it more smarts, so that it treats value types as inseparable groups of stack slots or locals (something like long or double). My initial thought was to make the fields always public, which would make the security problem moot. But public is not always the right answer; consider the case of String, where the underlying mutable character array must be encapsulated to prevent security holes. I believe we can win back both sides of the tradeoff, by training the verifier never to split up the components in an unboxed value. Just as the verifier encapsulates the two halves of a 64-bit primitive, it can encapsulate the the header and body of an unboxed String, so that no code other than that of class String itself can take apart the values. Similar to String, we could build an efficient multi-precision decimal type along these lines: public final class DecimalValue extends ValueType { protected final long header; protected private final BigInteger digits; public DecimalValue valueOf(int value, int scale) { assert(scale >= 0); return new DecimalValue(((long)value << 32) + scale, null); } public DecimalValue valueOf(long value, int scale) { if (value == (int) value) return valueOf((int)value, scale); return new DecimalValue(-scale, new BigInteger(value)); } } Values of this type would be passed between methods as two machine words. Small values (those with a significand which fits into 32 bits) would be represented without any heap data at all, unless the DecimalValue itself were boxed. (Note the tension between encapsulation and unboxing in this case. It would be better if the header and digits fields were private, but depending on where the unboxing information must “leak”, it is probably safer to make a public revelation of the internal structure.) Note that, although an array of Complex can be faked with a double-length array of double, there is no easy way to fake an array of unboxed DecimalValues. (Either an array of boxed values or a transposed pair of homogeneous arrays would be reasonable fallbacks, in a current JVM.) Getting the full benefit of unboxing and arrays will require some new JVM magic. Although the JVM emphasizes portability, system dependent code will benefit from using machine-level types larger than 64 bits. For example, the back end of a linear algebra package might benefit from value types like Float4 which map to stock vector types. This is probably only worthwhile if the unboxing arrays can be packed with such values. More Daydreams A more finely-divided design for dynamic enforcement of value safety could feature separate marker interfaces for each invariant. An empty marker interface Unsynchronizable could cause suitable exceptions for monitor instructions on objects in marked classes. More radically, a Interchangeable marker interface could cause JVM primitives that are sensitive to object identity to raise exceptions; the strangest result would be that the acmp instruction would have to be specified as raising an exception. @ValueSafe public interface ValueType extends java.io.Serializable, Unsynchronizable, Interchangeable { … public class Complex implements ValueType { // inherits Serializable, Unsynchronizable, Interchangeable, @ValueSafe … It seems possible that Integer and the other wrapper types could be retro-fitted as value-safe types. This is a major change, since wrapper objects would be unsynchronizable and their references interchangeable. It is likely that code which violates value-safety for wrapper types exists but is uncommon. It is less plausible to retro-fit String, since the prominent operation String.intern is often used with value-unsafe code. We should also reconsider the distinction between boxed and unboxed values in code. The design presented above obscures that distinction. As another thought experiment, we could imagine making a first class distinction in the type system between boxed and unboxed representations. Since only primitive types are named with a lower-case initial letter, we could define that the capitalized version of a value type name always refers to the boxed representation, while the initial lower-case variant always refers to boxed. For example: complex pi = complex.valueOf(Math.PI, 0); Complex boxPi = pi; // convert to boxed myList.add(boxPi); complex z = myList.get(0); // unbox Such a convention could perhaps absorb the current difference between int and Integer, double and Double. It might also allow the programmer to express a helpful distinction among array types. As said above, array types are crucial to bulk data interfaces, but are limited in the JVM. Extending arrays beyond the present limitations is worth thinking about; for example, the Maxine JVM implementation has a hybrid object/array type. Something like this which can also accommodate value type components seems worthwhile. On the other hand, does it make sense for value types to contain short arrays? And why should random-access arrays be the end of our design process, when bulk data is often sequentially accessed, and it might make sense to have heterogeneous streams of data as the natural “jumbo” data structure. These considerations must wait for another day and another note. More Work It seems to me that a good sequence for introducing such value types would be as follows: Add the value-safety restrictions to an experimental version of javac. Code some sample applications with value types, including Complex and DecimalValue. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so. Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. A staggered roll-out like this would decouple language changes from bytecode changes, which is always a convenient thing. A similar investigation should be applied (concurrently) to array types. In this case, it seems to me that the starting point is in the JVM: Add an experimental unboxing array data structure to a production JVM, perhaps along the lines of Maxine hybrids. No bytecode or language support is required at first; everything can be done with encapsulated unsafe operations and/or method handles. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so. Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. That’s enough musing me for now. Back to work!

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Django: TypeError: 'str' object is not callable, referer: http://xxx

