From ce4f3efd78c110c015c54eab05f201d1caac5f8d Mon Sep 17 00:00:00 2001 From: Guenter Bartsch Date: Sun, 20 Apr 2003 16:42:06 +0000 Subject: importing win32 contrib sources and msvc build environment CVS patchset: 4641 CVS date: 2003/04/20 16:42:06 --- win32/contrib/pthreads/semaphore.c | 557 +++++++++++++++++++++++++++++++++++++ 1 file changed, 557 insertions(+) create mode 100644 win32/contrib/pthreads/semaphore.c (limited to 'win32/contrib/pthreads/semaphore.c') diff --git a/win32/contrib/pthreads/semaphore.c b/win32/contrib/pthreads/semaphore.c new file mode 100644 index 000000000..2f43d05c9 --- /dev/null +++ b/win32/contrib/pthreads/semaphore.c @@ -0,0 +1,557 @@ +/* + * ------------------------------------------------------------- + * + * Module: semaphore.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 + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library 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 + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, + * MA 02111-1307, USA + */ + +/* ignore warning "unreferenced formal parameter" */ +#ifdef _MSC_VER +#pragma warning( disable : 4100 ) +#endif + +#include "pthread.h" +#include "semaphore.h" +#include "implement.h" + +int +sem_init (sem_t * sem, int pshared, unsigned int value) + /* + * ------------------------------------------------------ + * DOCPUBLIC + * This function initializes an unnamed semaphore. the + * initial value of the semaphore is 'value' + * + * PARAMETERS + * sem + * pointer to an instance of sem_t + * + * pshared + * if zero, this semaphore may only be shared between + * threads in the same process. + * if nonzero, the semaphore can be shared between + * processes + * + * value + * initial value of the semaphore counter + * + * DESCRIPTION + * This function initializes an unnamed semaphore. The + * initial value of the semaphore is set to 'value'. + * + * RESULTS + * 0 successfully created semaphore, + * -1 failed, error in errno + * ERRNO + * EINVAL 'sem' is not a valid semaphore, + * ENOSPC a required resource has been exhausted, + * ENOSYS semaphores are not supported, + * EPERM the process lacks appropriate privilege + * + * ------------------------------------------------------ + */ +{ + int result = 0; + sem_t s; + + if (pshared != 0) + { + /* + * Creating a semaphore that can be shared between + * processes + */ + result = EPERM; + + } + else + { + s = (sem_t) calloc (1, sizeof (*s)); + +#ifdef NEED_SEM + + if (NULL == s) + { + result = ENOMEM; + } + else + { + s->value = value; + s->event = CreateEvent (NULL, + FALSE, /* manual reset */ + FALSE, /* initial state */ + NULL); + if (0 == s->Event) + { + result = ENOSPC; + } + else + { + if (value != 0) + { + SetEvent(s->event); + } + + InitializeCriticalSection(&s->sem_lock_cs); + } + +#else /* NEED_SEM */ + + s->sem = CreateSemaphore (NULL, /* Always NULL */ + value, /* Initial value */ + 0x7FFFFFFFL, /* Maximum value */ + NULL); /* Name */ + + if (0 == s->sem) + { + result = ENOSPC; + } + +#endif /* NEED_SEM */ + + } + + if (result != 0) + { + errno = result; + return -1; + } + + *sem = s; + + return 0; + +} /* sem_init */ + + +int +sem_destroy (sem_t * sem) + /* + * ------------------------------------------------------ + * DOCPUBLIC + * This function destroys an unnamed semaphore. + * + * PARAMETERS + * sem + * pointer to an instance of sem_t + * + * DESCRIPTION + * This function destroys an unnamed semaphore. + * + * RESULTS + * 0 successfully destroyed semaphore, + * -1 failed, error in errno + * ERRNO + * EINVAL 'sem' is not a valid semaphore, + * ENOSYS semaphores are not supported, + * EBUSY threads (or processes) are currently + * blocked on 'sem' + * + * ------------------------------------------------------ + */ +{ + int result = 0; + sem_t s; + + if (sem == NULL || *sem == NULL) + { + result = EINVAL; + } + else + { + s = *sem; + *sem = NULL; + +#ifdef NEED_SEM + + if (! CloseHandle(s->event)) + { + *sem = s; + result = EINVAL; + } + else + { + DeleteCriticalSection(&s->sem_lock_cs); + free(s); + } + +#else /* NEED_SEM */ + + if (! CloseHandle (s->sem)) + { + *sem = s; + result = EINVAL; + } + +#endif /* NEED_SEM */ + + } + + if (result != 0) + { + errno = result; + return -1; + } + + return 0; + +} /* sem_destroy */ + + +int +sem_trywait (sem_t * sem) + /* + * ------------------------------------------------------ + * DOCPUBLIC + * This function tries to wait on a semaphore. + * + * PARAMETERS + * sem + * pointer to an instance of sem_t + * + * DESCRIPTION + * This function tries to wait on a semaphore. If the + * semaphore value is greater than zero, it decreases + * its value by one. If the semaphore value is zero, then + * this function returns immediately with the error EAGAIN + * + * RESULTS + * 0 successfully decreased semaphore, + * -1 failed, error