| // 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_ |