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// Copyright 2014 The Chromium OS 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 LIBCHROMEOS_BRILLO_ASYNCHRONOUS_SIGNAL_HANDLER_H_
#define LIBCHROMEOS_BRILLO_ASYNCHRONOUS_SIGNAL_HANDLER_H_
#include <signal.h>
#include <sys/signalfd.h>
#include <map>
#include <base/callback.h>
#include <base/compiler_specific.h>
#include <base/macros.h>
#include <base/memory/scoped_ptr.h>
#include <base/message_loop/message_loop.h>
#include <brillo/asynchronous_signal_handler_interface.h>
#include <brillo/brillo_export.h>
#include <brillo/message_loops/message_loop.h>
namespace brillo {
// Sets up signal handlers for registered signals, and converts signal receipt
// into a write on a pipe. Watches that pipe for data and, when some appears,
// execute the associated callback.
class BRILLO_EXPORT AsynchronousSignalHandler final :
public AsynchronousSignalHandlerInterface {
public:
AsynchronousSignalHandler();
~AsynchronousSignalHandler() override;
using AsynchronousSignalHandlerInterface::SignalHandler;
// Initialize the handler.
void Init();
// AsynchronousSignalHandlerInterface overrides.
void RegisterHandler(int signal, const SignalHandler& callback) override;
void UnregisterHandler(int signal) override;
private:
// Called from the main loop when we can read from |descriptor_|, indicated
// that a signal was processed.
void OnFileCanReadWithoutBlocking();
// Controller used to manage watching of signalling pipe.
MessageLoop::TaskId fd_watcher_task_{MessageLoop::kTaskIdNull};
// The registered callbacks.
typedef std::map<int, SignalHandler> Callbacks;
Callbacks registered_callbacks_;
// File descriptor for accepting signals indicated by |signal_mask_|.
int descriptor_;
// A set of signals to be handled after the dispatcher is running.
sigset_t signal_mask_;
// A copy of the signal mask before the dispatcher starts, which will be
// used to restore to the original state when the dispatcher stops.
sigset_t saved_signal_mask_;
// Resets the given signal to its default behavior. Doesn't touch
// |registered_callbacks_|.
BRILLO_PRIVATE void ResetSignal(int signal);
// Updates the set of signals that this handler listens to.
BRILLO_PRIVATE void UpdateSignals();
DISALLOW_COPY_AND_ASSIGN(AsynchronousSignalHandler);
};
} // namespace brillo
#endif // LIBCHROMEOS_BRILLO_ASYNCHRONOUS_SIGNAL_HANDLER_H_