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arangodb/lib/Dispatcher/DispatcherThread.cpp

324 lines
10 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// @brief dispatcher thread
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2004-2013 triAGENS 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 triAGENS GmbH, Cologne, Germany
///
/// @author Dr. Frank Celler
/// @author Martin Schoenert
/// @author Copyright 2009-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#include "DispatcherThread.h"
#include "Basics/Exceptions.h"
#include "Basics/StringUtils.h"
#include "Dispatcher/Dispatcher.h"
#include "Dispatcher/DispatcherQueue.h"
#include "Dispatcher/Job.h"
#include "Logger/Logger.h"
using namespace triagens::basics;
using namespace triagens::rest;
// -----------------------------------------------------------------------------
// --SECTION-- class DispatcherThread
// -----------------------------------------------------------------------------
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @addtogroup Dispatcher
/// @{
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/// @brief constructs a dispatcher thread
////////////////////////////////////////////////////////////////////////////////
DispatcherThread::DispatcherThread (DispatcherQueue* queue)
: Thread("dispatcher"),
_queue(queue),
_jobType(Job::READ_JOB) {
allowAsynchronousCancelation();
}
////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////
// -----------------------------------------------------------------------------
// --SECTION-- Thread methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @addtogroup Dispatcher
/// @{
////////////////////////////////////////////////////////////////////////////////
void DispatcherThread::run () {
_queue->_accessQueue.lock();
_queue->_nrStarted--;
_queue->_nrRunning++;
_queue->_nrUp++;
_queue->_startedThreads.insert(this);
// iterate until we are shutting down.
while (_jobType != Job::SPECIAL_JOB && _queue->_stopping == 0) {
// delete old jobs
for (list<DispatcherThread*>::iterator i = _queue->_stoppedThreads.begin(); i != _queue->_stoppedThreads.end(); ++i) {
delete *i;
}
_queue->_stoppedThreads.clear();
_queue->_nrStopped = 0;
// a job is waiting to execute
if ( ! _queue->_readyJobs.empty()
&& _queue->_monopolizer == 0
&& ! (_queue->_readyJobs.front()->type() == Job::WRITE_JOB && 1 < _queue->_nrRunning)) {
// try next job
Job* job = _queue->_readyJobs.front();
_queue->_readyJobs.pop_front();
// handle job type
_jobType = job->type();
// start a new thread for special jobs
if (_jobType == Job::SPECIAL_JOB) {
_queue->_nrRunning--;
_queue->_nrSpecial++;
_queue->startQueueThread();
}
// monopolize queue
else if (_jobType == Job::WRITE_JOB) {
_queue->_monopolizer = this;
}
// now release the queue lock (initialise is inside the lock, work outside)
_queue->_accessQueue.unlock();
// do the work (this might change the job type)
Job::status_e status = Job::JOB_FAILED;
try {
RequestStatisticsAgentSetQueueEnd(job);
// set current thread
job->setDispatcherThread(this);
// and do all the dirty work
status = job->work();
}
catch (TriagensError const& ex) {
try {
job->handleError(ex);
}
catch (TriagensError const& ex) {
LOGGER_WARNING("caught error while handling error: " << DIAGNOSTIC_INFORMATION(ex));
}
catch (std::exception const& ex) {
LOGGER_WARNING("caught error while handling error: " << ex.what());
}
catch (...) {
LOGGER_WARNING("caught error while handling error!");
}
status = Job::JOB_FAILED;
}
catch (std::exception const& ex) {
try {
InternalError err(string("job failed with unknown in work: ") + ex.what(), __FILE__, __LINE__);
job->handleError(err);
}
catch (TriagensError const& ex) {
LOGGER_WARNING("caught error while handling error: " << DIAGNOSTIC_INFORMATION(ex));
}
catch (std::exception const& ex) {
LOGGER_WARNING("caught error while handling error: " << ex.what());
}
catch (...) {
LOGGER_WARNING("caught error while handling error!");
}
status = Job::JOB_FAILED;
}
catch (...) {
#ifdef TRI_HAVE_POSIX_THREADS
if (_queue->_stopping != 0) {
LOGGER_WARNING("caught cancellation exception during work");
throw;
}
#endif
try {
InternalError err("job failed with unknown error in work", __FILE__, __LINE__);
job->handleError(err);
}
catch (TriagensError const& ex) {
LOGGER_WARNING("caught error while handling error: " << DIAGNOSTIC_INFORMATION(ex));
}
catch (std::exception const& ex) {
LOGGER_WARNING("caught error while handling error: " << ex.what());
}
catch (...) {
LOGGER_WARNING("caught error while handling error!");
}
status = Job::JOB_FAILED;
}
// trigger GC
tick(false);
// detached jobs (status == JOB::DETACH) might be killed asynchronously by other means
// it is not safe to use detached jobs after job->work()
// detached jobs
if (status == Job::JOB_DETACH) {
// we must do absolutely nothing with dispatched jobs here because they might be
// killed asynchronously and this is not under our control
}
// normal jobs
else {
// finish jobs
try {
job->setDispatcherThread(0);
if (status == Job::JOB_DONE) {
job->cleanup();
}
else if (status == Job::JOB_REQUEUE) {
_queue->_dispatcher->addJob(job);
}
else if (status == Job::JOB_FAILED) {
job->cleanup();
}
}
catch (...) {
#ifdef TRI_HAVE_POSIX_THREADS
if (_queue->_stopping != 0) {
LOGGER_WARNING("caught cancellation exception during cleanup");
throw;
}
#endif
LOGGER_WARNING("caught error while cleaning up!");
}
}
// require the lock
_queue->_accessQueue.lock();
// cleanup
_queue->_monopolizer = 0;
if (0 < _queue->_nrWaiting && ! _queue->_readyJobs.empty()) {
_queue->_accessQueue.broadcast();
}
}
else {
// cleanup without holding a lock
_queue->_accessQueue.unlock();
tick(true);
_queue->_accessQueue.lock();
// wait, if there are no jobs
if (_queue->_readyJobs.empty()) {
_queue->_nrRunning--;
_queue->_nrWaiting++;
_queue->_accessQueue.wait();
_queue->_nrWaiting--;
_queue->_nrRunning++;
}
}
}
_queue->_stoppedThreads.push_back(this);
_queue->_startedThreads.erase(this);
_queue->_nrRunning--;
_queue->_nrStopped++;
if (_jobType == Job::SPECIAL_JOB) {
_queue->_nrSpecial--;
}
_queue->_nrUp--;
_queue->_accessQueue.unlock();
LOGGER_TRACE("dispatcher thread has finished");
}
////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////
// -----------------------------------------------------------------------------
// --SECTION-- protected methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @addtogroup Dispatcher
/// @{
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/// @brief called to report the status of the thread
////////////////////////////////////////////////////////////////////////////////
void DispatcherThread::reportStatus () {
}
////////////////////////////////////////////////////////////////////////////////
/// @brief called in regular intervals
////////////////////////////////////////////////////////////////////////////////
void DispatcherThread::tick (bool) {
}
////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////
// -----------------------------------------------------------------------------
// --SECTION-- END-OF-FILE
// -----------------------------------------------------------------------------
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