1214152Sed/* spin_mutex.h -*-C++-*- 2214152Sed * 3214152Sed ************************************************************************* 4214152Sed * 5222656Sed * @copyright 6222656Sed * Copyright (C) 2009-2013, Intel Corporation 7214152Sed * All rights reserved. 8214152Sed * 9214152Sed * @copyright 10214152Sed * Redistribution and use in source and binary forms, with or without 11214152Sed * modification, are permitted provided that the following conditions 12214152Sed * are met: 13214152Sed * 14214152Sed * * Redistributions of source code must retain the above copyright 15214152Sed * notice, this list of conditions and the following disclaimer. 16214152Sed * * Redistributions in binary form must reproduce the above copyright 17222656Sed * notice, this list of conditions and the following disclaimer in 18214152Sed * the documentation and/or other materials provided with the 19214152Sed * distribution. 20214152Sed * * Neither the name of Intel Corporation nor the names of its 21222656Sed * contributors may be used to endorse or promote products derived 22214152Sed * from this software without specific prior written permission. 23214152Sed * 24214152Sed * @copyright 25214152Sed * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 26214152Sed * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 27214152Sed * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 28214152Sed * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 29214152Sed * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 30214152Sed * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 31214152Sed * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 32 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 33 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY 35 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 **************************************************************************/ 38 39/** 40 * @file spin_mutex.h 41 * 42 * @brief Support for Cilk runtime mutexes. 43 * 44 * Cilk runtime mutexes are implemented as simple spin loops. 45 * 46 * This file is similar to a worker_mutex, except it does not have an 47 * owner field. 48 * 49 * TBD: This class, worker_mutex, and os_mutex overlap quite a bit in 50 * functionality. Can we unify these mutexes somehow? 51 */ 52#ifndef INCLUDED_SPIN_MUTEX_DOT_H 53#define INCLUDED_SPIN_MUTEX_DOT_H 54 55#include <cilk/common.h> 56#include "rts-common.h" 57#include "cilk_malloc.h" 58 59__CILKRTS_BEGIN_EXTERN_C 60 61/** 62 * Mutexes are treated as an abstract data type within the Cilk 63 * runtime system. They are implemented as simple spin loops. 64 */ 65typedef struct spin_mutex { 66 /** Mutex spin loop variable. 0 if unowned, 1 if owned. */ 67 volatile int lock; 68 69 /** Padding so the mutex takes up a cache line. */ 70 char pad[64/sizeof(int) - 1]; 71} spin_mutex; 72 73 74/** 75 * @brief Create a new Cilk spin_mutex. 76 * 77 * @return Returns an initialized spin mutex. 78 */ 79COMMON_PORTABLE 80spin_mutex* spin_mutex_create(); 81 82/** 83 * @brief Initialize a Cilk spin_mutex. 84 * 85 * @param m Spin_Mutex to be initialized. 86 */ 87COMMON_PORTABLE 88void spin_mutex_init(spin_mutex *m); 89 90/** 91 * @brief Acquire a Cilk spin_mutex. 92 * 93 * If statistics are being gathered, the time spent 94 * acquiring the spin_mutex will be attributed to the specified worker. 95 * 96 * @param m Spin_Mutex to be initialized. 97 */ 98COMMON_PORTABLE 99void spin_mutex_lock(struct spin_mutex *m); 100/** 101 * @brief Attempt to lock a Cilk spin_mutex and fail if it isn't available. 102 * 103 * @param m Spin_Mutex to be acquired. 104 * 105 * @return 1 if the spin_mutex was acquired. 106 * @return 0 if the spin_mutex was not acquired. 107 */ 108COMMON_PORTABLE 109int spin_mutex_trylock(struct spin_mutex *m); 110 111/** 112 * @brief Release a Cilk spin_mutex. 113 * 114 * @param m Spin_Mutex to be released. 115 */ 116COMMON_PORTABLE 117void spin_mutex_unlock(struct spin_mutex *m); 118 119/** 120 * @brief Deallocate a Cilk spin_mutex. Currently does nothing. 121 * 122 * @param m Spin_Mutex to be deallocated. 123 */ 124COMMON_PORTABLE 125void spin_mutex_destroy(struct spin_mutex *m); 126 127__CILKRTS_END_EXTERN_C 128 129#endif // ! defined(INCLUDED_SPIN_MUTEX_DOT_H) 130