Search Results

Search found 6431 results on 258 pages for 'pthread join'.

Page 135/258 | < Previous Page | 131 132 133 134 135 136 137 138 139 140 141 142  | Next Page >

  • SUA + Visual Studio + pthreads

    - by vasek7
    Hi, I cannot compile this code under SUA: #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <pthread.h> void * thread_function(void *arg) { printf("thread_function started. Arg was %s\n", (char *)arg); // pause for 3 seconds sleep(3); // exit and return a message to another thread // that may be waiting for us to finish pthread_exit ("thread one all done"); } int main() { int res; pthread_t a_thread; void *thread_result; // create a thread that starts to run ‘thread_function’ pthread_create (&a_thread, NULL, thread_function, (void*)"thread one"); printf("Waiting for thread to finish...\n"); // now wait for new thread to finish // and get any returned message in ‘thread_result’ pthread_join(a_thread, &thread_result); printf("Thread joined, it returned %s\n", (char *)thread_result); exit(0); } I'm running on Windows 7 Ultimate x64 with Visual Studio 2008 and 2010 and I have installed: Windows Subsystem for UNIX Utilities and SDK for Subsystem for UNIX-based Applications in Microsoft Windows 7 and Windows Server 2008 R2 Include directories property of Visual Studio project is set to "C:\Windows\SUA\usr\include" What I have to configure in order to compile and run (and possibly debug) pthreads programs in Visual Studio 2010 (or 2008)?

    Read the article

  • Lightweight spinlocks built from GCC atomic operations?

    - by Thomas
    I'd like to minimize synchronization and write lock-free code when possible in a project of mine. When absolutely necessary I'd love to substitute light-weight spinlocks built from atomic operations for pthread and win32 mutex locks. My understanding is that these are system calls underneath and could cause a context switch (which may be unnecessary for very quick critical sections where simply spinning a few times would be preferable). The atomic operations I'm referring to are well documented here: http://gcc.gnu.org/onlinedocs/gcc-4.4.1/gcc/Atomic-Builtins.html Here is an example to illustrate what I'm talking about. Imagine a RB-tree with multiple readers and writers possible. RBTree::exists() is read-only and thread safe, RBTree::insert() would require exclusive access by a single writer (and no readers) to be safe. Some code: class IntSetTest { private: unsigned short lock; RBTree<int>* myset; public: // ... void add_number(int n) { // Aquire once locked==false (atomic) while (__sync_bool_compare_and_swap(&lock, 0, 0xffff) == false); // Perform a thread-unsafe operation on the set myset->insert(n); // Unlock (atomic) __sync_bool_compare_and_swap(&lock, 0xffff, 0); } bool check_number(int n) { // Increment once the lock is below 0xffff u16 savedlock = lock; while (savedlock == 0xffff || __sync_bool_compare_and_swap(&lock, savedlock, savedlock+1) == false) savedlock = lock; // Perform read-only operation bool exists = tree->exists(n); // Decrement savedlock = lock; while (__sync_bool_compare_and_swap(&lock, savedlock, savedlock-1) == false) savedlock = lock; return exists; } }; (lets assume it need not be exception-safe) Is this code indeed thread-safe? Are there any pros/cons to this idea? Any advice? Is the use of spinlocks like this a bad idea if the threads are not truly concurrent? Thanks in advance. ;)

    Read the article

  • Making a 64 bit shared library that dynamically links to a 32 bit library on Mac OS X Snow Leopard

    - by carneades
    Update: After some more reading I see that this problem is totally general, you can't mix architectures in the same process, so 64 bit Java cannot dlopen() a 32 bit library like FMOD. Is there any possible workaround for this, keeping in mind I'm writing my own C interface to the FMOD library? I need to make a 64-bit dylib on Max OS X because Java Native Access only likes 64-bit libraries on 64-bit machines. The problem is, my C source code dynamically includes FMOD which on Mac only provides 32-bit dylibs. When I try to compile without the -m32 option (since I must output a 64-bit dylib) I get the following error: gcc -dynamiclib -std=c99 -pedantic -Wall -O3 -fPIC -pthread -o ../bin/libpenntotalrecall_fmod.dylib ../../src/libpenntotalrecall_fmod.c -lfmodex -L../../lib/osx/ ld: warning: in /usr/lib/libfmodex.dylib, missing required architecture x86_64 in file Undefined symbols: "_FMOD_System_CreateSound", referenced from: _startPlayback in ccJnlwrd.o "_FMOD_Channel_GetPosition", referenced from: _streamPosition in ccJnlwrd.o "_FMOD_System_Create", referenced from: _startPlayback in ccJnlwrd.o "_FMOD_System_PlaySound", referenced from: _startPlayback in ccJnlwrd.o "_FMOD_Sound_Release", referenced from: _stopPlayback in ccJnlwrd.o "_FMOD_Channel_IsPlaying", referenced from: _playbackInProgress in ccJnlwrd.o "_FMOD_System_Update", referenced from: _streamPosition in ccJnlwrd.o _startPlayback in ccJnlwrd.o "_FMOD_Channel_SetPaused", referenced from: _startPlayback in ccJnlwrd.o "_FMOD_System_Release", referenced from: _stopPlayback in ccJnlwrd.o "_FMOD_System_Init", referenced from: _startPlayback in ccJnlwrd.o "_FMOD_Channel_SetVolume", referenced from: _startPlayback in ccJnlwrd.o "_FMOD_System_Close", referenced from: _stopPlayback in ccJnlwrd.o "_FMOD_Channel_SetCallback", referenced from: _startPlayback in ccJnlwrd.o ld: symbol(s) not found collect2: ld returned 1 exit status make: *** [all] Error 1 Shouldn't it be possible to get a 64 bit dylib from my source code that dynamically includes 32 bit libraries?!

