mono/utils/mono-semaphore.c

   1 /*
   2  * mono-semaphore.c: mono-semaphore functions
   3  *
   4  * Author:
   5  *      Gonzalo Paniagua Javier  <gonzalo@novell.com>
   6  *
   7  * (C) 2010 Novell, Inc.
   8  */
   9
  10 #include <config.h>
  11 #include <errno.h>
  12 #include "utils/mono-semaphore.h"
  13 #ifdef HAVE_SYS_TIME_H
  14 #include <sys/time.h>
  15 #endif
  16 #ifdef HAVE_UNISTD_H
  17 #include <unistd.h>
  18 #endif
  19
  20 #if (defined(HAVE_SEMAPHORE_H) || defined(USE_MACH_SEMA))
  21 /* sem_* or semaphore_* functions in use */
  22 #  ifdef USE_MACH_SEMA
  23 #    define TIMESPEC mach_timespec_t
  24 #    define WAIT_BLOCK(a,b) semaphore_timedwait (*(a), *(b))
  25 #  elif defined(__OpenBSD__)
  26 #    define TIMESPEC struct timespec
  27 #    define WAIT_BLOCK(a) sem_trywait(a)
  28 #  else
  29 #    define TIMESPEC struct timespec
  30 #    define WAIT_BLOCK(a,b) sem_timedwait (a, b)
  31 #  endif
  32
  33 int
  34 mono_sem_timedwait (MonoSemType *sem, guint32 timeout_ms, gboolean alertable)
  35 {
  36         TIMESPEC ts, copy;
  37         struct timeval t;
  38         int res = 0;
  39 #if defined(__OpenBSD__)
  40         int timeout;
  41 #endif
  42
  43 #ifndef USE_MACH_SEMA
  44         if (timeout_ms == 0)
  45                 return (!sem_trywait (sem));
  46 #endif
  47         if (timeout_ms == (guint32) 0xFFFFFFFF)
  48                 return mono_sem_wait (sem, alertable);
  49
  50         gettimeofday (&t, NULL);
  51         ts.tv_sec = timeout_ms / 1000 + t.tv_sec;
  52         ts.tv_nsec = (timeout_ms % 1000) * 1000000 + t.tv_usec * 1000;
  53         while (ts.tv_nsec > 1000000000) {
  54                 ts.tv_nsec -= 1000000000;
  55                 ts.tv_sec++;
  56         }
  57 #if defined(__OpenBSD__)
  58         timeout = ts.tv_sec;
  59         while (timeout) {
  60                 if ((res = WAIT_BLOCK (sem)) == 0)
  61                         return res;
  62
  63                 if (alertable)
  64                         return -1;
  65
  66                 usleep (ts.tv_nsec / 1000);
  67                 timeout--;
  68         }
  69 #else
  70         copy = ts;
  71         while ((res = WAIT_BLOCK (sem, &ts) == -1) && errno == EINTR) {
  72                 if (alertable)
  73                         return -1;
  74                 ts = copy;
  75         }
  76 #endif
  77         return res;
  78 }
  79
  80 int
  81 mono_sem_wait (MonoSemType *sem, gboolean alertable)
  82 {
  83         int res;
  84 #ifndef USE_MACH_SEMA
  85         while ((res = sem_wait (sem) == -1) && errno == EINTR)
  86 #else
  87         while ((res = semaphore_wait (*sem) == -1) && errno == EINTR)
  88 #endif
  89         {
  90                 if (alertable)
  91                         return -1;
  92         }
  93         return res;
  94 }
  95
  96 int
  97 mono_sem_post (MonoSemType *sem)
  98 {
  99         int res;
 100 #ifndef USE_MACH_SEMA
 101         while ((res = sem_post (sem) == -1) && errno == EINTR);
 102 #else
 103         while ((res = semaphore_signal (*sem) == -1) && errno == EINTR);
 104 #endif
 105         return res;
 106 }
 107
 108 #else
 109 /* Windows or io-layer functions in use */
 110 int
 111 mono_sem_wait (MonoSemType *sem, gboolean alertable)
 112 {
 113         return mono_sem_timedwait (sem, INFINITE, alertable);
 114 }
 115
 116 int
 117 mono_sem_timedwait (MonoSemType *sem, guint32 timeout_ms, gboolean alertable)
 118 {
 119         gboolean res;
 120
 121         res = WaitForSingleObjectEx (*sem, timeout_ms, alertable);
 122         if (!res)
 123                 return -1;
 124         return 0;
 125 }
 126
 127 int
 128 mono_sem_post (MonoSemType *sem)
 129 {
 130         if (!ReleaseSemaphore (*sem, 1, NULL))
 131                 return -1;
 132         return 0;
 133 }
 134 #endif
 135