runtime: New lock/note implementation.

From-SVN: r181633

1 files changed, 42 insertions, 74 deletions

diff --git a/libgo/runtime/thread.c b/libgo/runtime/thread.c
index 822d5da..821668b 100644
--- a/libgo/runtime/thread.c
+++ b/libgo/runtime/thread.c
@@ -6,98 +6,66 @@
 #include "runtime.h"
 #include "go-assert.h"
 
-void
-runtime_initlock(Lock *l)
-{
-	l->key = 0;
-	if(sem_init(&l->sem, 0, 0) != 0)
-		runtime_throw("sem_init failed");
-}
+/* For targets which don't have the required sync support.  Really
+   these should be provided by gcc itself.  FIXME.  */
 
-// noinline so that runtime_lock doesn't have to split the stack.
-static void runtime_lock_full(Lock *l) __attribute__ ((noinline));
+#if !defined (HAVE_SYNC_BOOL_COMPARE_AND_SWAP_4) || !defined (HAVE_SYNC_FETCH_AND_ADD_4)
 
-static void
-runtime_lock_full(Lock *l)
-{
-	for(;;){
-		if(sem_wait(&l->sem) == 0)
-			return;
-		if(errno != EINTR)
-			runtime_throw("sem_wait failed");
-	}
-}
+static pthread_mutex_t sync_lock = PTHREAD_MUTEX_INITIALIZER;
 
-void
-runtime_lock(Lock *l)
-{
-	if(m != nil) {
-		if(m->locks < 0)
-			runtime_throw("lock count");
-		m->locks++;
-	}
-
-	if(runtime_xadd(&l->key, 1) > 1)	// someone else has it; wait
-		runtime_lock_full(l);
-}
+#endif
 
-static void runtime_unlock_full(Lock *l) __attribute__ ((noinline));
+#ifndef HAVE_SYNC_BOOL_COMPARE_AND_SWAP_4
 
-static void
-runtime_unlock_full(Lock *l)
-{
-	if(sem_post(&l->sem) != 0)
-		runtime_throw("sem_post failed");
-}
+_Bool
+__sync_bool_compare_and_swap_4 (uint32*, uint32, uint32)
+  __attribute__ ((visibility ("hidden")));
 
-void
-runtime_unlock(Lock *l)
+_Bool
+__sync_bool_compare_and_swap_4 (uint32* ptr, uint32 old, uint32 new)
 {
-	if(m != nil) {
-		m->locks--;
-		if(m->locks < 0)
-			runtime_throw("lock count");
-	}
-
-	if(runtime_xadd(&l->key, -1) > 0)	// someone else is waiting
-		runtime_unlock_full(l);
-}
+  int i;
+  _Bool ret;
 
-void
-runtime_destroylock(Lock *l)
-{
-	sem_destroy(&l->sem);
-}
+  i = pthread_mutex_lock (&sync_lock);
+  __go_assert (i == 0);
 
-#ifndef HAVE_SYNC_BOOL_COMPARE_AND_SWAP_4
+  if (*ptr != old)
+    ret = 0;
+  else
+    {
+      *ptr = new;
+      ret = 1;
+    }
 
-// For targets which don't have the required sync support.  Really
-// this should be provided by gcc itself.  FIXME.
+  i = pthread_mutex_unlock (&sync_lock);
+  __go_assert (i == 0);
 
-static pthread_mutex_t sync_lock = PTHREAD_MUTEX_INITIALIZER;
+  return ret;
+}
 
-_Bool
-__sync_bool_compare_and_swap_4(uint32*, uint32, uint32)
-  __attribute__((visibility("hidden")));
+#endif
 
-_Bool
-__sync_bool_compare_and_swap_4(uint32* ptr, uint32 old, uint32 new)
+#ifndef HAVE_SYNC_FETCH_AND_ADD_4
+
+uint32
+__sync_fetch_and_add_4 (uint32*, uint32)
+  __attribute__ ((visibility ("hidden")));
+
+uint32
+__sync_fetch_and_add_4 (uint32* ptr, uint32 add)
 {
   int i;
-  _Bool ret;
+  uint32 ret;
 
-  i = pthread_mutex_lock(&sync_lock);
-  __go_assert(i == 0);
+  i = pthread_mutex_lock (&sync_lock);
+  __go_assert (i == 0);
 
-  if(*ptr != old) {
-    ret = 0;
-  } else {
-    *ptr = new;
-    ret = 1;
-  }
+  ret = *ptr;
+  *ptr += add;
 
-  i = pthread_mutex_unlock(&sync_lock);
-  __go_assert(i == 0);
+  i = pthread_mutex_unlock (&sync_lock);
+  __go_assert (i == 0);
 
   return ret;
 }