From 150a7a6e99d3cf8fd0b6315e7b184b5cce0f4ce4 Mon Sep 17 00:00:00 2001 From: rpj Date: Mon, 25 Apr 2005 00:45:59 +0000 Subject: Fix timeout bug --- sem_timedwait.c | 476 ++++++++++++++++++++++++++------------------------------ 1 file changed, 220 insertions(+), 256 deletions(-) (limited to 'sem_timedwait.c') diff --git a/sem_timedwait.c b/sem_timedwait.c index 7fba45f..01bab42 100644 --- a/sem_timedwait.c +++ b/sem_timedwait.c @@ -1,256 +1,220 @@ -/* - * ------------------------------------------------------------- - * - * Module: sem_timedwait.c - * - * Purpose: - * Semaphores aren't actually part of the PThreads standard. - * They are defined by the POSIX Standard: - * - * POSIX 1003.1b-1993 (POSIX.1b) - * - * ------------------------------------------------------------- - * - * -------------------------------------------------------------------------- - * - * Pthreads-win32 - POSIX Threads Library for Win32 - * Copyright(C) 1998 John E. Bossom - * Copyright(C) 1999,2005 Pthreads-win32 contributors - * - * Contact Email: rpj@callisto.canberra.edu.au - * - * The current list of contributors is contained - * in the file CONTRIBUTORS included with the source - * code distribution. The list can also be seen at the - * following World Wide Web location: - * http://sources.redhat.com/pthreads-win32/contributors.html - * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; either - * version 2 of the License, or (at your option) any later version. - * - * This library is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this library in the file COPYING.LIB; - * if not, write to the Free Software Foundation, Inc., - * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA - */ - -#ifndef _UWIN -//#include -#endif -#ifndef NEED_FTIME -#include -#endif - -#include "pthread.h" -#include "semaphore.h" -#include "implement.h" - -static void PTW32_CDECL -ptw32_sem_timedwait_cleanup (void * sem) -{ - sem_t s = (sem_t) sem; - - if (pthread_mutex_lock (&s->lock) == 0) - { - ++s->value; - /* - * Don't release the W32 sema, it doesn't need adjustment - * because it doesn't record the number of waiters. - */ - (void) pthread_mutex_unlock (&s->lock); - } -} - -int -sem_timedwait (sem_t * sem, const struct timespec *abstime) - /* - * ------------------------------------------------------ - * DOCPUBLIC - * This function waits on a semaphore possibly until - * 'abstime' time. - * - * PARAMETERS - * sem - * pointer to an instance of sem_t - * - * abstime - * pointer to an instance of struct timespec - * - * DESCRIPTION - * This function waits on a semaphore. If the - * semaphore value is greater than zero, it decreases - * its value by one. If the semaphore value is zero, then - * the calling thread (or process) is blocked until it can - * successfully decrease the value or until interrupted by - * a signal. - * - * If 'abstime' is a NULL pointer then this function will - * block until it can successfully decrease the value or - * until interrupted by a signal. - * - * RESULTS - * 0 successfully decreased semaphore, - * -1 failed, error in errno - * ERRNO - * EINVAL 'sem' is not a valid semaphore, - * ENOSYS semaphores are not supported, - * EINTR the function was interrupted by a signal, - * EDEADLK a deadlock condition was detected. - * ETIMEDOUT abstime elapsed before success. - * - * ------------------------------------------------------ - */ -{ - int result = 0; - sem_t s = *sem; - -#ifdef NEED_FTIME - - struct timespec currSysTime; - -#else /* NEED_FTIME */ - - struct _timeb currSysTime; - -#endif /* NEED_FTIME */ - - const int64_t NANOSEC_PER_MILLISEC = 1000000; - const int64_t MILLISEC_PER_SEC = 1000; - DWORD milliseconds; - int64_t tmpAbsMilliseconds; - int64_t