Search Results

Search found 21392 results on 856 pages for 'order of operations'.

Page 497/856 | < Previous Page | 493 494 495 496 497 498 499 500 501 502 503 504  | Next Page >

• NSMutableURLRequest wont turn on 3G

  - by Kyle

  I won't bother posting any code because my code works fine when I launch Safari or something that turns on the 3G connection first. When I put it Airport mode, then put back OFF, I will get the behavior of a connection error saying No internet connection with NSMutableURLRequest. I've personally mailed apple about how the Ant gets turned on and off, and they said anything that uses their base CFSocketStream object will turn on the Ant, and I quote: "such as NSURLRequest".. BSD Sockets do not, just so everyone knows.. However, I assumed NSMutableURLRequest would fall into the category of 'Does', but it seems like it doesnt. It never succeeds for me when I cycle Airport or have the phone idle for a long time. It will ALWAYS succeed when I open any other network app first to turn the Ant on. Shall I be forced to do a dummy NSURLRequest call to turn this on; or has anyone been able to get this class working just fine? Remember this is just an implementation of NSMutableURLRequest to upload a file Async, and no other Network operations are performed anywhere; no ads, no version checks, no nothing.

  Read the article

• C question: error: expected ')' before '*' token

  - by lhw

  ===EDIT I apologize for not putting the pcb struct into the code snippet. There is a struct called pcb defined in above the two structs I originally posted. Namely, typedef struct{ UINT32 proc; struct pcb *link; }pcb; Hi, I asked a question regarding structs in C a few minutes ago and got an answer blazing fast. But now I'm facing another problem, namely the error in the title of this question. I'm trying to implement a simple priority queue in C using arrays of queues. However, when I try to declare a function on pcb_pQ structure, I get the above error. I have the structs clearly defined in the heard file. In the header file: typedef struct{ pcb *head; pcb *tail; SINT32 size; } pcb_Q; typedef struct pcb_pQ { pcb_Q queues[5]; SINT32 size; } pcb_pQ; Function prototype in header file: /*priority queue operations*/ VOID pcb_pq_enqueue(pcb_pQ*, pcb*); Function impelmentation in .c file: VOID pcb_pq_enqueue(pcb_pQ* pcb_pQ, pcb* pcb) { pcb_Q* pcb_Q_p; int priority; priority = pcb->proc_priority; pcb_Q_p = &pcb_pQ->queues[priority]; pcb_enqueue(pcb_Q_p, pcb); } When I try to compile the above code, I get an "error: expected ')' before '*' token". This error is pointing to the function signature in the .c file, namely VOID pcb_pq_enqueue(pcb_pQ* pcb_pQ, pcb* pcb) { But I am not sure why I am getting this error, could someone give me a hand? Thanks a lot.

  Read the article

• Getting svn: E170000: Unrecognized URL scheme for my custom Svn Gradle plugin

  - by Ip Doh

  I wrote a custom gradle plugin using groovy to do basic svn tasks like, Checkout, Clean, Tag etc. The groovy class calls the svn command line client to do these operations, It works fine when i run it on my windows system but the same plugin gives the following error when i run it on a linux system (Centos). svn: E170000: Unrecognized URL scheme for '%22https://source.mycompany.net/svn/MyProject/trunk%22' Am able to make the same calls to the command line client through the command prompt or shell script without any issues. So what is the difference with Here is my code sample String command =String.format("svn co -r %d --non-interactive --trust-server-cert -- username %s --password %s --depth infinity \"%s\" \"%s\"", getRevision(), getUserName(), getUserPassword(), getSrcUrl(), getDir()); Process svnProcess = Runtime.getRuntime().exec(command); BufferedReader stdInput = new BufferedReader(new InputStreamReader(svnProcess.getInputStream())); BufferedReader stdError = new BufferedReader(new InputStreamReader(svnProcess.getErrorStream())); String statusOutputLine ="" while ((statusOutputLine = stdInput.readLine()) != null) { logger.quiet(" " + statusOutputLine); } while (( statusOutputLine = stdError.readLine()) != null) { logger.error(statusOutputLine) throw new Exception(statusOutputLine) } logger.quiet("Successfully Checked out the work space") i do have neon installed on the system -bash-4.1$ svn --version svn, version 1.6.11 (r934486) compiled Jun 25 2011, 11:30:15 Copyright (C) 2000-2009 CollabNet. Subversion is open source software, see http://subversion.tigris.org/ This product includes software developed by CollabNet (http://www.Collab.Net/). The following repository access (RA) modules are available: ra_neon : Module for accessing a repository via WebDAV protocol using Neon. handles 'http' scheme handles 'https' scheme ra_svn : Module for accessing a repository using the svn network protocol. with Cyrus SASL authentication handles 'svn' scheme ra_local : Module for accessing a repository on local disk. handles 'file' scheme

  Read the article

• What's the largest (most complex) PHP algorithm ever implemented in a single monolithic PHP script?