    Read the article

  • Why does my ActivePerl program report 'Sorry. Ran out of threads'?

    - by Zaid
    Tom Christiansen's example code (à la perlthrtut) is a recursive, threaded implementation of finding and printing all prime numbers between 3 and 1000. Below is a mildly adapted version of the script #!/usr/bin/perl # adapted from prime-pthread, courtesy of Tom Christiansen use strict; use warnings; use threads; use Thread::Queue; sub check_prime { my ($upstream,$cur_prime) = @_; my $child; my $downstream = Thread::Queue->new; while (my $num = $upstream->dequeue) { next unless ($num % $cur_prime); if ($child) { $downstream->enqueue($num); } else { $child = threads->create(\&check_prime, $downstream, $num); if ($child) { print "This is thread ",$child->tid,". Found prime: $num\n"; } else { warn "Sorry. Ran out of threads.\n"; last; } } } if ($child) { $downstream->enqueue(undef); $child->join; } } my $stream = Thread::Queue->new(3..shift,undef); check_prime($stream,2); When run on my machine (under ActiveState & Win32), the code was capable of spawning only 118 threads (last prime number found: 653) before terminating with a 'Sorry. Ran out of threads' warning. In trying to figure out why I was limited to the number of threads I could create, I replaced the use threads; line with use threads (stack_size => 1);. The resultant code happily dealt with churning out 2000+ threads. Can anyone explain this behavior?

    Read the article

  • GCC - How to realign stack?

    - by psihodelia
    I try to build an application which uses pthreads and __m128 SSE type. According to GCC manual, default stack alignment is 16 bytes. In order to use __m128, the requirement is the 16-byte alignment. My target CPU supports SSE. I use a GCC compiler which doesn't support runtime stack realignment (e.g. -mstackrealign). I cannot use any other GCC compiler version. My test application looks like: #include <xmmintrin.h> #include <pthread.h> void *f(void *x){ __m128 y; ... } int main(void){ pthread_t p; pthread_create(&p, NULL, f, NULL); } The application generates an exception and exits. After a simple debugging (printf "%p", &y), I found that the variable y is not 16-byte aligned. My question is: how can I realign the stack properly (16-byte) without using any GCC flags and attributes (they don't help)? Should I use GCC inline Assembler within this thread function f()?

    Read the article

  • How to mult-thread this?

    - by WilliamKF
    I wish to have two threads. The first thread1 occasionally calls the following pseudo function: void waitForThread2() { if (thread2 is not idle) { return; } notifyThread2IamReady(); while (thread2IsExclusive) { } } The second thread2 is forever in the following pseudo loop: for (;;) { Notify thread1 I am idle. while (!thread1IsReady()) { } Notify thread1 I am exclusive. Do some work while thread1 is blocked. Notify thread1 I am busy. Do some work in parallel with thread1. } What is the best way to write this such that both thread1 and thread2 are kept as busy as possible on a machine with multiple cores. I would like to avoid long delays between notification in one thread and detection by the other. I tried using pthread condition variables but found the delay between thread2 doing 'notify thread1 I am busy' and the loop in waitForThread2() on thear2IsExclusive() can be up to almost one second delay. I then tried using a volatile sig_atomic_t shared variable to control the same, but something is going wrong, so I must not be doing it correctly.

    Read the article

  • Compile subversion on CentOs

    - by peter
    I have downloaded, compiled and installed so far: apr-1.3.9 apr-util-1.3.9 sqlite-3.6.23 zlib-1.2.4 libtool-2.2.6b Now after downloading subversion-1.6.9, the config works fine but compiling it will end with the following error: cd subversion/svn && /bin/sh /root/subversion-1.6.9/libtool --tag=CC --silent --mode=link gcc -g -O2 -g -O2 -pthread -rpath /usr/local/lib -o svn add-cmd.o blame-cmd.o cat-cmd.o changelist-cmd.o checkout-cmd.o cleanup-cmd.o commit-cmd.o conflict-callbacks.o copy-cmd.o delete-cmd.o diff-cmd.o export-cmd.o help-cmd.o import-cmd.o info-cmd.o list-cmd.o lock-cmd.o log-cmd.o main.o merge-cmd.o mergeinfo-cmd.o mkdir-cmd.o move-cmd.o notify.o propdel-cmd.o propedit-cmd.o propget-cmd.o proplist-cmd.o props.o propset-cmd.o resolve-cmd.o resolved-cmd.o revert-cmd.o status-cmd.o status.o switch-cmd.o tree-conflicts.o unlock-cmd.o update-cmd.o util.o ../../subversion/libsvn_client/libsvn_client-1.la ../../subversion/libsvn_wc/libsvn_wc-1.la ../../subversion/libsvn_ra/libsvn_ra-1.la ../../subversion/libsvn_delta/libsvn_delta-1.la ../../subversion/libsvn_diff/libsvn_diff-1.la ../../subversion/libsvn_subr/libsvn_subr-1.la /usr/local/apr/lib/libaprutil-1.la -lexpat /usr/local/apr/lib/libapr-1.la -lrt -lcrypt -lpthread -ldl /usr/bin/ld: cannot find -lexpat collect2: ld returned 1 exit status make: * [subversion/svn/svn] Error 1 The file at /usr/local/apr/lib/libapr-1.la exists and seems to be OK (from permission perspective What could be the problem here? Thanks Peter

    Read the article

  • pthread_exit and/or pthread_join causing Abort and SegFaults.

