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// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "device/hid/device_monitor_linux.h"
#include "base/lazy_instance.h"
#include "base/logging.h"
#include "base/threading/thread_restrictions.h"
#include "device/udev_linux/udev.h"
namespace device {
namespace {
const char kUdevName[] = "udev";
const char kUdevActionAdd[] = "add";
const char kUdevActionRemove[] = "remove";
// The instance will be reset when message loop destroys.
base::LazyInstance<scoped_ptr<DeviceMonitorLinux> >::Leaky
g_device_monitor_linux_ptr = LAZY_INSTANCE_INITIALIZER;
} // namespace
DeviceMonitorLinux::DeviceMonitorLinux() : monitor_fd_(-1) {
base::ThreadRestrictions::AssertIOAllowed();
base::MessageLoop::current()->AddDestructionObserver(this);
udev_.reset(udev_new());
if (!udev_) {
LOG(ERROR) << "Failed to create udev.";
return;
}
monitor_.reset(udev_monitor_new_from_netlink(udev_.get(), kUdevName));
if (!monitor_) {
LOG(ERROR) << "Failed to create udev monitor.";
return;
}
int ret = udev_monitor_enable_receiving(monitor_.get());
if (ret != 0) {
LOG(ERROR) << "Failed to start udev monitoring.";
return;
}
monitor_fd_ = udev_monitor_get_fd(monitor_.get());
if (monitor_fd_ <= 0) {
LOG(ERROR) << "Failed to start udev monitoring.";
return;
}
if (!base::MessageLoopForIO::current()->WatchFileDescriptor(
monitor_fd_,
true,
base::MessageLoopForIO::WATCH_READ,
&monitor_watcher_,
this)) {
return;
}
}
// static
DeviceMonitorLinux* DeviceMonitorLinux::GetInstance() {
if (!HasInstance())
g_device_monitor_linux_ptr.Get().reset(new DeviceMonitorLinux());
return g_device_monitor_linux_ptr.Get().get();
}
// static
bool DeviceMonitorLinux::HasInstance() {
return g_device_monitor_linux_ptr.Get().get();
}
void DeviceMonitorLinux::AddObserver(Observer* observer) {
DCHECK(thread_checker_.CalledOnValidThread());
if (observer)
observers_.AddObserver(observer);
}
void DeviceMonitorLinux::RemoveObserver(Observer* observer) {
DCHECK(thread_checker_.CalledOnValidThread());
if (observer)
observers_.RemoveObserver(observer);
}
ScopedUdevDevicePtr DeviceMonitorLinux::GetDeviceFromPath(
const std::string& path) {
DCHECK(thread_checker_.CalledOnValidThread());
ScopedUdevDevicePtr device(
udev_device_new_from_syspath(udev_.get(), path.c_str()));
return device.Pass();
}
void DeviceMonitorLinux::Enumerate(const EnumerateCallback& callback) {
DCHECK(thread_checker_.CalledOnValidThread());
ScopedUdevEnumeratePtr enumerate(udev_enumerate_new(udev_.get()));
if (!enumerate) {
LOG(ERROR) << "Failed to enumerate devices.";
return;
}
if (udev_enumerate_scan_devices(enumerate.get()) != 0) {
LOG(ERROR) << "Failed to enumerate devices.";
return;
}
// This list is managed by |enumerate|.
udev_list_entry* devices = udev_enumerate_get_list_entry(enumerate.get());
for (udev_list_entry* i = devices; i != NULL;
i = udev_list_entry_get_next(i)) {
ScopedUdevDevicePtr device(
udev_device_new_from_syspath(udev_.get(), udev_list_entry_get_name(i)));
if (device)
callback.Run(device.get());
}
}
void DeviceMonitorLinux::WillDestroyCurrentMessageLoop() {
DCHECK(thread_checker_.CalledOnValidThread());
g_device_monitor_linux_ptr.Get().reset(NULL);
}
void DeviceMonitorLinux::OnFileCanReadWithoutBlocking(int fd) {
DCHECK(thread_checker_.CalledOnValidThread());
DCHECK_EQ(monitor_fd_, fd);
ScopedUdevDevicePtr device(udev_monitor_receive_device(monitor_.get()));
if (!device)
return;
std::string action(udev_device_get_action(device.get()));
if (action == kUdevActionAdd)
FOR_EACH_OBSERVER(Observer, observers_, OnDeviceAdded(device.get()));
else if (action == kUdevActionRemove)
FOR_EACH_OBSERVER(Observer, observers_, OnDeviceRemoved(device.get()));
}
void DeviceMonitorLinux::OnFileCanWriteWithoutBlocking(int fd) {}
DeviceMonitorLinux::~DeviceMonitorLinux() {
DCHECK(thread_checker_.CalledOnValidThread());
base::MessageLoop::current()->RemoveDestructionObserver(this);
monitor_watcher_.StopWatchingFileDescriptor();
close(monitor_fd_);
}
} // namespace device
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