  - by Alex R

  I'm working on a tool which converts PHP code to Scala. As one of the finishing touches, I'm in need of a really good (er, somewhat biased) benchmark. By dumb luck my first benchmark attempt was with some code which uses bcmath extensively, which unfortunately is 1000x slower in Java, making the Scala code 22x slower overall than the original PHP. So I'm looking for some meaningful PHP benchmark with the following characteristics: The source needs to be in a single file. I need it to be simple to setup - no databases, hard-to-find input files, etc. Simple text input and output preferred. It should not use features that are slow in Java (BigInteger, trigonometric functions, etc). It should not use exoteric or dynamic PHP functions (e.g. no "eval" or "variable vars"). It should not over-rely on built-in libraries, e.g. MD5, crypt, etc. It should not be I/O bound. A CPU-bound memory-hungry algorithm is preferred. Basically, intensive OO operations, integer and string manipulation, recursion, etc would be great. Thanks

  Read the article

• Temporary "Backup" of SharePoint Content During Feature and Solution Deployment

  - by ccomet

  I need to decide on a method for storing a subset of the content in a SharePoint site, so that when I delete and recreate certain lists as part of a feature activation, I can re-insert all of this content back where it should belong. I have an idea myself, but I don't know if it's the only method and more importantly, the right method. My client has me creating a SharePoint system for them to communicate with their clients. The business process has maybe 5 stages in it (maybe it's more, I don't even know because they don't tell me everything), and the current system I've written over the past months is maybe 2 stages through. This meets our deadline of completing those systems by Monday next week... but at that point my client is planning on making the site live from that point. In effect, their work with their clients will be running parallel with my work for them. As I complete my own work on a separate test server, I'll push each following stage of the process onto the live server. Scheduled downtimes during non-business times (like a weekend) will be available for me to perform these pushes. Keeping pace so that my development is faster than the actual business process is my own problem and off-topic... so let's get back to the problem I stated at the start of this post. In this system, we have sets of features which will create lists for their associated content types and field types when activated, and delete these lists when the feature is deactivated. Most updates don't need to deactivate and reactivate these features, such as workflow changes, custom actions, custom forms, and similar ilk. But there are some parts which do require this. On my test server, it's okay for me to obliterate lists, but once the site is live and there's real correspondence data, it's absolutely unacceptable to do this. So when I need to implement a new change in functionality, I need to be able to store the currently present data in several lists, deactivate the feature, reactivate the feature, and restore all of this data. Perhaps I have hoist myself by my own petard with the feature system I implemented. Unfortunately, the necessity to later on make several of these "project sites" meant I had to do a lot of my code with the concept of "Can be deployed repeatedly" in mind. My current plan is to run through lists and libraries which will be affected by the particular feature that is to be reset. Files and all of their versions will be saved in a directory on the server. Then, a set of text files will be used to store all of the important field values for the items. This includes a lot of cross-list reference lookups that will need to be maintained, but that's simple enough. Then, I deactivate the feature, deploy the new solution, and reactivate the feature. We upload all of the files in the order specified by their versions and update them with the stored fields for those versions, so that we retain the version structure. As each one is first uploaded, the new ID is picked out, and all relevant lookups in the rest of the files are updated (in some manner that I make sure I don't re-update it later with an incorrect value, of course). After that, we run through all the rest of the items in the order most conducive to keeping the relational data correct. This roughly summarizes what my current plan is. To my advantage, there are no long running workflows in the system that will be affected by this, so there's nothing I will have to worry about making sure nothing is "still running" when I do this stuff. I don't really know all the cons of this approach... I can imagine they're quite hefty. But I'm unsure what other choices I even have, and my searches haven't turned up anything. Is there anyone who can think of a better idea? Or will anyone just tell me that I really have no other choice? Thanks in advance!

  Read the article

• using Autofac in a multi-layered architecture

  - by Kamyar

  I'm fairly new to the DI/IoC concept and would like to use Autofac in a 3-layered ASP.NET Webforms application. UI layer: An ASP.NET webforms website. BLL: Business logic layer which calls the repositories on DAL. DAL: .EDMX file (Entity Model) and ObjectContext with Repository classes which abstract the CRUD operations for each entity. Entities: The POCO Entities. Persistence Ignorant. Generated by Microsoft's ADO.Net POCO Entity Generator. I have asked a more general question here. Basically, I'd like to create an obejctcontext per HttpContext in my DAL. But i don't want to add a reference to DAL in UI or access to HttpContext in DAL directly. I guess this is where IoC tools come to play. The answer to my previous question is a very good example of using Windsor Castle. I'd like to use Autofac as my IoC tool and Don't know how to achieve this. (How to access DAL in application_start to register the component while I don't want to reference it in my UI, what are the proper references to be able to use DAL component in BLL with Autofac, Should I register BLL as a component with Autofac too) Sorry folks for not providing an explicit question and requesting a kind of working example, But I'm very unfamiliar to the whole IoC concept and I don't think I can achieve it to use in my current time-limited project.

  Read the article

• How to estimate size of data to transfer when using DbCommand.ExecuteXXX?