    - by MJewkes
    The following code is a simple thread game, that switches between threads causing the timer to decrease. It works fine for 3 threads, causes and Abort(core dumped) for 4 threads, and causes a seg fault for 5 or more threads. Anyone have any idea why this might be happening? #include <stdio.h> #include <stdlib.h> #include <pthread.h> #include <errno.h> #include <assert.h> int volatile num_of_threads; int volatile time_per_round; int volatile time_left; int volatile turn_id; int volatile thread_running; int volatile can_check; void * player (void * id_in){ int id= (int)id_in; while(1){ if(can_check){ if (time_left<=0){ break; } can_check=0; if(thread_running){ if(turn_id==id-1){ turn_id=random()%num_of_threads; time_left--; } } can_check=1; } } pthread_exit(NULL); } int main(int argc, char *args[]){ int i; int buffer; pthread_t * threads =(pthread_t *)malloc(num_of_threads*sizeof(pthread_t)); thread_running=0; num_of_threads=atoi(args[1]); can_check=0; time_per_round = atoi(args[2]); time_left=time_per_round; srandom(time(NULL)); //Create Threads for (i=0;i<num_of_threads;i++){ do{ buffer=pthread_create(&threads[i],NULL,player,(void *)(i+1)); }while(buffer == EAGAIN); } can_check=1; time_left=time_per_round; turn_id=random()%num_of_threads; thread_running=1; for (i=0;i<num_of_threads;i++){ assert(!pthread_join(threads[i], NULL)); } return 0; }

    Read the article

  • How to interrupt a thread performing a blocking socket connect?

    - by Jason R
    I have some code that spawns a pthread that attempts to maintain a socket connection to a remote host. If the connection is ever lost, it attempts to reconnect using a blocking connect() call on its socket. Since the code runs in a separate thread, I don't really care about the fact that it uses the synchronous socket API. That is, until it comes time for my application to exit. I would like to perform some semblance of an orderly shutdown, so I use thread synchronization primitives to wake up the thread and signal for it to exit, then perform a pthread_join() on the thread to wait for it to complete. This works great, unless the thread is in the middle of a connect() call when I command the shutdown. In that case, I have to wait for the connect to time out, which could be a long time. This makes the application appear to take a long time to shut down. What I would like to do is to interrupt the call to connect() in some way. After the call returns, the thread will notice my exit signal and shut down cleanly. Since connect() is a system call, I thought that I might be able to intentionally interrupt it using a signal (thus making the call return EINTR), but I'm not sure if this is a robust method in a POSIX threads environment. Does anyone have any recommendations on how to do this, either using signals or via some other method? As a note, the connect() call is down in some library code that I cannot modify, so changing to a non-blocking socket is not an option.

    Read the article

  • Different standard streams per POSIX thread

    - by Roman Nikitchenko
    Is there any possibility to achieve different redirections for standard output like printf(3) for different POSIX thread? What about standard input? I have lot of code based on standard input/output and I only can separate this code into different POSIX thread, not process. Linux operation system, C standard library. I know I can refactor code to replace printf() to fprintf() and further in this style. But in this case I need to provide some kind of context which old code doesn't have. So doesn't anybody have better idea (look into code below)? #include <pthread.h> #include <stdio.h> void* different_thread(void*) { // Something to redirect standard output which doesn't affect main thread. // ... // printf() shall go to different stream. printf("subthread test\n"); return NULL; } int main() { pthread_t id; pthread_create(&id, NULL, different_thread, NULL); // In main thread things should be printed normally... printf("main thread test\n"); pthread_join(id, NULL); return 0; }

    Read the article

  • Does waitpid yield valid status information for a child process that has already exited?

    - by dtrebbien
    If I fork a child process, and the child process exits before the parent even calls waitpid, then is the exit status information that is set by waitpid still valid? If so, when does it become not valid; i.e., how do I ensure that I can call waitpid on the child pid and continue to get valid exit status information after an arbitrary amount of time, and how do I "clean up" (tell the OS that I am no longer interested in the exit status information for the finished child process)? I was playing around with the following code, and it appears that the exit status information is valid for at least a few seconds after the child finishes, but I do not know for how long or how to inform the OS that I won't be calling waitpid again: #include <assert.h> #include <pthread.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/wait.h> int main() { pid_t pid = fork(); if (pid < 0) { fprintf(stderr, "Failed to fork\n"); return EXIT_FAILURE; } else if (pid == 0) { // code for child process _exit(17); } else { // code for parent sleep(3); int status; waitpid(pid, &status, 0); waitpid(pid, &status, 0); // call `waitpid` again just to see if the first call had an effect assert(WIFEXITED(status)); assert(WEXITSTATUS(status) == 17); } return EXIT_SUCCESS; }

    Read the article

  • Are C++ exceptions sufficient to implement thread-local storage?

