| // Copyright 2016 Google Inc. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include "starboard/shared/signal/suspend_signals.h" |
| |
| #include <signal.h> |
| #include <sys/socket.h> |
| |
| #include "starboard/configuration.h" |
| #include "starboard/log.h" |
| #include "starboard/memory.h" |
| #include "starboard/shared/signal/signal_internal.h" |
| #include "starboard/shared/starboard/application.h" |
| #include "starboard/system.h" |
| |
| namespace starboard { |
| namespace shared { |
| namespace signal { |
| |
| namespace { |
| |
| int UnblockSignal(int signal_id) { |
| sigset_t mask; |
| ::sigemptyset(&mask); |
| ::sigaddset(&mask, signal_id); |
| |
| sigset_t previous_mask; |
| return ::sigprocmask(SIG_UNBLOCK, &mask, &previous_mask); |
| } |
| |
| void SetSignalHandler(int signal_id, SignalHandlerFunction handler) { |
| struct sigaction action = {0}; |
| |
| action.sa_handler = handler; |
| action.sa_flags = 0; |
| ::sigemptyset(&action.sa_mask); |
| |
| ::sigaction(signal_id, &action, NULL); |
| } |
| |
| void SuspendDone(void* /*context*/) { |
| // Stop all thread execution after fully transitioning into Suspended. |
| raise(SIGSTOP); |
| } |
| |
| void Suspend(int signal_id) { |
| LogSignalCaught(signal_id); |
| starboard::Application::Get()->Suspend(NULL, &SuspendDone); |
| } |
| |
| void Resume(int signal_id) { |
| LogSignalCaught(signal_id); |
| // TODO: Resume or Unpause based on state before suspend? |
| starboard::Application::Get()->Unpause(NULL, NULL); |
| } |
| |
| void LowMemory(int signal_id) { |
| LogSignalCaught(signal_id); |
| starboard::Application::Get()->InjectLowMemoryEvent(); |
| } |
| |
| void Ignore(int signal_id) { |
| LogSignalCaught(signal_id); |
| SbLogRawDumpStack(1); |
| SbLogFlush(); |
| } |
| |
| } // namespace |
| |
| #if !defined(MSG_NOSIGNAL) && defined(SO_NOSIGPIPE) |
| // See "#if !defined(MSG_NOSIGNAL)" below. |
| // OS X, which we do not build for today, has another mechanism which |
| // should be used. |
| #error On this platform, please use SO_NOSIGPIPE and leave the SIGPIPE \ |
| handler at default. |
| #endif |
| |
| void InstallSuspendSignalHandlers() { |
| #if !defined(MSG_NOSIGNAL) |
| // By default in POSIX, sending to a closed socket causes a SIGPIPE |
| // If we cannot disable that behavior, we must ignore SIGPIPE. |
| // Ignoring SIGPIPE means cases that use pipes to redirect the stdio |
| // log messages may behave in surprising ways, so it's not desirable. |
| SetSignalHandler(SIGPIPE, &Ignore); |
| #endif |
| SetSignalHandler(SIGUSR1, &Suspend); |
| UnblockSignal(SIGUSR1); |
| SetSignalHandler(SIGUSR2, &LowMemory); |
| UnblockSignal(SIGUSR2); |
| SetSignalHandler(SIGCONT, &Resume); |
| } |
| |
| void UninstallSuspendSignalHandlers() { |
| #if !defined(MSG_NOSIGNAL) |
| SetSignalHandler(SIGPIPE, SIG_DFL); |
| #endif |
| SetSignalHandler(SIGUSR1, SIG_DFL); |
| SetSignalHandler(SIGUSR2, SIG_DFL); |
| SetSignalHandler(SIGCONT, SIG_DFL); |
| } |
| |
| } // namespace signal |
| } // namespace shared |
| } // namespace starboard |