From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.inf.tu-dresden.de (mail.inf.tu-dresden.de [141.76.2.1]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mail.inf.tu-dresden.de", Issuer "orion.inf.tu-dresden.de" (not verified)) by ozlabs.org (Postfix) with ESMTP id 14966DDE29 for ; Fri, 1 Feb 2008 23:59:45 +1100 (EST) Received: from localhost (localhost [127.0.0.1]) by mail.inf.tu-dresden.de (8.14.2/8.14.2) with ESMTP id m11Cm0f5022799 for ; Fri, 1 Feb 2008 13:48:01 +0100 (CET) Received: from mail.inf.tu-dresden.de ([127.0.0.1]) by localhost (mail.inf.tu-dresden.de [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Ka9poWhwggXR for ; Fri, 1 Feb 2008 13:48:00 +0100 (CET) Received: from iai8236 (iai8236.inf.tu-dresden.de [141.76.82.36]) by mail.inf.tu-dresden.de (8.14.2/8.14.2) with ESMTP id m11CljD1022704 for ; Fri, 1 Feb 2008 13:47:45 +0100 (CET) From: "Sebastian Theiss" To: Subject: pthread / TQM5200 problem Date: Fri, 1 Feb 2008 13:47:45 +0100 Message-ID: <002c01c864d0$a4ad11c0$0101a8c0@tis> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi all. I've been having some headache using the pthread library with a TB5200 = box (based on a TQM5200 board with a Freescale MPC5200 PowerPC-CPU). I = created a small program to pin down the problem and it runs fine on all my Unix- = and Linux-machines but fails on the embedded box: The program contains a = class CSignal that provides thread-synchronisation based on the pthread_cond_signal and pthread_cond_wait calls and takes care of the "spurious wakeup" and "lost signal" problems. The program runs 159 additional threads (that seems to be some internal limit), each of them continuously increments a field variable and afterwards sleeps until the main thread wakes it up again. The main thread monitors the whole field = of variables that are incremented by the 159 other threads and continuously wakes them up. When running in the desired way, the program should show = a table with 160 entries and each entry (except for the last) should continuously increase. However, on the box the threads 31 to 64 never = wake up, once they call pthread_cond_wait. The code below lacks some error checking to keep it short, but besides that I don't see what's going = wrong. And, the code runs fine on my "real" Linux machines. Any ideas of what the problem might be and how to fix it? Your I help = would be greatly appreciated as I'm rather despaired right now. Regards, Sebastian #include #include class CSignal { public: CSignal() { m_bFlag =3D false; pthread_mutex_init(&m_Mutex, NULL); pthread_cond_init(&m_Condition, NULL); } ~CSignal() { pthread_mutex_destroy(&m_Mutex); pthread_cond_destroy(&m_Condition); } public: void Set(bool bValue =3D true) { pthread_mutex_lock(&m_Mutex); if( m_bFlag =3D bValue ) pthread_cond_broadcast(&m_Condition); pthread_mutex_unlock(&m_Mutex); } void Wait() { pthread_mutex_lock(&m_Mutex); while( !m_bFlag ) pthread_cond_wait(&m_Condition,&m_Mutex); pthread_mutex_unlock(&m_Mutex); } protected: volatile bool m_bFlag; pthread_mutex_t m_Mutex; pthread_cond_t m_Condition; }; #define THREAD_COUNT 160 unsigned char state[THREAD_COUNT]; CSignal signal[THREAD_COUNT]; void* threadproc(void* pParam) { int index =3D (int)pParam; while( true ) { state[index]++; // wait for the signal beeing set signal[index].Wait(); // reset signal, so that next Wait() will actually case the thread to sleep again signal[index].Set(false); } } int main() { // clear state field for( int i =3D 0; i < THREAD_COUNT; i++ ) { state[i] =3D 0; } // run 160 threads (creation of the last thread throws EAGAIN, so 159 (+ the main thread)=20 // seems to be some kind of limit, but that's not the point here) for( int i =3D 0; i < THREAD_COUNT; i++ ) { pthread_t id; printf("create thread %i: %i\n", i, pthread_create(&id, NULL, threadproc, (void*)i)); } for(;;) { // wake all threads for( int i =3D 0; i < THREAD_COUNT; i++ ) { signal[i].Set(); } // print state of each thread printf("\033[H"); int thread =3D 0; for( int i =3D 0; i < 16; i++ ) { for( int j =3D 0; j < 10; j++, thread++ ) { printf("%03i/%03i ", thread, state[thread]); } printf("\n"); } } return 0; } =20 =20 _________________________________________________________ Technische Universit=E4t Dresden Fakult=E4t Informatik Institut f=FCr Angewandte Informatik Lehrstuhl f=FCr Technische Informationssysteme D-01062 Dresden Besucheradresse: N=F6thnitzer Str. 46, Zi. 1079 Telefon +49 351 463-38399 Telefax +49 351 463-38460 st12@inf.tu-dresden.de _________________________________________________________ =20