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/*
*
* Copyright (c) 2006 The Apache Software Foundation
*
* 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 "qpid/Plugin.h"
#include "qpid/Options.h"
#include "qpid/log/Statement.h"
#include "qpid/broker/Broker.h"
#include "qpid/sys/Timer.h"
#include "qpid/sys/Fork.h"
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
namespace qpid {
namespace cluster {
using broker::Broker;
struct Settings {
Settings() : interval(0) {}
int interval;
};
struct WatchDogOptions : public qpid::Options {
Settings& settings;
WatchDogOptions(Settings& s) : settings(s) {
addOptions()
("watchdog-interval", optValue(settings.interval, "N"),
"broker is automatically killed if it is hung for more than \
N seconds. 0 disables watchdog.");
}
};
struct WatchDogTask : public sys::TimerTask {
int pid;
sys::Timer& timer;
int interval;
WatchDogTask(int pid_, sys::Timer& t, int _interval)
: TimerTask(_interval*sys::TIME_SEC/2), pid(pid_), timer(t), interval(_interval) {}
void fire() {
timer.add (new WatchDogTask(pid, timer, interval));
QPID_LOG(debug, "Sending keepalive signal to watchdog");
::kill(pid, SIGUSR1);
}
};
struct WatchDogPlugin : public qpid::Plugin, public qpid::sys::Fork {
Settings settings;
WatchDogOptions options;
Broker* broker;
int watchdogPid;
WatchDogPlugin() : options(settings), broker(0), watchdogPid(0) {}
~WatchDogPlugin() {
if (watchdogPid) ::kill(watchdogPid, SIGTERM);
::waitpid(watchdogPid, 0, 0);
}
Options* getOptions() { return &options; }
void earlyInitialize(qpid::Plugin::Target& target) {
broker = dynamic_cast<Broker*>(&target);
if (broker && settings.interval) {
QPID_LOG(notice, "Starting watchdog process with interval of " <<
settings.interval << " seconds");
fork();
}
}
void initialize(Target&) {}
protected:
void child() { // Child of fork
const char* watchdog = ::getenv("QPID_WATCHDOG_EXE"); // For use in tests
if (!watchdog) watchdog=QPID_EXEC_DIR "/qpidd_watchdog";
std::string interval = boost::lexical_cast<std::string>(settings.interval);
::execl(watchdog, watchdog, interval.c_str(), NULL);
QPID_LOG(critical, "Failed to exec watchdog program " << watchdog );
::kill(::getppid(), SIGKILL);
exit(1);
}
void parent(int pid) { // Parent of fork
watchdogPid = pid;
broker->getTimer().add(
new WatchDogTask(watchdogPid, broker->getTimer(), settings.interval));
// TODO aconway 2009-08-10: to be extra safe, we could monitor
// the watchdog child and re-start it if it exits.
}
};
static WatchDogPlugin instance; // Static initialization.
}} // namespace qpid::cluster
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