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/**
* Copyright (C) 2014 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kControl
#include "mongo/platform/basic.h"
#include "mongo/util/signal_handlers.h"
#include <signal.h>
#if !defined(_WIN32)
#include <unistd.h>
#endif
#include "mongo/db/client.h"
#include "mongo/db/log_process_details.h"
#include "mongo/db/server_options.h"
#include "mongo/platform/process_id.h"
#include "mongo/stdx/thread.h"
#include "mongo/util/assert_util.h"
#include "mongo/util/exit_code.h"
#include "mongo/util/log.h"
#include "mongo/util/quick_exit.h"
#include "mongo/util/scopeguard.h"
#include "mongo/util/signal_handlers_synchronous.h"
#include "mongo/util/signal_win32.h"
#if defined(_WIN32)
namespace {
const char* strsignal(int signalNum) {
// should only see SIGABRT on windows
switch (signalNum) {
case SIGABRT:
return "SIGABRT";
default:
return "UNKNOWN";
}
}
}
#endif
namespace mongo {
using std::endl;
/*
* WARNING: PLEASE READ BEFORE CHANGING THIS MODULE
*
* All code in this module must be signal-friendly. Before adding any system
* call or other dependency, please make sure that this still holds.
*
* All code in this file follows this pattern:
* Generic code
* #ifdef _WIN32
* Windows code
* #else
* Posix code
* #endif
*
*/
namespace {
#ifdef _WIN32
void consoleTerminate(const char* controlCodeName) {
Client::initThread("consoleTerminate");
log() << "got " << controlCodeName << ", will terminate after current cmd ends" << endl;
exitCleanly(EXIT_KILL);
}
BOOL WINAPI CtrlHandler(DWORD fdwCtrlType) {
switch (fdwCtrlType) {
case CTRL_C_EVENT:
log() << "Ctrl-C signal";
consoleTerminate("CTRL_C_EVENT");
return TRUE;
case CTRL_CLOSE_EVENT:
log() << "CTRL_CLOSE_EVENT signal";
consoleTerminate("CTRL_CLOSE_EVENT");
return TRUE;
case CTRL_BREAK_EVENT:
log() << "CTRL_BREAK_EVENT signal";
consoleTerminate("CTRL_BREAK_EVENT");
return TRUE;
case CTRL_LOGOFF_EVENT:
// only sent to services, and only in pre-Vista Windows; FALSE means ignore
return FALSE;
case CTRL_SHUTDOWN_EVENT:
log() << "CTRL_SHUTDOWN_EVENT signal";
consoleTerminate("CTRL_SHUTDOWN_EVENT");
return TRUE;
default:
return FALSE;
}
}
void eventProcessingThread() {
std::string eventName = getShutdownSignalName(ProcessId::getCurrent().asUInt32());
HANDLE event = CreateEventA(NULL, TRUE, FALSE, eventName.c_str());
if (event == NULL) {
warning() << "eventProcessingThread CreateEvent failed: " << errnoWithDescription();
return;
}
ON_BLOCK_EXIT(CloseHandle, event);
int returnCode = WaitForSingleObject(event, INFINITE);
if (returnCode != WAIT_OBJECT_0) {
if (returnCode == WAIT_FAILED) {
warning() << "eventProcessingThread WaitForSingleObject failed: "
<< errnoWithDescription();
return;
} else {
warning() << "eventProcessingThread WaitForSingleObject failed: "
<< errnoWithDescription(returnCode);
return;
}
}
Client::initThread("eventTerminate");
log() << "shutdown event signaled, will terminate after current cmd ends";
exitCleanly(EXIT_CLEAN);
}
#else
// The signals in asyncSignals will be processed by this thread only, in order to
// ensure the db and log mutexes aren't held. Because this is run in a different thread, it does
// not need to be safe to call in signal context.
sigset_t asyncSignals;
void signalProcessingThread() {
Client::initThread("signalProcessingThread");
while (true) {
int actualSignal = 0;
int status = sigwait(&asyncSignals, &actualSignal);
fassert(16781, status == 0);
switch (actualSignal) {
case SIGUSR1:
// log rotate signal
fassert(16782, rotateLogs(serverGlobalParams.logRenameOnRotate));
logProcessDetailsForLogRotate();
break;
default:
// interrupt/terminate signal
log() << "got signal " << actualSignal << " (" << strsignal(actualSignal)
<< "), will terminate after current cmd ends" << endl;
exitCleanly(EXIT_CLEAN);
break;
}
}
}
#endif
} // namespace
void setupSignalHandlers(bool handleControlC) {
setupSynchronousSignalHandlers();
#ifdef _WIN32
if (!handleControlC) {
massert(10297,
"Couldn't register Windows Ctrl-C handler",
SetConsoleCtrlHandler(static_cast<PHANDLER_ROUTINE>(CtrlHandler), TRUE));
}
#else
// asyncSignals is a global variable listing the signals that should be handled by the
// interrupt thread, once it is started via startSignalProcessingThread().
sigemptyset(&asyncSignals);
sigaddset(&asyncSignals, SIGHUP);
if (!handleControlC) {
sigaddset(&asyncSignals, SIGINT);
}
sigaddset(&asyncSignals, SIGTERM);
sigaddset(&asyncSignals, SIGUSR1);
sigaddset(&asyncSignals, SIGXCPU);
#endif
}
void startSignalProcessingThread() {
#ifdef _WIN32
stdx::thread(eventProcessingThread).detach();
#else
// Mask signals in the current (only) thread. All new threads will inherit this mask.
invariant(pthread_sigmask(SIG_SETMASK, &asyncSignals, 0) == 0);
// Spawn a thread to capture the signals we just masked off.
stdx::thread(signalProcessingThread).detach();
#endif
}
#ifdef _WIN32
void removeControlCHandler() {
massert(28600,
"Couldn't unregister Windows Ctrl-C handler",
SetConsoleCtrlHandler(static_cast<PHANDLER_ROUTINE>(CtrlHandler), FALSE));
}
#endif
} // namespace mongo
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