diff options
Diffstat (limited to 'gcc-4.9/libcilkrts/runtime/worker_mutex.c')
-rw-r--r-- | gcc-4.9/libcilkrts/runtime/worker_mutex.c | 121 |
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 new file mode 100644 index 000000000..380d6255a --- /dev/null +++ b/gcc-4.9/libcilkrts/runtime/worker_mutex.c @@ -0,0 +1,121 @@ +/* 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 */ |