blob: cd65abe08130123467118ff8e422ea6a0dbfe7e7 [file] [log] [blame]
// Copyright (c) 2012 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.
// UdevLinux listens for device change notifications from udev and runs
// callbacks when notifications occur.
//
// UdevLinux must be created on a MessageLoop of TYPE_IO.
// UdevLinux is not thread-safe.
//
// Example usage:
//
// class UdevLinux;
//
// class Foo {
// public:
// Foo() {
// std::vector<UdevLinux::UdevMonitorFilter> filters;
// filters.push_back(UdevLinux::UdevMonitorFilter("block", NULL));
// udev_.reset(new UdevLinux(filters,
// base::Bind(&Foo::Notify, this)));
// }
//
// // Called when a "block" device attaches/detaches.
// // To hold on to |device|, call udev_device_ref(device).
// void Notify(udev_device* device) {
// // Do something with |device|.
// }
//
// private:
// scoped_ptr<UdevLinux> udev_;
//
// DISALLOW_COPY_AND_ASSIGN(Foo);
// };
#ifndef DEVICE_UDEV_LINUX_UDEV_LINUX_H_
#define DEVICE_UDEV_LINUX_UDEV_LINUX_H_
#include <vector>
#include "base/callback.h"
#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/message_loop/message_pump_libevent.h"
#include "device/udev_linux/scoped_udev.h"
extern "C" {
struct udev;
struct udev_device;
struct udev_monitor;
}
namespace device {
class UdevLinux : public base::MessagePumpLibevent::Watcher {
public:
typedef base::Callback<void(udev_device*)> UdevNotificationCallback;
// subsystem and devtype parameter for
// udev_monitor_filter_add_match_subsystem_devtype().
struct UdevMonitorFilter {
UdevMonitorFilter(const char* subsystem_in, const char* devtype_in)
: subsystem(subsystem_in), devtype(devtype_in) {}
const char* subsystem;
const char* devtype;
};
// Filter incoming devices based on |filters|.
// Calls |callback| upon device change events.
UdevLinux(const std::vector<UdevMonitorFilter>& filters,
const UdevNotificationCallback& callback);
~UdevLinux() override;
// Returns the udev handle to be passed into other udev_*() functions.
udev* udev_handle();
private:
// base::MessagePump:Libevent::Watcher implementation.
void OnFileCanReadWithoutBlocking(int fd) override;
void OnFileCanWriteWithoutBlocking(int fd) override;
// libudev-related items, the main context, and the monitoring context to be
// notified about changes to device states.
const ScopedUdevPtr udev_;
const ScopedUdevMonitorPtr monitor_;
int monitor_fd_;
base::MessagePumpLibevent::FileDescriptorWatcher monitor_watcher_;
const UdevNotificationCallback callback_;
DISALLOW_COPY_AND_ASSIGN(UdevLinux);
};
} // namespace device
#endif // DEVICE_UDEV_LINUX_UDEV_LINUX_H_