Search Results

Search found 8166 results on 327 pages for 'thread syncronization'.

Page 72/327 | < Previous Page | 68 69 70 71 72 73 74 75 76 77 78 79  | Next Page >

  • wxPython, Threads, and PostEvent between modules

    - by Sam Starling
    I'm relatively new to wxPython (but not Python itself), so forgive me if I've missed something here. I'm writing a GUI application, which at a very basic level consists of "Start" and "Stop" buttons that start and stop a thread. This thread is an infinite loop, which only ends when the thread is stopped. The loop generates messages, which at the moment are just output using print. The GUI class and the infinite loop (using threading.Thread as a subclass) are held in separate files. What is the best way to get the thread to push an update to something like a TextCtrl in the GUI? I've been playing around with PostEvent and Queue, but without much luck. Here's some bare bones code, with portions removed to keep it concise: main_frame.py import wx from loop import Loop class MainFrame(wx.Frame): def __init__(self, parent, title): # Initialise and show GUI # Add two buttons, btnStart and btnStop # Bind the two buttons to the following two methods self.threads = [] def onStart(self): x = Loop() x.start() self.threads.append(x) def onStop(self): for t in self.threads: t.stop() loop.py class Loop(threading.Thread): def __init__(self): self._stop = threading.Event() def run(self): while not self._stop.isSet(): print datetime.date.today() def stop(self): self._stop.set() I did, at one point, have it working by having the classes in the same file by using wx.lib.newevent.NewEvent() along these lines. If anyone could point me in the right direction, that'd be much appreciated.

    Read the article

  • How to install DBD::mysql on OS X Server 10.6?

    - by Zoran Simic
    Trying to install DBD::mysql on OS X Server 10.6 (mac mini server). But I'm missing the mysql headers apparently. Since mysql is already part of OS X Server 10.6, I would like to NOT install anything else (no fink or darwin ports installs), just whatever's needed to get DBD::mysql installed and working. Do you know how I could do that? Do I have to install the headers somewhere? And if so, where? (again: I don't want to install another version of mysql on the box, want to use the version it came with). Is there a way to install DBD::mysql without compiling any C files? This is the error I get (the actual error is much longer, but these are the most meaningful bits, this is the first error reported). Checking if your kit is complete... Looks good Unrecognized argument in LIBS ignored: '-pipe' Note (probably harmless): No library found for -lmysqlclient Multiple copies of Driver.xst found in: /Library/Perl/5.10.0/darwin-thread-multi-2level/auto/DBI/ /System/Library/Perl/Extras/5.10.0/darwin-thread-multi-2level/auto/DBI/ at Makefile.PL line 907 Using DBI 1.611 (for perl 5.010000 on darwin-thread-multi-2level) installed in /Library/Perl/5.10.0/darwin-thread-multi-2level/auto/DBI/ Writing Makefile for DBD::mysql cp lib/DBD/mysql.pm blib/lib/DBD/mysql.pm cp lib/DBD/mysql/GetInfo.pm blib/lib/DBD/mysql/GetInfo.pm cp lib/DBD/mysql/INSTALL.pod blib/lib/DBD/mysql/INSTALL.pod cp lib/Bundle/DBD/mysql.pm blib/lib/Bundle/DBD/mysql.pm gcc-4.2 -c -I/Library/Perl/5.10.0/darwin-thread-multi-2level/auto/DBI -I/usr/include -fno-omit-frame-pointer -pipe -D_P1003_1B_VISIBLE -DSIGNAL_WITH_VIO_CLOSE -DSIGNALS_DONT_BREAK_READ -DIGNORE_SIGHUP_SIGQUIT -DDBD_MYSQL_INSERT_ID_IS_GOOD -g -arch x86_64 -arch i386 -arch ppc -g -pipe -fno-common -DPERL_DARWIN -fno-strict-aliasing -I/usr/local/include -Os -DVERSION=\"4.014\" -DXS_VERSION=\"4.014\" "-I/System/Library/Perl/5.10.0/darwin-thread-multi-2level/CORE" dbdimp.c In file included from dbdimp.c:20: dbdimp.h:22:49: error: mysql.h: No such file or directory dbdimp.h:23:45: error: mysqld_error.h: No such file or directory dbdimp.h:25:49: error: errmsg.h: No such file or directory

    Read the article

  • How to install DBD::mysql on OS X server?

