1 files changed, 103 insertions, 0 deletions
diff --git a/mysys/my_semaphore.c b/mysys/my_semaphore.c
new file mode 100644
index 00000000000..de4aac1cdbd
--- /dev/null
+++ b/mysys/my_semaphore.c
@@ -0,0 +1,103 @@
+/* Copyright (C) 2002 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program 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 General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+/*
+  Simple implementation of semaphores, needed to compile MySQL on systems
+  that doesn't support semaphores.
+*/
+
+#include <my_global.h>
+#include <my_semaphore.h>
+
+#if !defined(__WIN__) && !defined(HAVE_SEMAPHORE_H)
+
+int sem_init(sem_t * sem, int pshared, uint value)
+{
+  sem->count=value;
+  pthread_cond_init(&sem->cond, 0);
+  pthread_mutex_init(&sem->mutex, 0);
+  return 0;
+}
+
+int sem_destroy(sem_t * sem)
+{
+  int err1,err2;
+  err1=pthread_cond_destroy(&sem->cond);
+  err2=pthread_mutex_destroy(&sem->mutex);
+  if (err1 || err2)
+  {
+    errno=err1 ? err1 : err2;
+    return -1;
+  }
+  return 0;
+}
+
+int sem_wait(sem_t * sem)
+{
+  if ((errno=pthread_mutex_lock(&sem->mutex)))
+    return -1;
+  while (!sem->count)
+    pthread_cond_wait(&sem->cond, &sem->mutex);
+  if (errno)
+    return -1;
+  sem->count--; /* mutex is locked here */
+  pthread_mutex_unlock(&sem->mutex);
+  return 0;
+}
+
+int sem_trywait(sem_t * sem)
+{
+  if ((errno=pthread_mutex_lock(&sem->mutex)))
+    return -1;
+  if (sem->count)
+    sem->count--;
+  else
+    errno=EAGAIN;
+  pthread_mutex_unlock(&sem->mutex);
+  return errno ? -1 : 0;
+}
+
+
+int sem_post(sem_t * sem)
+{
+  if ((errno=pthread_mutex_lock(&sem->mutex)))
+    return -1;
+  sem->count++;
+  pthread_mutex_unlock(&sem->mutex);    /* does it really matter what to do */
+  pthread_cond_signal(&sem->cond);      /* first: x_unlock or x_signal ?    */
+  return 0;
+}
+
+int sem_post_multiple(sem_t * sem, uint count)
+{
+  if ((errno=pthread_mutex_lock(&sem->mutex)))
+    return -1;
+  sem->count+=count;
+  pthread_mutex_unlock(&sem->mutex);    /* does it really matter what to do */
+  pthread_cond_broadcast(&sem->cond);   /* first: x_unlock or x_broadcast ? */
+  return 0;
+}
+
+int sem_getvalue(sem_t * sem, uint *sval)
+{
+  if ((errno=pthread_mutex_lock(&sem->mutex)))
+    return -1;
+  *sval=sem->count;
+  pthread_mutex_unlock(&sem->mutex);
+  return 0;
+}
+
+#endif /* !defined(__WIN__) && !defined(HAVE_SEMAPHORE_H) */