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-rw-r--r--gcc-4.9/libcilkrts/runtime/worker_mutex.c121
1 files changed, 121 insertions, 0 deletions
diff --git a/gcc-4.9/libcilkrts/runtime/worker_mutex.c b/gcc-4.9/libcilkrts/runtime/worker_mutex.c
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+++ b/gcc-4.9/libcilkrts/runtime/worker_mutex.c
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+/* worker_mutex.c -*-C-*-
+ *
+ *************************************************************************
+ *
+ * @copyright
+ * Copyright (C) 2009-2013, Intel Corporation
+ * All rights reserved.
+ *
+ * @copyright
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * @copyright
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
+ * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ **************************************************************************/
+
+#include "worker_mutex.h"
+#include "bug.h"
+#include "os.h"
+#include "stats.h"
+
+/* m->lock == 1 means that mutex M is locked */
+#define TRY_ACQUIRE(m) (__cilkrts_xchg(&(m)->lock, 1) == 0)
+
+/* ICC 11.1+ understands release semantics and generates an
+ ordinary store with a software memory barrier. */
+#if __ICC >= 1110
+#define RELEASE(m) __sync_lock_release(&(m)->lock)
+#else
+#define RELEASE(m) __cilkrts_xchg(&(m)->lock, 0)
+#endif
+
+void __cilkrts_mutex_init(struct mutex *m)
+{
+ m->owner = 0;
+
+ // Use a simple assignment so Inspector doesn't bug us about the
+ // interlocked exchange doing a read of an uninitialized variable.
+ // By definition there can't be a race when we're initializing the
+ // lock...
+ m->lock = 0;
+}
+
+void __cilkrts_mutex_lock(__cilkrts_worker *w, struct mutex *m)
+{
+ int count;
+ const int maxspin = 1000; /* SWAG */
+
+ NOTE_INTERVAL(w, INTERVAL_MUTEX_LOCK);
+ if (!TRY_ACQUIRE(m)) {
+ START_INTERVAL(w, INTERVAL_MUTEX_LOCK_SPINNING);
+ count = 0;
+ do {
+ do {
+ __cilkrts_short_pause();
+ if (++count >= maxspin) {
+ STOP_INTERVAL(w, INTERVAL_MUTEX_LOCK_SPINNING);
+ START_INTERVAL(w, INTERVAL_MUTEX_LOCK_YIELDING);
+ /* let the OS reschedule every once in a while */
+ __cilkrts_yield();
+ STOP_INTERVAL(w, INTERVAL_MUTEX_LOCK_YIELDING);
+ START_INTERVAL(w, INTERVAL_MUTEX_LOCK_SPINNING);
+ count = 0;
+ }
+ } while (m->lock != 0);
+ } while (!TRY_ACQUIRE(m));
+ STOP_INTERVAL(w, INTERVAL_MUTEX_LOCK_SPINNING);
+ }
+
+ CILK_ASSERT(m->owner == 0);
+ m->owner = w;
+}
+
+int __cilkrts_mutex_trylock(__cilkrts_worker *w, struct mutex *m)
+{
+ NOTE_INTERVAL(w, INTERVAL_MUTEX_TRYLOCK);
+ if (TRY_ACQUIRE(m)) {
+ CILK_ASSERT(m->owner == 0);
+ m->owner = w;
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+void __cilkrts_mutex_unlock(__cilkrts_worker *w, struct mutex *m)
+{
+ CILK_ASSERT(m->owner == w);
+ m->owner = 0;
+ RELEASE(m);
+}
+
+void __cilkrts_mutex_destroy(__cilkrts_worker *w, struct mutex *m)
+{
+ (void)w; /* unused */
+ (void)m; /* unused */
+}
+
+/* End worker_mutex.c */