    - by Zoran Simic
    Trying to install DBD::mysql on OS X Server 10.6 (mac mini server). But I'm missing the mysql headers apparently. Since mysql is already part of OS X Server 10.6, I would like to NOT install anything else (no fink or darwin ports installs), just whatever's needed to get DBD::mysql installed and working. Do you know how I could do that? Do I have to install the headers somewhere? And if so, where? (again: I don't want to install another version of mysql on the box, want to use the version it came with). Is there a way to install DBD::mysql without compiling any C files? This is the error I get (the actual error is much longer, but these are the most meaningful bits, this is the first error reported). Checking if your kit is complete... Looks good Unrecognized argument in LIBS ignored: '-pipe' Note (probably harmless): No library found for -lmysqlclient Multiple copies of Driver.xst found in: /Library/Perl/5.10.0/darwin-thread-multi-2level/auto/DBI/ /System/Library/Perl/Extras/5.10.0/darwin-thread-multi-2level/auto/DBI/ at Makefile.PL line 907 Using DBI 1.611 (for perl 5.010000 on darwin-thread-multi-2level) installed in /Library/Perl/5.10.0/darwin-thread-multi-2level/auto/DBI/ Writing Makefile for DBD::mysql cp lib/DBD/mysql.pm blib/lib/DBD/mysql.pm cp lib/DBD/mysql/GetInfo.pm blib/lib/DBD/mysql/GetInfo.pm cp lib/DBD/mysql/INSTALL.pod blib/lib/DBD/mysql/INSTALL.pod cp lib/Bundle/DBD/mysql.pm blib/lib/Bundle/DBD/mysql.pm gcc-4.2 -c -I/Library/Perl/5.10.0/darwin-thread-multi-2level/auto/DBI -I/usr/include -fno-omit-frame-pointer -pipe -D_P1003_1B_VISIBLE -DSIGNAL_WITH_VIO_CLOSE -DSIGNALS_DONT_BREAK_READ -DIGNORE_SIGHUP_SIGQUIT -DDBD_MYSQL_INSERT_ID_IS_GOOD -g -arch x86_64 -arch i386 -arch ppc -g -pipe -fno-common -DPERL_DARWIN -fno-strict-aliasing -I/usr/local/include -Os -DVERSION=\"4.014\" -DXS_VERSION=\"4.014\" "-I/System/Library/Perl/5.10.0/darwin-thread-multi-2level/CORE" dbdimp.c In file included from dbdimp.c:20: dbdimp.h:22:49: error: mysql.h: No such file or directory dbdimp.h:23:45: error: mysqld_error.h: No such file or directory dbdimp.h:25:49: error: errmsg.h: No such file or directory

    Read the article

  • Understanding F# Asynchronous Programming

    - by Yin Zhu
    I kind of know the syntax of asynchronous programming in F#. E.g. let downloadUrl(url:string) = async { let req = HttpWebRequest.Create(url) // Run operation asynchronously let! resp = req.AsyncGetResponse() let stream = resp.GetResponseStream() // Dispose 'StreamReader' when completed use reader = new StreamReader(stream) // Run asynchronously and then return the result return! reader.AsyncReadToEnd() } In F# expert book (and many other sources), they say like let! var = expr simply means "perform the asynchronous operation expr and bind the result to var when the operation completes. Then continue by executing the rest of the computation body" I also know that a new thread is created when performing async operation. My original understanding was that there are two parallel threads after the async operation, one doing I/O and one continuing to execute the async body at the same time. But in this example, I am confused at let! resp = req.AsyncGetResponse() let stream = resp.GetResponseStream() What happens if resp has not started yet and the thread in the async body wants to GetResponseStream? Is this a possible error? So maybe my original understanding was wrong. The quoted sentences in the F# expert book actually means that "creating a new thread, hang the current thread up, when the new thread finishes, wake up the body thread and continue", but in this case I don't see we could save any time. In the original understanding, the time is saved when there are several independent IO operations in one async block so that they could be done at the same time without intervention with each other. But here, if I don't get the response, I cannot create the stream; only I have stream, I can start reading the stream. Where's the time gained?

    Read the article

  • Why delete-orphan needs "cascade all" to run in JPA/Hibernate ?

    - by Jerome C.
    Hello, I try to map a one-to-many relation with cascade "remove" (jpa) and "delete-orphan", because I don't want children to be saved or persist when the parent is saved or persist (security reasons due to client to server (GWT, Gilead)) But this configuration doesn't work. When I try with cascade "all", it runs. Why the delete-orphan option needs a cascade "all" to run ? here is the code (without id or other fields for simplicity, the class Thread defines a simple many-to-one property without cascade): when using the removeThread function in a transactional function, it does not run but if I edit cascade.Remove into cascade.All, it runs. @Entity public class Forum { private List<ForumThread> threads; /** * @return the topics */ @OneToMany(mappedBy = "parent", cascade = CascadeType.REMOVE, fetch = FetchType.LAZY) @Cascade(org.hibernate.annotations.CascadeType.DELETE_ORPHAN) public List<ForumThread> getThreads() { return threads; } /** * @param topics the topics to set */ public void setThreads(List<ForumThread> threads) { this.threads = threads; } public void addThread(ForumThread thread) { getThreads().add(thread); thread.setParent(this); } public void removeThread(ForumThread thread) { getThreads().remove(thread); } } thanks.

    Read the article

  • C++ socket concurrent server

    - by gregpi
    Hi all; Im writing a concurrent server that's supposed to have a communication channel and a data channel. The client initially connect to the communication channel to authenticate, upon successful authentication, the client is then connected to the data channel to access data. My program is already doing that, and im using threads.My only issue is that if I try to connect another client, I get a "cannot bind : address already in use" error. I have it this way: PART A Client connect to port 4567 (and enter his login info). A thread spawn to handle the client(repeated for each client that connects). In the thread created, I have a function(let's call it FUNC_A) that checks the client's login info(dont worry about how the check is done), if successful, the thread starts the data server(listening on 8976) then sends an OK to the client, once received the client attempts to connect to the data server. PART B Once a client connect to the data server, from inside FUNC_A the client is accepted and another thread is spawn to handle the client's connection to the data server.(hopefully everything is clear). Now, all that is working fine. However, if I try to connect with second client when it gets to PART B I get a "cannot bind error: address already in use". I've tried so many different ways, I've even tried spawning a thread to start the data server and accept the client and then start another thread to handle that connection. still no luck. Please give me a suggestion as to what I'm doing wrong, how do I go about doing this or what's the best way to implement it. Thank you

