1// Copyright (c) 2012 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4// 5// Implementation notes about interactions with VideoCaptureImpl. 6// 7// How is VideoCaptureImpl used: 8// 9// VideoCaptureImpl is an IO thread object while VideoCaptureImplManager 10// lives only on the render thread. It is only possible to access an 11// object of VideoCaptureImpl via a task on the IO thread. 12// 13// How is VideoCaptureImpl deleted: 14// 15// A task is posted to the IO thread to delete a VideoCaptureImpl. 16// Immediately after that the pointer to it is dropped. This means no 17// access to this VideoCaptureImpl object is possible on the render 18// thread. Also note that VideoCaptureImpl does not post task to itself. 19// 20// The use of Unretained: 21// 22// We make sure deletion is the last task on the IO thread for a 23// VideoCaptureImpl object. This allows the use of Unretained() binding. 24 25#include "content/renderer/media/video_capture_impl_manager.h" 26 27#include "base/bind.h" 28#include "base/bind_helpers.h" 29#include "content/child/child_process.h" 30#include "content/renderer/media/video_capture_impl.h" 31#include "content/renderer/media/video_capture_message_filter.h" 32#include "media/base/bind_to_current_loop.h" 33 34namespace content { 35 36VideoCaptureImplManager::VideoCaptureImplManager() 37 : next_client_id_(0), 38 filter_(new VideoCaptureMessageFilter()), 39 weak_factory_(this) { 40} 41 42VideoCaptureImplManager::~VideoCaptureImplManager() { 43 DCHECK(thread_checker_.CalledOnValidThread()); 44 if (devices_.empty()) 45 return; 46 // Forcibly release all video capture resources. 47 for (VideoCaptureDeviceMap::iterator it = devices_.begin(); 48 it != devices_.end(); ++it) { 49 VideoCaptureImpl* impl = it->second.second; 50 ChildProcess::current()->io_message_loop_proxy()->PostTask( 51 FROM_HERE, 52 base::Bind(&VideoCaptureImpl::DeInit, 53 base::Unretained(impl))); 54 ChildProcess::current()->io_message_loop_proxy()->PostTask( 55 FROM_HERE, 56 base::Bind(&base::DeletePointer<VideoCaptureImpl>, 57 base::Unretained(impl))); 58 } 59 devices_.clear(); 60} 61 62base::Closure VideoCaptureImplManager::UseDevice( 63 media::VideoCaptureSessionId id) { 64 DCHECK(thread_checker_.CalledOnValidThread()); 65 66 VideoCaptureImpl* impl = NULL; 67 VideoCaptureDeviceMap::iterator it = devices_.find(id); 68 if (it == devices_.end()) { 69 impl = CreateVideoCaptureImplForTesting(id, filter_.get()); 70 if (!impl) 71 impl = new VideoCaptureImpl(id, filter_.get()); 72 devices_[id] = std::make_pair(1, impl); 73 ChildProcess::current()->io_message_loop_proxy()->PostTask( 74 FROM_HERE, 75 base::Bind(&VideoCaptureImpl::Init, 76 base::Unretained(impl))); 77 } else { 78 ++it->second.first; 79 } 80 return base::Bind(&VideoCaptureImplManager::UnrefDevice, 81 weak_factory_.GetWeakPtr(), id); 82} 83 84base::Closure VideoCaptureImplManager::StartCapture( 85 media::VideoCaptureSessionId id, 86 const media::VideoCaptureParams& params, 87 const VideoCaptureStateUpdateCB& state_update_cb, 88 const VideoCaptureDeliverFrameCB& deliver_frame_cb) { 89 DCHECK(thread_checker_.CalledOnValidThread()); 90 VideoCaptureDeviceMap::iterator it = devices_.find(id); 91 DCHECK(it != devices_.end()); 92 VideoCaptureImpl* impl = it->second.second; 93 94 // This ID is used to identify a client of VideoCaptureImpl. 