1 // Copyright 2015 The Chromium OS Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef LIBBRILLO_BRILLO_ASYNCHRONOUS_SIGNAL_HANDLER_INTERFACE_H_ 6 #define LIBBRILLO_BRILLO_ASYNCHRONOUS_SIGNAL_HANDLER_INTERFACE_H_ 7 8 #include <sys/signalfd.h> 9 10 #include <base/callback.h> 11 #include <brillo/brillo_export.h> 12 13 namespace brillo { 14 15 // Sets up signal handlers for registered signals, and converts signal receipt 16 // into a write on a pipe. Watches that pipe for data and, when some appears, 17 // execute the associated callback. 18 class BRILLO_EXPORT AsynchronousSignalHandlerInterface { 19 public: 20 virtual ~AsynchronousSignalHandlerInterface() = default; 21 22 // The callback called when a signal is received. 23 using SignalHandler = base::Callback<bool(const struct signalfd_siginfo&)>; 24 25 // Register a new handler for the given |signal|, replacing any previously 26 // registered handler. |callback| will be called on the thread the 27 // |AsynchronousSignalHandlerInterface| implementation is bound to when a 28 // signal is received. The received |signalfd_siginfo| will be passed to 29 // |callback|. |callback| must returns |true| if the signal handler must be 30 // unregistered, and |false| otherwise. Due to an implementation detail, you 31 // cannot set any sigaction flags you might be accustomed to using. This might 32 // matter if you hoped to use SA_NOCLDSTOP to avoid getting a SIGCHLD when a 33 // child process receives a SIGSTOP. 34 virtual void RegisterHandler(int signal, const SignalHandler& callback) = 0; 35 36 // Unregister a previously registered handler for the given |signal|. 37 virtual void UnregisterHandler(int signal) = 0; 38 }; 39 40 } // namespace brillo 41 42 #endif // LIBBRILLO_BRILLO_ASYNCHRONOUS_SIGNAL_HANDLER_INTERFACE_H_ 43