  - by Yadyn

  I want to show the user detailed progress information when performing potentially lengthy database operations. Specifically, when inserting/updating data that may be on the order of hundreds of KB or MB. Currently, I'm using in-memory DataTables and DataRows which are then synced with the database via TableAdapter.Update calls. This works fine and dandy, but the single call leaves little opportunity to glean any kind of progress info to show to the user. I have no idea how much data is passing through the network to the remote DB or its progress. Basically, all I know is when Update returns and it is assumed complete (barring any errors or exceptions). But this means all I can show is 0% and then a pause and then 100%. I can count the number of rows, even going so far to cound how many are actually Modified or Added, and I could even maybe calculate per DataRow its estimated size based on the datatype of each column, using sizeof for value types like int and checking length for things like strings or byte arrays. With that, I could probably determine, before updating, an estimated total transfer size, but I'm still stuck without any progress info once Update is called on the TableAdapter. Am I stuck just using an indeterminate progress bar or mouse waiting cursor? Would I need to radically change our data access layer to be able to hook into this kind of information? Even if I can't get it down to the precise KB transferred (like a web browser file download progress bar), could I at least know when each DataRow/DataTable finishes or something? How do you best show this kind of progress info using ADO.NET?

  Read the article

• How to improve Java performance on Informix for Windows

  - by Michal Niklas

  I have problem with performance of Java UDR functions on Informix on Windows. On this server I already have some functions in C and SPL. I chose one function to write it in those 3 languages and I measured performance of this function on test table. Function calculates some kind of checksum so it does not use any db libraries etc. only string and math operations. I observed performance on 30k records with SQL like: select function(txt) from _tmp_perf_test and I changed function to 'function_c, function_spl or function_java. My performance tests showed that C function is the fastest, SPL function is about 5 times slower, where Java is 100 (one hundred!) times slower than C. I checked it few times and 1:100 ratio didn't improve. I changed Java function to simply return length of the string but even this do not help so it looks, that there is general problem with Java function invocation, because there was no difference in time between Java function that calculate checksum and Java function that returns length of the string. I increased JVM_MAX_HEAP_SIZE to 128 and it not helped too. I use IBM Informix Dynamic Server Version 11.50.TC6DE. The same test on Linux server: IBM Informix Dynamic Server Version 11.50.FC6 show more "normal" results, i.e. Java is slower from C and SPL but only 2 to 5 times. What can I do to improve Java performance on Informix server on Windows? More info about Java on servers: c:\Informix\extend\krakatoa\jre\bin>java -version java version "1.5.0" Java(TM) 2 Runtime Environment, Standard Edition (build pwi32dev-20081129a (SR9-0 )) IBM J9 VM (build 2.3, J2RE 1.5.0 IBM J9 2.3 Windows Server 2003 x86-32 j9vmwi3223-20081129 (JIT enabled) J9VM - 20081126_26240_lHdSMr JIT - 20081112_1511ifx1_r8 GC - 200811_07) JCL - 20081129 [root@informix11 bin]# ./java -version java version "1.5.0" Java(TM) 2 Runtime Environment, Standard Edition (build pxa64devifx-20071025 (SR6b)) IBM J9 VM (build 2.3, J2RE 1.5.0 IBM J9 2.3 Linux amd64-64 j9vmxa6423-20071005 (JIT enabled) J9VM - 20071004_14218_LHdSMr JIT - 20070820_1846ifx1_r8 GC - 200708_10) JCL - 20071025

  Read the article

• Grouped UITableView Footer Sometimes Hidden On Quick Scroll

  - by jdandrea

  OK, this one is a puzzler. There is one similar post but it's not similar enough to count, so I'm posting this one. :) I've got a grouped UITableView with a header and footer. The footer includes two UIButton views, side-by-side. Nothing major. Now … there is a toggle button in a UIToolbar at the bottom for more/less info in this table view. So I build my index paths to delete/insert with fade row animation, all the usual ingredients, sandwiched between beginUpdates and endUpdates calls on the UITableView … and this works fine! In also happens that my footer can sometimes be pushed off past the bottom of the display. Here's where it gets weird. If I drag my finger up the display, scrolling the view upward, I should see that footer eventually, right? Well … most of the time I do. BUT, if I flick my finger up, for a faster scroll, the footer is missing. Even if you try to tap in that area - no response. However, if I scroll back down again, just to hide that footer (or rather hide the area where the footer would normally be), and then scroll back up, it's there once again! This only happens when inserting rows. If I delete rows, the footer stays put … unless of course it was already hidden and I didn't perform the aforementioned incantation to get it back. :) I am trying to trace through this, but to no avail. I suppose tracing through scroll operations is a bit of a crazy proposition! Perhaps some creative logging … suggestions, anyone? Or is this a known issue in 3.1 where row insert/deletes are concerned? (I don't recall seeing it until 3.1.)

