src/thread-utils.h

   1 #ifndef INCLUDE_thread_utils_h__
   2 #define INCLUDE_thread_utils_h__
   3
   4 #if defined(GIT_HAS_PTHREAD)
   5         typedef pthread_t git_thread;
   6 #       define git_thread_create(thread, attr, start_routine, arg) pthread_create(thread, attr, start_routine, arg)
   7 #       define git_thread_kill(thread) pthread_cancel(thread)
   8 #       define git_thread_exit(status)  pthread_exit(status)
   9 #       define git_thread_join(id, status) pthread_join(id, status)
  10
  11         /* Pthreads Mutex */
  12         typedef pthread_mutex_t git_lck;
  13 #       define GITLCK_INIT      PTHREAD_MUTEX_INITIALIZER
  14 #       define gitlck_init(a)   pthread_mutex_init(a, NULL)
  15 #       define gitlck_lock(a)   pthread_mutex_lock(a)
  16 #       define gitlck_unlock(a) pthread_mutex_unlock(a)
  17 #       define gitlck_free(a)   pthread_mutex_destroy(a)
  18
  19         /* Pthreads condition vars */
  20         typedef pthread_cond_t git_cnd;
  21 #       define GITCND_INIT                      PTHREAD_COND_INITIALIZER
  22 #       define gitcnd_init(c, a)        pthread_cond_init(c, a)
  23 #       define gitcnd_free(c)           pthread_cond_destroy(c)
  24 #       define gitcnd_wait(c, l)        pthread_cond_wait(c, l)
  25 #       define gitcnd_signal(c)         pthread_cond_signal(c)
  26 #       define gitcnd_broadcast(c)      pthread_cond_broadcast(c)
  27
  28 #       if defined(GIT_HAS_ASM_ATOMIC)
  29 #               include <asm/atomic.h>
  30                 typedef atomic_t git_refcnt;
  31 #               define gitrc_init(a, v) atomic_set(a, v)
  32 #               define gitrc_inc(a)             atomic_inc_return(a)
  33 #               define gitrc_dec(a)             atomic_dec_and_test(a)
  34 #               define gitrc_free(a)    (void)0
  35 #       elif defined(GIT_WIN32)
  36                 typedef long git_refcnt;
  37 #               define gitrc_init(a, v) (*a = v)
  38 #               define gitrc_inc(a)             (InterlockedIncrement(a))
  39 #               define gitrc_dec(a)             (!InterlockedDecrement(a))
  40 #               define gitrc_free(a)    (void)0
  41 #       else
  42                 typedef struct { git_lck lock; int counter; } git_refcnt;
  43
  44                 /** Initialize to 0.  No memory barrier is issued. */
  45                 GIT_INLINE(void) gitrc_init(git_refcnt *p, int value)
  46                 {
  47                         gitlck_init(&p->lock);
  48                         p->counter = value;
  49                 }
  50
  51                 /**
  52                  * Increment.
  53                  *
  54                  * Atomically increments @p by 1.  A memory barrier is also
  55                  * issued before and after the operation.
  56                  *
  57                  * @param p pointer of type git_refcnt
  58                  */
  59                 GIT_INLINE(void) gitrc_inc(git_refcnt *p)
  60                 {
  61                         gitlck_lock(&p->lock);
  62                         p->counter++;
  63                         gitlck_unlock(&p->lock);
  64                 }
  65
  66                 /**
  67                  * Decrement and test.
  68                  *
  69                  * Atomically decrements @p by 1 and returns true if the
  70                  * result is 0, or false for all other cases.  A memory
  71                  * barrier is also issued before and after the operation.
  72                  *
  73                  * @param p pointer of type git_refcnt
  74                  */
  75                 GIT_INLINE(int) gitrc_dec(git_refcnt *p)
  76                 {
  77                         int c;
  78                         gitlck_lock(&p->lock);
  79                         c = --p->counter;
  80                         gitlck_unlock(&p->lock);
  81                         return !c;
  82                 }
  83
  84                 /** Free any resources associated with the counter. */
  85 #               define gitrc_free(p) gitlck_free(&(p)->lock)
  86 #       endif
  87
  88 #elif defined(GIT_THREADS)
  89 #       error GIT_THREADS but no git_lck implementation
  90
  91 #else
  92         /* no threads support */
  93         typedef struct { int dummy; } git_lck;
  94 #       define GIT_MUTEX_INIT   {}
  95 #       define gitlck_init(a)   (void)0
  96 #       define gitlck_lock(a)   (void)0
  97 #       define gitlck_unlock(a) (void)0
  98 #       define gitlck_free(a)   (void)0
  99
 100         typedef struct { int counter; } git_refcnt;
 101 #       define gitrc_init(a,v) ((a)->counter = v)
 102 #       define gitrc_inc(a)    ((a)->counter++)
 103 #       define gitrc_dec(a)    (--(a)->counter == 0)
 104 #       define gitrc_free(a)   (void)0
 105 #endif
 106
 107 extern int git_online_cpus(void);
 108
 109 #endif /* INCLUDE_thread_utils_h__ */