Search Results

Search found 8144 results on 326 pages for 'thread'.

Page 279/326 | < Previous Page | 275 276 277 278 279 280 281 282 283 284 285 286  | Next Page >

• Where do I put the logic of my MFC program?

  - by Matthew

  I created an application core, in C++, that I've compiled into a static library in Visual Studio. I am now at the process of writing a GUI for it. I am using MFC to do this. I figured out how to map button presses to execute certain methods of my application core's main class (i.e. buttons to have it start and stop). The core class however, should always be sampling data from an external source every second or two. The GUI should then populate some fields after each sample is taken. I can't seem to find a spot in my MFC objects like CDialog that I can constantly check to see if my class has grabbed the data.. then if it has put that data into some of the text boxes. A friend suggested that I create a thread on the OnInit() routine that would take care of this, but that solution isn't really working for me. Is there no spot where I can put an if statement that keeps being called until the program quits? i.e. if( coreapp.dataSampleReady() ) { // put coreapp.dataItem1() in TextBox1 // set progress bar to coreapp.dataItem2() // etc. // reset dataSampleReady }

  Read the article

• Issue with Callback method and maintaining CultureInfo and ASP.Net HttpRuntime

  - by Little Larry Sellers

  Hi All, Here is my issue. I am working on an E-commerce solution that is deployed to multiple European countries. We persist all exceptions within the application to SQL Server and I have found that there are records in the DB that have a DateTime in the future! We define the culture in the web.config, for example pt-PT, and the format expected is DD-MM-YYYY. After debugging I found the issue with these 'future' records in the DB is because of Callback methods we use. For example, in our Caching architecture we use Callbacks, as such - CacheItemRemovedCallback ReloadCallBack = new CacheItemRemovedCallback(OnRefreshRequest); When I check the current threads CultureInfo, on these Callbacks it is en-US instead of pt-PT and also the HttpContext is null. If an exception occurs on the Callback our exception manager reports it as MM-DD-YYYY and thus it is persisted to SQL Server incorrectly. Unfortunately, in the exception manager code, we use DateTime.Now, which is fine if it is not a callback. I can't change this code to be culture specific due to it being shared across other verticals. So, why don't callbacks into ASP.Net maintain context? Is there any way to maintain it on this callback thread? What are the best practices here? Thanks.

  Read the article

• Python 3.3 Webserver restarting problems

  - by IPDGino

  I have made a simple webserver in python, and had some problems with it before as described here: Python (3.3) Webserver script with an interesting error In that question, the answer was to use a While True: loop so that any crashes or errors would be resolved instantly, because it would just start itself again. I've used this for a while, and still want to make the server restart itself every few minutes, but on Linux for some reason it won't work for me. On windows the code below works fine, but on linux it keeps saying Handler class up here ... ... class Server: def __init__(self): self.server_class = HTTPServer self.server_adress = ('MY IP GOES HERE, or localhost', 8080) global httpd httpd = self.server_class(self.server_adress, Handler) self.main() def main(self): if count > 1: global SERVER_UP_SINCE HOUR_CHECK = int(((count - 1) * RESTART_INTERVAL) / 60) SERVER_UPTIME = str(HOUR_CHECK) + " MINUTES" if HOUR_CHECK > 60: minutes = int(HOUR_CHECK % 60) hours = int(HOUR_CHECK // 60) SERVER_UPTIME = ("%s HOURS, %s MINUTES" % (str(hours), str(minutes))) SERVING_ON_ADDR = self.server_adress SERVER_UP_SINCE = str(SERVER_UP_SINCE) SERVER_RESTART_NUMBER = count - 1 print(""" SERVER INFO ------------------------------------- SERVER_UPTIME: %s SERVER_UP_SINCE: %s TOTAL_FILES_SERVED: %d SERVING_ON_ADDR: %s SERVER_RESTART_NUMBER: %s \n\nSERVER HAS RESTARTED """ % (SERVER_UPTIME, SERVER_UP_SINCE, TOTAL_FILES, SERVING_ON_ADDR, SERVER_RESTART_NUMBER)) else: print("SERVER_BOOT=1\nSERVER_ONLINE=TRUE\nRESTART_LOOP=TRUE\nSERVING_ON_ADDR:%s" % str(self.server_adress)) while True: try: httpd.serve_forever() except KeyboardInterrupt: print("Shutting down...") break httpd.shutdown() httpd.socket.close() raise(SystemExit) return def server_restart(): """If you want the restart timer to be longer, replace the number after the RESTART_INTERVAL variable""" global RESTART_INTERVAL RESTART_INTERVAL = 10 threading.Timer(RESTART_INTERVAL, server_restart).start() global count count = count + 1 instance = Server() if __name__ == "__main__": global SERVER_UP_SINCE SERVER_UP_SINCE = strftime("%d-%m-%Y %H:%M:%S", gmtime()) server_restart() Basically, I make a thread to restart it every 10 seconds (For testing purposes) and start the server. After ten seconds it will say File "/home/username/Desktop/Webserver/server.py", line 199, in __init__ httpd = self.server_class(self.server_adress, Handler) File "/usr/lib/python3.3/socketserver.py", line 430, in __init__ self.server_bind() File "/usr/lib/python3.3/http/server.py", line 135, in server_bind socketserver.TCPServer.server_bind(self) File "/usr/lib/python3.3/socketserver.py", line 441, in server_bind self.socket.bind(self.server_address) OSError: [Errno 98] Address already in use As you can see in the except KeyboardInterruption line, I tried everything to make the server stop, and the program stop, but it will NOT stop. But the thing I really want to know is how to make this server able to restart, without giving some wonky errors.

