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arangodb/arangod/Scheduler/ApplicationScheduler.cpp

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C++

////////////////////////////////////////////////////////////////////////////////
/// @brief application server scheduler implementation
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2014 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 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 ArangoDB GmbH, Cologne, Germany
///
/// @author Dr. Frank Celler
/// @author Copyright 2014, ArangoDB GmbH, Cologne, Germany
/// @author Copyright 2009-2014, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#ifdef _WIN32
#include "Basics/win-utils.h"
#endif
#include <iostream>
#include "ApplicationScheduler.h"
#include "Basics/Exceptions.h"
#include "Basics/logging.h"
#include "Basics/process-utils.h"
#include "Scheduler/PeriodicTask.h"
#include "Scheduler/SchedulerLibev.h"
#include "Scheduler/SignalTask.h"
using namespace std;
using namespace triagens::basics;
using namespace triagens::rest;
// -----------------------------------------------------------------------------
// --SECTION-- private classes
// -----------------------------------------------------------------------------
namespace {
////////////////////////////////////////////////////////////////////////////////
/// @brief forward declared handler for crtl c for windows
////////////////////////////////////////////////////////////////////////////////
#ifdef _WIN32
#include <windows.h>
#include <stdio.h>
class ControlCTask;
bool static CtrlHandler(DWORD eventType);
static ControlCTask* localControlCTask;
#endif
////////////////////////////////////////////////////////////////////////////////
/// @brief handles control-c
////////////////////////////////////////////////////////////////////////////////
#ifdef _WIN32
class ControlCTask : public SignalTask {
public:
explicit ControlCTask (ApplicationServer* server)
: Task("Control-C"), SignalTask(), _server(server), _seen(0) {
localControlCTask = this;
int result = SetConsoleCtrlHandler((PHANDLER_ROUTINE) CtrlHandler, true);
if (result == 0) {
LOG_WARNING("unable to install control-c handler");
}
}
public:
bool handleSignal () {
return true;
}
public:
ApplicationServer* _server;
uint32_t _seen;
};
#else
class ControlCTask : public SignalTask {
public:
explicit ControlCTask (ApplicationServer* server)
: Task("Control-C"), SignalTask(), _server(server), _seen(0) {
addSignal(SIGINT);
addSignal(SIGTERM);
addSignal(SIGQUIT);
}
public:
bool handleSignal () {
string msg = _server->getName() + " [shutting down]";
TRI_SetProcessTitle(msg.c_str());
if (_seen == 0) {
LOG_INFO("control-c received, beginning shut down sequence");
_server->beginShutdown();
}
else {
LOG_ERROR("control-c received (again!), terminating");
_exit(1);
// TRI_EXIT_FUNCTION(EXIT_FAILURE,0);
}
++_seen;
return true;
}
private:
ApplicationServer* _server;
uint32_t _seen;
};
#endif
////////////////////////////////////////////////////////////////////////////////
/// @brief handles hangup
////////////////////////////////////////////////////////////////////////////////
#ifdef _WIN32
class HangupTask : public SignalTask {
public:
HangupTask ()
: Task("Hangup"), SignalTask() {
}
public:
bool handleSignal () {
LOG_INFO("hangup received, about to reopen logfile");
TRI_ReopenLogging();
LOG_INFO("hangup received, reopened logfile");
return true;
}
};
#else
class HangupTask : public SignalTask {
public:
HangupTask ()
: Task("Hangup"), SignalTask() {
addSignal(SIGHUP);
}
public:
bool handleSignal () {
LOG_INFO("hangup received, about to reopen logfile");
TRI_ReopenLogging();
LOG_INFO("hangup received, reopened logfile");
return true;
}
};
#endif
////////////////////////////////////////////////////////////////////////////////
/// @brief handles sigusr1 signals
////////////////////////////////////////////////////////////////////////////////
class Sigusr1Task : public SignalTask {
public:
explicit Sigusr1Task (ApplicationScheduler* scheduler)
: Task("Sigusr1"), SignalTask(), _scheduler(scheduler) {
#ifndef _WIN32
addSignal(SIGUSR1);
#endif
}
public:
bool handleSignal () {
Scheduler* scheduler = this->_scheduler->scheduler();
if (scheduler != nullptr) {
bool isActive = scheduler->isActive();
LOG_INFO("sigusr1 received - setting active flag to %d", (int) (! isActive));
scheduler->setActive(! isActive);
}
return true;
}
private:
ApplicationScheduler* _scheduler;
};
////////////////////////////////////////////////////////////////////////////////
/// @brief produces a scheduler status report
////////////////////////////////////////////////////////////////////////////////
class SchedulerReporterTask : public PeriodicTask {
public:
SchedulerReporterTask (Scheduler* scheduler, double _reportInterval)
: Task("Scheduler-Reporter"),
PeriodicTask("Scheduler-Reporter", 1.0, _reportInterval),
_scheduler(scheduler) {
}
public:
bool handlePeriod () {
_scheduler->reportStatus();
return true;
}
public:
Scheduler* _scheduler;
};
////////////////////////////////////////////////////////////////////////////////
/// @brief handler for crtl c for windows
////////////////////////////////////////////////////////////////////////////////
#ifdef _WIN32
bool CtrlHandler (DWORD eventType) {
ControlCTask* ccTask = localControlCTask;
// string msg = ccTask->_server->getName() + " [shutting down]";
bool shutdown = false;
string shutdownMessage;
// .........................................................................
