Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 181 insertions, 0 deletions

diff --git a/ipc/chromium/src/base/message_pump_libevent.h b/ipc/chromium/src/base/message_pump_libevent.h
new file mode 100644
index 0000000000..b1a7d474b3
--- /dev/null
+++ b/ipc/chromium/src/base/message_pump_libevent.h
@@ -0,0 +1,181 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+// Copyright (c) 2006-2008 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.
+
+#ifndef BASE_MESSAGE_PUMP_LIBEVENT_H_
+#define BASE_MESSAGE_PUMP_LIBEVENT_H_
+
+#include "base/message_pump.h"
+#include "base/time.h"
+
+// Declare structs we need from libevent.h rather than including it
+struct event_base;
+struct event;
+
+namespace base {
+
+// Class to monitor sockets and issue callbacks when sockets are ready for I/O
+// TODO(dkegel): add support for background file IO somehow
+class MessagePumpLibevent : public MessagePump {
+ public:
+  // Object returned by WatchFileDescriptor to manage further watching.
+  class FileDescriptorWatcher {
+   public:
+    FileDescriptorWatcher();
+    ~FileDescriptorWatcher();  // Implicitly calls StopWatchingFileDescriptor.
+
+    // NOTE: These methods aren't called StartWatching()/StopWatching() to
+    // avoid confusion with the win32 ObjectWatcher class.
+
+    // Stop watching the FD, always safe to call.  No-op if there's nothing
+    // to do.
+    bool StopWatchingFileDescriptor();
+
+   private:
+    // Called by MessagePumpLibevent, ownership of |e| is transferred to this
+    // object.
+    void Init(event* e, bool is_persistent);
+
+    // Used by MessagePumpLibevent to take ownership of event_.
+    event* ReleaseEvent();
+    friend class MessagePumpLibevent;
+
+   private:
+    bool is_persistent_;  // false if this event is one-shot.
+    event* event_;
+    DISALLOW_COPY_AND_ASSIGN(FileDescriptorWatcher);
+  };
+
+  // Used with WatchFileDescptor to asynchronously monitor the I/O readiness of
+  // a File Descriptor.
+  class Watcher {
+   public:
+    virtual ~Watcher() {}
+    // Called from MessageLoop::Run when an FD can be read from/written to
+    // without blocking
+    virtual void OnFileCanReadWithoutBlocking(int fd) = 0;
+    virtual void OnFileCanWriteWithoutBlocking(int fd) = 0;
+  };
+
+  MessagePumpLibevent();
+
+  enum Mode {
+    WATCH_READ = 1 << 0,
+    WATCH_WRITE = 1 << 1,
+    WATCH_READ_WRITE = WATCH_READ | WATCH_WRITE
+  };
+
+  // Have the current thread's message loop watch for a a situation in which
+  // reading/writing to the FD can be performed without Blocking.
+  // Callers must provide a preallocated FileDescriptorWatcher object which
+  // can later be used to manage the Lifetime of this event.
+  // If a FileDescriptorWatcher is passed in which is already attached to
+  // an event, then the effect is cumulative i.e. after the call |controller|
+  // will watch both the previous event and the new one.
+  // If an error occurs while calling this method in a cumulative fashion, the
+  // event previously attached to |controller| is aborted.
+  // Returns true on success.
+  // TODO(dkegel): switch to edge-triggered readiness notification
+  bool WatchFileDescriptor(int fd, bool persistent, Mode mode,
+                           FileDescriptorWatcher* controller,
+                           Watcher* delegate);
+
+  // This is analagous to FileDescriptorWatcher above, which really is
+  // just a wrapper around libevent's |struct event|.  This class acts
+  // as a sort of "scoped event watcher" in that it guarantees that
+  // when this class is out of scope, the signal-event it wraps is
+  // removed from libevent's guts.
+  //
+  // XXX/cjones: this isn't my favorite API, but preserving it in
+  // order to match code above
+  class SignalEvent {
+    friend class MessagePumpLibevent;
+
+   public:
+    SignalEvent();
+    ~SignalEvent();  // implicitly calls StopCatching()
+
+    // Have libevent forget this event.
+    bool StopCatching();
+
+   private:
+    void Init(event* e);
+    event* ReleaseEvent();
+
+    event* event_;
+
+    DISALLOW_COPY_AND_ASSIGN(SignalEvent);
+  };
+
+  class SignalWatcher {
+   public:
+    virtual ~SignalWatcher() {}
+    // Called from MessageLoop::Run when |sig| has been delivered to
+    // this process
+    virtual void OnSignal(int sig) = 0;
+  };
+
+  // Have the current thread's message loop catch the signal |sig|.
+  // Multiple watchers can catch the same signal; they're all notified
+  // upon its delivery.  Callers must provide a preallocated
+  // SignalEvent object which can be used to manage the lifetime of
+  // this event.  Returns true on success.
+  bool CatchSignal(int sig, SignalEvent* sigevent, SignalWatcher* delegate);
+
+  // MessagePump methods:
+  virtual void Run(Delegate* delegate) override;
+  virtual void Quit() override;
+  virtual void ScheduleWork() override;
+  virtual void ScheduleDelayedWork(const TimeTicks& delayed_work_time) override;
+
+ protected:
+  virtual ~MessagePumpLibevent();
+
+ private:
+  // Risky part of constructor.  Returns true on success.
+  bool Init();
+
+  // This flag is set to false when Run should return.
+  bool keep_running_;
+
+  // This flag is set when inside Run.
+  bool in_run_;
+
+  // The time at which we should call DoDelayedWork.
+  TimeTicks delayed_work_time_;
+
+  // Libevent dispatcher.  Watches all sockets registered with it, and sends
+  // readiness callbacks when a socket is ready for I/O.
+  event_base* event_base_;
+
+  // Called by libevent to tell us a registered FD can be read/written to.
+  static void OnLibeventNotification(int fd, short flags, void* context);
+
+  // Called by libevent upon receiving a signal
+  static void OnLibeventSignalNotification(int sig, short flags, void* context);
+
+  // Unix pipe used to implement ScheduleWork()
+  // ... callback; called by libevent inside Run() when pipe is ready to read
+  static void OnWakeup(int socket, short flags, void* context);
+  // ... write end; ScheduleWork() writes a single byte to it
+  int wakeup_pipe_in_;
+  // ... read end; OnWakeup reads it and then breaks Run() out of its sleep
+  int wakeup_pipe_out_;
+  // ... libevent wrapper for read end
+  event* wakeup_event_;
+
+  // Set to false when calling event_base_loop and to true when either of the
+  // OnWakeup, OnLibeventNotification or OnLibeventSignalNotification callbacks
+  // is called.
+  // Used to ensure our calls to profiler_thread_sleep and profiler_thread_wake
+  // are paired correctly.
+  static bool awake_;
+
+  DISALLOW_COPY_AND_ASSIGN(MessagePumpLibevent);
+};
+
+}  // namespace base
+
+#endif  // BASE_MESSAGE_PUMP_LIBEVENT_H_