  Read the article

• Dependency Injection into your Singleton

  - by Langali

  I have a singleton that has a spring injected Dao (simplified below): public class MyService<T> implements Service<T> { private final Map<String, T> objects; private static MyService instance; MyDao myDao; public void set MyDao(MyDao myDao) { this. myDao = myDao; } private MyService() { this.objects = Collections.synchronizedMap(new HashMap<String, T>()); // start a background thread that runs for ever } public static synchronized MyService getInstance() { if(instance == null) { instance = new MyService(); } return instance; } public void doSomething() { myDao.persist(objects); } } My spring config will probably look like this: <bean id="service" class="MyService" factory-method="getInstance"/> But this will instantiate the MyService during startup. Is there a programmatic way to do a dependency injection of MyDao into MyService, but not have spring manage the MyService? Basically I want to be able to do this from my code: MyService.getInstance().doSomething(); while having spring inject the MyDao for me.

  Read the article

• How to add deploy.jar to classpath?

  - by dma_k

  I am facing the problem: I need to add ${java.home}/lib/deploy.jar JAR file to classpath in the runtime (dynamically from java). The solution with Thread#setContextClassLoader(ClassLoader) (mentioned here) does not work because of this bug (if somebody can explain what is really a problem – you are welcome). The solution with -Xbootclasspath/a:"%JAVA_HOME%/jre/lib/deploy.jar" does not work well for me, because I want to have "pure executable jar" as a deliverable: no wrapping scripts please (more over %JAVA_HOME% may not be defined in user's environment in Windows for example, plus I need to write a script per platform) The solution with merging deploy.jar file into my deliverable works only if I make a build on Windows platform. Unfortunately, when the deliverable is produced on build server running on Linux, I got Linux-dependant JAR, which does not execute on Windows – it fails with the trace below. I have read How the Java Launcher Finds Classes and Java programming dynamics: Java classes and class loading articles but I've got no extra ideas, how to correctly handle this situation. Any advices or solutions are very welcomed. Trace: java.lang.NoClassDefFoundError: Could not initialize class com.sun.deploy.config.Config at com.sun.deploy.net.proxy.UserDefinedProxyConfig.getBrowserProxyInfo(UserDefinedProxyConfig.java:43) at com.sun.deploy.net.proxy.DynamicProxyManager.reset(DynamicProxyManager.java:235) at com.sun.deploy.net.proxy.DeployProxySelector.reset(DeployProxySelector.java:59) ... java.lang.NullPointerException at com.sun.deploy.net.proxy.DynamicProxyManager.getProxyList(DynamicProxyManager.java:63) at com.sun.deploy.net.proxy.DeployProxySelector.select(DeployProxySelector.java:166)