    - by Potatoswatter
    I was commenting on an answer that thread-local storage is nice and recalled another informative discussion about exceptions where I supposed The only special thing about the execution environment within the throw block is that the exception object is referenced by rethrow. Putting two and two together, wouldn't executing an entire thread inside a function-catch-block of its main function imbue it with thread-local storage? It seems to work fine: #include <iostream> #include <pthread.h> using namespace std; struct thlocal { string name; thlocal( string const &n ) : name(n) {} }; thlocal &get_thread() { try { throw; } catch( thlocal &local ) { return local; } } void print_thread() { cerr << get_thread().name << endl; } void *kid( void *local_v ) try { thlocal &local = * static_cast< thlocal * >( local_v ); throw local; } catch( thlocal & ) { print_thread(); return NULL; } int main() try { thlocal local( "main" ); throw local; } catch( thlocal & ) { print_thread(); pthread_t th; thlocal kid_local( "kid" ); pthread_create( &th, NULL, &kid, &kid_local ); pthread_join( th, NULL ); print_thread(); return 0; } Is this novel or well-characterized? Was my initial premise correct? What kind of overhead does get_thread incur in, say, GCC and VC++? It would require throwing only exceptions derived from struct thlocal, but altogether this doesn't feel like an unproductive insomnia-ridden Sunday morning…

    Read the article

  • how to emulate thread local storage at user space in C++ ?

    - by vprajan
    I am working on a mobile platform over Nucleus RTOS. It uses Nucleus Threading system but it doesn't have support for explicit thread local storage i.e, TlsAlloc, TlsSetValue, TlsGetValue, TlsFree APIs. The platform doesn't have user space pthreads as well. I found that __thread storage modifier is present in most of the C++ compilers. But i don't know how to make it work for my kind of usage. How does __thread keyword can be mapped with explicit thread local storage? I read many articles but nothing is so clear for giving me the following basic information will __thread variable different for each thread ? How to write to that and read from it ? does each thread has exactly one copy of the variable ? following is the pthread based implementation: pthread_key_t m_key; struct Data : Noncopyable { Data(T* value, void* owner) : value(value), owner(owner) {} int* value; }; inline ThreadSpecific() { int error = pthread_key_create(&m_key, destroy); if (error) CRASH(); } inline ~ThreadSpecific() { pthread_key_delete(m_key); // Does not invoke destructor functions. } inline T* get() { Data* data = static_cast<Data*>(pthread_getspecific(m_key)); return data ? data->value : 0; } inline void set(T* ptr) { ASSERT(!get()); pthread_setspecific(m_key, new Data(ptr, this)); } How to make the above code use __thread way to set & get specific value ? where/when does the create & delete happen? If this is not possible, how to write custom pthread_setspecific, pthread_getspecific kind of APIs. I tried using a C++ global map and index it uniquely for each thread and retrieved data from it. But it didn't work well.

    Read the article

  • Strange thread behavior in Perl

    - by Zaid
    Tom Christiansen's example code (à la perlthrtut) is a recursive, threaded implementation of finding and printing all prime numbers between 3 and 1000. Below is a mildly adapted version of the script #!/usr/bin/perl # adapted from prime-pthread, courtesy of Tom Christiansen use strict; use warnings; use threads; use Thread::Queue; sub check_prime { my ($upstream,$cur_prime) = @_; my $child; my $downstream = Thread::Queue->new; while (my $num = $upstream->dequeue) { next unless ($num % $cur_prime); if ($child) { $downstream->enqueue($num); } else { $child = threads->create(\&check_prime, $downstream, $num); if ($child) { print "This is thread ",$child->tid,". Found prime: $num\n"; } else { warn "Sorry. Ran out of threads.\n"; last; } } } if ($child) { $downstream->enqueue(undef); $child->join; } } my $stream = Thread::Queue->new(3..shift,undef); check_prime($stream,2); When run on my machine (under ActiveState & Win32), the code was capable of spawning only 118 threads (last prime number found: 653) before terminating with a 'Sorry. Ran out of threads' warning. In trying to figure out why I was limited to the number of threads I could create, I replaced the use threads; line with use threads (stack_size => 1);. The resultant code happily dealt with churning out 2000+ threads. Can anyone explain this behavior?

    Read the article

  • NDK app onDestroy cleanup - how to DetachCurrentThread

    - by Aristarhys
    So if we attach we must detach thread after after it finish, right? JNIEnv* get_jni_env() { JNIEnv* res; JAVA_VM->GetEnv((void**) &res, JNI_VERSION_1_6);//Using cached JavaVM JAVA_VM->AttachCurrentThread(&res, NULL); return res; } I call next native method from @Override protected void onDestroy() of my Activity class void free_jni_manager() { JNIEnv* env = get_jni_env(); ... //Here i delete global refs (jclass) //JAVA_VM->DetachCurrentThread(); } ERROR: detaching thread with interp frames (count=16) - main thread still running and we try to detach it. Even if we take any function that use JNIEnv (for example calling java methods), putting DetachCurrentThread will cause same error. DetachCurrentThread works flawlessly if used in pthread function static void* thread_func(void* arg) { get_jni_env(); // attach new thread //Do thread stuff JAVA_VM->DetachCurrentThread();//thread done detached it with ok return NULL; } Do we need detach main thread then we done with JNI, there do it? Or then activity will be destroyed, it will freed itself with JavaVM? Do we need do call DestroyJavaVM() (just doing crash if use onDestroy), how free cached JavaVM or garbage cleaner will handle this? P.S. What benefits of using AttachCurrentThreadAsDaemon()

