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arangodb/arangod/Scheduler/JobQueue.cpp

140 lines
4.0 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2016 ArangoDB GmbH, Cologne, Germany
///
/// 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.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Dr. Frank Celler
////////////////////////////////////////////////////////////////////////////////
#include "JobQueue.h"
#include "Basics/ConditionLocker.h"
#include "GeneralServer/RestHandler.h"
#include "Logger/Logger.h"
#include "Scheduler/Scheduler.h"
#include "Scheduler/SchedulerFeature.h"
using namespace arangodb;
namespace arangodb {
class JobQueueThread final
: public Thread,
public std::enable_shared_from_this<JobQueueThread> {
public:
JobQueueThread(JobQueue* server, rest::Scheduler* scheduler)
: Thread("JobQueueThread"), _jobQueue(server), _scheduler(scheduler) {}
~JobQueueThread() { shutdown(); }
void beginShutdown() {
Thread::beginShutdown();
_jobQueue->wakeup();
}
public:
void run() {
int idleTries = 0;
auto self = shared_from_this();
// iterate until we are shutting down
while (!isStopping()) {
++idleTries;
LOG_TOPIC(TRACE, Logger::THREADS)
<< "size of job queue: " << _jobQueue->queueSize();
while (_scheduler->shouldQueueMore()) {
Job* jobPtr = nullptr;
if (!_jobQueue->pop(jobPtr)) {
break;
}
LOG_TOPIC(TRACE, Logger::THREADS) << "starting next queued job";
idleTries = 0;
std::shared_ptr<Job> job(jobPtr);
_scheduler->post([this, self, job]() {
RequestStatistics::SET_QUEUE_END(job->_handler->statistics());
try {
job->_callback(std::move(job->_handler));
} catch (std::exception const& e) {
LOG_TOPIC(WARN, Logger::THREADS)
<< "caught exception while executing job callback: " << e.what();
} catch (...) {
LOG_TOPIC(WARN, Logger::THREADS)
<< "caught unknown exception while executing job callback";
}
this->_jobQueue->wakeup();
});
}
if (idleTries >= 2) {
LOG_TOPIC(TRACE, Logger::THREADS) << "queue manager going to sleep";
_jobQueue->waitForWork();
}
}
// clear all non-processed jobs
Job* job = nullptr;
while (_jobQueue->pop(job)) {
delete job;
}
}
private:
JobQueue* _jobQueue;
rest::Scheduler* _scheduler;
};
} // namespace arangodb
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
JobQueue::JobQueue(size_t maxQueueSize, rest::Scheduler* scheduler)
: _maxQueueSize(static_cast<int64_t>(maxQueueSize)),
_queue(maxQueueSize == 0 ? 512 : maxQueueSize),
_queueSize(0),
_queueThread(new JobQueueThread(this, scheduler)) {}
// -----------------------------------------------------------------------------
// --SECTION-- public methods
// -----------------------------------------------------------------------------
void JobQueue::start() { _queueThread->start(); }
void JobQueue::beginShutdown() { _queueThread->beginShutdown(); }
void JobQueue::wakeup() {
CONDITION_LOCKER(guard, _queueCondition);
guard.signal();
}
void JobQueue::waitForWork() {
static uint64_t WAIT_TIME = 1000 * 1000;
CONDITION_LOCKER(guard, _queueCondition);
guard.wait(WAIT_TIME);
}