summaryrefslogtreecommitdiff
path: root/deps/uv/src/unix/spinlock.h
diff options
context:
space:
mode:
authorTimothy J Fontaine <tjfontaine@gmail.com>2013-10-29 16:33:17 -0700
committerTimothy J Fontaine <tjfontaine@gmail.com>2013-10-29 16:33:17 -0700
commita35a212f258812bd178f7f002660a0ddc0bf10b2 (patch)
tree32a27fca226d843207ccb93f08b5d12cd6b53ac6 /deps/uv/src/unix/spinlock.h
parent613d76ef6a00ec091367de1e63bc51e3ab672cbd (diff)
downloadandroid-node-v8-a35a212f258812bd178f7f002660a0ddc0bf10b2.tar.gz
android-node-v8-a35a212f258812bd178f7f002660a0ddc0bf10b2.tar.bz2
android-node-v8-a35a212f258812bd178f7f002660a0ddc0bf10b2.zip
uv: Upgrade to v0.11.14
Diffstat (limited to 'deps/uv/src/unix/spinlock.h')
-rw-r--r--deps/uv/src/unix/spinlock.h53
1 files changed, 53 insertions, 0 deletions
diff --git a/deps/uv/src/unix/spinlock.h b/deps/uv/src/unix/spinlock.h
new file mode 100644
index 0000000000..a20c83cc60
--- /dev/null
+++ b/deps/uv/src/unix/spinlock.h
@@ -0,0 +1,53 @@
+/* Copyright (c) 2013, Ben Noordhuis <info@bnoordhuis.nl>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef UV_SPINLOCK_H_
+#define UV_SPINLOCK_H_
+
+#include "internal.h" /* ACCESS_ONCE, UV_UNUSED */
+#include "atomic-ops.h"
+
+#define UV_SPINLOCK_INITIALIZER { 0 }
+
+typedef struct {
+ int lock;
+} uv_spinlock_t;
+
+UV_UNUSED(static void uv_spinlock_init(uv_spinlock_t* spinlock));
+UV_UNUSED(static void uv_spinlock_lock(uv_spinlock_t* spinlock));
+UV_UNUSED(static void uv_spinlock_unlock(uv_spinlock_t* spinlock));
+UV_UNUSED(static int uv_spinlock_trylock(uv_spinlock_t* spinlock));
+
+UV_UNUSED(static void uv_spinlock_init(uv_spinlock_t* spinlock)) {
+ ACCESS_ONCE(int, spinlock->lock) = 0;
+}
+
+UV_UNUSED(static void uv_spinlock_lock(uv_spinlock_t* spinlock)) {
+ while (!uv_spinlock_trylock(spinlock)) cpu_relax();
+}
+
+UV_UNUSED(static void uv_spinlock_unlock(uv_spinlock_t* spinlock)) {
+ ACCESS_ONCE(int, spinlock->lock) = 0;
+}
+
+UV_UNUSED(static int uv_spinlock_trylock(uv_spinlock_t* spinlock)) {
+ /* TODO(bnoordhuis) Maybe change to a ticket lock to guarantee fair queueing.
+ * Not really critical until we have locks that are (frequently) contended
+ * for by several threads.
+ */
+ return 0 == cmpxchgi(&spinlock->lock, 0, 1);
+}
+
+#endif /* UV_SPINLOCK_H_ */