    Read the article

  • Is this a correct way to stop Execution Task

    - by Yan Cheng CHEOK
    I came across code to stop execution's task. private final ExecutorService executor = Executors.newSingleThreadExecutor(); public void stop() { executor.shutdownNow(); try { executor.awaitTermination(100, TimeUnit.DAYS); } catch (InterruptedException ex) { log.error(null, ex); } } public Runnable getRunnable() { return new Runnable() { public void run() { while (!Thread.currentThread().isInterrupted()) { // What if inside fun(), someone try to clear the interrupt flag? // Say, through Thread.interrupted(). We will stuck in this loop // forever. fun(); } } }; } I realize that, it is possible for Runnable to be in forever loop, as Unknown fun may Thread.sleep, clear the interrupt flag and ignore the InterruptedException Unknown fun may Thread.interrupted, clear the interrupt flag. I was wondering, is the following way correct way to fix the code? private final ExecutorService executor = Executors.newSingleThreadExecutor(); private volatile boolean flag = true; public void stop() { flag = false; executor.shutdownNow(); try { executor.awaitTermination(100, TimeUnit.DAYS); } catch (InterruptedException ex) { log.error(null, ex); } } public Runnable getRunnable() { return new Runnable() { public void run() { while (flag && !Thread.currentThread().isInterrupted()) { // What if inside fun(), someone try to clear the interrupt flag? // Say, through Thread.interrupted(). We will stuck in this loop // forever. fun(); } } }; }

    Read the article

  • synchronize threads - no UI

    - by UshaP
    I'm trying to write multithreading code and facing some synchronization questions. I know there are lots of posts here but I couldn't find anything that fits. I have a System.Timers.Timer that elapsed every 30 seconds it goes to the db and checks if there are any new jobs. If he finds one, he executes the job on the current thread (timer open new thread for every elapsed). While the job is running I need to notify the main thread (where the timer is) about the progress. Notes: I don't have UI so I can't do beginInvoke (or use background thread) as I usually do in winforms. I thought to implement ISynchronizeInvoke on my main class but that looks a little bit overkill (maybe I'm wrong here). I have an event in my job class and the main class register to it and I invoke the event whenever I need but I'm worrying it might cause blocking. Each job can take up to 20 minutes. I can have up to 20 jobs running concurrently. My question is: What is the right way to notify my main thread about any progress in my job thread? Thanks for any help.

    Read the article

  • ThreadExceptionEventHandler and invoking delegates

    - by QmunkE
    If I assign a ThreadExceptionEventHandler to Application.ThreadException, why when I invoke a delegate method using a control on the main application thread are any exceptions thrown by that delegate not triggering the event handler? i.e. static void Main() { ... Application.ThreadException += new System.Threading.ThreadExceptionEventHandler(Application_ThreadException); Application.Run(new Form1()); } static void Application_ThreadException(object sender, System.Threading.ThreadExceptionEventArgs e) { Console.Error.Write("A thread exception occurred!"); } ... private void Form1_Load(object sender, EventArgs e) { Thread syncThread = new Thread(new ThreadStart(this.ThrowException)); syncThread.Start(); } private void ThrowException() { button1.Invoke(new MethodInvoker(delegate { // Not handled by ThreadExceptionEventHandler? throw new Exception(); })); } The context on this is that I have a background thread started from a form which is throwing an unhandled exception which terminates the application. I know this thread is going to be unreliable since it is network connectivity reliant and so subject to being terminated at any point, but I'm just interested as to why this scenario doesn't play out as I expect?

    Read the article

  • Invoking different methods on threads

    - by Kraken
    I have a main process main. It creates 10 threads (say) and then what i want to do is the following: while(required){ Thread t= new Thread(new ClassImplementingRunnable()); t.start(); counter++; } Now i have the list of these threads, and for each thread i want to do a set of process, same for all, hence i put that implementation in the run method of ClassImplementingRunnable. Now after the threads have done their execution, i wan to wait for all of them to stop, and then evoke them again, but this time i want to do them serially not in parallel. for this I join each thread, to wait for them to finish execution but after that i am not sure how to evoke them again and run that piece of code serially. Can i do something like for(each thread){ t.reevoke(); //how can i do that. t.doThis(); // Also where does `dothis()` go, given that my ClassImplementingRunnable is an inner class. } Also, i want to use the same thread, i.e. i want the to continue from where they left off, but in a serial manner. I am not sure how to go about the last piece of pseudo code. Kindly help. Working with with java.

    Read the article

  • Do the 'up to date' guarantees provided by final field in Java's memory model extend to indirect ref

    - by mattbh
    The Java language spec defines semantics of final fields in section 17.5: The usage model for final fields is a simple one. Set the final fields for an object in that object's constructor. Do not write a reference to the object being constructed in a place where another thread can see it before the object's constructor is finished. If this is followed, then when the object is seen by another thread, that thread will always see the correctly constructed version of that object's final fields. It will also see versions of any object or array referenced by those final fields that are at least as up-to-date as the final fields are. My question is - does the 'up-to-date' guarantee extend to the contents of nested arrays, and nested objects? An example scenario: Thread A constructs a HashMap of ArrayLists, then assigns the HashMap to final field 'myFinal' in an instance of class 'MyClass' Thread B sees a (non-synchronized) reference to the MyClass instance and reads 'myFinal', and accesses and reads the contents of one of the ArrayLists In this scenario, are the members of the ArrayList as seen by Thread B guaranteed to be at least as up to date as they were when MyClass's constructor completed?

    Read the article

  • Can foreground threads be aborted on application shutdown in C#.Net?