  Read the article

• Getting parameters values blank and null when using custom wsdl in axis2

  - by Narendra

  Hi All, I am using axis2 for my web services creation. I want to user my own wsdl file instead of using generated wsdl file. When I am placing my own wsdl file in META-INF directory and deploying my web services they are deploying successfully. But the problem is when i try to test these web service using soapui it throwing null pointer exception. For example I am invoking following operations in soap ui. public String testWebService(String a, String b) { LogHelper.info("Value of a is:"+a); LogHelper.info("Value of b is :"+b); String c=a.trim()+b.Trim(); return "suceess" } output in console: value of a is: value of b is:null 19:58:47,781 ERROR [RPCMessageReceiver] Exception occurred while trying to invoke service method testWebService java.lang.reflect.InvocationTargetException at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.axis2.rpc.receivers.RPCUtil.invokeServiceClass(RPCUtil.java:194) at org.apache.axis2.rpc.receivers.RPCMessageReceiver.invokeBusinessLogic(RPCMessageReceiver.java:102) at org.apache.axis2.receivers.AbstractInOutMessageReceiver.invokeBusinessLogic(AbstractInOutMessageReceiver.java:40) at org.apache.axis2.receivers.AbstractMessageReceiver.receive(AbstractMessageReceiver.java:114) at org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:173) at org.apache.axis2.transport.http.HTTPTransportUtils.processHTTPPostRequest(HTTPTransportUtils.java:173) at org.apache.axis2.transport.http.AxisServlet.doPost(AxisServlet.java:142) at javax.servlet.http.HttpServlet.service(HttpServlet.java:637) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:235) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:190) at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:92) at o...................................................... SO What i understand is i am getting value for a is black and value of b is null. Can any one give me any suggestions please. Thanks, Narendra

  Read the article

• Status Code from FTPWebRequest GetResponse method

  - by nick

  This is slightly tricky. I am uploading files to FTP asynchronously. After uploading each file I am checking the status of the upload operation for that file. This can be done with StatusCode property of the FtpWebResponse object for that request. The code snippet is as give below. System.IO.FileStream fs = System.IO.File.Open(fileName, System.IO.FileMode.Open); while ((iWork = fs.Read(buf, 0, buf.Length)) > 0) requestStream.Write(buf, 0, iWork); requestStream.Close(); FtpWebResponse wrRet = ((FtpWebResponse)state.Request.GetResponse()); There are about 37 StatusCode values as per msdn. I am unaware as to which of these status code values will assure that the file is uploaded successfully. Some of them I used in my code to check for success are : wrRet.StatusCode == FtpStatusCode.CommandOK wrRet.StatusCode == FtpStatusCode.ClosingData wrRet.StatusCode == FtpStatusCode.ClosingControl wrRet.StatusCode == FtpStatusCode.ConnectionClosed wrRet.StatusCode == FtpStatusCode.FileActionOK wrRet.StatusCode == FtpStatusCode.FileStatus But I am unaware of the rest. I need to be sure about these codes because based on the failure or success of the upload operation I have other dependant operations to be carried out. A wrong condition can affect the remaining code. Another thought that crossed my mind was to simply put the above code into a try..catch and not depend on these status codes. With this I would not be depending on the status codes and assuming that any failure will always be directed to the catch block. Kindly let me know if this is the right way. Thanks in advance.

  Read the article

• Appending data to NSFetchedResultsController during find or create loop

  - by Justin Williams

  I have a table view that is managed by an NSFetchedResultsController. I am having an issue with a find-or-create operation, however. When the user hits the bottom of my table view, I am querying my server for another batch of content. If it doesn't exist in the local cache, we create it and store it. If it does exist, however, I want to append that data to the fetched results controller and display it. I can't quite figure that part out. Here's what I'm doing thus far: Passing the returned array of values from my server to an NSOperation to process. In the operation, create a new managed object context to work with. In the operation, I iterate through the array and execute a fetch request to see if the object exists (based on its server id). If the object doesn't exist, we create it and insert it into the operations' managed object context. After the iteration completes, we save the managed object context, which triggers a merge notification on my main thread. At this point, any objects that weren't locally cached in my Core Data store before will appear, but the ones that previously existed do not come along for the ride. I feel like it's something simple I'm missing, and could use a nudge in the right direction.

  Read the article

• Pair-wise iteration in C# or sliding window enumerator

  - by f3lix

  If I have an IEnumerable like: string[] items = new string[] { "a", "b", "c", "d" }; I would like to loop thru all the pairs of consecutive items (sliding window of size 2). Which would be ("a","b"), ("b", "c"), ("c", "d") My solution was is this public static IEnumerable<Pair<T, T>> Pairs(IEnumerable<T> enumerable) { IEnumerator<T> e = enumerable.GetEnumerator(); e.MoveNext(); T current = e.Current; while ( e.MoveNext() ) { T next = e.Current; yield return new Pair<T, T>(current, next); current = next; } } // used like this : foreach (Pair<String,String> pair in IterTools<String>.Pairs(items)) { System.Out.PrintLine("{0}, {1}", pair.First, pair.Second) } When I wrote this code, I wondered if there are already functions in the .NET framework that do the same thing and do it not just for pairs but for any size tuples. IMHO there should be a nice way to do this kind of sliding window operations. I use C# 2.0 and I can imagine that with C# 3.0 (w/ LINQ) there are more (and nicer) ways to do this, but I'm primarily interested in C# 2.0 solutions. Though, I will also appreciate C# 3.0 solutions.