- by user705415

I've been wondering why when I set the settings.py of my django project 'arvindemo' debug = Flase and deploy it on Apache with mod_wsgi, I got the 500 Internal Server Error. Env: Django 1.4.0 Python 2.7.2 mod_wsgi 2.8 OS centOS Here is the recap: Visit the homepage, go to sub page A/B/C/D, and fill some forms, then submit it to the Apache server. Once click 'submit' button, I will get the '500 Internal Server Error', and the error_log listed below(Traceback): [Tue Apr 10 10:07:20 2012] [error] [client 122.198.133.250] Traceback (most recent call last): [Tue Apr 10 10:07:20 2012] [error] [client 122.198.133.250] File "/opt/python2.7/lib/python2.7/site-packages/django/core/handlers/wsgi.py", line 241, in __call__ [Tue Apr 10 10:07:20 2012] [error] [client 122.198.133.250] response = self.get_response(request) [Tue Apr 10 10:07:20 2012] [error] [client 122.198.133.250] File "/opt/python2.7/lib/python2.7/site-packages/django/core/handlers/base.py", line 179, in get_response [Tue Apr 10 10:07:20 2012] [error] [client 122.198.133.250] response = self.handle_uncaught_exception(request, resolver, sys.exc_info()) [Tue Apr 10 10:07:20 2012] [error] [client 122.198.133.250] File "/opt/python2.7/lib/python2.7/site-packages/django/core/handlers/base.py", line 224, in handle_uncaught_exception [Tue Apr 10 10:07:20 2012] [error] [client 122.198.133.250] if resolver.urlconf_module is None: [Tue Apr 10 10:07:20 2012] [error] [client 122.198.133.250] File "/opt/python2.7/lib/python2.7/site-packages/django/core/urlresolvers.py", line 323, in urlconf_module [Tue Apr 10 10:07:20 2012] [error] [client 122.198.133.250] self._urlconf_module = import_module(self.urlconf_name) [Tue Apr 10 10:07:20 2012] [error] [client 122.198.133.250] File "/opt/python2.7/lib/python2.7/site-packages/django/utils/importlib.py", line 35, in import_module [Tue Apr 10 10:07:20 2012] [error] [client 122.198.133.250] __import__(name) [Tue Apr 10 10:07:20 2012] [error] [client 122.198.133.250] File "/opt/web/django/arvindemo/arvindemo/../arvindemo/urls.py", line 23, in <module> [Tue Apr 10 10:07:20 2012] [error] [client 122.198.133.250] url(r'^submitPage$', name=submitPage), [Tue Apr 10 10:07:20 2012] [error] [client 122.198.133.250] TypeError: url() takes at least 2 arguments (2 given) When using django runserver, I set arvindemo.settings debug = True, everything is OK. But things changed once I set debug = Flase. Here is my views.py from django.http import HttpResponseRedirect from django.http import HttpResponse, HttpResponseServerError from django.shortcuts import render_to_response import datetime, string from user_info.models import * from django.template import Context, loader, RequestContext import settings def hello(request): return HttpResponse("hello girl") def helpPage(request): return render_to_response('kktHelp.html') def server_error(request, template_name='500.html'): return render_to_response(template_name, context_instance = RequestContext(request) ) def page404(request): return render_to_response('404.html') def submitPage(request): post = request.POST Mall = 'goodsName' Contest = 'ojs' Presentation = 'addr' WeatherReport = 'city' Habit = 'task' if Mall in post: return submitMall(request) elif Contest in post: return submitContest(request) elif Presentation in post: return submitPresentation(request) elif Habit in post: return submitHabit(request) elif WeatherReport in post: return submitWeather(request) else: return HttpResponse(request.POST) return HttpResponseRedirect('404') def submitXXX(): ..... def xxxx(): .... Here comes the urls.py from django.conf.urls import patterns, include, url from views import * from django.conf import settings handler500 = 'server_error' urlpatterns = patterns('', url(r'^hello/$', hello), # hello world url(r'^$', homePage), url(r'^time/$', getTime), url(r'^time/plus/(\d{1,2})/$', hoursAhead), url(r'^Ttime/$', templateGetTime), url(r'^Mall$', templateMall), url(r'^Contest$', templateContest), url(r'^Presentation$', templatePresentation), url(r'^Habit$', templateHabit), url(r'^Weather$', templateWeather), url(r'^Help$', helpPage), url(r'^404$', page404), url(r'^500$', server_error), url(r'^submitPage$', submitPage), url(r'^submitMall$', submitMall), url(r'^submitContest$', submitContest), url(r'^submitPresentation$', submitPresentation), url(r'^submitHabit$', submitHabit), url(r'^submitWeather$', submitWeather), url(r'^terms$', terms), url(r'^privacy$', privacy), url(r'^thanks$', thanks), url(r'^about$', about), url(r'^static/(?P<path>.*)$','django.views.static.serve',{'document_root':settings.STATICFILES_DIRS}), ) I'm sure there is no syntax error in my django project,cause when I use django runserver, everything is fine. Anyone can help ? Best regards

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trying to use mod_proxy with httpd and tomcat

- by techsjs2012

I been trying to use mod_proxy with httpd and tomcat... I have on VirtualBox running Scientific Linux which has httpd and tomcat 6 on it.. I made two nodes of tomcat6. I followed this guide like 10 times and still cant get the 2nd node of tomcat working.. http://www.richardnichols.net/2010/08/5-minute-guide-clustering-apache-tomcat/ Here is the lines from my http.conf file <Proxy balancer://testcluster stickysession=JSESSIONID> BalancerMember ajp://127.0.0.1:8009 min=10 max=100 route=node1 loadfactor=1 BalancerMember ajp://127.0.0.1:8109 min=10 max=100 route=node2 loadfactor=1 </Proxy> ProxyPass /examples balancer://testcluster/examples <Location /balancer-manager> SetHandler balancer-manager AuthType Basic AuthName "Balancer Manager" AuthUserFile "/etc/httpd/conf/.htpasswd" Require valid-user </Location> Now here is my server.xml from node1 <?xml version='1.0' encoding='utf-8'?>   <Server port="8005" shutdown="SHUTDOWN">  <Listener className="org.apache.catalina.core.AprLifecycleListener" SSLEngine="on" />  <Listener className="org.apache.catalina.core.JasperListener" />  <Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener" />  <Listener className="org.apache.catalina.mbeans.ServerLifecycleListener" /> <Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" />  <GlobalNamingResources>  <Resource name="UserDatabase" auth="Container" type="org.apache.catalina.UserDatabase" description="User database that can be updated and saved" factory="org.apache.catalina.users.MemoryUserDatabaseFactory" pathname="conf/tomcat-users.xml" /> </GlobalNamingResources>  <Service name="Catalina">         <Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />   <Engine name="Catalina" defaultHost="localhost" jvmRoute="node1">      <Realm className="org.apache.catalina.realm.UserDatabaseRealm" resourceName="UserDatabase"/>  <Host name="localhost" appBase="webapps" unpackWARs="true" autoDeploy="true" xmlValidation="false" xmlNamespaceAware="false">     </Host> </Engine> </Service> </Server> now here is the server.xml file from node2 <?xml version='1.0' encoding='utf-8'?>   <Server port="8105" shutdown="SHUTDOWN">  <Listener className="org.apache.catalina.core.AprLifecycleListener" SSLEngine="on" />  <Listener className="org.apache.catalina.core.JasperListener" />  <Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener" />  <Listener className="org.apache.catalina.mbeans.ServerLifecycleListener" /> <Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" />  <GlobalNamingResources>  <Resource name="UserDatabase" auth="Container" type="org.apache.catalina.UserDatabase" description="User database that can be updated and saved" factory="org.apache.catalina.users.MemoryUserDatabaseFactory" pathname="conf/tomcat-users.xml" /> </GlobalNamingResources>  <Service name="Catalina">         <Connector port="8109" protocol="AJP/1.3" redirectPort="8443" />   <Engine name="Catalina" defaultHost="localhost" jvmRoute="node2">      <Realm className="org.apache.catalina.realm.UserDatabaseRealm" resourceName="UserDatabase"/>  <Host name="localhost" appBase="webapps" unpackWARs="true" autoDeploy="true" xmlValidation="false" xmlNamespaceAware="false">     </Host> </Engine> </Service> </Server> I dont know what it is. but I been trying for days

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Windows Phone 7 Prototype 001: Speech Recognition on WP7

