mono/io-layer/critical-sections.c

   1 /*
   2  * critical-sections.c:  Critical sections
   3  *
   4  * Author:
   5  *      Dick Porter (dick@ximian.com)
   6  *
   7  * (C) 2002 Ximian, Inc.
   8  */
   9
  10 #include <config.h>
  11 #include <glib.h>
  12 #include <pthread.h>
  13 #include <errno.h>
  14
  15 #include <mono/io-layer/wapi.h>
  16 #include <mono/io-layer/critical-section-private.h>
  17
  18 #include <mono/utils/mono-mutex.h>
  19
  20 /* A critical section is really just like a lightweight mutex. It
  21  * can't be waited for, and doesn't have a handle.
  22  */
  23
  24 /**
  25  * InitializeCriticalSection:
  26  * @section: The critical section to initialise
  27  *
  28  * Initialises a critical section.
  29  */
  30 void InitializeCriticalSection(WapiCriticalSection *section)
  31 {
  32         int ret;
  33
  34         ret = mono_mutex_init_recursive (&section->mutex);
  35         g_assert (ret == 0);
  36 }
  37
  38 /**
  39  * InitializeCriticalSectionAndSpinCount:
  40  * @section: The critical section to initialise.
  41  * @spincount: The spin count for this critical section.  Not
  42  * currently used.
  43  *
  44  * Initialises a critical section and sets the spin count.  This
  45  * implementation just calls InitializeCriticalSection().
  46  *
  47  * Return value: %TRUE on success, %FALSE otherwise.  (%FALSE never
  48  * happens).
  49  */
  50 gboolean InitializeCriticalSectionAndSpinCount(WapiCriticalSection *section,
  51                                                guint32 spincount G_GNUC_UNUSED)
  52 {
  53         InitializeCriticalSection(section);
  54
  55         return(TRUE);
  56 }
  57
  58 /**
  59  * DeleteCriticalSection:
  60  * @section: The critical section to delete.
  61  *
  62  * Releases all resources owned by critical section @section.
  63  */
  64 void DeleteCriticalSection(WapiCriticalSection *section)
  65 {
  66         int ret;
  67
  68         ret = mono_mutex_destroy(&section->mutex);
  69         if (ret)
  70                 g_error ("Failed to destroy mutex %p error code %d errno %d", &section->mutex, ret, errno);
  71 }
  72
  73 /**
  74  * SetCriticalSectionSpinCount:
  75  * @section: The critical section to set
  76  * @spincount: The new spin count for this critical section.  Not
  77  * currently used.
  78  *
  79  * Sets the spin count for the critical section @section.  The spin
  80  * count is currently ignored, and set to zero.
  81  *
  82  * Return value: The previous spin count.  (Currently always zero).
  83  */
  84 guint32 SetCriticalSectionSpinCount(WapiCriticalSection *section G_GNUC_UNUSED, guint32 spincount G_GNUC_UNUSED)
  85 {
  86         return(0);
  87 }
  88
  89 /**
  90  * TryEnterCriticalSection:
  91  * @section: The critical section to try and enter
  92  *
  93  * Attempts to enter a critical section without blocking.  If
  94  * successful the calling thread takes ownership of the critical
  95  * section.
  96  *
  97  * A thread can recursively call EnterCriticalSection() and
  98  * TryEnterCriticalSection(), but must call LeaveCriticalSection() an
  99  * equal number of times.
 100  *
 101  * Return value: %TRUE if the thread successfully locked the critical
 102  * section, %FALSE otherwise.
 103  */
 104 gboolean TryEnterCriticalSection(WapiCriticalSection *section)
 105 {
 106         int ret;
 107
 108         ret=mono_mutex_trylock(&section->mutex);
 109         if(ret==0) {
 110                 return(TRUE);
 111         } else {
 112                 return(FALSE);
 113         }
 114 }
 115