    Read the article

  • Sheet and thread memory problem

    - by Xident
    Hi Guys, recently I started a project which can export some precalculated Grafix/Audio to files, for after processing. All I was doing is to put a new Window (with progressindicator and an Abort Button) in my main xib and opened it using the following code: [NSApp beginSheet: REC_Sheet modalForWindow: MOTHER_WINDOW modalDelegate: self didEndSelector: nil contextInfo: nil]; NSModalSession session=[NSApp beginModalSessionForWindow:REC_Sheet]; RECISNOTDONE=YES; while (RECISNOTDONE) { if ([NSApp runModalSession:session]!=NSRunContinuesResponse) break; usleep(100); } [NSApp endModalSession:session]; A Background Thread (pthread) was started earlier, to actually perform the work and save all the targas/wave file. Which worked great, but after an amount of time, it turned out that the main thread was not responding anymore and my memory footprint raised unstoppable. I tried to debug it with Instruments, and saw a lot of CFHash etc stuff growing to infinity. By accident i clicked below the sheet, and temporary it helped, the main thread (AppKit ?) was releasing it's stuff, but just for a little time. I can't explain it to me, first of all I thought it was the access from my thread to the Progressbar to update the Progress (intervalled at 0,5sec), so I cut it out. But even if I'm not updating anything and did nothing with the Progressbar, my Application eat up all the Memory, because of not releasing it's "Main-Event" or whatsoever Stuff. Is there any possibility to "drain" this Main thread Memory stuff (Runloop / NSApp call?). And why the heck doesn't the Main thread respond anymore (after this simple task) ??? I don't have a clou anymore, please help ! Thanks in advance ! P.S. How do you guys implement "threaded long task" Stuff and updating your gui ???

    Read the article

  • Passing Data to Multi Threads

    - by alaamh
    I study this code from some book: #include <pthread.h> #include <stdio.h> /* Parameters to print_function. */ struct char_print_parms { /* The character to print. */ char character; /* The number of times to print it. */ int count; }; /* Prints a number of characters to stderr, as given by PARAMETERS, which is a pointer to a struct char_print_parms. */ void* char_print(void* parameters) { /* Cast the cookie pointer to the right type. */ struct char_print_parms* p = (struct char_print_parms*) parameters; int i; for (i = 0; i < p->count; ++i) fputc(p->character, stderr); return NULL; } /* The main program. */ int main() { pthread_t thread1_id; pthread_t thread2_id; struct char_print_parms thread1_args; struct char_print_parms thread2_args; /* Create a new thread to print 30,000 ’x’s. */ thread1_args.character = 'x'; thread1_args.count = 30000; pthread_create(&thread1_id, NULL, &char_print, &thread1_args); /* Create a new thread to print 20,000 o’s. */ thread2_args.character = 'o'; thread2_args.count = 20000; pthread_create(&thread2_id, NULL, &char_print, &thread2_args); usleep(20); return 0; } after running this code, I see different result each time. and some time corrupted result. what is wrong and what the correct way to do that?

    Read the article

  • How to multi-thread this?

    - by WilliamKF
    I wish to have two threads. The first thread1 occasionally calls the following pseudo function: void waitForThread2() { if (thread2 is not idle) { return; } notifyThread2IamReady(); while (thread2IsExclusive) { } } The second thread2 is forever in the following pseudo loop: for (;;) { Notify thread1 I am idle. while (!thread1IsReady()) { } Notify thread1 I am exclusive. Do some work while thread1 is blocked. Notify thread1 I am busy. Do some work in parallel with thread1. } What is the best way to write this such that both thread1 and thread2 are kept as busy as possible on a machine with multiple cores. I would like to avoid long delays between notification in one thread and detection by the other. I tried using pthread condition variables but found the delay between thread2 doing 'notify thread1 I am busy' and the loop in waitForThread2() on thear2IsExclusive() can be up to almost one second delay. I then tried using a volatile sig_atomic_t shared variable to control the same, but something is going wrong, so I must not be doing it correctly.

    Read the article

  • How should a multi-threaded C application handle a failed malloc()?

    - by user294463
    A part of an application I'm working on is a simple pthread-based server that communicates over a TCP/IP socket. I am writing it in C because it's going to be running in a memory constrained environment. My question is: what should the program do if one of the threads encounters a malloc() that returns NULL? Possibilities I've come up with so far: No special handling. Let malloc() return NULL and let it be dereferenced so that the whole thing segfaults. Exit immediately on a failed malloc(), by calling abort() or exit(-1). Assume that the environment will clean everything up. Jump out of the main event loop and attempt to pthread_join() all the threads, then shut down. The first option is obviously the easiest, but seems very wrong. The second one also seems wrong since I don't know exactly what will happen. The third option seems tempting except for two issues: first, all of the threads need not be joined back to the main thread under normal circumstances and second, in order to complete the thread execution, most of the remaining threads will have to call malloc() again anyway. What shall I do?

    Read the article

  • compile error:c language in telnet(linux)

    - by lilyrose07
    #include<stdio.h> #include<unistd.h> #include<stdlib.h> #include<pthread.h> int count=0; void *thread_function(void *arg) { while(count<10) { if(count%2==1) { count++; } else {sleep(1);} } } int main(int argc,int *argv) { int res; pthread_t a_thread[2]; void *thread_result; int n; while(count<10) { if(count%2==0) {printf("%d",count); count++; } else{sleep(1);} } for(n=0;n<2;n++) { pthread_create(&(a_thread[n]),NULL,thread_function,NULL); } while(count==9) {pthread_join(a_thread[0],&thread_result); } while(count==10) { pthread_join(a_thread[1],&thread_result); } printf("%d",count); return 0; } in telnet,linux i write gcc za.c error list: undefined reference to pthread_create,pthread_join in function 'main' //why??