  Read the article

• Rotating an object in OpenGL ES for iPhone [translate to origin --> rotate --> translate back is not

  - by ayanonagon

  I recently started working with OpenGL ES for the iPhone, and I am having a bit of trouble with it. I want to be able to rotate an object with your fingers. My problem is that I have my object placed at (0, 0, -3), and I would like to rotate it about its center. I know that I need to translate back to the origin, rotate, and then bring it back to the original place. I think I am facing a problem because I am using a matrix to keep track (?) of all of my rotations/translation/scaling etc, and I think it may be combining the operations in a way that order is not even considered (so the two translations would cancel each other). I just started learning OpenGL a day ago and am a complete newbie, so my assumption may be wrong. Here is the part of the in drawView that I am having trouble with: GLfloat matrix[16]; glGetFloatv(GL_MODELVIEW_MATRIX, matrix); glLoadIdentity(); glTranslatef(0, 0, 3); // bring to origin glRotatef(self.angle, self.dy, self.dx, 0); // rotate glTranslatef(0, 0, -3); // put it back in place glMultMatrixf(matrix); // save the transformations performed Help would be much appreciated, thank you!

  Read the article

• Is there a PHP benchmark that meets these specific criteria? [closed]

  - by Alex R

  I'm working on a tool which converts PHP code to Scala. As one of the finishing touches, I'm in need of a really good (er, somewhat biased) benchmark. By dumb luck my first benchmark attempt was with some code which uses bcmath extensively, which unfortunately is 1000x slower in Java, making the Scala code 22x slower overall than the original PHP. So I'm looking for some meaningful PHP benchmark with the following characteristics: The PHP source needs to be in a single file. It should solve a real-world problem. No silly looping over empty methods etc. I need it to be simple to setup - no databases, hard-to-find input files, etc. Simple text input and output preferred. It should not use features that are slow in Java (BigInteger, trigonometric functions, etc). It should not use exoteric or dynamic PHP functions (e.g. no "eval" or "variable vars"). It should not over-rely on built-in libraries, e.g. MD5, crypt, etc. It should not be I/O bound. A CPU-bound memory-hungry algorithm is preferred. Basically, intensive OO operations, integer and string manipulation, recursion, etc would be great. Thanks

  Read the article

• Merging: hg/git vs. svn

  - by stmax

  I often read that hg (and git and...) are better at merging than svn but I have never seen practical examples of where hg/git can merge something where svn fails (or where svn needs manual intervention). Could you post a few step-by-step lists of branch/modify/commit/...-operations that show where svn would fail while hg/git happily moves on? Practical, not highly exceptional cases please... Some background: we have a few dozen developers working on projects using svn, with each project (or group of similar projects) in its own repo. We know how to apply release- and feature-branches so we don't run into problems very often (i.e. we've been there, but we've learned to overcome joel's problems of "one programmer causing trauma to the whole team" or "needing six developers for two weeks to reintegrate a branch"). We have release-branches that are very stable and only used to apply bugfixes. We have trunks that should be stable enough to be able to create a release within one week. And we have feature-branches that single developers or groups of developers can work on. Yes, they are deleted after reintegration so they don't clutter up the repository. ;) So I'm still trying to find the advantages of hg/git over svn. I'd love to get some hands-on experience, but there aren't any bigger projects we could move to hg/git yet, so I'm stuck with playing with small artifical projects that only contain a few made up files. And I'm looking for a few cases where you can feel the impressive power of hg/git, since so far I have often read about them but failed to find them myself.

  Read the article

• Multithreading and Interrupts

  - by Nicholas Flynt

  I'm doing some work on the input buffers for my kernel, and I had some questions. On Dual Core machines, I know that more than one "process" can be running simultaneously. What I don't know is how the OS and the individual programs work to protect collisions in data. There are two things I'd like to know on this topic: (1) Where do interrupts occur? Are they guaranteed to occur on one core and not the other, and could this be used to make sure that real-time operations on one core were not interrupted by, say, file IO which could be handled on the other core? (I'd logically assume that the interrupts would happen on the 1st core, but is that always true, and how would you tell? Or perhaps does each core have its own settings for interrupts? Wouldn't that lead to a scenario where each core could react simultaneously to the same interrupt, possibly in different ways?) (2) How does the dual core processor handle opcode memory collision? If one core is reading an address in memory at exactly the same time that another core is writing to that same address in memory, what happens? Is an exception thrown, or is a value read? (I'd assume the write would work either way.) If a value is read, is it guaranteed to be either the old or new value at the time of the collision? I understand that programs should ideally be written to avoid these kinds of complications, but the OS certainly can't expect that, and will need to be able to handle such events without choking on itself.