  Read the article

• Blackberry (Java) - Can't get KeyListener to work

  - by paullb

  I am trying to get the KeyListener working for Blackberry, but none of the Dialogs pop up indicating that a key has been pressed (see code below, each action has a dialog popup in them). Any ideas on what i might be doing wrong? public class CityInfo extends UiApplication implements KeyListener { static CityInfo application; public static void main(String[] args) { //create a new instance of the application //and start the application on the event thread application.enterEventDispatcher(); } public CityInfo() { //display a new screen application = new CityInfo(); pushScreen(new WorkflowDisplayScreen()); this.addKeyListener(this); } public boolean keyChar(char arg0, int arg1, int arg2) { // TODO Auto-generated method stub Dialog.alert("key pressed : " + arg0); return true; } public boolean keyDown(int keycode, int time) { // TODO Auto-generated method stub Dialog.alert("keyDown : " + keycode); return false; } public boolean keyRepeat(int keycode, int time) { // TODO Auto-generated method stub Dialog.alert("keyRepeat : " + keycode); return false; } public boolean keyStatus(int keycode, int time) { // TODO Auto-generated method stub Dialog.alert("keyStatus : " + keycode); return false; } public boolean keyUp(int keycode, int time) { Dialog.alert("keyUp : " + keycode); // TODO Auto-generated method stub return false; } } I also tried implementing keyChar on the MainScreen class but that did not yield any results either.

  Read the article

• ReaderWriterLockSlim and Pulse/Wait

  - by Jono

  Is there an equivalent of Monitor.Pulse and Monitor.Wait that I can use in conjunction with a ReaderWriterLockSlim? I have a class where I've encapsulated multi-threaded access to an underlying queue. To enqueue something, I acquire a lock that protects the underlying queue (and a couple of other objects) then add the item and Monitor.Pulse the locked object to signal that something was added to the queue. public void Enqueue(ITask task) { lock (mutex) { underlying.Enqueue(task); Monitor.Pulse(mutex); } } On the other end of the queue, I have a single background thread that continuously processes messages as they arrive on the queue. It uses Monitor.Wait when there are no items in the queue, to avoid unnecessary polling. (I consider this to be good design, but any flames (within reason) are welcome if they help me learn otherwise.) private void DequeueForProcessing(object state) { while (true) { ITask task; lock (mutex) { while (underlying.Count == 0) { Monitor.Wait(mutex); } task = underlying.Dequeue(); } Process(task); } } As more operations are added to this class (requiring read-only access to the lock protected underlying), someone suggested using ReaderWriterLockSlim. I've never used the class before, and assuming it can offer some performance benefit, I'm not against it, but only if I can keep the Pulse/Wait design.

  Read the article

• How to use Comparator in Java to sort

  - by Dan

  I learned how to use the comparable but I'm having difficulty with the Comparator. I am having a error in my code: Exception in thread "main" java.lang.ClassCastException: New.People cannot be cast to java.lang.Comparable at java.util.Arrays.mergeSort(Unknown Source) at java.util.Arrays.sort(Unknown Source) at java.util.Collections.sort(Unknown Source) at New.TestPeople.main(TestPeople.java:18) Here is my code: import java.util.Comparator; public class People implements Comparator{ private int id; private String info; private double price; public People(int newid, String newinfo, double newprice){ setid(newid); setinfo(newinfo); setprice(newprice); } public int getid() { return id; } public void setid(int id) { this.id = id; } public String getinfo() { return info; } public void setinfo(String info) { this.info = info; } public double getprice() { return price; } public void setprice(double price) { this.price = price; } public int compare(Object obj1, Object obj2) { Integer p1 = ((People)obj1).getid(); Integer p2 = ((People)obj2).getid(); if (p1 p2 ){ return 1; } else if (p1 < p2){ return -1; } else return 0; } } import java.util.ArrayList; import java.util.Collections; public class TestPeople { public static void main(String[] args) { ArrayList peps = new ArrayList(); peps.add(new People(123, "M", 14.25)); peps.add(new People(234, "M", 6.21)); peps.add(new People(362, "F", 9.23)); peps.add(new People(111, "M", 65.99)); peps.add(new People(535, "F", 9.23)); Collections.sort(peps); for(int i=0;i I believe it has to do something with the casting in the compare method but I was playing around with it and still could not find the solution

  Read the article

• How important is the programming language when you choose a new job?