    - by Cartman
    I inherited a c# winforms app (.NET 2.0) which creates a thread upon startup in a singleton class. This thread handles messages from a messaging topic (Tibco EMS). When the app is shutdown, the thread doesn't remain the the background? How is this possible? Is there something else happening that can abort this thread? Code snippet: public class Startup { public static void main(string [] args) { MySingletonClass.Instance.Init(); // do other things below Application.Run(new MainForm()); } public class MySingletonClass { // singleton code //.. //.. private Thread t; public void Init() { t = new Thread(new ThreadStart(poll)); } private void poll() { while(true} { // listen for messages and process but there is no break clause // exceptions are also handled within to ensure control doesnt go out } } Pls. don't write to tell me this is bad code. I know it and i was going to refactor it when i realised that the app actually shutdowns correctly inspite of this aberration. So i want to understand how this is possible. Thanks for your help

    Read the article

  • How can I join 3 tables with mysql & php?

    - by steven
    check out the page [url]http://www.mujak.com/test/test3.php[/url] It pulls the users Post,username,xbc/xlk tags etc which is perfect... BUT since I am pulling information from a MyBB bulletin board system, its quite different. When replying, people are are allowed to change the "Thread Subject" by simplying replying and changing it. I dont want it to SHOW the changed subject title, just the original title of all posts in that thread. By default it repies with "RE:thread title". They can easily edit this and it will show up in the "Subject" cell & people wont know which thread it was posted in because they changed their thread to when replying to the post. So I just want to keep the orginial thread title when they are replying. Make sense~?? Tables:mybb_users Fields:uid,username Tables:mybb_userfields Fields:ufid Tables:mybb_posts Fields:pid,tid,replyto,subject,ufid,username,uid,message Tables:mybb_threads Fields:tid,fid,subject,uid,username,lastpost,lastposter,lastposteruid I haev tried multiple queries with no success: $result = mysql_query(" SELECT * FROM mybb_users LEFT JOIN (mybb_posts, mybb_userfields, mybb_threads) ON ( mybb_userfields.ufid=mybb_posts.uid AND mybb_threads.tid=mybb_posts.tid AND mybb_users.uid=mybb_userfields.ufid ) WHERE mybb_posts.fid=42"); $result = mysql_query(" SELECT * FROM mybb_users LEFT JOIN (mybb_posts, mybb_userfields, mybb_threads) ON ( mybb_userfields.ufid=mybb_posts.uid AND mybb_threads.tid=mybb_posts.tid AND mybb_users.uid=mybb_posts.uid ) WHERE mybb_threads.fid=42"); $result = mysql_query(" SELECT * FROM mybb_posts LEFT JOIN (mybb_userfields, mybb_threads) ON ( mybb_userfields.ufid=mybb_posts.uid AND mybb_threads.tid=mybb_posts.tid ) WHERE mybb_posts.fid=42");

    Read the article

  • lock statement not working when there is a loop inside it?

    - by Ngu Soon Hui
    See this code: public class multiply { public Thread myThread; public int Counter { get; private set; } public string name { get; private set; } public void RunConsolePrint() { lock(this) { RunLockCode("lock"); } } private void RunLockCode(string lockCode) { Console.WriteLine("Now thread "+lockCode+" " + name + " has started"); for (int i = 1; i <= Counter; i++) { Console.WriteLine(lockCode+" "+name + ": count has reached " + i + ": total count is " + Counter); } Console.WriteLine("Thread " + lockCode + " " + name + " has finished"); } public multiply(string pname, int pCounter) { name = pname; Counter = pCounter; myThread = new Thread(new ThreadStart(RunConsolePrint)); } } And this is the test run code: static void Main(string[] args) { int counter = 50; multiply m2 = new multiply("Second", counter); multiply m1 = new multiply("First", counter); m1.myThread.Start(); m2.myThread.Start(); Console.ReadLine(); } I would expect that m2 must execute from start to finish before m1 starts executing, or vice versa, because of the lock statement. But the result I found was the call to lock first and lock second was intermingled together, i.e., something like this Now thread lock First has started Now thread lock Second has started lock First: Count has reached 1: total count is 50 lock First: Count has reached 2: total count is 50 lock Second: Count has reached 1: total count is 50 What did I do wrong?

    Read the article

  • Equvalent c++0x program withought using boost threads..

    - by Eternal Learner
    I have the below simple program using boost threads, what would be the changes needed to do the same in c++0X #include<iostream> #include<boost/thread/thread.hpp> boost::mutex mutex; struct count { count(int i): id(i){} void operator()() { boost::mutex::scoped_lock lk(mutex); for(int i = 0 ; i < 10000 ; i++) { std::cout<<"Thread "<<id<<"has been called "<<i<<" Times"<<std::endl; } } private: int id; }; int main() { boost::thread thr1(count(1)); boost::thread thr2(count(2)); boost::thread thr3(count(3)); thr1.join(); thr2.join(); thr3.join(); return 0; }

    Read the article

  • vs2002: c# multi threading question..

    - by dotnet-practitioner
    I would like to invoke heavy duty method dowork on a separate thread and kill it if its taking longer than 3 seconds. Is there any problem with the following code? class Class1 { /// <summary> /// The main entry point for the application. /// </summary> /// [STAThread] static void Main(string[] args) { Console.WriteLine("starting new thread"); Thread t = new Thread(new ThreadStart(dowork)); t.Start(); DateTime start = DateTime.Now; TimeSpan span = DateTime.Now.Subtract(start); bool wait = true; while (wait == true) { if (span.Seconds>3) { t.Abort(); wait = false; } span = DateTime.Now.Subtract(start); } Console.WriteLine("ending new thread after seconds = {0}", span.Seconds); Console.WriteLine("all done"); Console.ReadLine(); } static void dowork() { Console.WriteLine("doing heavy work inside hello"); Thread.Sleep(7000); Console.WriteLine("*** finished**** doing heavy work inside hello"); } }

    Read the article

  • Multi threading question..