  Read the article

• Polymorphic Numerics on .Net and In C#

  - by Bent Rasmussen

  It's a real shame that in .Net there is no polymorphism for numbers, i.e. no INumeric interface that unifies the different kinds of numerical types such as bool, byte, uint, int, etc. In the extreme one would like a complete package of abstract algebra types. Joe Duffy has an article about the issue: http://www.bluebytesoftware.com/blog/CommentView,guid,14b37ade-3110-4596-9d6e-bacdcd75baa8.aspx How would you express this in C#, in order to retrofit it, without having influence over .Net or C#? I have one idea that involves first defining one or more abstract types (interfaces such as INumeric - or more abstract than that) and then defining structs that implement these and wrap types such as int while providing operations that return the new type (e.g. Integer32 : INumeric; where addition would be defined as public Integer32 Add(Integer32 other) { return Return(Value + other.Value); } I am somewhat afraid of the execution speed of this code but at least it is abstract. No operator overloading goodness... Any other ideas? .Net doesn't look like a viable long-term platform if it cannot have this kind of abstraction I think - and be efficient about it. Abstraction is reuse.

  Read the article

• How would I go about sharing variables in a class with Lua?

  - by Nicholas Flynt

  I'm fairly new to Lua, I've been working on trying to implement Lua scripting for logic in a Game Engine I'm putting together. I've had no trouble so far getting Lua up and running through the engine, and I'm able to call Lua functions from C and C functions from Lua. The way the engine works now, each Object class contains a set of variables that the engine can quickly iterate over to draw or process for physics. While game objects all need to access and manipulate these variables in order for the Game Engine itself to see any changes, they are free to create their own variables, a Lua is exceedingly flexible about this so I don't forsee any issues. Anyway, currently the Game Engine side of things are sitting in C land, and I really want them to stay there for performance reasons. So in an ideal world, when spawning a new game object, I'd need to be able to give Lua read/write access to this standard set of variables as part of the Lua object's base class, which its game logic could then proceed to run wild with. So far, I'm keeping two separate tables of objects in place-- Lua spawns a new game object which adds itself to a numerically indexed global table of objects, and then proceeds to call a C++ function, which creates a new GameObject class and registers the Lua index (an int) with the class. So far so good, C++ functions can now see the Lua object and easily perform operations or call functions in Lua land using dostring. What I need to do now is take the C++ variables, part of the GameObject class, and expose them to Lua, and this is where google is failing me. I've encountered a very nice method here which details the process using tags, but I've read that this method is deprecated in favor of metatables. What is the ideal way to accomplish this? Is it worth the hassle of learning how to pass class definitions around using libBind or some equivalent method, or is there a simple way I can just register each variable (once, at spawn time) with the global lua object? What's the "current" best way to do this, as of Lua 5.1.4?

  Read the article

• Domain Validation in a CQRS architecture

  - by Jupaol

  Basically I want to know if there is a better way to validate my domain entities. This is how I am planning to do it but I would like your opinion The first approach I considered was: class Customer : EntityBase<Customer> { public void ChangeEmail(string email) { if(string.IsNullOrWhitespace(email)) throw new DomainException(“...”); if(!email.IsEmail()) throw new DomainException(); if(email.Contains(“@mailinator.com”)) throw new DomainException(); } } I actually do not like this validation because even when I am encapsulating the validation logic in the correct entity, this is violating the Open/Close principle (Open for extension but Close for modification) and I have found that violating this principle, code maintenance becomes a real pain when the application grows up in complexity. Why? Because domain rules change more often than we would like to admit, and if the rules are hidden and embedded in an entity like this, they are hard to test, hard to read, hard to maintain but the real reason why I do not like this approach is: if the validation rules change, I have to come and edit my domain entity. This has been a really simple example but in RL the validation could be more complex So following the philosophy of Udi Dahan, making roles explicit, and the recommendation from Eric Evans in the blue book, the next try was to implement the specification pattern, something like this class EmailDomainIsAllowedSpecification : IDomainSpecification<Customer> { private INotAllowedEmailDomainsResolver invalidEmailDomainsResolver; public bool IsSatisfiedBy(Customer customer) { return !this.invalidEmailDomainsResolver.GetInvalidEmailDomains().Contains(customer.Email); } } But then I realize that in order to follow this approach I had to mutate my entities first in order to pass the value being valdiated, in this case the email, but mutating them would cause my domain events being fired which I wouldn’t like to happen until the new email is valid So after considering these approaches, I came out with this one, since I am going to implement a CQRS architecture: class EmailDomainIsAllowedValidator : IDomainInvariantValidator<Customer, ChangeEmailCommand> { public void IsValid(Customer entity, ChangeEmailCommand command) { if(!command.Email.HasValidDomain()) throw new DomainException(“...”); } } Well that’s the main idea, the entity is passed to the validator in case we need some value from the entity to perform the validation, the command contains the data coming from the user and since the validators are considered injectable objects they could have external dependencies injected if the validation requires it. Now the dilemma, I am happy with a design like this because my validation is encapsulated in individual objects which brings many advantages: easy unit test, easy to maintain, domain invariants are explicitly expressed using the Ubiquitous Language, easy to extend, validation logic is centralized and validators can be used together to enforce complex domain rules. And even when I know I am placing the validation of my entities outside of them (You could argue a code smell - Anemic Domain) but I think the trade-off is acceptable But there is one thing that I have not figured out how to implement it in a clean way. How should I use this components... Since they will be injected, they won’t fit naturally inside my domain entities, so basically I see two options: Pass the validators to each method of my entity Validate my objects externally (from the command handler) I am not happy with the option 1 so I would explain how I would do it with the option 2 class ChangeEmailCommandHandler : ICommandHandler<ChangeEmailCommand> { public void Execute(ChangeEmailCommand command) { private IEnumerable<IDomainInvariantValidator> validators; // here I would get the validators required for this command injected, and in here I would validate them, something like this using (var t = this.unitOfWork.BeginTransaction()) { var customer = this.unitOfWork.Get<Customer>(command.CustomerId); this.validators.ForEach(x =. x.IsValid(customer, command)); // here I know the command is valid // the call to ChangeEmail will fire domain events as needed customer.ChangeEmail(command.Email); t.Commit(); } } } Well this is it. Can you give me your thoughts about this or share your experiences with Domain entities validation EDIT I think it is not clear from my question, but the real problem is: Hiding the domain rules has serious implications in the future maintainability of the application, and also domain rules change often during the life-cycle of the app. Hence implementing them with this in mind would let us extend them easily. Now imagine in the future a rules engine is implemented, if the rules are encapsulated outside of the domain entities, this change would be easier to implement