  - by Luhmann

  We are currently hiring at the company where I work, and here the codebase is in VB.Net. We are worried that we miss out on a lot of brilliant programmers, who would never ever consider working with VB.Net. My own background is Java and C#, and I was somewhat sceptical as to whether it would work out with VB, as - to be honest - i didn't care much for VB. After a month or so, I was completely fluent in VB, and a few months later i discovered to my surprise, that I actually like VB. I still code my free time projects in C# and Boo though. So my question is firstly, how important is language for you, when you choose a new programming job? Lets say if its a great company, salary is good, and generally an attractive work-place. Would you say no to the perfect job, if the language wasn't your preferred dialect? VB or C# is one thing, but how about Java or C# etc. Secondly if the best developers won't join your company because of your language or platform, would you consider changing, to get the right people? (This is not a language bashing thread, so please no religious language wars) NB: This is Community Wiki

  Read the article

• http_access.log on WebSphere 6.1.0.29

  - by DavidG

  I am running WebSphere 6.1.0.29 and I need to track the requests being made to an Enterprise Application. Previously I did this by routing the requests through a proxy server, but I need to repeat the exercise and I figure there must be a simpler way. Does anyone know how to enable HTTP access logging? I have been through the console an thought I had enabled http_access.log and http_error.log via: Application servers server1 HTTP error and NCSA access logging (where 'server1' is the application server) I've enabled the service at startup, and ticked the boxes to enable access logging and error logging - however... nothing has happened. I have restarted the server, restarted the Enterprise apps and even did a "find . -name" for the log files - but they don't seem to be anywhere on the system. I saw on a JavaRanch thread someone suggested writing a custom filter for requests in an application, but this seems like wild overkill - plus I am doing the logs to test a pre-built binary, so I don't want to mess with the code. Anyone have any ideas/suggestions? Help! :-)

  Read the article

• why does entity framework+mysql provider enumeration returns partial results with no exceptions

  - by Freddy Rios

  I'm trying to make sense of a situation I have using entity framework on .net 3.5 sp1 + MySQL 6.1.2.0 as the provider. It involves the following code: Response.Write("Products: " + plist.Count() + "<br />"); var total = 0; foreach (var p in plist) { //... some actions total++; //... other actions } Response.Write("Total Products Checked: " + total + "<br />"); Basically the total products is varying on each run, and it isn't matching the full total in plist. Its varies widely, from ~ 1/5th to half. There isn't any control flow code inside the foreach i.e. no break, continue, try/catch, conditions around total++, anything that could affect the count. As confirmation, there are other totals captured inside the loop related to the actions, and those match the lower and higher total runs. I don't find any reason to the above, other than something in entity framework or the mysql provider that causes it to end the foreach when retrieving an item. The body of the foreach can have some good variation in time, as the actions involve file & network access, my best shot at the time is that when the .net code takes beyond certain threshold there is some type of timeout in the underlying framework/provider and instead of causing an exception it is silently reporting no more items for enumeration. Can anyone give some light in the above scenario and/or confirm if the entity framework/mysql provider has the above behavior? Update: I can't reproduce the behavior by using Thread.Sleep in a simple foreach in a test project, not sure where else to look for this weird behavior :(.

  Read the article

• Hide Image Title in Slimbox

  - by Stephen

  My issue is a lot like this solved thread, except I'm using Slimbox 2: http://stackoverflow.com/questions/940994/hide-image-title-tool-tip-popup-on-mouse-rollover-or-hover When you hover over an image, the "Title" attribute pops up. I need HTML in my image title in Slimbox. So, of course, when you're hovering, the "Title" attribute shows all the HTML code. The code works perfectly when you're viewing the image in Slimbox so no problems there. I just need the Title attribute to be hidden/modified not to show this HTML code. I tried to change Q.title in slimbox.js to something else (like captionname). Then changed the HTML to call for: <a href="images/team/large.jpg" title="Joe Smith" captionname="URL" rel="lightbox-team"><img src="images/team/small.jpg" class ="headline" border="1" hspace="2" /></a> "Joe Smith" displays as the Title but when you view the image in Slimbox, captionname does not come up at all and neither does the Title. It's just blank where it should be. What do I need to modify in slimbox2.js to make this work?