    - by dotnet-practitioner
    I would like to invoke heavy duty method dowork on a separate thread and kill it if its taking longer than 3 seconds. Is there any problem with the following code? class Class1 { /// <summary> /// The main entry point for the application. /// </summary> [STAThread] static void Main(string[] args) { Console.WriteLine("starting new thread"); Thread t = new Thread(new ThreadStart(dowork)); t.Start(); DateTime start = DateTime.Now; TimeSpan span = DateTime.Now.Subtract(start); bool wait = true; while (wait == true) { if (span.Seconds > 3) { t.Abort(); wait = false; } span = DateTime.Now.Subtract(start); } Console.WriteLine("ending new thread after seconds = {0}", span.Seconds); Console.WriteLine("all done"); Console.ReadLine(); } static void dowork() { Console.WriteLine("doing heavy work inside hello"); Thread.Sleep(7000); Console.WriteLine("*** finished**** doing heavy work inside hello"); } }

    Read the article

  • java threads don't see shared boolean changes

    - by andymur
    Here the code class Aux implements Runnable { private Boolean isOn = false; private String statusMessage; private final Object lock; public Aux(String message, Object lock) { this.lock = lock; this.statusMessage = message; } @Override public void run() { for (;;) { synchronized (lock) { if (isOn && "left".equals(this.statusMessage)) { isOn = false; System.out.println(statusMessage); } else if (!isOn && "right".equals(this.statusMessage)) { isOn = true; System.out.println(statusMessage); } if ("left".equals(this.statusMessage)) { System.out.println("left " + isOn); } } } } } public class Question { public static void main(String [] args) { Object lock = new Object(); new Thread(new Aux("left", lock)).start(); new Thread(new Aux("right", lock)).start(); } } In this code I expect to see: left, right, left right and so on, but when Thread with "left" message changes isOn to false, Thread with "right" message don't see it and I get ("right true" and "left false" console messages), left thread don't get isOn in true, but right Thread can't change it cause it always see old isOn value (true). When i add volatile modifier to isOn nothing changes, but if I change isOn to some class with boolean field and change this field then threads are see changes and it works fine Thanks in advance.

    Read the article

  • Identify memory leak in Java app

    - by Vincent Ma
    One important advantage of java is programer don't care memory management and GC handle it well. Maybe this is one reason why java is more popular. As Java programer you real dont care it? After you meet Out of memory you will realize it it’s not true. Java GC and memory is big topic you can get some information in here Today just let me show how to identify memory leak quickly. Let quickly review demo java code, it’s one kind of memory leak in our code, using static collection and always add some object. import java.util.ArrayList;import java.util.List; public class MemoryTest { public static void main(String[] args) { new Thread(new MemoryLeak(), "MemoryLeak").start(); }} class MemoryLeak implements Runnable { public static List<Integer> leakList = new ArrayList<Integer>(); public void run() { int num =0; while(true) { try { Thread.sleep(1); } catch (InterruptedException e) { } num++; Integer i = new Integer(num); leakList.add(i); } }} run it with java -verbose:gc -XX:+PrintGCDetails -Xmx60m -XX:MaxPermSize=160m MemoryTest after about some minuts you will get Exception in thread "MemoryLeak" java.lang.OutOfMemoryError: Java heap space at java.util.Arrays.copyOf(Arrays.java:2760) at java.util.Arrays.copyOf(Arrays.java:2734) at java.util.ArrayList.ensureCapacity(ArrayList.java:167) at java.util.ArrayList.add(ArrayList.java:351) at MemoryLeak.run(MemoryTest.java:25) at java.lang.Thread.run(Thread.java:619)Heap def new generation total 18432K, used 3703K [0x045e0000, 0x059e0000, 0x059e0000) eden space 16384K, 22% used [0x045e0000, 0x0497dde0, 0x055e0000) from space 2048K, 0% used [0x055e0000, 0x055e0000, 0x057e0000) to space 2048K, 0% used [0x057e0000, 0x057e0000, 0x059e0000) tenured generation total 40960K, used 40959K [0x059e0000, 0x081e0000, 0x081e0000) the space 40960K, 99% used [0x059e0000, 0x081dfff8, 0x081e0000, 0x081e0000) compacting perm gen total 12288K, used 2083K [0x081e0000, 0x08de0000, 0x10de0000) the space 12288K, 16% used [0x081e0000, 0x083e8c50, 0x083e8e00, 0x08de0000)No shared spaces configured. OK let us quickly identify it using JProfile Download JProfile in here  Run JProfile and attach MemoryTest get largest size of  Objects in Memory View in here is Integer then select Integer and go to Heap Walker. get GC Graph for this object  Then you get detail code raise this issue quickly now.  That is enjoy it.

    Read the article

  • Are there deprecated practices for multithread and multiprocessor programming that I should no longer use?