At some point in the future it will be awesome when you can just tell your computer what to do and it does it - without typing to help those of us with a blistering 11 WPM hunk and peck technique. Siri, a mobile digital assistant using speech recognition was voted best tech at SXSW. I dont know about that one. Although, I'm sure it will get better when Apple rebuilds it and bundles on iPhone 5. So how would you do that on WP7? There have been some videos floating around showing Bing with some voice control so obviously the phone has speech recognition. So what options are there: System.Speech? Not included in WP7/SL Nuance software like Siri? No WP7/SL version yet. Invoking the SAPI dlls on the phone? No automation factory in WP7 SL. Web services using System.Speech and mic on the phone? YES! The last one was my least favorite but that works for now. I built a quick sample app to show how to do text-to-speech and speech recognition on WP7. @eklimczak will not be happy with the developer designed UI. In this sample there is web service with provides access to the system.speech APIs in .NET. Basically its just passing around byte arrays. On the phone its using the XNA audio frameworks to play the text-to-speech stream and to record using the microphone. The code is pretty simple and you can download from the link at the end of this post. The only things to note are adjusting the WCF config to handle larger byte uploads and the Microphone API is a little weird with that 1 second buffer. It would be nice if you could just to mic.start and mic.end which would return an array of bytes instead of managing your own stream inside the buffer ready callback. Couple of downsides to this approach: Recoding from the phone has some static. Could be my code or the my mic is bad / not calibrated right. Having to make web service calls instead of local access is not ideal (Microsoft, please add an API for the SAPI dlls) Although in the context of an app like Siri its not so bad since you need to do web service lookups to get data back Speech recognition quality really depends on either a) a limited grammar set like that pizza grammar in the sample or b) training the recognizer. For the latter it would be annoying to have users train the system. Using the System.Speech stuff youd have to have a profile for each user. So until Microsoft adds some speech client APIs on the phone or Nuance releases a wp7 product, this is a decent workaround. In the future Id like to build something similar to Siri. I shall call it Iris in homage. Im a big fan of mobile speech apps because frankly its just not safe to Google while driving. Since some of my designer co-workers have been posting UI sketches for WP7, Id like to start posting some code prototypes for things I try out on the phone. That will probably last 2 weeks, but for the moment I have like 10 posts in the queue. Sample Code 100% guaranteed to work on my emulatorDid you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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Parallelism in .NET – Part 19, TaskContinuationOptions

- by Reed

My introduction to Task continuations demonstrates continuations on the Task class. In addition, I’ve shown how continuations allow handling of multiple tasks in a clean, concise manner. Continuations can also be used to handle exceptional situations using a clean, simple syntax. In addition to standard Task continuations , the Task class provides some options for filtering continuations automatically. This is handled via the TaskContinationOptions enumeration, which provides hints to the TaskScheduler that it should only continue based on the operation of the antecedent task. This is especially useful when dealing with exceptions. For example, we can extend the sample from our earlier continuation discussion to include support for handling exceptions thrown by the Factorize method: // Get a copy of the UI-thread task scheduler up front to use later var uiScheduler = TaskScheduler.FromCurrentSynchronizationContext(); // Start our task var factorize = Task.Factory.StartNew( () => { int primeFactor1 = 0; int primeFactor2 = 0; bool result = Factorize(10298312, ref primeFactor1, ref primeFactor2); return new { Result = result, Factor1 = primeFactor1, Factor2 = primeFactor2 }; }); // When we succeed, report the results to the UI factorize.ContinueWith(task => textBox1.Text = string.Format("{0}/{1} [Succeeded {2}]", task.Result.Factor1, task.Result.Factor2, task.Result.Result), CancellationToken.None, TaskContinuationOptions.NotOnFaulted, uiScheduler); // When we have an exception, report it factorize.ContinueWith(task => textBox1.Text = string.Format("Error: {0}", task.Exception.Message), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, uiScheduler); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The above code works by using a combination of features. First, we schedule our task, the same way as in the previous example. However, in this case, we use a different overload of Task.ContinueWith which allows us to specify both a specific TaskScheduler (in order to have your continuation run on the UI’s synchronization context) as well as a TaskContinuationOption. In the first continuation, we tell the continuation that we only want it to run when there was not an exception by specifying TaskContinuationOptions.NotOnFaulted. When our factorize task completes successfully, this continuation will automatically run on the UI thread, and provide the appropriate feedback. However, if the factorize task has an exception – for example, if the Factorize method throws an exception due to an improper input value, the second continuation will run. This occurs due to the specification of TaskContinuationOptions.OnlyOnFaulted in the options. In this case, we’ll report the error received to the user. We can use TaskContinuationOptions to filter our continuations by whether or not an exception occurred and whether or not a task was cancelled. This allows us to handle many situations, and is especially useful when trying to maintain a valid application state without ever blocking the user interface. The same concepts can be extended even further, and allow you to chain together many tasks based on the success of the previous ones. Continuations can even be used to create a state machine with full error handling, all without blocking the user interface thread.

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Text inside <p> shrinks on mobile devices while div does not [migrated]

- by guisasso

I asked this question on stack overflow, but didn't get any answers, so I'm trying here. Does anybody know whats happening here? I tested on opera, dolphin and the factory android browser. (although it seems now to be working on opera) The div doesn't change size, but the text somehow is shrunk to fit on part of a div. Anyway to prevent this? Just to be clear, I'm trying to achieve on the mobile browser the same look as the pc version. As the problem seems to be with the browsers, how can I force the text to take the full width of the div? I tried setting the p tag to 100% with no success. The div has to have that width and be aligned to the left of the page. On a Pc, as it should be: I shrunk the code as much as I could: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" lang="en-us"> <head> <meta content="text/html; charset=utf-8" http-equiv="Content-Type" /> <meta content="" name="keywords" /> <meta content="" name="description" /> <title></title> </head> <body> <div style="width:1000px; margin-left:auto; margin-right:auto;" > <div style="float:left; width:758px; background-color:aqua;"> <p> Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text .<br /> <br /> Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text Random text .<br /> <br /> Random text Random text Random text Random text <a href="http://www.a.com/a.html"> Random text </a> Random text Random text . </p> </div> </div> </body> </html> Thanks.