  Read the article

• ExecutorSerrvice memory leak on exception

  - by TofuBeer

  I am having a hard time tracking this down since the profiler keeps crashing (hotspot error). Before I go too deep into figuring it out I'd like to know if I really have a problem or not :-) I have a few thread pools created via: Executors.newFixedThreadPool(10); The threads connect to different web sites and, on occasion, I get connection refused and wind up throwing an exception. When I later on call Future.get() to get the result it will then catch the ExecutionException that wraps the exception that was thrown when the connection could not be made. The program uses a fairly constant amount of memory up until the point in time that the exceptions get thrown (they tend to happen in batches when a particular site is overloaded). After that point the memory again remains constant but at a higher level. So my question is along the lines of is the memory behaviour (reported by "top" on Unix) expected because the exceptions just triggered something or do I probably have an actual leak that I'll need to track down? Additionally when Future.get() throws an exception is there anything else I need to do besides catch the exception (such as call Future.cancel() on it)?

  Read the article

• What's a reasonable way to mutate a primitive variable from an anonymous Java class?

  - by Steve

  I would like to write the following code: boolean found = false; search(new SearchCallback() { @Override void onFound(Object o) { found = true; } }); Obviously this is not allowed, since found needs to be final. I can't make found a member field for thread-safety reasons. What is the best alternative? One workaround is to define final class MutableReference<T> { private T value; MutableReference(T value) { this.value = value; } T get() { return value; } void set(T value) { this.value = value; } } but this ends up taking a lot of space when formatted properly, and I'd rather not reinvent the wheel if at all possible. I could use a List<Boolean> with a single element (either mutating that element, or else emptying the list) or even a Boolean[1]. But everything seems to smell funny, since none of the options are being used as they were intended. What is a reasonable way to do this?

  Read the article

• Checking if a console application is still running using the Process class

  - by Ced

  I'm making an application that will monitor the state of another process and restart it when it stops responding, exits, or throws an error. However, I'm having trouble to make it reliably check if the process (Being a C++ Console window) has stopped responding. My code looks like this: public void monitorserver() { while (true) { server.StartInfo = new ProcessStartInfo(textbox_srcdsexe.Text, startstring); server.Start(); log("server started"); log("Monitor started."); while (server.Responding) { if (server.HasExited) { log("server exitted, Restarting."); break; } log("server is running: " + server.Responding.ToString()); Thread.Sleep(1000); } log("Server stopped responding, terminating.."); try { server.Kill(); } catch (Exception) { } } } The application I'm monitoring is Valve's Source Dedicated Server, running Garry's Mod, and I'm over stressing the physics engine to simulate it stopping responding. However, this never triggers the process class recognizing it as 'stopped responding'. I know there are ways to directly query the source server using their own protocol, but i'd like to keep it simple and universal (So that i can maybe use it for different applications in the future). Any help appreciated

  Read the article

• java bubblesort with acm dialog

  - by qzar

  Hi, the program gives following exception: Exception in thread "main" java.lang.NullPointerException at myclasses.BubbleSort.run(BubbleSort.java:42) at acm.program.Program.runHook(Program.java:1519) at acm.program.Program.startRun(Program.java:1508) at acm.program.Program.start(Program.java:729) at myclasses.BubbleSort.main(BubbleSort.java:49) what is wrong? thank you very much! package myclasses; import acm.program.DialogProgram; public class BubbleSort extends DialogProgram { int[] array; public int[] getArray() { return array; } public void setArray(int[] array) { this.array = array; } void swap(int firstPos, int secondPos) { int temp = array[firstPos]; array[firstPos] = array[secondPos]; array[secondPos] = temp; } public void bubblesort() { int i, j, k; for (i = 1; i < array.length; i++) { j = i; k = array[i]; while (j > 0 && array[j - 1] > k) { array[j] = array[j - 1]; --j; } array[j] = k; } } public void run() { BubbleSort a = new BubbleSort(); a.setArray(new int[] {1, 3, 5, 7, 6, 2}); a.bubblesort(); StringBuffer sb = new StringBuffer(a.array.length * 2); for (int i = 0; i < getArray().length; i++) sb.append(getArray()[i]).append(" "); println(sb); } public static void main(String[] args) { new BubbleSort().start(args); } }