in errno + * ERRNO + * EAGAIN the semaphore was already locked, + * 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. + * + * ------------------------------------------------------ + */ +{ +#ifdef NEED_SEM + + /* + * not yet implemented! + */ + int result = EINVAL; + return -1; + +#else /* NEED_SEM */ + + int result = 0; + + if (sem == NULL || *sem == NULL) + { + result = EINVAL; + } + else if (WaitForSingleObject ((*sem)->sem, 0) == WAIT_TIMEOUT) + { + result = EAGAIN; + } + + if (result != 0) + { + errno = result; + return -1; + } + + return 0; + +#endif /* NEED_SEM */ + +} /* sem_trywait */ + + +#ifdef NEED_SEM + +void +ptw32_decrease_semaphore(sem_t * sem) +{ + register sem_t s = *sem; + + EnterCriticalSection(&s->sem_lock_cs); + + if (s->value != 0) + { + s->value--; + if (s->value != 0) + { + SetEvent(s->event); + } + } + else + { + /* this case should not happen! */ + } + + LeaveCriticalSection(&s->sem_lock_cs); +} + +BOOL +ptw32_increase_semaphore(sem_t * sem, unsigned int n) +{ + BOOL result; + register sem_t s = *sem; + + EnterCriticalSection(&s->sem_lock_cs); + + if (s->value + n > s->value) + { + s->value += n; + SetEvent(s->event); + result = TRUE; + } + else + { + result = FALSE; + } + + LeaveCriticalSection(&s->sem_lock_cs); + return result; +} + +#endif /* NEED_SEM */ + +int +sem_wait (sem_t * sem) + /* + * ------------------------------------------------------ + * DOCPUBLIC + * This function waits on a semaphore. + * + * PARAMETERS + * sem + * pointer to an instance of sem_t + * + * 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. + * + * 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. + * + * ------------------------------------------------------ + */ +{ + int result = 0; + + if (sem == NULL || *sem == NULL) + { + result = EINVAL; + } + else + { + +#ifdef NEED_SEM + + result = pthreadCancelableWait ((*sem)->event); + +#else /* NEED_SEM */ + + result = pthreadCancelableWait ((*sem)->sem); + +#endif /* NEED_SEM */ + + } + + if (result != 0) + { + errno = result; + return -1; + } + +#ifdef NEED_SEM + + ptw32_decrease_semaphore(sem); + +#endif /* NEED_SEM */ + + return 0; + +} /* sem_wait */ + + +int +sem_post (sem_t * sem) + /* + * ------------------------------------------------------ + * DOCPUBLIC + * This function posts a wakeup to a semaphore. + * + * PARAMETERS + * sem + * pointer to an instance of sem_t + * + * DESCRIPTION + * This function posts a wakeup to a semaphore. If there + * are waiting threads (or processes), one is awakened; + * otherwise, the semaphore value is incremented by one. + * + * RESULTS + * 0 successfully posted semaphore, + * -1 failed, error in errno + * ERRNO + * EINVAL 'sem' is not a valid semaphore, + * ENOSYS semaphores are not supported, + * + * ------------------------------------------------------ + */ +{ + int result = 0; + + if (sem == NULL || *sem == NULL) + { + result = EINVAL; + } + +#ifdef NEED_SEM + + else if (! ptw32_increase_semaphore (sem, 1)) + +#else /* NEED_SEM */ + + else if (! ReleaseSemaphore ((*sem)->sem, 1, 0)) + +#endif /* NEED_SEM */ + + { + result = EINVAL; + } + + if (result != 0) + { + errno = result; + return -1; + } + + return 0; + +} /* sem_post */ + + +int +sem_post_multiple (sem_t * sem, int count ) + /* + * ------------------------------------------------------ + * DOCPUBLIC + * This function posts multiple wakeups to a semaphore. + * + * PARAMETERS + * sem + * pointer to an instance of sem_t + * + * count + * counter, must be greater than zero. + * + * DESCRIPTION + * This function posts multiple wakeups to a semaphore. If there + * are waiting threads (or processes), n <= count are awakened; + * the semaphore value is incremented by count - n. + * + * RESULTS + * 0 successfully posted semaphore, + * -1 failed, error in errno + * ERRNO + * EINVAL 'sem' is not a valid semaphore + * or count is less than or equal to zero. + * + * ------------------------------------------------------ + */ +{ + int result = 0; + + if (sem == NULL || *sem == NULL || count <= 0) + { + result = EINVAL; + } + +#ifdef NEED_SEM + + else if (! ptw32_increase_semaphore (sem, count)) + +#else /* NEED_SEM */ + + else if (! ReleaseSemaphore ((*sem)->sem, count, 0)) + +#endif /* NEED_SEM */ + + { + result = EINVAL; + } + + if (result != 0) + { + errno = result; + return -1; + } + + return 0; + +} /* sem_post_multiple */ + + +int +sem_open (const char * name, int oflag, mode_t mode, unsigned int value) +{ + errno = ENOSYS; + return -1; +} /* sem_open */ + + +int +sem_close (sem_t * sem) +{ + errno = ENOSYS; + return -1; +} /* sem_close */ + + +int +sem_unlink (const char * name) +{ + errno = ENOSYS; + return -1; +} /* sem_unlink */ + + +int +sem_getvalue (sem_t * sem, int * sval) +{ + errno = ENOSYS; + return -1; +} /* sem_getvalue */ + -- cgit v1.2.3