    - by DeveloperDon
    In the early days of FORTRAN and BASIC, essentially all programs were written with GOTO statements. The result was spaghetti code and the solution was structured programming. Similarly, pointers can have difficult to control characteristics in our programs. C++ started with plenty of pointers, but use of references are recommended. Libraries like STL can reduce some of our dependency. There are also idioms to create smart pointers that have better characteristics, and some version of C++ permit references and managed code. Programming practices like inheritance and polymorphism use a lot of pointers behind the scenes (just as for, while, do structured programming generates code filled with branch instructions). Languages like Java eliminate pointers and use garbage collection to manage dynamically allocated data instead of depending on programmers to match all their new and delete statements. In my reading, I have seen examples of multi-process and multi-thread programming that don't seem to use semaphores. Do they use the same thing with different names or do they have new ways of structuring protection of resources from concurrent use? For example, a specific example of a system for multithread programming with multicore processors is OpenMP. It represents a critical region as follows, without the use of semaphores, which seem not to be included in the environment. th_id = omp_get_thread_num(); #pragma omp critical { cout << "Hello World from thread " << th_id << '\n'; } This example is an excerpt from: http://en.wikipedia.org/wiki/OpenMP Alternatively, similar protection of threads from each other using semaphores with functions wait() and signal() might look like this: wait(sem); th_id = get_thread_num(); cout << "Hello World from thread " << th_id << '\n'; signal(sem); In this example, things are pretty simple, and just a simple review is enough to show the wait() and signal() calls are matched and even with a lot of concurrency, thread safety is provided. But other algorithms are more complicated and use multiple semaphores (both binary and counting) spread across multiple functions with complex conditions that can be called by many threads. The consequences of creating deadlock or failing to make things thread safe can be hard to manage. Do these systems like OpenMP eliminate the problems with semaphores? Do they move the problem somewhere else? How do I transform my favorite semaphore using algorithm to not use semaphores anymore?

    Read the article

  • why client can not receive message from server (java) [migrated]

    - by user1745931
    I have just started learning java. I modified the client side code for a server/client communication program, by creating two threads for the client side, main thread for receiving user's input, and inputThread for receiving server's response. I am sure that server has sent the response to client, however, no response message is obtain at client. Here is my code. Can anyone help me to figure it out? Thanks package clientnio; import java.net.*; import java.nio.*; import java.io.*; import java.nio.channels.*; import java.util.Scanner; public class ClientNIO { public static int bufferLen = 50; public static SocketChannel client; public static ByteBuffer writeBuffer; public static ByteBuffer readBuffer; public static void main(String[] args) { writeBuffer = ByteBuffer.allocate(bufferLen); readBuffer = ByteBuffer.allocate(bufferLen); try { SocketAddress address = new InetSocketAddress("localhost",5505); System.out.println("Local address: "+ address); client=SocketChannel.open(address); client.configureBlocking(false); //readBuffer.flip(); new inputThread(readBuffer); /* String a="asdasdasdasddffasfas"; writeBuffer.put(a.getBytes()); writeBuffer.clear(); int d=client.write(writeBuffer); writeBuffer.flip(); */ while (true) { InputStream inStream = System.in; Scanner scan = new Scanner(inStream); if (scan.hasNext()==true) { String inputLine = scan.nextLine(); writeBuffer.put(inputLine.getBytes()); //writeBuffer.clear(); System.out.println(writeBuffer.remaining()); client.write(writeBuffer); System.out.println("Sending data: "+new String(writeBuffer.array())); writeBuffer.flip(); Thread.sleep(300); } } } catch(Exception e) { System.out.println(e); } } } class inputThread extends Thread { private ByteBuffer readBuffer; public inputThread(ByteBuffer readBuffer1) { System.out.println("Receiving thread starts."); this.readBuffer = readBuffer1; start(); } @Override public void run() { try { while (true) { readBuffer.flip(); int i=ClientNIO.client.read(readBuffer); if(i>0) { byte[] b=readBuffer.array(); System.out.println("Receiving data: "+new String(b)); //client.close(); //System.out.println("Connection closed."); //break; } Thread.sleep(100); } } catch (Exception e) { System.out.println(e); } } }

    Read the article

  • Can I query DOM Document with xpath expression from multiple threads safely?

    - by Dan
    I plan to use dom4j DOM Document as a static cache in an application where multiples threads can query the document. Taking into the account that the document itself will never change, is it safe to query it from multiple threads? I wrote the following code to test it, but I am not sure that it actually does prove that operation is safe? package test.concurrent_dom; import org.dom4j.Document; import org.dom4j.DocumentException; import org.dom4j.DocumentHelper; import org.dom4j.Element; import org.dom4j.Node; /** * Hello world! * */ public class App extends Thread { private static final String xml = "<Session>" + "<child1 attribute1=\"attribute1value\" attribute2=\"attribute2value\">" + "ChildText1</child1>" + "<child2 attribute1=\"attribute1value\" attribute2=\"attribute2value\">" + "ChildText2</child2>" + "<child3 attribute1=\"attribute1value\" attribute2=\"attribute2value\">" + "ChildText3</child3>" + "</Session>"; private static Document document; private static Element root; public static void main( String[] args ) throws DocumentException { document = DocumentHelper.parseText(xml); root = document.getRootElement(); Thread t1 = new Thread(){ public void run(){ while(true){ try { sleep(3); } catch (InterruptedException e) { e.printStackTrace(); } Node n1 = root.selectSingleNode("/Session/child1"); if(!n1.getText().equals("ChildText1")){ System.out.println("WRONG!"); } } } }; Thread t2 = new Thread(){ public void run(){ while(true){ try { sleep(3); } catch (InterruptedException e) { e.printStackTrace(); } Node n1 = root.selectSingleNode("/Session/child2"); if(!n1.getText().equals("ChildText2")){ System.out.println("WRONG!"); } } } }; Thread t3 = new Thread(){ public void run(){ while(true){ try { sleep(3); } catch (InterruptedException e) { e.printStackTrace(); } Node n1 = root.selectSingleNode("/Session/child3"); if(!n1.getText().equals("ChildText3")){ System.out.println("WRONG!"); } } } }; t1.start(); t2.start(); t3.start(); System.out.println( "Hello World!" ); } }