  Read the article

• Select Multiple Images Using GalleryView

  - by hwrdprkns

  Hi guys, I was just wondering if Android had built in code so that I could select multiple images in a gallery-view and then have those images exported as filenames in a string array(ex /sdcard/~f1.jpg, /sdcard/~f2.jpg,...). I have the gallery code here, but I'm not sure what modifications need to be made. Any help is appreciated. Thanks! // take_picture = (Button)findViewById(R.id.take_picture); // Here we set up a string array of the thumbnail ID column we want to // get back String[] proj = { MediaStore.Images.Thumbnails._ID }; if(proj.length == 0) { nopic.setVisibility(View.VISIBLE); } // Now we create the cursor pointing to the external thumbnail store cursor = managedQuery( MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI, proj, // Which // columns // to // return null, // WHERE clause; which rows to return (all rows) null, // WHERE clause selection arguments (none) null); // Order-by clause (ascending by name) /* take_picture.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { Intent i = new Intent(GalleryActivity.this, CameraActivity.class); startActivity(i); } }); */ // We now get the column index of the thumbnail id column_index = cursor .getColumnIndexOrThrow(MediaStore.Images.Thumbnails._ID); // Reference the Gallery view g = (Gallery) findViewById(R.id.gallery); if(proj.length == 0) { nopic.setVisibility(View.VISIBLE); g.setVisibility(View.GONE); } // Set the adapter to our custom adapter (below) g.setAdapter(new ImageAdapter(this)); // Set a item click listener, and just Toast the clicked position g.setOnItemClickListener(new OnItemClickListener() { public void onItemClick(AdapterView parent, View v, int position, long id) { // Now we want to actually get the data location of the file String[] proj = { MediaStore.Images.Media.DATA }; // We request our cursor again cursor = managedQuery( MediaStore.Images.Media.EXTERNAL_CONTENT_URI, proj, // Which // columns // to // return null, // WHERE clause; which rows to return (all rows) null, // WHERE clause selection arguments (none) null); // Order-by clause (ascending by name) // We want to get the column index for the data uri column_index = cursor .getColumnIndexOrThrow(MediaStore.Images.Media.DATA); // Lets move to the selected item in the cursor cursor.moveToPosition((int) g.getSelectedItemId()); // And here we get the filename String filename = cursor.getString(column_index); Log.v("GalleryActivity", filename); Toast.makeText(GalleryActivity.this, filename, Toast.LENGTH_SHORT).show(); setPrefs(filename); Intent i = new Intent(GalleryActivity.this, OtherClass.class); startActivity(i); } }); } And the ImageAdapter code here: public class ImageAdapter extends BaseAdapter { int mGalleryItemBackground; public ImageAdapter(Context c) { mContext = c; // See res/values/attrs.xml for the that defines // Gallery1. TypedArray a = obtainStyledAttributes(R.styleable.Gallery); mGalleryItemBackground = a.getResourceId( R.styleable.Gallery_android_galleryItemBackground, 0); a.recycle(); } public int getCount() { return cursor.getCount(); } public Object getItem(int position) { return position; } public long getItemId(int position) { return position; } public View getView(int position, View convertView, ViewGroup parent) { ImageView i = new ImageView(mContext); if (convertView == null) { cursor.moveToPosition(position); int id = cursor.getInt(column_index); i.setImageURI(Uri.withAppendedPath( MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI, "" + id)); i.setScaleType(ImageView.ScaleType.FIT_XY); i.setLayoutParams(new Gallery.LayoutParams(200, 200)); // The preferred Gallery item background i.setBackgroundResource(mGalleryItemBackground); } return i; } } Again any help is appreciateds! Just to let you guys know, the gallery works fine (for one image) as in it exports the filename correctly. Just need to know if there is an easy way to select multiples and export them. Thanks again!

