diff options
| -rw-r--r-- | GNUmakefile | 3 | ||||
| -rw-r--r-- | pthread.h | 20 | ||||
| -rw-r--r-- | pthread_mutex_timedlock.c | 340 | ||||
| -rw-r--r-- | sem_getvalue.c | 116 | ||||
| -rw-r--r-- | sem_init.c | 54 | ||||
| -rw-r--r-- | tests/semaphore2.c | 29 |
6 files changed, 300 insertions, 262 deletions
diff --git a/GNUmakefile b/GNUmakefile index c205458..44fc4d7 100644 --- a/GNUmakefile +++ b/GNUmakefile @@ -458,6 +458,7 @@ clean: -$(RM) *~ -$(RM) *.i -$(RM) *.o + -$(RM) *.obj -$(RM) *.exe -$(RM) $(PTHREAD_DEF) @@ -466,6 +467,8 @@ realclean: clean -$(RM) $(GCE_LIB) -$(RM) $(GC_DLL) -$(RM) $(GCE_DLL) + -$(RM) $(GC_INLINED_STAMP) + -$(RM) $(GCE_INLINED_STAMP) attr.o: attr.c $(ATTR_SRCS) $(INCL) barrier.o: barrier.c $(BARRIER_SRCS) $(INCL) @@ -198,6 +198,7 @@ #endif /* HAVE_SIGNAL_H */ #include <setjmp.h> +#include <limits.h> /* * This is a duplicate of what is in the autoconf config.h, @@ -385,12 +386,12 @@ extern "C" * process (must be at least 64). * * _POSIX_SEM_NSEMS_MAX - * The maximum number of semaphores a process can have. - * (only defined if not already defined) + * The maximum number of semaphores a process can have. + * (only defined if not already defined) * * _POSIX_SEM_VALUE_MAX - * The maximum value a semaphore can have. - * (only defined if not already defined) + * The maximum value a semaphore can have. + * (only defined if not already defined) * * ------------------------------------------------------------- */ @@ -459,14 +460,15 @@ extern "C" * */ #define PTHREAD_DESTRUCTOR_ITERATIONS 4 -#define PTHREAD_KEYS_MAX 64 -#define PTHREAD_STACK_MIN 0 -#define PTHREAD_THREADS_MAX 2019 +#define PTHREAD_KEYS_MAX 64 +#define PTHREAD_STACK_MIN 0 +#define PTHREAD_THREADS_MAX 2019 #ifndef _POSIX_SEM_NSEMS_MAX -# define _POSIX_SEM_NSEMS_MAX (INT_MAX) +/* Not used and only an arbitrary value. */ +# define _POSIX_SEM_NSEMS_MAX 1024 #endif #ifndef _POSIX_SEM_VALUE_MAX -# define _POSIX_SEM_VALUE_MAX (INT_MAX - 1) +# define _POSIX_SEM_VALUE_MAX (INT_MAX/2) #endif #if __GNUC__ && ! defined (__declspec) diff --git a/pthread_mutex_timedlock.c b/pthread_mutex_timedlock.c index ec1caa9..da03c03 100644 --- a/pthread_mutex_timedlock.c +++ b/pthread_mutex_timedlock.c @@ -99,58 +99,58 @@ ptw32_timed_semwait (sem_t * sem, const struct timespec * abstime) else { if (abstime == NULL) - { - milliseconds = INFINITE; - } + { + milliseconds = INFINITE; + } else - { - /* - * Calculate timeout as milliseconds from current system time. - */ - - /* get current system time */ - + { + /* + * Calculate timeout as milliseconds from current system time. + */ + + /* 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); - } - - /* - * subtract current system time from abstime - */ - milliseconds = (abstime->tv_sec - currSysTime.tv_sec) * MILLISEC_PER_SEC; - milliseconds += ((abstime->tv_nsec - currSysTime.tv_nsec) - + (NANOSEC_PER_MILLISEC/2)) / NANOSEC_PER_MILLISEC; + + { + 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); + } + + /* + * subtract current system time from abstime + */ + milliseconds = (abstime->tv_sec - currSysTime.tv_sec) * MILLISEC_PER_SEC; + milliseconds += ((abstime->tv_nsec - currSysTime.tv_nsec) + + (NANOSEC_PER_MILLISEC/2)) / NANOSEC_PER_MILLISEC; #else /* NEED_FTIME */ - _ftime(&currSysTime); + _ftime(&currSysTime); - /* - * subtract current system time from abstime - */ - milliseconds = (abstime->tv_sec - currSysTime.time) * MILLISEC_PER_SEC; - milliseconds += ((abstime->tv_nsec + (NANOSEC_PER_MILLISEC/2)) / NANOSEC_PER_MILLISEC) + /* + * subtract current system time from abstime + */ + milliseconds = (abstime->tv_sec - currSysTime.time) * MILLISEC_PER_SEC; + milliseconds += ((abstime->tv_nsec + (NANOSEC_PER_MILLISEC/2)) / NANOSEC_PER_MILLISEC) - currSysTime.millitm; #endif /* NEED_FTIME */ - if (((int) milliseconds) < 0) - { - return 2; - } - } + if (((int) milliseconds) < 0) + { + return 2; + } + } #ifdef NEED_SEM @@ -163,24 +163,24 @@ ptw32_timed_semwait (sem_t * sem, const struct timespec * abstime) #endif if (status == WAIT_OBJECT_0) - { + { #ifdef NEED_SEM - ptw32_decrease_semaphore(sem); + ptw32_decrease_semaphore(sem); #endif /* NEED_SEM */ - return 0; - } + return 0; + } else if (status == WAIT_TIMEOUT) - { - return 1; - } + { + return 1; + } else - { - result = EINVAL; - } + { + result = EINVAL; + } } if (result != 0) @@ -219,9 +219,9 @@ pthread_mutex_timedlock(pthread_mutex_t *mutex, const struct timespec *abstime) if (*mutex == PTHREAD_MUTEX_INITIALIZER) { if ((result = ptw32_mutex_check_need_init(mutex)) != 0) - { - return(result); - } + { + return(result); + } } mx = *mutex; @@ -230,126 +230,126 @@ pthread_mutex_timedlock(pthread_mutex_t *mutex, const struct timespec *abstime) { mx->recursive_count = 1; mx->ownerThread = (mx->kind != PTHREAD_MUTEX_FAST_NP - ? pthread_self() - : (pthread_t) PTW32_MUTEX_OWNER_ANONYMOUS); + ? pthread_self() + : (pthread_t) PTW32_MUTEX_OWNER_ANONYMOUS); } else { if( mx->kind != PTHREAD_MUTEX_FAST_NP && - pthread_equal( mx->ownerThread, pthread_self() ) ) - { - (void) InterlockedDecrement( &mx->lock_idx ); - - if( mx->kind == PTHREAD_MUTEX_RECURSIVE_NP ) - { - mx->recursive_count++; - } - else - { - result = EDEADLK; - } - } + pthread_equal( mx->ownerThread, pthread_self() ) ) + { + (void) InterlockedDecrement( &mx->lock_idx ); + + if( mx->kind == PTHREAD_MUTEX_RECURSIVE_NP ) + { + mx->recursive_count++; + } + else + { + result = EDEADLK; + } + } else - { - if (abstime == NULL) - { - result = EINVAL; - } - else - { - switch (ptw32_timed_semwait( &mx->wait_sema, abstime )) - { - case 0: /* We got the mutex. */ - { - mx->recursive_count = 1; - mx->ownerThread = (mx->kind != PTHREAD_MUTEX_FAST_NP - ? pthread_self() - : (pthread_t) PTW32_MUTEX_OWNER_ANONYMOUS); - break; - } - case 1: /* Timedout, try a second grab. */ - { - EnterCriticalSection(&mx->wait_cs); - - /* - * If we timeout, it is up to us to adjust lock_idx to say - * we're no longer waiting. If the mutex was also unlocked - * while we were timing out, and we simply return ETIMEDOUT, - * then wait_sema would be left in a state that is not consistent - * with the state of lock_idx. - * - * We must check to see if wait_sema has just been posted - * but we can't just call sem_getvalue - we must compete for - * the semaphore using sem_trywait(), otherwise we would need - * additional critical sections elsewhere, which would make the - * logic too inefficient. - * - * If sem_trywait returns EAGAIN then either wait_sema - * was given directly to another waiting thread or - * another thread has called sem_*wait() before us and - * taken the lock. Then we MUST decrement lock_idx and return - * ETIMEDOUT. - * - * Otherwise we MUST return success (because we have