tmpCurrMilliseconds; - - if (sem == NULL) - { - result = EINVAL; - } - else - { - if (abstime == NULL) - { - milliseconds = INFINITE; - } - else - { - /* - * Calculate timeout as milliseconds from current system time. - */ - - /* - * subtract current system time from abstime in a way that checks - * that abstime is never in the past, or is never equivalent to the - * defined INFINITE value (0xFFFFFFFF). - * - * Assume all integers are unsigned, i.e. cannot test if less than 0. - */ - tmpAbsMilliseconds = (int64_t)abstime->tv_sec * MILLISEC_PER_SEC; - tmpAbsMilliseconds += ((int64_t)abstime->tv_nsec + (NANOSEC_PER_MILLISEC/2)) / NANOSEC_PER_MILLISEC; - - /* get current system time */ - -#ifdef NEED_FTIME - - { - FILETIME ft; - SYSTEMTIME st; - - GetSystemTime(&st); - SystemTimeToFileTime(&st, &ft); - /* - * GetSystemTimeAsFileTime(&ft); would be faster, - * but it does not exist on WinCE - */ - - ptw32_filetime_to_timespec(&ft, &currSysTime); - } - - tmpCurrMilliseconds = (int64_t)currSysTime.tv_sec * MILLISEC_PER_SEC; - tmpCurrMilliseconds += ((int64_t)currSysTime.tv_nsec + (NANOSEC_PER_MILLISEC/2)) / NANOSEC_PER_MILLISEC; - -#else /* ! NEED_FTIME */ - - _ftime(&currSysTime); - - tmpCurrMilliseconds = (int64_t) currSysTime.time * MILLISEC_PER_SEC; - tmpCurrMilliseconds += (int64_t) currSysTime.millitm; - -#endif /* NEED_FTIME */ - - if (tmpAbsMilliseconds > tmpCurrMilliseconds) - { - milliseconds = (DWORD) (tmpAbsMilliseconds - tmpCurrMilliseconds); - if (milliseconds == INFINITE) - { - /* Timeouts must be finite */ - milliseconds--; - } - } - else - { - /* The abstime given is in the past */ - milliseconds = 0; - } - } - -#ifdef NEED_SEM - - result = (pthreadCancelableTimedWait (s->event, milliseconds)); - -#else /* NEED_SEM */ - - pthread_testcancel(); - - if ((result = pthread_mutex_lock (&s->lock)) == 0) - { - int v = --s->value; - (void) pthread_mutex_unlock (&s->lock); - - if (v < 0) - { - /* Must wait */ -#ifdef _MSC_VER -#pragma inline_depth(0) -#endif - pthread_cleanup_push(ptw32_sem_timedwait_cleanup, (void *) s); - result = pthreadCancelableTimedWait (s->sem, milliseconds); - /* - * Restore the semaphore counter if no longer waiting - * and not taking the semaphore. This will occur if the - * thread is cancelled while waiting, or the wake was - * not the result of a post event given to us, e.g. a timeout. - */ - pthread_cleanup_pop(result); -#ifdef _MSC_VER -#pragma inline_depth() -#endif - } - } - -#endif - - } - - if (result != 0) - { - - errno = result; - return -1; - - } - -#ifdef NEED_SEM - - ptw32_decrease_semaphore (sem); - -#endif /* NEED_SEM */ - - return 0; - -} /* sem_timedwait */ +/* + * ------------------------------------------------------------- + * + * Module: sem_timedwait.c + * + * Purpose: + * Semaphores aren't actually part of the PThreads standard. + * They are defined by the POSIX Standard: + * + * POSIX 1003.1b-1993 (POSIX.1b) + * + * ------------------------------------------------------------- + * + * -------------------------------------------------------------------------- + * + * Pthreads-win32 - POSIX Threads Library for Win32 + * Copyright(C) 1998 John E. Bossom + * Copyright(C) 1999,2005 Pthreads-win32 contributors + * + * Contact Email: rpj@callisto.canberra.edu.au + * + * The current list of contributors is contained + * in the file CONTRIBUTORS included with the source + * code distribution. The list can also be seen at the + * following World Wide Web location: + * http://sources.redhat.com/pthreads-win32/contributors.html + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library in the file COPYING.LIB; + * if not, write to the Free Software Foundation, Inc., + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + */ + +#include "pthread.h" +#include "semaphore.h" +#include "implement.h" + + +typedef struct { + sem_t sem; + int * resultPtr; +} sem_timedwait_cleanup_args_t; + + +static void PTW32_CDECL +ptw32_sem_timedwait_cleanup (void * args) +{ + sem_timedwait_cleanup_args_t * a = (sem_timedwait_cleanup_args_t *)args; + sem_t s = a->sem; + + if (pthread_mutex_lock (&s->lock) == 0) + { + /* + * We either timed out or were cancelled. + * If someone posted since then we try to take the semaphore. + * Otherwise the semaphore count may be wrong after we + * return. In the case of a cancellation, it is as if we + * were cancelled just before we return (after taking the semaphore) + * which is ok. + */ + if (WaitForSingleObject(s->sem, 0) == WAIT_OBJECT_0) + { + /* We got the semaphore on the second attempt */ + *(a->resultPtr) = 0; + } + else + { + /* Indicate we're no longer waiting */ + s->value++; +#ifdef NEED_SEM + if (s->value > 0) + { + s->leftToUnblock = 0; + } +#else + /* + * Don't release the W32 sema, it doesn't need adjustment + * because it doesn't record the number of waiters. + */ +#endif + } + (void) pthread_mutex_unlock (&s->lock); + } +} + + +int +sem_timedwait (sem_t * sem, const struct timespec *abstime) + /* + * ------------------------------------------------------ + * DOCPUBLIC + * This function waits on a semaphore possibly until + * 'abstime' time. + * + * PARAMETERS + * sem + * pointer to an instance of sem_t + * + * abstime + * pointer to an instance of struct timespec + * + * DESCRIPTION + * This function waits on a semaphore. If the + * semaphore value is greater than zero, it decreases + * its value by one. If the semaphore value is zero, then + * the calling thread (or process) is blocked until it can + * successfully decrease the value or until interrupted by + * a signal. + * + * If 'abstime' is a NULL pointer then this function will + * block until it can successfully decrease the value or + * until interrupted by a signal. + * + * RESULTS + * 0 successfully decreased semaphore, + * -1 failed, error in errno + * ERRNO + * EINVAL 'sem' is not a valid semaphore, + * ENOSYS semaphores are not supported, + * EINTR the function was interrupted by a signal, + * EDEADLK a deadlock condition was detected. + * ETIMEDOUT abstime elapsed before success. + * + * ------------------------------------------------------ + */ +{ + int result = 0; + sem_t s = *sem; + + if (sem == NULL) + { + result = EINVAL; + } + else + { + DWORD milliseconds; + + if (abstime == NULL) + { + milliseconds = INFINITE; + } + else + { + /* + * Calculate timeout as milliseconds from current system time. + */ + milliseconds = ptw32_relmillisecs (abstime); + } + + pthread_testcancel(); + + if ((result = pthread_mutex_lock (&s->lock)) == 0) + { + int v = --s->value; + (void) pthread_mutex_unlock (&s->lock); + + if (v < 0) + { +#ifdef NEED_SEM + int timedout; +#endif + sem_timedwait_cleanup_args_t cleanup_args; + + cleanup_args.sem = s; + cleanup_args.resultPtr = &result; + +#ifdef _MSC_VER +#pragma inline_depth(0) +#endif + /* Must wait */ + pthread_cleanup_push(ptw32_sem_timedwait_cleanup, (void *) &cleanup_args); +#ifdef NEED_SEM + timedout = +#endif + result = pthreadCancelableTimedWait (s->sem, milliseconds); + pthread_cleanup_pop(result); +#ifdef _MSC_VER +#pragma inline_depth() +#endif + +#ifdef NEED_SEM + + if (!timedout && pthread_mutex_lock (&s->lock) == 0) + { + if (s->leftToUnblock > 0) + { + --s->leftToUnblock; + SetEvent(s->sem); + } + (void) pthread_mutex_unlock (&s->lock); + } + +#endif /* NEED_SEM */ + + } + } + + } + + if (result != 0) + { + + errno = result; + return -1; + + } + + return 0; + +} /* sem_timedwait */ -- cgit v1.2.3