  Read the article

• Using JavaMail to send a mail containing Unicode characters

  - by NoozNooz42

  I'm successfully sending emails through GMail's SMTP servers using the following piece of code: Properties props = new Properties(); props.put("mail.smtp.host", "smtp.gmail.com"); props.put("mail.smtp.socketFactory.port", "465"); props.put("mail.smtp.socketFactory.class","javax.net.ssl.SSLSocketFactory"); props.put("mail.smtp.auth", "true"); props.put("mail.smtp.port", "465"); props.put("mail.smtp.ssl", "true"); props.put("mail.smtp.starttls.enable","true"); props.put("mail.smtp.timeout", "5000"); props.put("mail.smtp.connectiontimeout", "5000"); // Do NOT use Session.getDefaultInstance but Session.getInstance // See: http://forums.sun.com/thread.jspa?threadID=5301696 final Session session = Session.getInstance( props, new javax.mail.Authenticator() { protected PasswordAuthentication getPasswordAuthentication() { return new PasswordAuthentication( USER, PWD ); } }); try { final Message message = new MimeMessage(session); message.setFrom( new InternetAddress( USER ) ); message.setRecipients( Message.RecipientType.TO, InternetAddress.parse( TO ) ); message.setSubject( emailSubject ); message.setText( emailContent ); Transport.send(message); emailSent = true; } catch ( final MessagingException e ) { e.printStackTrace(); } where emailContent is a String that does contain Unicode characters (like the euro symbol). When the email arrives (in another GMail account), the euro symbol has been converted to the ASCII '?' question mark. I don't know much about emails: can email use any character encoding? What should I modify in the code above so that an encoding allowing Unicode characters is used?

  Read the article

• Fastest inline-assembly spinlock

  - by sigvardsen

  I'm writing a multithreaded application in c++, where performance is critical. I need to use a lot of locking while copying small structures between threads, for this I have chosen to use spinlocks. I have done some research and speed testing on this and I found that most implementations are roughly equally fast: Microsofts CRITICAL_SECTION, with SpinCount set to 1000, scores about 140 time units Implementing this algorithm with Microsofts InterlockedCompareExchange scores about 95 time units Ive also tried to use some inline assembly with __asm {} using something like this code and it scores about 70 time units, but I am not sure that a proper memory barrier has been created. Edit: The times given here are the time it takes for 2 threads to lock and unlock the spinlock 1,000,000 times. I know this isn't a lot of difference but as a spinlock is a heavily used object, one would think that programmers would have agreed on the fastest possible way to make a spinlock. Googling it leads to many different approaches however. I would think this aforementioned method would be the fastest if implemented using inline assembly and using the instruction CMPXCHG8B instead of comparing 32bit registers. Furthermore memory barriers must be taken into account, this could be done by LOCK CMPXHG8B (I think?), which guarantees "exclusive rights" to the shared memory between cores. At last [some suggests] that for busy waits should be accompanied by NOP:REP that would enable Hyper-threading processors to switch to another thread, but I am not sure whether this is true or not? From my performance-test of different spinlocks, it is seen that there is not much difference, but for purely academic purpose I would like to know which one is fastest. However as I have extremely limited experience in the assembly-language and with memory barriers, I would be happy if someone could write the assembly code for the last example I provided with LOCK CMPXCHG8B and proper memory barriers in the following template: __asm { spin_lock: ;locking code. spin_unlock: ;unlocking code. }

  Read the article

• How to improve multi-threaded access to Cache (custom implementation)

  - by Andy

  I have a custom Cache implementation, which allows to cache TCacheable<TKey> descendants using LRU (Least Recently Used) cache replacement algorithm. Every time an element is accessed, it is bubbled up to the top of the LRU queue using the following synchronized function: // a single instance is created to handle all TCacheable<T> elements public class Cache() { private object syncQueue = new object(); private void topQueue(TCacheable<T> el) { lock (syncQueue) if (newest != el) { if (el.elder != null) el.elder.newer = el.newer; if (el.newer != null) el.newer.elder = el.elder; if (oldest == el) oldest = el.newer; if (oldest == null) oldest = el; if (newest != null) newest.newer = el; el.newer = null; el.elder = newest; newest = el; } } } The bottleneck in this function is the lock() operator, which limits cache access to just one thread at a time. Question: Is it possible to get rid of lock(syncQueue) in this function while still preserving the queue integrity?