effectively - * acquired the lock that would have been ours had we not - * timed out), and NOT decrement lock_idx. - * - * We can almost guarrantee that EAGAIN is the only - * possible error, so no need to test errno. - */ - - if ( -1 == sem_trywait( &mx->wait_sema ) ) - { - (void) InterlockedDecrement( &mx->lock_idx ); - result = ETIMEDOUT; - } - - LeaveCriticalSection(&mx->wait_cs); - break; - } - case 2: /* abstime passed before we started to wait. */ - { - /* - * If we timeout, it is up to us to adjust lock_idx to say - * we're no longer waiting. - * - * The owner thread may still have posted wait_sema thinking - * we were waiting. I believe we must check but then NOT do any - * programmed work if we have acquired the mutex because - * we don't how long ago abstime was. We MUST just release it - * immediately. - */ - EnterCriticalSection(&mx->wait_cs); - - result = ETIMEDOUT; - - if ( -1 == sem_trywait( &mx->wait_sema ) ) - { - (void) InterlockedDecrement( &mx->lock_idx ); - } - else - { - if ( InterlockedDecrement( &mx->lock_idx ) >= 0 ) - { - /* Someone else is waiting on that mutex */ - if ( sem_post( &mx->wait_sema ) != 0 ) - { - result = errno; - } - } - } - - LeaveCriticalSection(&mx->wait_cs); - break; - } - default: - { - result = errno; - break; - } - } - } - } + { + if (abstime == NULL) + { + result = EINVAL; + } + else + { + switch (ptw32_timed_semwait( &mx->wait_sema, abstime )) + { + case 0: /* We got the mutex. */ + { + mx->recursive_count = 1; + mx->ownerThread = (mx->kind != PTHREAD_MUTEX_FAST_NP + ? pthread_self() + : (pthread_t) PTW32_MUTEX_OWNER_ANONYMOUS); + break; + } + case 1: /* Timedout, try a second grab. */ + { + EnterCriticalSection(&mx->wait_cs); + + /* + * If we timeout, it is up to us to adjust lock_idx to say + * we're no longer waiting. If the mutex was also unlocked + * while we were timing out, and we simply return ETIMEDOUT, + * then wait_sema would be left in a state that is not consistent + * with the state of lock_idx. + * + * We must check to see if wait_sema has just been posted + * but we can't just call sem_getvalue - we must compete for + * the semaphore using sem_trywait(), otherwise we would need + * additional critical sections elsewhere, which would make the + * logic too inefficient. + * + * If sem_trywait returns EAGAIN then either wait_sema + * was given directly to another waiting thread or + * another thread has called sem_*wait() before us and + * taken the lock. Then we MUST decrement lock_idx and return + * ETIMEDOUT. + * + * Otherwise we MUST return success (because we have effectively + * acquired the lock that would have been ours had we not + * timed out), and NOT decrement lock_idx. + * + * We can almost guarrantee that EAGAIN is the only + * possible error, so no need to test errno. + */ + + if ( -1 == sem_trywait( &mx->wait_sema ) ) + { + (void) InterlockedDecrement( &mx->lock_idx ); + result = ETIMEDOUT; + } + + LeaveCriticalSection(&mx->wait_cs); + break; + } + case 2: /* abstime passed before we started to wait. */ + { + /* + * If we timeout, it is up to us to adjust lock_idx to say + * we're no longer waiting. + * + * The owner thread may still have posted wait_sema thinking + * we were waiting. I believe we must check but then NOT do any + * programmed work if we have acquired the mutex because + * we don't how long ago