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 // libudev is used for monitoring device changes. 6 7 #include "content/browser/device_monitor_linux.h" 8 9 #include <libudev.h> 10 11 #include <string> 12 13 #include "base/system_monitor/system_monitor.h" 14 #include "content/browser/udev_linux.h" 15 #include "content/public/browser/browser_thread.h" 16 17 namespace { 18 19 struct SubsystemMap { 20 base::SystemMonitor::DeviceType device_type; 21 const char* subsystem; 22 const char* devtype; 23 }; 24 25 const char kAudioSubsystem[] = "sound"; 26 const char kVideoSubsystem[] = "video4linux"; 27 28 // Add more subsystems here for monitoring. 29 const SubsystemMap kSubsystemMap[] = { 30 { base::SystemMonitor::DEVTYPE_AUDIO_CAPTURE, kAudioSubsystem, NULL }, 31 { base::SystemMonitor::DEVTYPE_VIDEO_CAPTURE, kVideoSubsystem, NULL }, 32 }; 33 34 } // namespace 35 36 namespace content { 37 38 DeviceMonitorLinux::DeviceMonitorLinux() { 39 DCHECK(BrowserThread::IsMessageLoopValid(BrowserThread::IO)); 40 BrowserThread::PostTask(BrowserThread::IO, 41 FROM_HERE, 42 base::Bind(&DeviceMonitorLinux::Initialize, base::Unretained(this))); 43 } 44 45 DeviceMonitorLinux::~DeviceMonitorLinux() { 46 } 47 48 void DeviceMonitorLinux::Initialize() { 49 DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO)); 50 51 // We want to be notified of IO message loop destruction to delete |udev_|. 52 base::MessageLoop::current()->AddDestructionObserver(this); 53 54 std::vector<UdevLinux::UdevMonitorFilter> filters; 55 for (size_t i = 0; i < arraysize(kSubsystemMap); ++i) { 56 filters.push_back(UdevLinux::UdevMonitorFilter( 57 kSubsystemMap[i].subsystem, kSubsystemMap[i].devtype)); 58 } 59 udev_.reset(new UdevLinux(filters, 60 base::Bind(&DeviceMonitorLinux::OnDevicesChanged, 61 base::Unretained(this)))); 62 } 63 64 void DeviceMonitorLinux::WillDestroyCurrentMessageLoop() { 65 // Called on IO thread. 66 udev_.reset(); 67 } 68 69 void DeviceMonitorLinux::OnDevicesChanged(udev_device* device) { 70 DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO)); 71 DCHECK(device); 72 73 base::SystemMonitor::DeviceType device_type = 74 base::SystemMonitor::DEVTYPE_UNKNOWN; 75 std::string subsystem(udev_device_get_subsystem(device)); 76 for (size_t i = 0; i < arraysize(kSubsystemMap); ++i) { 77 if (subsystem == kSubsystemMap[i].subsystem) { 78 device_type = kSubsystemMap[i].device_type; 79 break; 80 } 81 } 82 DCHECK_NE(device_type, base::SystemMonitor::DEVTYPE_UNKNOWN); 83 84 base::SystemMonitor::Get()->ProcessDevicesChanged(device_type); 85 } 86 87 } // namespace content 88