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Dynamic Class Inheritance For PHP

- by VirtuosiMedia

I have a situation where I think I might need dynamic class inheritance in PHP 5.3, but the idea doesn't sit well and I'm looking for a different design pattern to solve my problem if it's possible. Use Case I have a set of DB abstraction layer classes that dynamically compiles SQL queries, with one DAL class for each DB type (MySQL, MsSQL, Oracle, etc.). Each table in the database has its own class that extends the appropriate DAL class. The idea is that you interact with the table classes, but never directly use the DAL class. If you want to support a different DB type for your app, you don't need to rewrite any queries or even any code, you simply change a setting that swaps one DAL class out for another...and that's it. To give you a better idea of how this is used, you can take a look at the DAL class, the table classes, and how they are used on this StackExchange Code Review page. To really understand what I'm trying to do, please take a look at my implementation first before suggesting a solution. Issues The strategy that I had used previously was to have all of the DAL classes share the same class name. This eliminated autoloading, so I had to manually load the appropriate DAL class in a switch statement. However, this approach presents some problems for testing and documentation purposes, so I'd like to find a different way to solve the problem of loading the correct DAL class more elegantly. Update to clarify the issue The problem basically boils down to inconsistencies in the class name (pre-PHP 5.3) or class namespace (PHP 5.3) and its location in the directory structure. At this point, all of my DAL classes have the same name, DBObject, but reside in different folders, MySQL, Oracle, etc. My table classes all extend DBObject, but which DBObject they extend varies depending on which one has been loaded. Basically, I'm trying to have my cake and eat it too. The table classes act as a stable API and extend a dynamic backend, the DAL (DBObject) classes. It works great, but I outsmarted myself and because of the inconsistencies with the class names and their locations, I can't autoload the DBObject, which makes running unit tests and generating API docs impossible for the DBObject classes because the tests and docs rely on auto-loading. Just loading the appropriate DBObject into memory using a factory method won't work because there will be times when I need to load multiple DBObjects for testing. Because the classes currently share a name, this causes a class is already defined error. I can make exceptions for the DBObjects in my test code, obviously, but I'm looking for something a little less hacky as there may future instances where something similar would need to be done. Solutions? Worst case scenario, I can continue my current strategy, but I don't like it very much, especially as I'll soon be converting my code to PHP 5.3. I suspect that I can use some sort of dynamic inheritance via either namespaces (preferred) or a dynamic class extension, but I haven't been able to find good examples of this implemented in the wild. In your answers, please suggest either an alternate pattern that would work for this use case or an example of dynamic inheritance done right. Please assume PHP 5.3 with namespaced code. Any code examples are greatly encouraged. The preferred constraints for the solution are: DAL class can be autoloaded. DAL classes don't share the same exact same namespace, but share the same class name. As an example, I would prefer to use classes named DbObject that use namespaces like Vm\Db\MySql and Vm\Db\Oracle. Table classes don't have to be rewritten with a change in DB type. The appropriate DB type is determined via a single setting only. That setting is the only thing that should need to change to interchange DB types. Ideally, the setting check should occur only once per page load, but I'm flexible on that.

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Is there a low carbon future for the retail industry?

- by user801960

Recently Oracle published a report in conjunction with The Future Laboratory and a global panel of experts to highlight the issue of energy use in modern industry and the serious need to reduce carbon emissions radically by 2050. Emissions must be cut by 80-95% below the levels in 1990 – but what can the retail industry do to keep up with this? There are three key aspects to the retail industry where carbon emissions can be cut: manufacturing, transport and IT. Manufacturing Naturally, manufacturing is going to be a big area where businesses across all industries will be forced to make considerable savings in carbon emissions as well as other forms of pollution. Many retailers of all sizes will use third party factories and will have little control over specific environmental impacts from the factory, but retailers can reduce environmental impact at the factories by managing orders more efficiently – better planning for stock requirements means economies of scale both in terms of finance and the environment. The John Lewis Partnership has made detailed commitments to reducing manufacturing and packaging waste on both its own-brand products and products it sources from third party suppliers. It aims to divert 95 percent of its operational waste from landfill by 2013, which is a huge logistics challenge. The John Lewis Partnership’s website provides a large amount of information on its responsibilities towards the environment. Transport Similarly to manufacturing, tightening up on logistical planning for stock distribution will make savings on carbon emissions from haulage. More accurate supply and demand analysis will mean less stock re-allocation after initial distribution, and better warehouse management will mean more efficient stock distribution. UK grocery retailer Morrisons has introduced double-decked trailers to its haulage fleet and adjusted distribution logistics accordingly to reduce the number of kilometers travelled by the fleet. Morrisons measures route planning efficiency in terms of cases moved per kilometre and has, over the last two years, increased the number of cases per kilometre by 12.7%. See Morrisons Corporate Responsibility report for more information. IT IT infrastructure is often initially overlooked by businesses when considering environmental efficiency. Datacentres and web servers often need to run 24/7 to handle both consumer orders and internal logistics, and this both requires a lot of energy and puts out a lot of heat. Many businesses are lowering environmental impact by reducing IT system fragmentation in their offices, while an increasing number of businesses are outsourcing their datacenters to cloud-based services. Using centralised datacenters reduces the power usage at smaller offices, while using cloud based services means the datacenters can be based in a more environmentally friendly location. For example, Facebook is opening a massive datacentre in Sweden – close to the Arctic Circle – to reduce the need for artificial cooling methods. In addition, moving to a cloud-based solution makes IT services more easily scaleable, reducing redundant IT systems that would still use energy. In store, the UK’s Carbon Trust reports that on average, lighting accounts for 25% of a retailer’s electricity costs, and for grocery retailers, up to 50% of their electricity bill comes from refrigeration units. On a smaller scale, retailers can invest in greener technologies in store and in their offices. The report concludes that widely shared objectives of energy security, reduced emissions and continued economic growth are dependent on the development of a smart grid capable of delivering energy efficiency and demand response, as well as integrating renewable and variable sources of energy. The report is available to download from http://emeapressoffice.oracle.com/imagelibrary/detail.aspx?MediaDetailsID=1766I’d be interested to hear your thoughts on the report.

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30 Steps to Master ASP.NET MVC Application development

