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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 LIBBRILLO_BRILLO_ASYNCHRONOUS_SIGNAL_HANDLER_H_
#define LIBBRILLO_BRILLO_ASYNCHRONOUS_SIGNAL_HANDLER_H_
#include <sys/signalfd.h>
#include <map>
#include <memory>
#include <base/callback.h>
#include <base/files/file_descriptor_watcher_posix.h>
#include <base/files/scoped_file.h>
#include <brillo/asynchronous_signal_handler_interface.h>
#include <brillo/brillo_export.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:
using AsynchronousSignalHandlerInterface::SignalHandler;
AsynchronousSignalHandler();
~AsynchronousSignalHandler() override;
AsynchronousSignalHandler(const AsynchronousSignalHandler&) = delete;
AsynchronousSignalHandler&
operator=(const AsynchronousSignalHandler&) = delete;
// 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 OnReadable();
// Updates the set of signals that this handler listens to.
BRILLO_PRIVATE void UpdateSignals();
// Map from signal to its registered callback.
using Callbacks = std::map<int, SignalHandler>;
Callbacks registered_callbacks_;
// File descriptor for accepting signals indicated by |signal_mask_|.
base::ScopedFD descriptor_;
// Controller used to manage watching of signalling pipe.
std::unique_ptr<base::FileDescriptorWatcher::Controller> fd_watcher_;
// 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_;
};
} // namespace brillo
#endif // LIBBRILLO_BRILLO_ASYNCHRONOUS_SIGNAL_HANDLER_H_