    Read the article

  • Python: nonblocking read from stdout of threaded subprocess

    - by sberry2A
    I have a script (worker.py) that prints unbuffered output in the form... 1 2 3 . . . n where n is some constant number of iterations a loop in this script will make. In another script (service_controller.py) I start a number of threads, each of which starts a subprocess using subprocess.Popen(stdout=subprocess.PIPE, ...); Now, in my main thread (service_controller.py) I want to read the output of each thread's worker.py subprocess and use it to calculate an estimate for the time remaining till completion. I have all of the logic working that reads the stdout from worker.py and determines the last printed number. The problem is that I can not figure out how to do this in a non-blocking way. If I read a constant bufsize then each read will end up waiting for the same data from each of the workers. I have tried numerous ways including using fcntl, select + os.read, etc. What is my best option here? I can post my source if needed, but I figured the explanation describes the problem well enough. Thanks for any help here. EDIT Adding sample code I have a worker that starts a subprocess. class WorkerThread(threading.Thread): def __init__(self): self.completed = 0 self.process = None self.lock = threading.RLock() threading.Thread.__init__(self) def run(self): cmd = ["/path/to/script", "arg1", "arg2"] self.process = subprocess.Popen(cmd, stdout=subprocess.PIPE, bufsize=1, shell=False) #flags = fcntl.fcntl(self.process.stdout, fcntl.F_GETFL) #fcntl.fcntl(self.process.stdout.fileno(), fcntl.F_SETFL, flags | os.O_NONBLOCK) def get_completed(self): self.lock.acquire(); fd = select.select([self.process.stdout.fileno()], [], [], 5)[0] if fd: self.data += os.read(fd, 1) try: self.completed = int(self.data.split("\n")[-2]) except IndexError: pass self.lock.release() return self.completed I then have a ThreadManager. class ThreadManager(): def __init__(self): self.pool = [] self.running = [] self.lock = threading.Lock() def clean_pool(self, pool): for worker in [x for x in pool is not x.isAlive()]: worker.join() pool.remove(worker) del worker return pool def run(self, concurrent=5): while len(self.running) + len(self.pool) > 0: self.clean_pool(self.running) n = min(max(concurrent - len(self.running), 0), len(self.pool)) if n > 0: for worker in self.pool[0:n]: worker.start() self.running.extend(self.pool[0:n]) del self.pool[0:n] time.sleep(.01) for worker in self.running + self.pool: worker.join() and some code to run it. threadManager = ThreadManager() for i in xrange(0, 5): threadManager.pool.append(WorkerThread()) threadManager.run() I have stripped out a log of the other code in hopes to try to pinpoint the issue.