  Read the article

• Parallel Tasking Concurrency with Dependencies on Python like GNU Make

  - by Brian Bruggeman

  I'm looking for a method or possibly a philosophical approach for how to do something like GNU Make within python. Currently, we utilize makefiles to execute processing because the makefiles are extremely good at parallel runs with changing single option: -j x. In addition, gnu make already has the dependency stacks built into it, so adding a secondary processor or the ability to process more threads just means updating that single option. I want that same power and flexibility in python, but I don't see it. As an example: all: dependency_a dependency_b dependency_c dependency_a: dependency_d stuff dependency_b: dependency_d stuff dependency_c: dependency_e stuff dependency_d: dependency_f stuff dependency_e: stuff dependency_f: stuff If we do a standard single thread operation (-j 1), the order of operation might be: dependency_f -> dependency_d -> dependency_a -> dependency_b -> dependency_e \ -> dependency_c For two threads (-j 2), we might see: 1: dependency_f -> dependency_d -> dependency_a -> dependency_b 2: dependency_e -> dependency_c Does anyone have any suggestions on either a package already built or an approach? I'm totally open, provided it's a pythonic solution/approach. Please and Thanks in advance!

  Read the article

• Would an immutable keyword in Java be a good idea?

  - by berry120

  Generally speaking, the more I use immutable objects in Java the more I'm thinking they're a great idea. They've got lots of advantages from automatically being thread-safe to not needing to worry about cloning or copy constructors. This has got me thinking, would an "immutable" keyword go amiss? Obviously there's the disadvantages with adding another reserved word to the language, and I doubt it will actually happen primarily for the above reason - but ignoring that I can't really see many disadvantages. At present great care has to be taken to make sure objects are immutable, and even then a dodgy javadoc comment claiming a component object is immutable when it's in fact not can wreck the whole thing. There's also the argument that even basic objects like string aren't truly immutable because they're easily vunerable to reflection attacks. If we had an immutable keyword the compiler could surely recursively check and give an iron clad guarantee that all instances of a class were immutable, something that can't presently be done. Especially with concurrency becoming more and more used, I personally think it'd be good to add a keyword to this effect. But are there any disadvantages or implementation details I'm missing that makes this a bad idea?

  Read the article

• Time with and without OpenMP

  - by was

  I have a question.. I tried to improve a well known program algorithm in C, FOX algorithm for matrix multiplication.. relative link without openMP: (http://web.mst.edu/~ercal/387/MPI/ppmpi_c/chap07/fox.c). The initial program had only MPI and I tried to insert openMP in the matrix multiplication method, in order to improve the time of computation: (This program runs in a cluster and computers have 2 cores, thus I created 2 threads.) The problem is that there is no difference of time, with and without openMP. I observed that using openMP sometimes, time is equivalent or greater than the time without openMP. I tried to multiply two 600x600 matrices. void Local_matrix_multiply( LOCAL_MATRIX_T* local_A /* in */, LOCAL_MATRIX_T* local_B /* in */, LOCAL_MATRIX_T* local_C /* out */) { int i, j, k; chunk = CHUNKSIZE; // 100 #pragma omp parallel shared(local_A, local_B, local_C, chunk, nthreads) private(i,j,k,tid) num_threads(2) { /* tid = omp_get_thread_num(); if(tid == 0){ nthreads = omp_get_num_threads(); printf("O Pollaplasiamos pinakwn ksekina me %d threads\n", nthreads); } printf("Thread %d use the matrix: \n", tid); */ #pragma omp for schedule(static, chunk) for (i = 0; i < Order(local_A); i++) for (j = 0; j < Order(local_A); j++) for (k = 0; k < Order(local_B); k++) Entry(local_C,i,j) = Entry(local_C,i,j) + Entry(local_A,i,k)*Entry(local_B,k,j); } //end pragma omp parallel } /* Local_matrix_multiply */