abstime was. We MUST just release it + * immediately. + */ + EnterCriticalSection(&mx->wait_cs); + + result = ETIMEDOUT; + + if ( -1 == sem_trywait( &mx->wait_sema ) ) + { + (void) InterlockedDecrement( &mx->lock_idx ); + } + else + { + if ( InterlockedDecrement( &mx->lock_idx ) >= 0 ) + { + /* Someone else is waiting on that mutex */ + if ( sem_post( &mx->wait_sema ) != 0 ) + { + result = errno; + } + } + } + + LeaveCriticalSection(&mx->wait_cs); + break; + } + default: + { + result = errno; + break; + } + } + } + } } return(result); diff --git a/sem_getvalue.c b/sem_getvalue.c index 297bc6c..9d37c38 100644 --- a/sem_getvalue.c +++ b/sem_getvalue.c @@ -11,32 +11,32 @@ * * ------------------------------------------------------------- * - * Pthreads-win32 - POSIX Threads Library for Win32 - * Copyright(C) 1998 John E. Bossom - * Copyright(C) 1999,2002 Pthreads-win32 contributors + * Pthreads-win32 - POSIX Threads Library for Win32 + * Copyright(C) 1998 John E. Bossom + * Copyright(C) 1999,2002 Pthreads-win32 contributors * - * Contact Email: rpj@ise.canberra.edu.au + * Contact Email: rpj@ise.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 + * 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 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. + * 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 + * 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" @@ -55,20 +55,20 @@ sem_getvalue(sem_t * sem, int * sval) * * Return value * - * 0 sval has been set. - * -1 failed, error in errno + * 0 sval has been set. + * -1 failed, error in errno * * in global errno * - * EINVAL 'sem' is not a valid semaphore, - * ENOSYS this function is not supported, + * EINVAL 'sem' is not a valid semaphore, + * ENOSYS this function is not supported, * * * PARAMETERS * - * sem pointer to an instance of sem_t + * sem pointer to an instance of sem_t * - * sval pointer to int. + * sval pointer to int. * * DESCRIPTION * This function stores the current count value of the semaphore @@ -86,27 +86,57 @@ sem_getvalue(sem_t * sem, int * sval) { #ifdef NEED_SEM - + result = ENOSYS; - + #else - + + /* + * There appears to be NO atomic means of determining the + * value of the semaphore. Using only ReleaseSemaphore() + * with either a zero or oversized count parameter has been + * suggested but this trick doesn't produce consistent results + * across Windows versions (the technique uses values that are + * knowingly illegal but hopes to extract the current value + * anyway - the zero parameter appears to work for Win9x but + * neither work reliably for WinNT). + * + * The intrusive method below will give false results + * at times but it at least errs on the side of + * caution. Competing threads might occasionally believe + * the semaphore has a count of one less than it actually + * would have and possibly block momentarily unecessarily, + * but they will never see a higher semaphore value than + * there should be. + * + * + * Multiple threads calling sem_getvalue() at the same time + * may not all return the same value (assuming no calls to + * other semaphore routines). They will always return the + * correct value or a lesser value. This problem could be fixed + * with a global or a per-semaphore critical section here. + * + * An equally approximate but IMO slightly riskier approach + * would be to