blob: 1b0083a00e475ba87f9105ddcc34ab3292707927 [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.
#include <memory>
#include "base/base_export.h"
#include "base/macros.h"
#include "base/message_loop/message_pump.h"
#include "base/message_loop/watchable_io_message_pump_posix.h"
#include "base/observer_list.h"
#include "base/threading/thread_checker.h"
#include "base/time/time.h"
typedef struct _GMainContext GMainContext;
typedef struct _GPollFD GPollFD;
typedef struct _GSource GSource;
namespace base {
// This class implements a base MessagePump needed for TYPE_UI MessageLoops on
// platforms using GLib.
class BASE_EXPORT MessagePumpGlib : public MessagePump,
public WatchableIOMessagePumpPosix {
class FdWatchController : public FdWatchControllerInterface {
explicit FdWatchController(const Location& from_here);
~FdWatchController() override;
// FdWatchControllerInterface:
bool StopWatchingFileDescriptor() override;
friend class MessagePumpGlib;
friend class MessagePumpGLibFdWatchTest;
// FdWatchController instances can be reused (unless fd changes), so we
// need to keep track of initialization status and taking it into account
// when setting up a fd watching. Please refer to
// WatchableIOMessagePumpPosix docs for more details. This is called by
// WatchFileDescriptor() and sets up a GSource for the input parameters.
// The source is not attached here, so the events will not be fired until
// Attach() is called.
bool InitOrUpdate(int fd, int mode, FdWatcher* watcher);
// Returns the current initialization status.
bool IsInitialized() const;
// Tries to attach the internal GSource instance to the |pump|'s
// GMainContext, so IO events start to be dispatched. Returns false if
// |this| is not correctly initialized, otherwise returns true.
bool Attach(MessagePumpGlib* pump);
// Forward read and write events to |watcher_|. It is a no-op if watcher_
// is null, which can happen when controller is suddenly stopped through
// StopWatchingFileDescriptor().
void NotifyCanRead();
void NotifyCanWrite();
FdWatcher* watcher_ = nullptr;
GSource* source_ = nullptr;
std::unique_ptr<GPollFD> poll_fd_;
// If this pointer is non-null, the pointee is set to true in the
// destructor.
bool* was_destroyed_ = nullptr;
~MessagePumpGlib() override;
// Part of WatchableIOMessagePumpPosix interface.
// Please refer to WatchableIOMessagePumpPosix docs for more details.
bool WatchFileDescriptor(int fd,
bool persistent,
int mode,
FdWatchController* controller,
FdWatcher* delegate);
// Internal methods used for processing the pump callbacks. They are public
// for simplicity but should not be used directly. HandlePrepare is called
// during the prepare step of glib, and returns a timeout that will be passed
// to the poll. HandleCheck is called after the poll has completed, and
// returns whether or not HandleDispatch should be called. HandleDispatch is
// called if HandleCheck returned true.
int HandlePrepare();
bool HandleCheck();
void HandleDispatch();
// Overridden from MessagePump:
void Run(Delegate* delegate) override;
void Quit() override;
void ScheduleWork() override;
void ScheduleDelayedWork(const TimeTicks& delayed_work_time) override;
// Internal methods used for processing the FdWatchSource callbacks. As for
// main pump callbacks, they are public for simplicity but should not be used
// directly.
bool HandleFdWatchCheck(FdWatchController* controller);
void HandleFdWatchDispatch(FdWatchController* controller);
bool ShouldQuit() const;
// We may make recursive calls to Run, so we save state that needs to be
// separate between them in this structure type.
struct RunState;
RunState* state_;
// This is a GLib structure that we can add event sources to. We use the
// default GLib context, which is the one to which all GTK events are
// dispatched.
GMainContext* context_;
// The work source. It is shared by all calls to Run and destroyed when
// the message pump is destroyed.
GSource* work_source_;
// We use a wakeup pipe to make sure we'll get out of the glib polling phase
// when another thread has scheduled us to do some work. There is a glib
// mechanism g_main_context_wakeup, but this won't guarantee that our event's
// Dispatch() will be called.
int wakeup_pipe_read_;
int wakeup_pipe_write_;
// Use a unique_ptr to avoid needing the definition of GPollFD in the header.
std::unique_ptr<GPollFD> wakeup_gpollfd_;
} // namespace base