Ticket #69517: npth-patch-for-tiger-leopard.diff

configure.ac

@@ -175 +175 @@
     *-apple-darwin*)
         AC_SEARCH_LIBS([dispatch_semaphore_create],[dispatch],
         [AC_DEFINE([HAVE_LIB_DISPATCH],1,[Defined if we have libdispatch])])
+        if test "$ac_cv_search_dispatch_semaphore_create" = no; then
+           AC_DEFINE(HAVE_NO_POSIX_SEMAPHORE,1,[Define if no good semaphore.])
+        fi
         ;;
     *-*-aix*)
         have_fork_unsafe_semaphore=yes

src/npth.c

@@ -62 +62 @@
   dispatch_semaphore_wait (*sem, DISPATCH_TIME_FOREVER);
   return 0;
 }
+#elif HAVE_NO_POSIX_SEMAPHORE
+/* Fallback implementation without POSIX semaphore,
+   for a system like MacOS Tiger */
+typedef struct {
+  pthread_mutex_t mutex;
+  pthread_cond_t cond;
+  unsigned int value;
+} sem_t;
+
+static int
+sem_init (sem_t *sem, int is_shared, unsigned int value)
+{
+  int r;
+
+  (void)is_shared;              /* Not supported.  */
+  r = pthread_mutex_init (&sem->mutex, NULL);
+  if (r)
+    return r;
+  r = pthread_cond_init (&sem->cond, NULL);
+  if (r)
+    return r;
+  sem->value = value;
+  return 0;
+}
+
+static int
+sem_post (sem_t *sem)
+{
+  int r;
+
+  r = pthread_mutex_lock (&sem->mutex);
+  if (r)
+    return r;
+
+  sem->value++;
+  pthread_cond_signal (&sem->cond);
+
+  r = pthread_mutex_unlock (&sem->mutex);
+  if (r)
+    return r;
+  return 0;
+}
+
+static int
+sem_wait (sem_t *sem)
+{
+  int r;
+
+  r = pthread_mutex_lock (&sem->mutex);
+  if (r)
+    return r;
+
+  while (sem->value == 0)
+    pthread_cond_wait (&sem->cond, &sem->mutex);
+  sem->value--;
+
+  r = pthread_mutex_unlock (&sem->mutex);
+  if (r)
+    return r;
+  return 0;
+}
 #else
 # include <semaphore.h>
 #endif