    Read the article

  • Windows forms application blocks after station lock

    - by Silviu
    We're having a serious issue at work. We've discovered that after the station where the client was running is locked/unlocked the client is blocked. No repaint. So the UI thread is blocked with something. Looking at the callstack of the UI thread (thread 0) using windbg we see that a UserPreferenceChanged event gets raised. It is marshalled through a WindowsFormsSynchronizationContext using it's controlToSend field to the UI. It gets blocked by a call to the marshalling control. The method called is MarshaledInvoke it builds a ThreadMethodEntry entry = new ThreadMethodEntry(caller, method, args, synchronous, executionContext); This entry is supposed to do the magic. The call is a synchronous call and because of that (still in the MarshaledInvoke of the Control class) the wait call is reached: if (!entry.IsCompleted) { this.WaitForWaitHandle(entry.AsyncWaitHandle); } The last thing that i can see on the stack is the WaitOne called on the previously mentioned AsyncWaitHandle. This is very annoying because having just the callstack of the runtime and not one of our methods being invoked we cannot really point to a bug in our code. I might be wrong, but I'm guessing that the marshaling control is not "marshaling" to the ui thread. But another one...i don't really know which one because the other threads are being used by us and are blocked...maybe this is the issue. But none of the other threads are running a message loop. This is very annoying. We had some issues in the past with marshaling controls to the right ui thread. That is because the first form that is constructed is a splash form. Which is not the main form. We used to use the main form to marshal call to the ui thread. But from time to time some calls would go to a non ui thread and some grids would broke with a big red X on them. I fixed this by creating a specific class: public class WindowsFormsSynchronizer { private static readonly WindowsFormsSynchronizationContext = new WindowsFormsSynchronizationContext(); //Methods are following that would build the same interface of the synchronization context. } This class gets build as one of the first objects in the first form being constructed. We've noticed some other strange thing. Looking at the heap there are 7 WindowsFormsSynchronizationContext objects. 6 of these have the same instance of controlToSend, and the other one has some different instance of controlToSend. This last one is the one that should marshal the calls to the UI. I don't have any other idea...maybe some of you guys had this same issue?

    Read the article

  • Jboss AS 7 - Dependency Injection

    - by Nic Willemse
    Im attempting to make use of dependency injection in Jboss AS 7 and im having huge difficulties. I have setup a EAR which contains both a EJB jar and a war. The war contains a richfaces web app. Im attempting to inject an EJB from the ejb jar into a faces managed bean with the code below : public class UserController { @EJB(mappedName="UserService") private UserFacadeService userService; public String getService(){ if(userService == null){ however when i deploy jboss puts the error in the console : rolled back with failure message {"Services with missing/unavailable dependencies" => ["jboss.deployment.subunit.\"GoodByeJohnEAR.ear\".\"GoodByeJohnWeb-1.0-SNAPSHOT.war\".component.\"managed-bean.za.co.gbj.UserController\".START missing [ jboss.naming.context.java.module.GoodByeJohnEAR.\"GoodByeJohnWeb-1.0-SNAPSHOT\".\"env/za.co.gbj.UserController/userService\" ]","jboss.deployment.subunit.\"GoodByeJohnEAR.ear\".\"GoodByeJohnWeb-1.0-SNAPSHOT.war\".jndiDependencyService missing [ jboss.naming.context.java.module.GoodByeJohnEAR.\"GoodByeJohnWeb-1.0-SNAPSHOT\".\"env/za.co.gbj.UserController/userService\" ]","jboss.naming.context.java.module.GoodByeJohnEAR.\"GoodByeJohnWeb-1.0-SNAPSHOT\".\"env/za.co.gbj.UserController/userService\".jboss.deployment.subunit.\"GoodByeJohnEAR.ear\".\"GoodByeJohnWeb-1.0-SNAPSHOT.war\".module.GoodByeJohnEAR.\"GoodByeJohnWeb-1.0-SNAPSHOT\".2 missing [ jboss.naming.context.java.module.GoodByeJohnEAR.\"GoodByeJohnWeb-1.0-SNAPSHOT\".env/UserService ]"]} 09:03:50,576 INFO [org.jboss.as.server.deployment] (MSC service thread 1-8) Starting deployment of "GoodByeJohnEAR.ear" 09:03:50,670 INFO [org.jboss.as.server.deployment] (MSC service thread 1-3) Starting deployment of "GoodByeJohnWeb-1.0-SNAPSHOT.war" 09:03:50,670 INFO [org.jboss.as.server.deployment] (MSC service thread 1-8) Starting deployment of "GoodByeJohnEJB-1.0-SNAPSHOT.jar" 09:03:51,367 WARN [org.jboss.as.server.deployment.service-loader] (MSC service thread 1-2) Encountered invalid class name "com.sun.faces.vendor.Tomcat6InjectionProvider:org.apache.catalina.util.DefaultAnnotationProcessor" for service type "com.sun.faces.spi.injectionprovider" 09:03:51,367 WARN [org.jboss.as.server.deployment.service-loader] (MSC service thread 1-2) Encountered invalid class name "com.sun.faces.vendor.Jetty6InjectionProvider:org.mortbay.jetty.plus.annotation.InjectionCollection" for service type "com.sun.faces.spi.injectionprovider" 09:03:51,375 INFO [org.jboss.as.ejb3.deployment.processors.EjbJndiBindingsDeploymentUnitProcessor] (MSC service thread 1-8) JNDI bindings for session bean named UserFacadeBean in deployment unit subdeployment "GoodByeJohnEJB-1.0-SNAPSHOT.jar" of deployment "GoodByeJohnEAR.ear" are as follows: java:global/GoodByeJohnEAR/GoodByeJohnEJB-1.0-SNAPSHOT/UserFacadeBean!za.co.gbj.UserFacadeService java:app/GoodByeJohnEJB-1.0-SNAPSHOT/UserFacadeBean!za.co.gbj.UserFacadeService java:module/UserFacadeBean!za.co.gbj.UserFacadeService java:global/GoodByeJohnEAR/GoodByeJohnEJB-1.0-SNAPSHOT/UserFacadeBean java:app/GoodByeJohnEJB-1.0-SNAPSHOT/UserFacadeBean java:module/UserFacadeBean 09:03:51,406 INFO [org.jboss.as.ejb3.deployment.processors.EjbJndiBindingsDeploymentUnitProcessor] (MSC service thread 1-4) JNDI bindings for session bean named UserFacadeBean in deployment unit subdeployment "GoodByeJohnWeb-1.0-SNAPSHOT.war" of deployment "GoodByeJohnEAR.ear" are as follows: java:global/GoodByeJohnEAR/GoodByeJohnWeb-1.0-SNAPSHOT/UserFacadeBean!za.co.gbj.UserFacadeService java:app/GoodByeJohnWeb-1.0-SNAPSHOT/UserFacadeBean!za.co.gbj.UserFacadeService java:module/UserFacadeBean!za.co.gbj.UserFacadeService java:global/GoodByeJohnEAR/GoodByeJohnWeb-1.0-SNAPSHOT/UserFacadeBean java:app/GoodByeJohnWeb-1.0-SNAPSHOT/UserFacadeBean java:module/UserFacadeBean 09:03:51,577 INFO [org.jboss.as.controller] (DeploymentScanner-threads - 1) Service status report New missing/unsatisfied dependencies: service jboss.naming.context.java.module.GoodByeJohnEAR."GoodByeJohnWeb-1.0-SNAPSHOT".env/UserService (missing) service jboss.naming.context.java.module.GoodByeJohnEAR."GoodByeJohnWeb-1.0-SNAPSHOT"."env/za.co.gbj.UserController/userService" (missing) Please assist!