    Read the article

  • ASP.NET MVC validation problem

    - by ile
    ArticleRepostitory.cs: using System; using System.Collections.Generic; using System.Linq; using System.Web; using CMS.Model; using System.Web.Mvc; namespace CMS.Models { public class ArticleDisplay { public ArticleDisplay() { } public int CategoryID { set; get; } public string CategoryTitle { set; get; } public int ArticleID { set; get; } public string ArticleTitle { set; get; } public DateTime ArticleDate; public string ArticleContent { set; get; } } public class ArticleRepository { private DB db = new DB(); // // Query Methods public IQueryable<ArticleDisplay> FindAllArticles() { var result = from category in db.ArticleCategories join article in db.Articles on category.CategoryID equals article.CategoryID select new ArticleDisplay { CategoryID = category.CategoryID, CategoryTitle = category.Title, ArticleID = article.ArticleID, ArticleTitle = article.Title, ArticleDate = article.Date, ArticleContent = article.Content }; return result; } public IQueryable<ArticleDisplay> FindTodayArticles() { var result = from category in db.ArticleCategories join article in db.Articles on category.CategoryID equals article.CategoryID where article.Date == DateTime.Today select new ArticleDisplay { CategoryID = category.CategoryID, CategoryTitle = category.Title, ArticleID = article.ArticleID, ArticleTitle = article.Title, ArticleDate = article.Date, ArticleContent = article.Content }; return result; } public Article GetArticle(int id) { return db.Articles.SingleOrDefault(d => d.ArticleID == id); } public IQueryable<ArticleDisplay> DetailsArticle(int id) { var result = from category in db.ArticleCategories join article in db.Articles on category.CategoryID equals article.CategoryID where id == article.ArticleID select new ArticleDisplay { CategoryID = category.CategoryID, CategoryTitle = category.Title, ArticleID = article.ArticleID, ArticleTitle = article.Title, ArticleDate = article.Date, ArticleContent = article.Content }; return result; } // // Insert/Delete Methods public void Add(Article article) { db.Articles.InsertOnSubmit(article); } public void Delete(Article article) { db.Articles.DeleteOnSubmit(article); } // // Persistence public void Save() { db.SubmitChanges(); } } } ArticleController.cs: using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc; using System.Web.Mvc.Ajax; using CMS.Models; using CMS.Model; namespace CMS.Controllers { public class ArticleController : Controller { ArticleRepository articleRepository = new ArticleRepository(); ArticleCategoryRepository articleCategoryRepository = new ArticleCategoryRepository(); // // GET: /Article/ public ActionResult Index() { var allArticles = articleRepository.FindAllArticles().ToList(); return View(allArticles); } // // GET: /Article/Details/5 public ActionResult Details(int id) { var article = articleRepository.DetailsArticle(id).Single(); if (article == null) return View("NotFound"); return View(article); } // // GET: /Article/Create public ActionResult Create() { ViewData["categories"] = new SelectList ( articleCategoryRepository.FindAllCategories().ToList(), "CategoryId", "Title" ); Article article = new Article() { Date = DateTime.Now, CategoryID = 1 }; return View(article); } // // POST: /Article/Create [AcceptVerbs(HttpVerbs.Post)] public ActionResult Create(Article article) { if (ModelState.IsValid) { try { // TODO: Add insert logic here articleRepository.Add(article); articleRepository.Save(); return RedirectToAction("Index"); } catch { return View(article); } } else { return View(article); } } // // GET: /Article/Edit/5 public ActionResult Edit(int id) { ViewData["categories"] = new SelectList ( articleCategoryRepository.FindAllCategories().ToList(), "CategoryId", "Title" ); var article = articleRepository.GetArticle(id); return View(article); } // // POST: /Article/Edit/5 [AcceptVerbs(HttpVerbs.Post)] public ActionResult Edit(int id, FormCollection collection) { Article article = articleRepository.GetArticle(id); try { // TODO: Add update logic here UpdateModel(article, collection.ToValueProvider()); articleRepository.Save(); return RedirectToAction("Details", new { id = article.ArticleID }); } catch { return View(article); } } // // HTTP GET: /Article/Delete/1 public ActionResult Delete(int id) { Article article = articleRepository.GetArticle(id); if (article == null) return View("NotFound"); else return View(article); } // // HTTP POST: /Article/Delete/1 [AcceptVerbs(HttpVerbs.Post)] public ActionResult Delete(int id, string confirmButton) { Article article = articleRepository.GetArticle(id); if (article == null) return View("NotFound"); articleRepository.Delete(article); articleRepository.Save(); return View("Deleted"); } } } View/Article/Create.aspx: <%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<CMS.Model.Article>" %> <asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server"> Create </asp:Content> <asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server"> <h2>Create</h2> <%= Html.ValidationSummary("Create was unsuccessful. Please correct the errors and try again.") %> <% using (Html.BeginForm()) {%> <fieldset> <legend>Fields</legend> <p> <label for="Title">Title:</label> <%= Html.TextBox("Title") %> <%= Html.ValidationMessage("Title", "*") %> </p> <p> <label for="Content">Content:</label> <%= Html.TextArea("Content", new { id = "Content" })%> <%= Html.ValidationMessage("Content", "*")%> </p> <p> <label for="Date">Date:</label> <%= Html.TextBox("Date") %> <%= Html.ValidationMessage("Date", "*") %> </p> <p> <label for="CategoryID">Category:</label> <%= Html.DropDownList("CategoryId", (IEnumerable<SelectListItem>)ViewData["categories"])%> </p> <p> <input type="submit" value="Create" /> </p> </fieldset> <% } %> <div> <%=Html.ActionLink("Back to List", "Index") %> </div> </asp:Content> If I remove DropDownList from .aspx file then validation (on date only because no other validation exists) works, but of course I can't create new article because one value is missing. If I leave dropdownlist and try to insert wrong date I get following error: System.InvalidOperationException: The ViewData item with the key 'CategoryId' is of type 'System.Int32' but needs to be of type 'IEnumerable'. If I enter correct date than the article is properly inserted. There's one other thing that's confusing me... For example, if I try manually add the categoyID: [AcceptVerbs(HttpVerbs.Post)] public ActionResult Create(Article article) { if (ModelState.IsValid) { try { // TODO: Add insert logic here // Manually add category value article.CategoryID = 1; articleRepository.Add(article); articleRepository.Save(); return RedirectToAction("Index"); } catch { return View(article); } } else { return View(article); } } ..I also get the above error. There's one other thing I noticed. If I add partial class Article, when returning to articleRepository.cs I get error that 'Article' is an ambiguous reference between 'CMS.Models.Article' and 'CMS.Model.Article' Any thoughts on this one?