- by Rajesh Pillai

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} Welcome Readers!, I am starting out a new series on ASP.NET MVC skill building which will be posted over the next couple of weeks. Let me know your thoughts on the content, which I have planned and a couple of them has been taken from ASP.NET MVC2 Cookbook. (NOTE: Only the heading has been taken, the content will be not :)). Do let me know what you would like to see, or any additional inputs or ideas to cover in this topics. The 30 steps are oultined below for quick reference. Will start filling this out quickly. Outlined is the ‘30’ step to master ASP.NET MVC. A Peek Into Model What is a model? Different types of model Presentation/ViewModel Model Mapping (AutoMapper) A Peak into View How view works in ASP.NET MVC? View Engine Design Custom View Engine View Best Practices Templated Helpers Partial Views A Peak into Controller Introduction Controller Design Controller Best Practices Asynchronous Controller Custom Action Result Action Filters Controller Factory to use with IOC Routes Explanation Routes from the database Routes from XML More complex routing Master Pages Basics Setting Master Page Dynamically Working with data in the view Repeating Views Array of check boxes Array of radio buttons Paged data CRUD Client side action Confirmation Dialog (modal window) jqGrid Working with Forms Validation Model Validation with DataAnnotations Using the xVal validation framework Client side validation with jQuery Validation Fluent Validation Model Binders Templating Create strongly typed helper using T4 Custom View Templates with T4 Create custom MVC project template using T4 IOC AutoFac Ninject Unity Application Areas jQuery, Ajax and jQuery Plugins State Maintenance Application State User state Cookies Webfarm Error Handling View error handling Controller error handling ELMAH (Error Logging Modules and Handlers) Authentication and Authorization User Registration form SignOn Process Password Reminder Membership and Roles Windows authentication Restricting access to all pages Restricting access to selected pages Restricting access to pages by role Restricting access to a controller Restricting access to selected area Profiles and Themes Using Profiles Inheriting a Profile Migrating an anonymous profile Creating custom themes Using themes User personalized themes Configuration Adding custom application settings in web.config Displaying custom error messages Accessing other web.config configuration elements Adding custom configuration elements to web.config Encrypting web.config sections Tracing, Debugging and Logging Caching Caching a whole page Caching pages based on route details Caching pages based on browser type and version Caching pages based custom strings Caching partial pages Caching application data Object Caching Using Microsoft Velocity Using MemCache Using AppFabric cache Localization HTTP Handlers and Modules Security XSS/CSRF AnitForgery Encoding HtmlHelpers Strongly typed helpers Writing custom helpers Repository Pattern (Data access) WF/WCF Unit Testing Mocking Framework Integration Testing Load / Performance Testing Deployment Once again let me know your thoughts on this. Till then, Enjoy MVC'ing!!!

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ArchBeat Top 10 for December 2-8, 2012

- by Bob Rhubart

The Top 10 most-clicked items shared on the OTN ArchBeat Facebook page for the week of December 2-8, 2012 Configure Oracle SOA JMSAdatper to Work with WLS JMS Topics Another of the four posts published on Dec 4 by the Fusion Middleware A-Team blogger identified as "fip" illlustrates "how to configure the JMS Topic, the JmsAdapter connection factory, as well as the composite so that the JMS Topic messages will be evenly distributed to same composite running off different SOA cluster nodes without causing duplication." Web Service Example - Part 3: Asynchronous Part 3 in this series from the Oracle ADF Mobile blog looks at "firing the web service asynchronously and then filling in the UI when it completes." Denis says, "This can be useful when you have data on the device in a local store and want to show that to the user while the application uses lazy loading from a web service to load more data." Advanced Oracle SOA Suite Oracle Open World 2012 SOA Presentations Oracle SOA & BPM Partner Community blogger Juergen Kress shares a list of 13 SOA presentations delivered or moderated by Oracle SOA Product Management at OOW12 in San Francisco. Oracle WebLogic Server WLS Domain Browser My colleague Jeff Davies, a frequent speaker at OTN Architect Day events and a genuinely nice guy, emailed me last night with this message: "I just came across this app on Google Play. It allows WebLogic administrators to browse WLS 12c domain information. I installed it on my phone and tried it out. Works very fast." I'm an iPhone guy, but I'm perfectly comfortable taking Jeff at his word. The app is called WLS Domain Browser. Follow the link for more info from the Google Play site. Retrieve Performance Data from SOA Infrastructure Database Another of the four blog posts published on Dec 4 by very busy Oracle Fusion Middleware A-Team member "fip," this one offers "examples of some basic SQL queries you can run against the infrastructure database of Oracle SOA Suite 11G to acquire the performance statistics for a given period of time." How to Achieve OC4J RMI Load Balancing "Having returned from a customer who faced challenges with OC4J RMI load balancing, I felt there is still some confusion in the field [about] how OC4J RMI load balancing works," says the Oracle Fusion Middleware A-Team member known only as "fip." "Hence I decide to dust off an old tech note that I wrote a few years back and share it with the general public." From XaaS to Java EE – Which damn cloud is right for me in 2012? Oracle ACE Director Markus Eisele wrestles with a timely technical issue and shares his observations on several of the alternatives. Exalogic 2.0.1 Tea Break Snippets - Creating a ModifyJeOS VirtualBox "One of the main advantages of this is that Templates can be created away from the Exalogic Environment," explains The Old Toxophilist. (BTW: I had to look it up: a toxophilist is one who collects bows and arrows.) ADF Mobile - Implementing Reusable Mobile Architecture "Reusability was always a strong part of ADF," says Oracle ACE Director Andrejus Baranovskis. "The same high reusability level is supported now in ADF Mobile." The objective of this post is "to prove technically that [the] reusable architecture concept works for ADF Mobile." Using BPEL Performance Statistics to Diagnose Performance Bottlenecks Someone had a busy day… This post, one of four published on DeC 4 by a member of the Oracle Fusion Middleware A-Team identified only as "fip," offers details on how to "enable, retrieve and interpret the performance statistics, before the future versions provides a more pleasant user experience." Thought for the Day "If you're afraid to change something it is clearly poorly designed." — Martin Fowler Source: SoftwareQuotes.com

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#altnetseattle – REST Services

- by GeekAgilistMercenary

Below are the notes I made in the REST Architecture Session I helped kick off with Andrew. RSS, ATOM, and such needed for better discovery. i.e. there still is a need for some type of discovery. Difficult is modeling behaviors in a RESTful way. ?? Invoking some type of state against an object. For instance in the case of a POST vs. a GET. The GET is easy, comes back as is, but what about a POST, which often changes some state or something. Challenge is doing multiple workflows with stateful workflows. How does batch work. Maybe model the batch as a resource. Frameworks aren’t particularly part of REST, REST is REST. But point argued that REST is modeled, or part of modeling a state machine of some sort… ? Nothing is 100% reliable w/ REST – comparisons drawn with TCP/IP. Sufficient probability is made however for the communications, but the idea of a possible failure has to be built into the usage model of REST. Ruby on Rails / RESTfully, and others used. What were their issues, what do they do. ATOM feeds, object serialized, using LINQ to XML w/ this. No state machine libraries. Idempotent areas around REST and single change POST changes are inherent in the architecture. REST – one of the constrained languages is for the interaction w/ the system. Limiting what can be done on the resources. - disagreement, there is no agreed upon REST verbs. Sam Ruby – RESTful services. Expanded the verbs within REST/HTTP pushes you off the web. Of the existing verbs POST leaves the most up for debate. Robert Reem used Factory to deal with the POST to handle the new state. The POST identifying what it just did by the return. Different states are put into POST, so that new prospective verbs, without creating verbs for REST/HTTP can be used to advantage without breaking universal clients. Biggest issue with REST services is their lack of state, yet it is also one of their biggest strengths. What happens is that the client takes up the often onerous task of handling all state, state machines, and other extraneous resource management. All the GETs, POSTs, DELETEs, INSERTs get all pushed into abstraction. My 2 cents is that this in a way ends up pushing a huge proprietary burden onto the REST services often removing the point of REST to be simple and to the point. WADL does provide discovery and some state control (sort of?) Statement made, "WADL" isn't needed. The JSON, XML, or other client side returned data handles this. I then applied the law of 2 feet rule for myself and headed to finish up these notes, post to the Wiki, and figure out what I was going to do next. For the original Wiki entry check it out here. I will be adding more to this post with a subsequent post. Please do feel free to post your thoughts and ideas about this, as I am sure everyone in the session will have more for elaboration.

