1 /* Copyright (c) 2009, Google Inc. 2 * All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 * 30 * --- 31 * This file is a Posix-specific part of spinlock_internal.cc 32 */ 33 34 #include <config.h> 35 #include <errno.h> 36 #ifdef HAVE_SCHED_H 37 #include <sched.h> /* For sched_yield() */ 38 #endif 39 #include <time.h> /* For nanosleep() */ 40 41 namespace base { 42 namespace internal { 43 44 void SpinLockDelay(volatile Atomic32 *w, int32 value, int loop) { 45 int save_errno = errno; 46 if (loop == 0) { 47 } else if (loop == 1) { 48 sched_yield(); 49 } else { 50 struct timespec tm; 51 tm.tv_sec = 0; 52 tm.tv_nsec = base::internal::SuggestedDelayNS(loop); 53 nanosleep(&tm, NULL); 54 } 55 errno = save_errno; 56 } 57 58 void SpinLockWake(volatile Atomic32 *w, bool all) { 59 } 60 61 } // namespace internal 62 } // namespace base 63