  Read the article

• DQL delete from multiple tables (doctrine)

  - by singer

  Need to perform DQL delete from multple related tables. In SQL it is something like this: DELETE r1,r2 FROM ComRealty_objects r1, com_realty_objects_phones r2 WHERE r1.id IN (10,20) AND r2.id_object IN (10,20) I need to perform this statement using DQL, but I'm stuck on this :( <?php $dql = Doctrine_Query::create() ->delete('phones, comrealtyobjects') ->from('ComRealtyObjects comrealtyobjects') ->from('ComRealtyObjectsPhones phones') ->whereIn("comrealtyobjects.id", $ids) ->whereIn("phones.id_object", $ids); echo($dql->getSqlQuery()); ?> But DQL parser gives me this result: DELETE FROM `com_realty_objects_phones`, `ComRealty_objects` WHERE (`id` IN (?) AND `id_object` IN (?)) Searching google and stack overflow I found this(useful) topic: http://stackoverflow.com/questions/2247905/what-is-the-syntax-for-a-multi-table-delete-on-a-mysql-database-using-doctrine But this is not exactly my case - there was delete from single table. If there is a way to override dql parser behaviour? Or maybe some other way to delete records from multiple tables using doctrine. Note: If you are using doctrine behaviours(Doctrine_Record_Generator) you need first to initialize those tables using Doctrine_Core::initializeModels() to perform DQL operations on them.

  Read the article

• Application log aggregation, management and notifications...

  - by Matthew Savage

  I'm wondering what everyone is using for logging, log management and log aggregation on their systems. I am working in a company which uses .NET for all it's applications and all systems are Windows based. Currently each application looks after its own logging and notifications of failures (e.g. if app A fails it will send out its own 'call for help' to an admin). While this current practice works its a bit hacky and hard to manage. I've been trying to find some options for making this work better and I've come up with the following: log4net & Chainsaw (ah, if it works). Logging via log4net or another framework into a central database & rolling our own management tool. Logging to the Windows event log and using MOM or System Center Operations Manager to aggregate and manage each of these servers & their apps. A hand-rolled solution to suck all the log files into one point and work some magic across them. Essentially what we are after is something which can pull log entries all together and allow for some analytics to be run across them, plus use a kind of event based system to, for example, send out a warning email when there have been 30+ warning level logs for an application in the last x minutes. So is there anything I've missed, or something someone else can suggest?

  Read the article

• Is a red-black tree my ideal data structure?

  - by Hugo van der Sanden

  I have a collection of items (big rationals) that I'll be processing. In each case, processing will consist of removing the smallest item in the collection, doing some work, and then adding 0-2 new items (which will always be larger than the removed item). The collection will be initialised with one item, and work will continue until it is empty. I'm not sure what size the collection is likely to reach, but I'd expect in the range 1M-100M items. I will not need to locate any item other than the smallest. I'm currently planning to use a red-black tree, possibly tweaked to keep a pointer to the smallest item. However I've never used one before, and I'm unsure whether my pattern of use fits its characteristics well. 1) Is there a danger the pattern of deletion from the left + random insertion will affect performance, eg by requiring a significantly higher number of rotations than random deletion would? Or will delete and insert operations still be O(log n) with this pattern of use? 2) Would some other data structure give me better performance, either because of the deletion pattern or taking advantage of the fact I only ever need to find the smallest item? Update: glad I asked, the binary heap is clearly a better solution for this case, and as promised turned out to be very easy to implement. Hugo

  Read the article

• What is the 'page lifecycle' of an ASP.NET MVC page, compared to ASP.NET WebForms?

  - by Simon

  What is the 'page lifecycle' of an ASP.NET MVC page, compared to ASP.NET WebForms? I'm tryin to better understand this 'simple' question in order to determine whether or not existing pages I have in a (very) simple site can be easily converted from ASP.NET WebForms. Either a 'conversion' of the process below, or an alternative lifecycle would be what I'm looking for. What I'm currently doing: (yes i know that anyone capable of answering my question already knows all this -- i'm just tryin to get a comparison of the 'lifecycle' so i thought i'd start by filling in what we already all know) Rendering the page: I have a master page which contains my basic template I have content pages that give me named regions from the master page into which I put content. In an event handler for each content page I load data from the database (mostly read-only). I bind this data to ASP.NET controls representing grids, dropdowns or repeaters. This data all 'lives' inside the HTML generated. Some of it gets into ViewState (but I wont go into that too much!) I set properties or bind data to certain items like Image or TextBox controls on the page. The page gets sent to the client rendered as non-reusable HTML. I try to avoid using ViewState other than what the page needs as a minimum. Client side (not using ASP.NET AJAX): I may use JQuery and some nasty tricks to find controls on the page and perform operations on them. If the user selects from a dropdown -- a postback is generated which triggers a C# event in my codebehind. This event may go to the database, but whatever it does a completely newly generated HTML page ends up getting sent back to the client. I may use Page.Session to store key value pairs I need to reuse later So with MVC how does this 'lifecycle' change?

  Read the article

< Previous Page | 493 494 495 496 497 498 499 500 501 502 503 504  | Next Page >