| /* Copyright (c) 2010, Google Inc. |
| * All rights reserved. |
| * |
| * 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 Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * 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 |
| * OWNER 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. |
| * |
| * --- |
| * This file is an internal part spinlock.cc and once.cc |
| * It may not be used directly by code outside of //base. |
| */ |
| |
| #ifndef BASE_SPINLOCK_INTERNAL_H_ |
| #define BASE_SPINLOCK_INTERNAL_H_ |
| |
| #include <config.h> |
| #include "base/basictypes.h" |
| #include "base/atomicops.h" |
| |
| namespace base { |
| namespace internal { |
| |
| // SpinLockWait() waits until it can perform one of several transitions from |
| // "from" to "to". It returns when it performs a transition where done==true. |
| struct SpinLockWaitTransition { |
| int32 from; |
| int32 to; |
| bool done; |
| }; |
| |
| // Wait until *w can transition from trans[i].from to trans[i].to for some i |
| // satisfying 0<=i<n && trans[i].done, atomically make the transition, |
| // then return the old value of *w. Make any other atomic tranistions |
| // where !trans[i].done, but continue waiting. |
| int32 SpinLockWait(volatile Atomic32 *w, int n, |
| const SpinLockWaitTransition trans[]); |
| void SpinLockWake(volatile Atomic32 *w, bool all); |
| void SpinLockDelay(volatile Atomic32 *w, int32 value, int loop); |
| |
| } // namespace internal |
| } // namespace base |
| #endif |
