/* * pthread_mutex_timedlock.c * * Description: * This translation unit implements mutual exclusion (mutex) primitives. * * -------------------------------------------------------------------------- * * Pthreads-win32 - POSIX Threads Library for Win32 * Copyright(C) 1998 John E. Bossom * Copyright(C) 1999,2003 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 "implement.h" static INLINE int ptw32_timed_semwait (sem_t * sem, const struct timespec *abstime) /* * ------------------------------------------------------ * DESCRIPTION * This function waits on a POSIX 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 abstime. * If abstime has passed when this routine is called then * it returns a result to indicate this. * * If 'abstime' is a NULL pointer then this function will * block until it can successfully decrease the value or * until interrupted by a signal. * * Unlike sem_timedwait(), this routine is not a cancelation point. * * Unlike sem_timedwait(), this routine is non-cancelable. * * RESULTS * 2 abstime has passed already * 1 abstime timed out while waiting * 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; #ifdef NEED_FTIME struct timespec currSysTime; #else /* NEED_FTIME */ struct _timeb currSysTime; #endif /* NEED_FTIME */ const DWORD NANOSEC_PER_MILLISEC = 1000000; const DWORD MILLISEC_PER_SEC = 1000; DWORD milliseconds; DWORD status; if (sem == NULL) { result = EINVAL; } else { if (abstime == NULL) { milliseconds = INFINITE; } else { /* * 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; #else /* NEED_FTIME */ _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) - currSysTime.millitm; #endif /* NEED_FTIME */ if (((int) milliseconds) < 0) { return 2; } } #ifdef NEED_SEM status = WaitForSingleObject ((*sem)->event, milliseconds); #else /* NEED_SEM */ status = WaitForSingleObject ((*sem)->sem, milliseconds); #endif if (status == WAIT_OBJECT_0) { #ifdef NEED_SEM ptw32_decrease_semaphore (sem); #endif /* NEED_SEM */ return 0; } else if (status == WAIT_TIMEOUT) { return 1; } else { result = EINVAL; } } if (result != 0) { errno = result; return -1; } return 0; } /* ptw32_timed_semwait */ int pthread_mutex_timedlock (pthread_mutex_t * mutex, const struct timespec *abstime) { LONG c; pthread_mutex_t mx; #ifdef NEED_SEM errno = ENOTSUP; return -1; #endif /* * Let the system deal with invalid pointers. */ /* * We do a quick check to see if we need to do more work * to initialise a static mutex. We check * again inside the guarded section of ptw32_mutex_check_need_init() * to avoid race conditions. */ if (*mutex >= PTHREAD_ERRORCHECK_MUTEX_INITIALIZER) { int result; if ((result = ptw32_mutex_check_need_init (mutex)) != 0) { return (result); } } mx = *mutex; if (mx->kind == PTHREAD_MUTEX_NORMAL) { if ((c = (LONG) PTW32_INTERLOCKED_COMPARE_EXCHANGE( (PTW32_INTERLOCKED_LPLONG) &mx->lock_idx, (PTW32_INTERLOCKED_LONG) 0, (PTW32_INTERLOCKED_LONG) -1)) != -1) { do { if (c == 1 || (LONG) PTW32_INTERLOCKED_COMPARE_EXCHANGE( (PTW32_INTERLOCKED_LPLONG) &mx->lock_idx, (PTW32_INTERLOCKED_LONG) 1, (PTW32_INTERLOCKED_LONG) 0) != -1) { switch (ptw32_timed_semwait (&mx->wait_sema, abstime)) { case 0: /* We got woken up so try get the lock again. */ { break; } case 1: /* Timed out. */ case 2: /* abstime passed before we started to wait. */ { return ETIMEDOUT; } default: { return errno; } } } } while ((c = (LONG) PTW32_INTERLOCKED_COMPARE_EXCHANGE( (PTW32_INTERLOCKED_LPLONG) &mx->lock_idx, (PTW32_INTERLOCKED_LONG) 1, (PTW32_INTERLOCKED_LONG) -1)) != -1); } } else { pthread_t self = pthread_self(); if ((c = (LONG) PTW32_INTERLOCKED_COMPARE_EXCHANGE( (PTW32_INTERLOCKED_LPLONG) &mx->lock_idx, (PTW32_INTERLOCKED_LONG) 0, (PTW32_INTERLOCKED_LONG) -1)) == -1) { mx->recursive_count = 1; mx->ownerThread = self; } else { if (pthread_equal (mx->ownerThread, self)) { if (mx->kind == PTHREAD_MUTEX_RECURSIVE) { mx->recursive_count++; } else { return EDEADLK; } } else { do { if (c == 1 || (LONG) PTW32_INTERLOCKED_COMPARE_EXCHANGE( (PTW32_INTERLOCKED_LPLONG) &mx->lock_idx, (PTW32_INTERLOCKED_LONG) 1, (PTW32_INTERLOCKED_LONG) 0) != -1) { switch (ptw32_timed_semwait (&mx->wait_sema, abstime)) { case 0: /* We got woken up so try get the lock again. */ { break; } case 1: /* Timed out. */ case 2: /* abstime passed before we started to wait. */ { return ETIMEDOUT; } default: { return errno; } } } } while ((c = (LONG) PTW32_INTERLOCKED_COMPARE_EXCHANGE( (PTW32_INTERLOCKED_LPLONG) &mx->lock_idx, (PTW32_INTERLOCKED_LONG) 1, (PTW32_INTERLOCKED_LONG) -1)) != -1); mx->recursive_count = 1; mx->ownerThread = self; } } } return 0; }