content/browser/udev_linux.cc

   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 #include "content/browser/udev_linux.h"
   6
   7 #include "base/message_loop/message_loop.h"
   8
   9 namespace content {
  10
  11 UdevLinux::UdevLinux(const std::vector<UdevMonitorFilter>& filters,
  12                      const UdevNotificationCallback& callback)
  13     : udev_(device::udev_new()),
  14       monitor_(device::udev_monitor_new_from_netlink(udev_.get(), "udev")),
  15       monitor_fd_(-1),
  16       callback_(callback) {
  17   CHECK(udev_);
  18   CHECK(monitor_);
  19
  20   for (size_t i = 0; i < filters.size(); ++i) {
  21     int ret = device::udev_monitor_filter_add_match_subsystem_devtype(
  22         monitor_.get(), filters[i].subsystem, filters[i].devtype);
  23     CHECK_EQ(0, ret);
  24   }
  25
  26   int ret = device::udev_monitor_enable_receiving(monitor_.get());
  27   CHECK_EQ(0, ret);
  28   monitor_fd_ = device::udev_monitor_get_fd(monitor_.get());
  29   CHECK_GE(monitor_fd_, 0);
  30
  31   bool success = base::MessageLoopForIO::current()->WatchFileDescriptor(
  32       monitor_fd_,
  33       true,
  34       base::MessageLoopForIO::WATCH_READ,
  35       &monitor_watcher_,
  36       this);
  37   CHECK(success);
  38 }
  39
  40 UdevLinux::~UdevLinux() {
  41   monitor_watcher_.StopWatchingFileDescriptor();
  42 }
  43
  44 udev* UdevLinux::udev_handle() {
  45   return udev_.get();
  46 }
  47
  48 void UdevLinux::OnFileCanReadWithoutBlocking(int fd) {
  49   // Events occur when devices attached to the system are added, removed, or
  50   // change state. udev_monitor_receive_device() will return a device object
  51   // representing the device which changed and what type of change occured.
  52   DCHECK_EQ(monitor_fd_, fd);
  53   device::ScopedUdevDevicePtr dev(
  54       device::udev_monitor_receive_device(monitor_.get()));
  55   if (!dev)
  56     return;
  57
  58   callback_.Run(dev.get());
  59 }
  60
  61 void UdevLinux::OnFileCanWriteWithoutBlocking(int fd) {
  62 }
  63
  64 }  // namespace content