    Read the article

  • TcpListener is queuing connections faster than I can clear them

    - by Matthew Brindley
    As I understand it, TcpListener will queue connections once you call Start(). Each time you call AcceptTcpClient (or BeginAcceptTcpClient), it will dequeue one item from the queue. If we load test our TcpListener app by sending 1,000 connections to it at once, the queue builds far faster than we can clear it, leading (eventually) to timeouts from the client because it didn't get a response because its connection was still in the queue. However, the server doesn't appear to be under much pressure, our app isn't consuming much CPU time and the other monitored resources on the machine aren't breaking a sweat. It feels like we're not running efficiently enough right now. We're calling BeginAcceptTcpListener and then immediately handing over to a ThreadPool thread to actually do the work, then calling BeginAcceptTcpClient again. The work involved doesn't seem to put any pressure on the machine, it's basically just a 3 second sleep followed by a dictionary lookup and then a 100 byte write to the TcpClient's stream. Here's the TcpListener code we're using: // Thread signal. private static ManualResetEvent tcpClientConnected = new ManualResetEvent(false); public void DoBeginAcceptTcpClient(TcpListener listener) { // Set the event to nonsignaled state. tcpClientConnected.Reset(); listener.BeginAcceptTcpClient( new AsyncCallback(DoAcceptTcpClientCallback), listener); // Wait for signal tcpClientConnected.WaitOne(); } public void DoAcceptTcpClientCallback(IAsyncResult ar) { // Get the listener that handles the client request, and the TcpClient TcpListener listener = (TcpListener)ar.AsyncState; TcpClient client = listener.EndAcceptTcpClient(ar); if (inProduction) ThreadPool.QueueUserWorkItem(state => HandleTcpRequest(client, serverCertificate)); // With SSL else ThreadPool.QueueUserWorkItem(state => HandleTcpRequest(client)); // Without SSL // Signal the calling thread to continue. tcpClientConnected.Set(); } public void Start() { currentHandledRequests = 0; tcpListener = new TcpListener(IPAddress.Any, 10000); try { tcpListener.Start(); while (true) DoBeginAcceptTcpClient(tcpListener); } catch (SocketException) { // The TcpListener is shutting down, exit gracefully CheckBuffer(); return; } } I'm assuming the answer will be related to using Sockets instead of TcpListener, or at least using TcpListener.AcceptSocket, but I wondered how we'd go about doing that? One idea we had was to call AcceptTcpClient and immediately Enqueue the TcpClient into one of multiple Queue<TcpClient> objects. That way, we could poll those queues on separate threads (one queue per thread), without running into monitors that might block the thread while waiting for other Dequeue operations. Each queue thread could then use ThreadPool.QueueUserWorkItem to have the work done in a ThreadPool thread and then move onto dequeuing the next TcpClient in its queue. Would you recommend this approach, or is our problem that we're using TcpListener and no amount of rapid dequeueing is going to fix that?

    Read the article

< Previous Page | 68 69 70 71 72 73 74 75 76 77 78 79  | Next Page >