henrike@webrtc.org | 0e118e7 | 2013-07-10 00:45:36 +0000 | [diff] [blame] | 1 | /* |
| 2 | * libjingle |
| 3 | * Copyright 2004--2010, 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/worker.h" |
| 29 | |
| 30 | #include "talk/base/common.h" |
| 31 | #include "talk/base/logging.h" |
| 32 | #include "talk/base/thread.h" |
| 33 | |
| 34 | namespace talk_base { |
| 35 | |
| 36 | enum { |
| 37 | MSG_HAVEWORK = 0, |
| 38 | }; |
| 39 | |
| 40 | Worker::Worker() : worker_thread_(NULL) {} |
| 41 | |
| 42 | Worker::~Worker() { |
| 43 | // We need to already be stopped before being destroyed. We cannot call |
| 44 | // StopWork() from here because the subclass's data has already been |
| 45 | // destructed, so OnStop() cannot be called. |
| 46 | ASSERT(!worker_thread_); |
| 47 | } |
| 48 | |
| 49 | bool Worker::StartWork() { |
| 50 | talk_base::Thread *me = talk_base::Thread::Current(); |
| 51 | if (worker_thread_) { |
| 52 | if (worker_thread_ == me) { |
| 53 | // Already working on this thread, so nothing to do. |
| 54 | return true; |
| 55 | } else { |
| 56 | LOG(LS_ERROR) << "Automatically switching threads is not supported"; |
| 57 | ASSERT(false); |
| 58 | return false; |
| 59 | } |
| 60 | } |
| 61 | worker_thread_ = me; |
| 62 | OnStart(); |
| 63 | return true; |
| 64 | } |
| 65 | |
| 66 | bool Worker::StopWork() { |
| 67 | if (!worker_thread_) { |
| 68 | // Already not working, so nothing to do. |
| 69 | return true; |
| 70 | } else if (worker_thread_ != talk_base::Thread::Current()) { |
| 71 | LOG(LS_ERROR) << "Stopping from a different thread is not supported"; |
| 72 | ASSERT(false); |
| 73 | return false; |
| 74 | } |
| 75 | OnStop(); |
| 76 | worker_thread_->Clear(this, MSG_HAVEWORK); |
| 77 | worker_thread_ = NULL; |
| 78 | return true; |
| 79 | } |
| 80 | |
| 81 | void Worker::HaveWork() { |
| 82 | ASSERT(worker_thread_ != NULL); |
| 83 | worker_thread_->Post(this, MSG_HAVEWORK); |
| 84 | } |
| 85 | |
| 86 | void Worker::OnMessage(talk_base::Message *msg) { |
| 87 | ASSERT(msg->message_id == MSG_HAVEWORK); |
| 88 | ASSERT(worker_thread_ == talk_base::Thread::Current()); |
| 89 | OnHaveWork(); |
| 90 | } |
| 91 | |
| 92 | } // namespace talk_base |