keep a separate per-semaphore counter and + * decrement/increment it inside of sem_wait() and sem_post() + * etc using the Interlocked* functions. + */ if ( WaitForSingleObject( (*sem)->sem, 0 ) == WAIT_TIMEOUT ) - { - /* Failed - must be zero. */ - value = 0; - } + { + /* Failed - must be zero */ + value = 0; + } else - { - /* Decremented sema - release it and note the value. */ - (void) ReleaseSemaphore( (*sem)->sem, 1L, &value ); - value++; - } - + { + /* Decremented semaphore - release it and note the value */ + (void) ReleaseSemaphore( (*sem)->sem, 1L, &value); + value++; + } + #endif } - - + + if ( result != 0 ) { errno = result; @@ -115,5 +145,5 @@ sem_getvalue(sem_t * sem, int * sval) *sval = value; return 0; - + } /* sem_getvalue */ @@ -11,32 +11,32 @@ * * ------------------------------------------------------------- * - * Pthreads-win32 - POSIX Threads Library for Win32 - * Copyright(C) 1998 John E. Bossom - * Copyright(C) 1999,2002 Pthreads-win32 contributors + * Pthreads-win32 - POSIX Threads Library for Win32 + * Copyright(C) 1998 John E. Bossom + * Copyright(C) 1999,2002 Pthreads-win32 contributors * - * Contact Email: rpj@ise.canberra.edu.au + * Contact Email: rpj@ise.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 + * 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 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. + * 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 + * 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 @@ -126,17 +126,17 @@ sem_init (sem_t * sem, int pshared, unsigned int value) { SetEvent(s->event); } - + InitializeCriticalSection(&s->sem_lock_cs); } } - + #else /* NEED_SEM */ - s->sem = CreateSemaphore (NULL, /* Always NULL */ - value, /* Initial value */ - _POSIX_SEM_VALUE_MAX, /* Maximum value */ - NULL); /* Name */ + s->sem = CreateSemaphore (NULL, /* Always NULL */ + (long) value, /* Initial value */ + (long) _POSIX_SEM_VALUE_MAX, /* Maximum value */ + NULL); /* Name */ if (0 == s->sem) { diff --git a/tests/semaphore2.c b/tests/semaphore2.c index 133443c..855662f 100644 --- a/tests/semaphore2.c +++ b/tests/semaphore2.c @@ -46,13 +46,13 @@ * - * * Cases Tested: - * - + * - * * Description: - * - + * - * * Environment: - * - + * - * * Input: * - None. @@ -62,7 +62,7 @@ * - No output on success. * * Assumptions: - * - + * - * * Pass Criteria: * - Process returns zero exit status. @@ -73,30 +73,33 @@ #include "test.h" -#define BIG_NUM 10000 +#define MAX_COUNT 100000 int main() { sem_t s; int value = 0; - int result; + int i; - assert(sem_init(&s, PTHREAD_PROCESS_PRIVATE, BIG_NUM) == 0); - assert((result = sem_getvalue(&s, &value)) == 0); - assert(value == BIG_NUM); + assert(sem_init(&s, PTHREAD_PROCESS_PRIVATE, MAX_COUNT) == 0); + assert(sem_getvalue(&s, &value) == 0); + assert(value == MAX_COUNT); +// printf("Value = %ld\n", value); - for (i = BIG_NUM - 1; i >= 0; i--) + for (i = MAX_COUNT - 1; i >= 0; i--) { assert(sem_wait(&s) == 0); - assert((result = sem_getvalue(&s, &value)) == 0); + assert(sem_getvalue(&s, &value) == 0); +// printf("Value = %ld\n", value); assert(value == i); } - for (i = 1; i <= BIG_NUM; i--) + for (i = 1; i <= MAX_COUNT; i++) { assert(sem_post(&s) == 0); - assert((result = sem_getvalue(&s, &value)) == 0); + assert(sem_getvalue(&s, &value) == 0); +// printf("Value = %ld\n", value); assert(value == i); } |