  Read the article

• Java: ResultSet exception - before start of result set

  - by Rosarch

  I'm having trouble getting data from a ResultSet object. Here is my code: String sql = "SELECT type FROM node WHERE nid = ?"; PreparedStatement prep = conn.prepareStatement(sql); int meetNID = Integer.parseInt(node.get(BoutField.field_meet_nid)); prep.setInt(1, meetNID); ResultSet result = prep.executeQuery(); result.beforeFirst(); String foundType = result.getString(1); if (! foundType.equals("meet")) { throw new IllegalArgumentException(String.format("Node %d must be of type 'meet', but was %s", meetNID, foundType)); } The error trace: Exception in thread "main" java.sql.SQLException: Before start of result set at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1072) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:986) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:981) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:926) at com.mysql.jdbc.ResultSetImpl.checkRowPos(ResultSetImpl.java:841) at com.mysql.jdbc.ResultSetImpl.getStringInternal(ResultSetImpl.java:5656) at com.mysql.jdbc.ResultSetImpl.getString(ResultSetImpl.java:5576) at nth.cumf3.nodeImport.Validator.validate(Validator.java:43) at nth.cumf3.nodeImport.Main.main(Main.java:38) What am I doing wrong here?

  Read the article

• Creating PowerShell Automatic Variables from C#

  - by Uros Calakovic

  I trying to make automatic variables available to Excel VBA (like ActiveSheet or ActiveCell) also available to PowerShell as 'automatic variables'. PowerShell engine is hosted in an Excel VSTO add-in and Excel.Application is available to it as Globals.ThisAddin.Application. I found this thread here on StackOverflow and started created PSVariable derived classes like: public class ActiveCell : PSVariable { public ActiveCell(string name) : base(name) { } public override object Value { get { return Globals.ThisAddIn.Application.ActiveCell; } } } public class ActiveSheet : PSVariable { public ActiveSheet(string name) : base(name) { } public override object Value { get { return Globals.ThisAddIn.Application.ActiveSheet; } } } and adding their instances to the current POwerShell session: runspace.SessionStateProxy.PSVariable.Set(new ActiveCell("ActiveCell")); runspace.SessionStateProxy.PSVariable.Set(new ActiveSheet("ActiveSheet")); This works and I am able to use those variables from PowerShell as $ActiveCell and $ActiveSheet (their value change as Excel active sheet or cell change). Then I read PSVariable documentation here and saw this: "There is no established scenario for deriving from this class. To programmatically create a shell variable, create an instance of this class and set it by using the PSVariableIntrinsics class." As I was deriving from PSVariable, I tried to use what was suggested: PSVariable activeCell = new PSVariable("ActiveCell"); activeCell.Value = Globals.ThisAddIn.Application.ActiveCell; runspace.SessionStateProxy.PSVariable.Set(activeCell); Using this, $ActiveCell appears in my PowerShell session, but its value doesn't change as I change the active cell in Excel. Is the above comment from PSVariable documentation something I should worry about, or I can continue creating PSVariable derived classes? Is there another way of making Excel globals available to PowerShell?

  Read the article

• Generating a canonical path

  - by Joel

  Does any one know of any Java libraries I could use to generate canonical paths (basically remove back-references). I need something that will do the following: Raw Path - Canonical Path /../foo/ -> /foo /foo/ -> /foo /../../../ -> / /./foo/./ -> /foo //foo//bar -> /foo/bar //foo/../bar -> /bar etc... At the moment I lazily rely on using: new File("/", path).getCanonicalPath(); But this resolves the path against the actual file system, and is synchronised. java.lang.Thread.State: BLOCKED (on object monitor) at java.io.ExpiringCache.get(ExpiringCache.java:55) - waiting to lock <0x93a0d180> (a java.io.ExpiringCache) at java.io.UnixFileSystem.canonicalize(UnixFileSystem.java:137) at java.io.File.getCanonicalPath(File.java:559) The paths that I am canonicalising do not exist on my file system, so just the logic of the method will do me fine, thus not requiring any synchronisation. I'm hoping for a well tested library rather than having to write my own.

  Read the article

< Previous Page | 275 276 277 278 279 280 281 282 283 284 285 286  | Next Page >