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SPARC T5-4 LDoms for RAC and WebLogic Clusters

- by Jeff Taylor-Oracle

I wanted to use two Oracle SPARC T5-4 servers to simultaneously host both Oracle RAC and a WebLogic Server Cluster. I chose to use Oracle VM Server for SPARC to create a cluster like this: There are plenty of trade offs and decisions that need to be made, for example: Rather than configuring the system by hand, you might want to use an Oracle SuperCluster T5-8 My configuration is similar to jsavit's: Availability Best Practices - Example configuring a T5-8 but I chose to ignore some of the advice. Maybe I should have included an alternate service domain, but I decided that I already had enough redundancy Both Oracle SPARC T5-4 servers were to be configured like this: Cntl 0.25 4 64GB App LDom 2.75 CPU's 44 cores 704 GB DB LDom One CPU 16 cores 256 GB The systems started with everything in the primary domain: # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL NORM UPTIME primary active -n-c-- UART 512 1023G 0.0% 0.0% 11m # ldm list-spconfig factory-default [current] primary # ldm list -o core,memory,physio NAME primary CORE CID CPUSET 0 (0, 1, 2, 3, 4, 5, 6, 7) 1 (8, 9, 10, 11, 12, 13, 14, 15) 2 (16, 17, 18, 19, 20, 21, 22, 23) -- SNIP 62 (496, 497, 498, 499, 500, 501, 502, 503) 63 (504, 505, 506, 507, 508, 509, 510, 511) MEMORY RA PA SIZE 0x30000000 0x30000000 255G 0x80000000000 0x80000000000 256G 0x100000000000 0x100000000000 256G 0x180000000000 0x180000000000 256G # Give this memory block to the DB LDom IO DEVICE PSEUDONYM OPTIONS pci@300 pci_0 pci@340 pci_1 pci@380 pci_2 pci@3c0 pci_3 pci@400 pci_4 pci@440 pci_5 pci@480 pci_6 pci@4c0 pci_7 pci@300/pci@1/pci@0/pci@6 /SYS/RCSA/PCIE1 pci@300/pci@1/pci@0/pci@c /SYS/RCSA/PCIE2 pci@300/pci@1/pci@0/pci@4/pci@0/pci@c /SYS/MB/SASHBA0 pci@300/pci@1/pci@0/pci@4/pci@0/pci@8 /SYS/RIO/NET0 pci@340/pci@1/pci@0/pci@6 /SYS/RCSA/PCIE3 pci@340/pci@1/pci@0/pci@c /SYS/RCSA/PCIE4 pci@380/pci@1/pci@0/pci@a /SYS/RCSA/PCIE9 pci@380/pci@1/pci@0/pci@4 /SYS/RCSA/PCIE10 pci@3c0/pci@1/pci@0/pci@e /SYS/RCSA/PCIE11 pci@3c0/pci@1/pci@0/pci@8 /SYS/RCSA/PCIE12 pci@400/pci@1/pci@0/pci@e /SYS/RCSA/PCIE5 pci@400/pci@1/pci@0/pci@8 /SYS/RCSA/PCIE6 pci@440/pci@1/pci@0/pci@e /SYS/RCSA/PCIE7 pci@440/pci@1/pci@0/pci@8 /SYS/RCSA/PCIE8 pci@480/pci@1/pci@0/pci@a /SYS/RCSA/PCIE13 pci@480/pci@1/pci@0/pci@4 /SYS/RCSA/PCIE14 pci@4c0/pci@1/pci@0/pci@8 /SYS/RCSA/PCIE15 pci@4c0/pci@1/pci@0/pci@4 /SYS/RCSA/PCIE16 pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c /SYS/MB/SASHBA1 pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@4 /SYS/RIO/NET2 Added an additional service processor configuration: # ldm add-spconfig split # ldm list-spconfig factory-default primary split [current] And removed many of the resources from the primary domain: # ldm start-reconf primary # ldm set-core 4 primary # ldm set-memory 32G primary # ldm rm-io pci@340 primary # ldm rm-io pci@380 primary # ldm rm-io pci@3c0 primary # ldm rm-io pci@400 primary # ldm rm-io pci@440 primary # ldm rm-io pci@480 primary # ldm rm-io pci@4c0 primary # init 6 Needed to add resources to the guest domains: # ldm add-domain db # ldm set-core cid=`seq -s"," 48 63` db # ldm add-memory mblock=0x180000000000:256G db # ldm add-io pci@480 db # ldm add-io pci@4c0 db # ldm add-domain app # ldm set-core 44 app # ldm set-memory 704G app # ldm add-io pci@340 app # ldm add-io pci@380 app # ldm add-io pci@3c0 app # ldm add-io pci@400 app # ldm add-io pci@440 app Needed to set up services: # ldm add-vds primary-vds0 primary # ldm add-vcc port-range=5000-5100 primary-vcc0 primary Needed to add a virtual network port for the WebLogic application domain: # ipadm NAME CLASS/TYPE STATE UNDER ADDR lo0 loopback ok -- -- lo0/v4 static ok -- ... lo0/v6 static ok -- ... net0 ip ok -- ... net0/v4 static ok -- xxx.xxx.xxx.xxx/24 net0/v6 addrconf ok -- .... net0/v6 addrconf ok -- ... net8 ip ok -- -- net8/v4 static ok -- ... # dladm show-phys LINK MEDIA STATE SPEED DUPLEX DEVICE net1 Ethernet unknown 0 unknown ixgbe1 net0 Ethernet up 1000 full ixgbe0 net8 Ethernet up 10 full usbecm2 # ldm add-vsw net-dev=net0 primary-vsw0 primary # ldm add-vnet vnet1 primary-vsw0 app Needed to add a virtual disk to the WebLogic application domain: # format Searching for disks...done AVAILABLE DISK SELECTIONS: 0. c0t5000CCA02505F874d0 <HITACHI-H106060SDSUN600G-A2B0-558.91GB> /scsi_vhci/disk@g5000cca02505f874 /dev/chassis/SPARC_T5-4.AK00084038/SYS/SASBP0/HDD0/disk 1. c0t5000CCA02506C468d0 <HITACHI-H106060SDSUN600G-A2B0-558.91GB> /scsi_vhci/disk@g5000cca02506c468 /dev/chassis/SPARC_T5-4.AK00084038/SYS/SASBP0/HDD1/disk 2. c0t5000CCA025067E5Cd0 <HITACHI-H106060SDSUN600G-A2B0-558.91GB> /scsi_vhci/disk@g5000cca025067e5c /dev/chassis/SPARC_T5-4.AK00084038/SYS/SASBP0/HDD2/disk 3. c0t5000CCA02506C258d0 <HITACHI-H106060SDSUN600G-A2B0-558.91GB> /scsi_vhci/disk@g5000cca02506c258 /dev/chassis/SPARC_T5-4.AK00084038/SYS/SASBP0/HDD3/disk Specify disk (enter its number): ^C # ldm add-vdsdev /dev/dsk/c0t5000CCA02506C468d0s2 HDD1@primary-vds0 # ldm add-vdisk HDD1 HDD1@primary-vds0 app Add some additional spice to the pot: # ldm set-variable auto-boot\\?=false db # ldm set-variable auto-boot\\?