95 const int client_id = ++next_client_id_; 96 97 ChildProcess::current()->io_message_loop_proxy()->PostTask( 98 FROM_HERE, 99 base::Bind(&VideoCaptureImpl::StartCapture, 100 base::Unretained(impl), 101 client_id, 102 params, 103 state_update_cb, 104 deliver_frame_cb)); 105 return base::Bind(&VideoCaptureImplManager::StopCapture, 106 weak_factory_.GetWeakPtr(), 107 client_id, id); 108} 109 110void VideoCaptureImplManager::GetDeviceSupportedFormats( 111 media::VideoCaptureSessionId id, 112 const VideoCaptureDeviceFormatsCB& callback) { 113 DCHECK(thread_checker_.CalledOnValidThread()); 114 VideoCaptureDeviceMap::iterator it = devices_.find(id); 115 DCHECK(it != devices_.end()); 116 VideoCaptureImpl* impl = it->second.second; 117 ChildProcess::current()->io_message_loop_proxy()->PostTask( 118 FROM_HERE, 119 base::Bind(&VideoCaptureImpl::GetDeviceSupportedFormats, 120 base::Unretained(impl), callback)); 121} 122 123void VideoCaptureImplManager::GetDeviceFormatsInUse( 124 media::VideoCaptureSessionId id, 125 const VideoCaptureDeviceFormatsCB& callback) { 126 DCHECK(thread_checker_.CalledOnValidThread()); 127 VideoCaptureDeviceMap::iterator it = devices_.find(id); 128 DCHECK(it != devices_.end()); 129 VideoCaptureImpl* impl = it->second.second; 130 ChildProcess::current()->io_message_loop_proxy()->PostTask( 131 FROM_HERE, 132 base::Bind(&VideoCaptureImpl::GetDeviceFormatsInUse, 133 base::Unretained(impl), callback)); 134} 135 136VideoCaptureImpl* 137VideoCaptureImplManager::CreateVideoCaptureImplForTesting( 138 media::VideoCaptureSessionId id, 139 VideoCaptureMessageFilter* filter) const { 140 return NULL; 141} 142 143void VideoCaptureImplManager::StopCapture( 144 int client_id, media::VideoCaptureSessionId id) { 145 DCHECK(thread_checker_.CalledOnValidThread()); 146 VideoCaptureDeviceMap::iterator it = devices_.find(id); 147 DCHECK(it != devices_.end()); 148 VideoCaptureImpl* impl = it->second.second; 149 ChildProcess::current()->io_message_loop_proxy()->PostTask( 150 FROM_HERE, 151 base::Bind(&VideoCaptureImpl::StopCapture, 152 base::Unretained(impl), client_id)); 153} 154 155void VideoCaptureImplManager::UnrefDevice( 156 media::VideoCaptureSessionId id) { 157 DCHECK(thread_checker_.CalledOnValidThread()); 158 VideoCaptureDeviceMap::iterator it = devices_.find(id); 159 DCHECK(it != devices_.end()); 160 VideoCaptureImpl* impl = it->second.second; 161 162 // Unref and destroy on the IO thread if there's no more client. 163 DCHECK(it->second.first); 164 --it->second.first; 165 if (!it->second.first) { 166 devices_.erase(id); 167 ChildProcess::current()->io_message_loop_proxy()->PostTask( 168 FROM_HERE, 169 base::Bind(&VideoCaptureImpl::DeInit, 170 base::Unretained(impl))); 171 ChildProcess::current()->io_message_loop_proxy()->PostTask( 172 FROM_HERE, 173 base::Bind(&base::DeletePointer<VideoCaptureImpl>, 174 base::Unretained(impl))); 175 } 176} 177 178void VideoCaptureImplManager::SuspendDevices(bool suspend) { 179 DCHECK(thread_checker_.CalledOnValidThread()); 180 for (VideoCaptureDeviceMap::iterator it = devices_.begin(); 181 it != devices_.end(); ++it) { 182 VideoCaptureImpl* impl = it->second.second; 183 ChildProcess::current()->io_message_loop_proxy()->PostTask( 184 FROM_HERE, 185 base::Bind(&VideoCaptureImpl::SuspendCapture, 186 base::Unretained(impl), suspend)); 187 } 188} 189 190} // namespace content 191