summaryrefslogtreecommitdiff
path: root/libgo/runtime/go-note.c
diff options
context:
space:
mode:
authorupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
committerupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
commit554fd8c5195424bdbcabf5de30fdc183aba391bd (patch)
tree976dc5ab7fddf506dadce60ae936f43f58787092 /libgo/runtime/go-note.c
downloadcbb-gcc-4.6.4-upstream.tar.bz2
cbb-gcc-4.6.4-upstream.tar.xz
obtained gcc-4.6.4.tar.bz2 from upstream website;upstream
verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository.
Diffstat (limited to 'libgo/runtime/go-note.c')
-rw-r--r--libgo/runtime/go-note.c74
1 files changed, 74 insertions, 0 deletions
diff --git a/libgo/runtime/go-note.c b/libgo/runtime/go-note.c
new file mode 100644
index 000000000..3b750f30e
--- /dev/null
+++ b/libgo/runtime/go-note.c
@@ -0,0 +1,74 @@
+/* go-note.c -- implement notesleep, notewakeup and noteclear.
+
+ 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. */
+
+/* A note is a one-time notification. noteclear clears the note.
+ notesleep waits for a call to notewakeup. notewakeup wakes up
+ every thread waiting on the note. */
+
+#include "go-assert.h"
+#include "runtime.h"
+
+/* We use a single global lock and condition variable. It would be
+ better to use a futex on Linux. */
+
+static pthread_mutex_t note_lock = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t note_cond = PTHREAD_COND_INITIALIZER;
+
+/* noteclear is called before any calls to notesleep or
+ notewakeup. */
+
+void
+noteclear (Note* n)
+{
+ int32 i;
+
+ i = pthread_mutex_lock (&note_lock);
+ __go_assert (i == 0);
+
+ n->woken = 0;
+
+ i = pthread_mutex_unlock (&note_lock);
+ __go_assert (i == 0);
+}
+
+/* Wait until notewakeup is called. */
+
+void
+notesleep (Note* n)
+{
+ int32 i;
+
+ i = pthread_mutex_lock (&note_lock);
+ __go_assert (i == 0);
+
+ while (!n->woken)
+ {
+ i = pthread_cond_wait (&note_cond, &note_lock);
+ __go_assert (i == 0);
+ }
+
+ i = pthread_mutex_unlock (&note_lock);
+ __go_assert (i == 0);
+}
+
+/* Wake up every thread sleeping on the note. */
+
+void
+notewakeup (Note *n)
+{
+ int32 i;
+
+ i = pthread_mutex_lock (&note_lock);
+ __go_assert (i == 0);
+
+ n->woken = 1;
+
+ i = pthread_cond_broadcast (&note_cond);
+ __go_assert (i == 0);
+
+ i = pthread_mutex_unlock (&note_lock);
+ __go_assert (i == 0);
+}