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 <libudev.h>
   8
   9 #include "base/message_loop/message_loop.h"
  10
  11 namespace content {
  12
  13 UdevLinux::UdevLinux(const std::vector<UdevMonitorFilter>& filters,
  14                      const UdevNotificationCallback& callback)
  15     : udev_(udev_new()),
  16       monitor_(udev_monitor_new_from_netlink(udev_.get(), "udev")),
  17       monitor_fd_(-1),
  18       callback_(callback) {
  19   CHECK(udev_);
  20   CHECK(monitor_);
  21
  22   for (size_t i = 0; i < filters.size(); ++i) {
  23     int ret = udev_monitor_filter_add_match_subsystem_devtype(
  24         monitor_.get(), filters[i].subsystem, filters[i].devtype);
  25     CHECK_EQ(0, ret);
  26   }
  27
  28   int ret = udev_monitor_enable_receiving(monitor_.get());
  29   CHECK_EQ(0, ret);
  30   monitor_fd_ = udev_monitor_get_fd(monitor_.get());
  31   CHECK_GE(monitor_fd_, 0);
  32
  33   bool success = base::MessageLoopForIO::current()->WatchFileDescriptor(
  34       monitor_fd_,
  35       true,
  36       base::MessageLoopForIO::WATCH_READ,
  37       &monitor_watcher_,
  38       this);
  39   CHECK(success);
  40 }
  41
  42 UdevLinux::~UdevLinux() {
  43   monitor_watcher_.StopWatchingFileDescriptor();
  44 }
  45
  46 udev* UdevLinux::udev_handle() {
  47   return udev_.get();
  48 }
  49
  50 void UdevLinux::OnFileCanReadWithoutBlocking(int fd) {
  51   // Events occur when devices attached to the system are added, removed, or
  52   // change state. udev_monitor_receive_device() will return a device object
  53   // representing the device which changed and what type of change occured.
  54   DCHECK_EQ(monitor_fd_, fd);
  55   device::ScopedUdevDevicePtr dev(
  56       udev_monitor_receive_device(monitor_.get()));
  57   if (!dev)
  58     return;
  59
  60   callback_.Run(dev.get());
  61 }
  62
  63 void UdevLinux::OnFileCanWriteWithoutBlocking(int fd) {
  64 }
  65
  66 }  // namespace content