runtime: New lock/note implementation.

From-SVN: r181633

1 files changed, 74 insertions, 0 deletions

diff --git a/libgo/runtime/thread-sema.c b/libgo/runtime/thread-sema.c
new file mode 100644
index 0000000..b0a6dc3
--- /dev/null
+++ b/libgo/runtime/thread-sema.c
@@ -0,0 +1,74 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "runtime.h"
+
+#include <errno.h>
+#include <stdlib.h>
+#include <time.h>
+#include <semaphore.h>
+
+/* Create a semaphore.  */
+
+uintptr
+runtime_semacreate(void)
+{
+  sem_t *p;
+
+  /* Call malloc rather than runtime_malloc.  This will allocate space
+     on the C heap.  We can't call runtime_malloc here because it
+     could cause a deadlock.  */
+  p = malloc (sizeof (sem_t));
+  if (sem_init (p, 0, 0) != 0)
+    runtime_throw ("sem_init");
+  return (uintptr) p;
+}
+
+/* Acquire m->waitsema.  */
+
+int32
+runtime_semasleep (int64 ns)
+{
+  int r;
+
+  if (ns >= 0)
+    {
+      struct timespec ts;
+
+      ns += runtime_nanotime ();
+      ts.tv_sec = ns / 1000000000LL;
+      ts.tv_nsec = ns % 1000000000LL;
+      r = sem_timedwait ((sem_t *) m->waitsema, &ts);
+      if (r != 0)
+	{
+	  if (errno == ETIMEDOUT || errno == EINTR)
+	    return -1;
+	  runtime_throw ("sema_timedwait");
+	}
+      return 0;
+    }
+
+  while (sem_wait ((sem_t *) m->waitsema) != 0)
+    {
+      if (errno == EINTR)
+	continue;
+      runtime_throw ("sem_wait");
+    }
+
+  return 0;
+}
+
+/* Wake up mp->waitsema.  */
+
+void
+runtime_semawakeup (M *mp)
+{
+  if (sem_post ((sem_t *) mp->waitsema) != 0)
+    runtime_throw ("sem_post");
+}
+
+void
+runtime_osinit(void)
+{
+}