=false app # ldm set-var boot-device=HDD1 app Bind the logical domains: # ldm bind db # ldm bind app At the end of the process, the system is set up like this: # ldm list -o core,memory,physio NAME primary CORE CID CPUSET 0 (0, 1, 2, 3, 4, 5, 6, 7) 1 (8, 9, 10, 11, 12, 13, 14, 15) 2 (16, 17, 18, 19, 20, 21, 22, 23) 3 (24, 25, 26, 27, 28, 29, 30, 31) MEMORY RA PA SIZE 0x30000000 0x30000000 32G IO DEVICE PSEUDONYM OPTIONS pci@300 pci_0 pci@300/pci@1/pci@0/pci@6 /SYS/RCSA/PCIE1 pci@300/pci@1/pci@0/pci@c /SYS/RCSA/PCIE2 pci@300/pci@1/pci@0/pci@4/pci@0/pci@c /SYS/MB/SASHBA0 pci@300/pci@1/pci@0/pci@4/pci@0/pci@8 /SYS/RIO/NET0 ------------------------------------------------------------------------------ NAME app CORE CID CPUSET 4 (32, 33, 34, 35, 36, 37, 38, 39) 5 (40, 41, 42, 43, 44, 45, 46, 47) 6 (48, 49, 50, 51, 52, 53, 54, 55) 7 (56, 57, 58, 59, 60, 61, 62, 63) 8 (64, 65, 66, 67, 68, 69, 70, 71) 9 (72, 73, 74, 75, 76, 77, 78, 79) 10 (80, 81, 82, 83, 84, 85, 86, 87) 11 (88, 89, 90, 91, 92, 93, 94, 95) 12 (96, 97, 98, 99, 100, 101, 102, 103) 13 (104, 105, 106, 107, 108, 109, 110, 111) 14 (112, 113, 114, 115, 116, 117, 118, 119) 15 (120, 121, 122, 123, 124, 125, 126, 127) 16 (128, 129, 130, 131, 132, 133, 134, 135) 17 (136, 137, 138, 139, 140, 141, 142, 143) 18 (144, 145, 146, 147, 148, 149, 150, 151) 19 (152, 153, 154, 155, 156, 157, 158, 159) 20 (160, 161, 162, 163, 164, 165, 166, 167) 21 (168, 169, 170, 171, 172, 173, 174, 175) 22 (176, 177, 178, 179, 180, 181, 182, 183) 23 (184, 185, 186, 187, 188, 189, 190, 191) 24 (192, 193, 194, 195, 196, 197, 198, 199) 25 (200, 201, 202, 203, 204, 205, 206, 207) 26 (208, 209, 210, 211, 212, 213, 214, 215) 27 (216, 217, 218, 219, 220, 221, 222, 223) 28 (224, 225, 226, 227, 228, 229, 230, 231) 29 (232, 233, 234, 235, 236, 237, 238, 239) 30 (240, 241, 242, 243, 244, 245, 246, 247) 31 (248, 249, 250, 251, 252, 253, 254, 255) 32 (256, 257, 258, 259, 260, 261, 262, 263) 33 (264, 265, 266, 267, 268, 269, 270, 271) 34 (272, 273, 274, 275, 276, 277, 278, 279) 35 (280, 281, 282, 283, 284, 285, 286, 287) 36 (288, 289, 290, 291, 292, 293, 294, 295) 37 (296, 297, 298, 299, 300, 301, 302, 303) 38 (304, 305, 306, 307, 308, 309, 310, 311) 39 (312, 313, 314, 315, 316, 317, 318, 319) 40 (320, 321, 322, 323, 324, 325, 326, 327) 41 (328, 329, 330, 331, 332, 333, 334, 335) 42 (336, 337, 338, 339, 340, 341, 342, 343) 43 (344, 345, 346, 347, 348, 349, 350, 351) 44 (352, 353, 354, 355, 356, 357, 358, 359) 45 (360, 361, 362, 363, 364, 365, 366, 367) 46 (368, 369, 370, 371, 372, 373, 374, 375) 47 (376, 377, 378, 379, 380, 381, 382, 383) MEMORY RA PA SIZE 0x30000000 0x830000000 192G 0x4000000000 0x80000000000 256G 0x8080000000 0x100000000000 256G IO DEVICE PSEUDONYM OPTIONS pci@340 pci_1 pci@380 pci_2 pci@3c0 pci_3 pci@400 pci_4 pci@440 pci_5 pci@340/pci@1/pci@0/pci@6 /SYS/RCSA/PCIE3 pci@340/pci@1/pci@0/pci@c /SYS/RCSA/PCIE4 pci@380/pci@1/pci@0/pci@a /SYS/RCSA/PCIE9 pci@380/pci@1/pci@0/pci@4 /SYS/RCSA/PCIE10 pci@3c0/pci@1/pci@0/pci@e /SYS/RCSA/PCIE11 pci@3c0/pci@1/pci@0/pci@8 /SYS/RCSA/PCIE12 pci@400/pci@1/pci@0/pci@e /SYS/RCSA/PCIE5 pci@400/pci@1/pci@0/pci@8 /SYS/RCSA/PCIE6 pci@440/pci@1/pci@0/pci@e /SYS/RCSA/PCIE7 pci@440/pci@1/pci@0/pci@8 /SYS/RCSA/PCIE8 ------------------------------------------------------------------------------ NAME db CORE CID CPUSET 48 (384, 385, 386, 387, 388, 389, 390, 391) 49 (392, 393, 394, 395, 396, 397, 398, 399) 50 (400, 401, 402, 403, 404, 405, 406, 407) 51 (408, 409, 410, 411, 412, 413, 414, 415) 52 (416, 417, 418, 419, 420, 421, 422, 423) 53 (424, 425, 426, 427, 428, 429, 430, 431) 54 (432, 433, 434, 435, 436, 437, 438, 439) 55 (440, 441, 442, 443, 444, 445, 446, 447) 56 (448, 449, 450, 451, 452, 453, 454, 455) 57 (456, 457, 458, 459, 460, 461, 462, 463) 58 (464, 465, 466, 467, 468, 469, 470, 471) 59 (472, 473, 474, 475, 476, 477, 478, 479) 60 (480, 481, 482, 483, 484, 485, 486, 487) 61 (488, 489, 490, 491, 492, 493, 494, 495) 62 (496, 497, 498, 499, 500, 501, 502, 503) 63 (504, 505, 506, 507, 508, 509, 510, 511) MEMORY RA PA SIZE 0x80000000 0x180000000000 256G IO DEVICE PSEUDONYM OPTIONS pci@480 pci_6 pci@4c0 pci_7 pci@480/pci@1/pci@0/pci@a /SYS/RCSA/PCIE13 pci@480/pci@1/pci@0/pci@4 /SYS/RCSA/PCIE14 pci@4c0/pci@1/pci@0/pci@8 /SYS/RCSA/PCIE15 pci@4c0/pci@1/pci@0/pci@4 /SYS/RCSA/PCIE16 pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c /SYS/MB/SASHBA1 pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@4 /SYS/RIO/NET2 Start the domains: # ldm start app LDom app started # ldm start db LDom db started Make sure to start the vntsd service that was created, above. # svcs -a | grep ldo disabled 8:38:38 svc:/ldoms/vntsd:default online 8:38:58 svc:/ldoms/agents:default online 8:39:25 svc:/ldoms/ldmd:default # svcadm enable vntsd Now use the MAC address to configure the Solaris 11 Automated Installation. Database Logical Domain # telnet localhost 5000 {0} ok devalias screen /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@7/display@0 disk7 /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c/scsi@0/disk@p3 disk6 /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c/scsi@0/disk@p2 disk5 /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c/scsi@0/disk@p1 disk4 /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c/scsi@0/disk@p0 scsi1 /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c/scsi@0 net3 /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@4/network@0,1 net2 /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@4/network@0 virtual-console /virtual-devices/console@1 name aliases {0} ok boot net2 Boot device: /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@4/network@0 File and args: 1000 Mbps full duplex Link up Requesting Internet Address for xx:xx:xx:xx:xx:xx Requesting Internet Address for xx:xx:xx:xx:xx:xx WLS Logical Domain # telnet localhost 5001 {0} ok devalias hdd1 /virtual-devices@100/channel-devices@200/disk@0 vnet1 /virtual-devices@100/channel-devices@200/network@0 net /virtual-devices@100/channel-devices@200/network@0 disk /virtual-devices@100/channel-devices@200/disk@0 virtual-console /virtual-devices/console@1 name aliases {0} ok boot net Boot device: /virtual-devices@100/channel-devices@200/network@0 File and args: Requesting Internet Address for xx:xx:xx:xx:xx:xx Requesting Internet Address for xx:xx:xx:xx:xx:xx Repeat the process for the second SPARC T5-4, install Solaris, RAC and WebLogic Cluster, and you are ready to go. Maybe buying a SuperCluster would have been easier.

