| henrike@webrtc.org | 0e118e7 | 2013-07-10 00:45:36 +0000 | [diff] [blame] | 1 | /* |
| 2 | * libjingle |
| 3 | * Copyright 2011, Google Inc. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions are met: |
| 7 | * |
| 8 | * 1. Redistributions of source code must retain the above copyright notice, |
| 9 | * this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright notice, |
| 11 | * this list of conditions and the following disclaimer in the documentation |
| 12 | * and/or other materials provided with the distribution. |
| 13 | * 3. The name of the author may not be used to endorse or promote products |
| 14 | * derived from this software without specific prior written permission. |
| 15 | * |
| 16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| 17 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| 18 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO |
| 19 | * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 20 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 21 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
| 22 | * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| 23 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
| 24 | * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| 25 | * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 26 | */ |
| 27 | |
| 28 | #include "talk/base/sharedexclusivelock.h" |
| 29 | |
| 30 | namespace talk_base { |
| 31 | |
| 32 | SharedExclusiveLock::SharedExclusiveLock() |
| 33 | : shared_count_is_zero_(true, true), |
| 34 | shared_count_(0) { |
| 35 | } |
| 36 | |
| 37 | void SharedExclusiveLock::LockExclusive() { |
| 38 | cs_exclusive_.Enter(); |
| 39 | shared_count_is_zero_.Wait(talk_base::kForever); |
| 40 | } |
| 41 | |
| 42 | void SharedExclusiveLock::UnlockExclusive() { |
| 43 | cs_exclusive_.Leave(); |
| 44 | } |
| 45 | |
| 46 | void SharedExclusiveLock::LockShared() { |
| 47 | CritScope exclusive_scope(&cs_exclusive_); |
| 48 | CritScope shared_scope(&cs_shared_); |
| 49 | if (++shared_count_ == 1) { |
| 50 | shared_count_is_zero_.Reset(); |
| 51 | } |
| 52 | } |
| 53 | |
| 54 | void SharedExclusiveLock::UnlockShared() { |
| 55 | CritScope shared_scope(&cs_shared_); |
| 56 | if (--shared_count_ == 0) { |
| 57 | shared_count_is_zero_.Set(); |
| 58 | } |
| 59 | } |
| 60 | |
| 61 | } // namespace talk_base |