    Read the article

  • NoPrimaryKeyException from DBUnit when loading a dataset into a databse

    - by Omar Kooheji
    I'm getting NoPrimaryKeyException when I try to run one of my unit tests which uses DBUnit. The datatable is created using Hibernate and is a join table between two classes mapping a many to many relationship. The annotations that define the relationship are as follows: @Override @ManyToMany @JoinTable(name="offset_file_offset_entries", joinColumns={@JoinColumn(name="offset_entry_id")},inverseJoinColumns={@JoinColumn(name="file_description_id")}) public List<OffsetEntry> getOffsets() { The other entries in in the XML file I'm using to define the dataset seem to work fine but not the join table. I get the following exception: org.dbunit.dataset.NoPrimaryKeyException: offset_file_offset_entries at org.dbunit.operation.UpdateOperation.getOperationData(UpdateOperation.java:72) at org.dbunit.operation.RefreshOperation$UpdateRowOperation.<init>(RefreshOperation.java:266) at org.dbunit.operation.RefreshOperation.createUpdateOperation(RefreshOperation.java:142) at org.dbunit.operation.RefreshOperation.execute(RefreshOperation.java:100) at org.dbunit.ext.mssql.InsertIdentityOperation.execute(InsertIdentityOperation.java:217) at uk.co.sabio.obscheduler.application.dao.AbstractBaseDatabaseTest.setUp(AbstractBaseDatabaseTest.java:57) at org.springframework.test.context.junit38.AbstractJUnit38SpringContextTests.runManaged(AbstractJUnit38SpringContextTests.java:332) at org.springframework.test.context.junit38.AbstractJUnit38SpringContextTests.access$0(AbstractJUnit38SpringContextTests.java:326) at org.springframework.test.context.junit38.AbstractJUnit38SpringContextTests$1.run(AbstractJUnit38SpringContextTests.java:216) at org.springframework.test.context.junit38.AbstractJUnit38SpringContextTests.runTest(AbstractJUnit38SpringContextTests.java:296) at org.springframework.test.context.junit38.AbstractJUnit38SpringContextTests.runTestTimed(AbstractJUnit38SpringContextTests.java:253) at org.springframework.test.context.junit38.AbstractJUnit38SpringContextTests.runBare(AbstractJUnit38SpringContextTests.java:213) at junit.framework.TestResult$1.protect(TestResult.java:110) at junit.framework.TestResult.runProtected(TestResult.java:128) at junit.framework.TestResult.run(TestResult.java:113) at junit.framework.TestCase.run(TestCase.java:124) at junit.framework.TestSuite.runTest(TestSuite.java:232) at junit.framework.TestSuite.run(TestSuite.java:227) at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:83) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:46) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197) the Dataset entry in question looks like this: <offset_file_offset_entries offset_entry_id="1" file_description_id="1" /> And matches up with the database which has both fields as primary keys (The Databse is MS SQL Server if that helps) There are corresponding entries in the two tables being Joined defined in the following xml: <dataset> <file_description file_path="src/test/resources/" file_pattern=".txt" file_description_id="1"/> <offset_file_description file_description_id="1"/> <offset_entries offset_entry_id="1" field_name="Field1" field_length="10" start_index="0"/> <offset_file_offset_entries offset_entry_id="1" file_description_id="1" /> </dataset> Do I have to define the primary keys in the hibernate annotations? If so How do I do so? do I have to change the way I define my dataset to imply that the two columns are a joint primary key? I'm not very proficient with hibernate or DBUnit for that matter and I'm at my wits end so any assistance would be really appreciated.

    Read the article

  • The Schema returned by the new query differ from the base query

    - by sochandara
    I am working on class project which required to work with Windows Application and this issue occurred to me that i don understand how to solved it can anybody help please? I want to show the NATIONALITYNAME instead of showing NATIONALITYID in the grid view SELECT COACH.COACHID, COACH.COACHFIRSTNAME, COACH.COACHLASTNAME, NATIONALITY.NATIONALITY FROM COACH INNER JOIN NATIONALITY ON COACH.NATIONALITYID = NATIONALITY.NATIONALITYID Error Message: "The Schema returned by the new query differ from the base query"![alt text][1]

    Read the article

  • C# Silverlight - Delay Child Window Load?!

    - by Goober
    The Scenario Currently I have a C# Silverlight Application That uses the domainservice class and the ADO.Net Entity Framework to communicate with my database. I want to load a child window upon clicking a button with some data that I retrieve from a server-side query to the database. The Process The first part of this process involves two load operations to load separate data from 2 tables. The next part of the process involves combining those lists of data to display in a listbox. The Problem The problem with this is that the first two asynchronous load operations haven't returned the data by the time the section of code to combine these lists of data is reached, thus result in a null value exception..... Initial Load Operations To Get The Data: public void LoadAudits(Guid jobID) { var context = new InmZenDomainContext(); var imageLoadOperation = context.Load(context.GetImageByIDQuery(jobID)); imageLoadOperation.Completed += (sender3, e3) => { imageList = ((LoadOperation<InmZen.Web.Image>)sender3).Entities.ToList(); }; var auditLoadOperation = context.Load(context.GetAuditByJobIDQuery(jobID)); auditLoadOperation.Completed += (sender2, e2) => { auditList = ((LoadOperation<Audit>)sender2).Entities.ToList(); }; } I Then Want To Execute This Immediately: IEnumerable<JobImageAudit> jobImageAuditList = from a in auditList join ai in imageList on a.ImageID equals ai.ImageID select new JobImageAudit { JobID = a.JobID, ImageID = a.ImageID.Value, CreatedBy = a.CreatedBy, CreatedDate = a.CreatedDate, Comment = a.Comment, LowResUrl = ai.LowResUrl, }; auditTrailList.ItemsSource = jobImageAuditList; However I can't because the async calls haven't returned with the data yet... Thus I have to do this (Perform the Load Operations, Then Press A Button On The Child Window To Execute The List Concatenation and binding): private void LoadAuditsButton_Click(object sender, RoutedEventArgs e) { IEnumerable<JobImageAudit> jobImageAuditList = from a in auditList join ai in imageList on a.ImageID equals ai.ImageID select new JobImageAudit { JobID = a.JobID, ImageID = a.ImageID.Value, CreatedBy = a.CreatedBy, CreatedDate = a.CreatedDate, Comment = a.Comment, LowResUrl = ai.LowResUrl, }; auditTrailList.ItemsSource = jobImageAuditList; } Potential Ideas for Solutions: Delay the child window displaying somehow? Potentially use DomainDataSource and the Activity Load control?! Any thoughts, help, solutions, samples comments etc. greatly appreciated.

    Read the article

< Previous Page | 131 132 133 134 135 136 137 138 139 140 141 142  | Next Page >