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The WaitForAll Roadshow

- by adweigert

OK, so I took for granted some imaginative uses of WaitForAll but lacking that, here is how I am using. First, I have a nice little class called Parallel that allows me to spin together a list of tasks (actions) and then use WaitForAll, so here it is, WaitForAll's 15 minutes of fame ... First Parallel that allows me to spin together several Action delegates to execute, well in parallel. public static class Parallel { public static ParallelQuery Task(Action action) { return new Action[] { action }.AsParallel(); } public static ParallelQuery> Task(Action action) { return new Action[] { action }.AsParallel(); } public static ParallelQuery Task(this ParallelQuery actions, Action action) { var list = new List(actions); list.Add(action); return list.AsParallel(); } public static ParallelQuery> Task(this ParallelQuery> actions, Action action) { var list = new List>(actions); list.Add(action); return list.AsParallel(); } } Next, this is an example usage from an app I'm working on that just is rendering some basic computer information via WMI and performance counters. The WMI calls can be expensive given the distance and link speed of some of the computers it will be trying to communicate with. This is the actual MVC action from my controller to return the data for an individual computer. public PartialViewResult Detail(string computerName) { var computer = this.Computers.Get(computerName); var perf = Factory.GetInstance(); var detail = new ComputerDetailViewModel() { Computer = computer }; try { var work = Parallel .Task(delegate { // Win32_ComputerSystem var key = computer.Name + "_Win32_ComputerSystem"; var system = this.Cache.Get(key); if (system == null) { using (var impersonation = computer.ImpersonateElevatedIdentity()) { system = computer.GetWmiContext().GetInstances().Single(); } this.Cache.Set(key, system); } detail.TotalMemory = system.TotalPhysicalMemory; detail.Manufacturer = system.Manufacturer; detail.Model = system.Model; detail.NumberOfProcessors = system.NumberOfProcessors; }) .Task(delegate { // Win32_OperatingSystem var key = computer.Name + "_Win32_OperatingSystem"; var os = this.Cache.Get(key); if (os == null) { using (var impersonation = computer.ImpersonateElevatedIdentity()) { os = computer.GetWmiContext().GetInstances().Single(); } this.Cache.Set(key, os); } detail.OperatingSystem = os.Caption; detail.OSVersion = os.Version; }) // Performance Counters .Task(delegate { using (var impersonation = computer.ImpersonateElevatedIdentity()) { detail.AvailableBytes = perf.GetSample(computer, "Memory", "Available Bytes"); } }) .Task(delegate { using (var impersonation = computer.ImpersonateElevatedIdentity()) { detail.TotalProcessorUtilization = perf.GetValue(computer, "Processor", "% Processor Time", "_Total"); } }).WithExecutionMode(ParallelExecutionMode.ForceParallelism); if (!work.WaitForAll(TimeSpan.FromSeconds(15), task => task())) { return PartialView("Timeout"); } } catch (Exception ex) { this.LogException(ex); return PartialView("Error.ascx"); } return PartialView(detail); }

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