// TODO: popup message
// .........................................................................
switch (eventType) {
case CTRL_BREAK_EVENT: {
//TODO: windows does not appreciate changing the environment in this manner
//TRI_SetProcessTitle(msg.c_str());
shutdown = true;
shutdownMessage = "control-break received";
break;
}
case CTRL_C_EVENT: {
//TODO: windows does not appreciate changing the environment in this manner
//TRI_SetProcessTitle(msg.c_str());
shutdown = true;
shutdownMessage = "control-c received";
break;
}
case CTRL_CLOSE_EVENT: {
//TODO: windows does not appreciate changing the environment in this manner
//TRI_SetProcessTitle(msg.c_str());
shutdown = true;
shutdownMessage = "window-close received";
break;
}
case CTRL_LOGOFF_EVENT: {
//TODO: windows does not appreciate changing the environment in this manner
//TRI_SetProcessTitle(msg.c_str());
shutdown = true;
shutdownMessage = "user-logoff received";
break;
}
case CTRL_SHUTDOWN_EVENT: {
//TODO: windows does not appreciate changing the environment in this manner
//TRI_SetProcessTitle(msg.c_str());
shutdown = true;
shutdownMessage = "system-shutdown received";
break;
}
default: {
shutdown = false;
break;
}
} // end of switch statement
if (shutdown == false) {
LOG_ERROR("Invalid CTRL HANDLER event received - ignoring event");
return true;
}
if (ccTask->_seen == 0) {
LOG_INFO("%s, beginning shut down sequence", shutdownMessage.c_str());
ccTask->_server->beginShutdown();
++ccTask->_seen;
return true;
}
// ............................................................................
// user is desperate to kill the server!
// ............................................................................
LOG_INFO("%s, terminating", shutdownMessage.c_str());
_exit(EXIT_FAILURE); // quick exit for windows
return true;
}
#endif
}
// -----------------------------------------------------------------------------
// --SECTION-- class ApplicationScheduler
// -----------------------------------------------------------------------------
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief constructor
////////////////////////////////////////////////////////////////////////////////
ApplicationScheduler::ApplicationScheduler (ApplicationServer* applicationServer)
: ApplicationFeature("scheduler"),
_applicationServer(applicationServer),
_scheduler(nullptr),
_tasks(),
_reportInterval(0.0),
_multiSchedulerAllowed(true),
_nrSchedulerThreads(4),
_backend(0),
_descriptorMinimum(256),
_disableControlCHandler(false) {
}
////////////////////////////////////////////////////////////////////////////////
/// @brief destructor
////////////////////////////////////////////////////////////////////////////////
ApplicationScheduler::~ApplicationScheduler () {
delete _scheduler;
}
// -----------------------------------------------------------------------------
// --SECTION-- public methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief allows a multi scheduler to be build
////////////////////////////////////////////////////////////////////////////////
void ApplicationScheduler::allowMultiScheduler (bool value) {
_multiSchedulerAllowed = value;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the scheduler
////////////////////////////////////////////////////////////////////////////////
Scheduler* ApplicationScheduler::scheduler () const {
return _scheduler;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief installs a signal handler
////////////////////////////////////////////////////////////////////////////////
void ApplicationScheduler::installSignalHandler (SignalTask* task) {
if (_scheduler == nullptr) {
LOG_FATAL_AND_EXIT("no scheduler is known, cannot install signal handler");
}
_scheduler->registerTask(task);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the number of used threads
////////////////////////////////////////////////////////////////////////////////
size_t ApplicationScheduler::numberOfThreads () {
return _nrSchedulerThreads;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief sets the processor affinity
////////////////////////////////////////////////////////////////////////////////
void ApplicationScheduler::setProcessorAffinity (std::vector<size_t> const& cores) {
#ifdef TRI_HAVE_THREAD_AFFINITY
size_t j = 0;
for (uint32_t i = 0; i < _nrSchedulerThreads; ++i) {
size_t c = cores[j];
LOG_DEBUG("using core %d for scheduler thread %d", (int) c, (int) i);
_scheduler->setProcessorAffinity(i, c);
++j;
if (j >= cores.size()) {
j = 0;
}
}
#endif
}
////////////////////////////////////////////////////////////////////////////////
/// @brief disables CTRL-C handling (because taken over by console input)
////////////////////////////////////////////////////////////////////////////////
void ApplicationScheduler::disableControlCHandler () {
_disableControlCHandler = true;
}
// -----------------------------------------------------------------------------
// --SECTION-- ApplicationFeature methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// {@inheritDoc}
////////////////////////////////////////////////////////////////////////////////
void ApplicationScheduler::setupOptions (std::map<std::string, ProgramOptionsDescription>& options) {
// .............................................................................
// command line options
// .............................................................................
options["General Options:help-admin"]
("show-io-backends", "show available io backends")
;
// .............................................................................
// application server options
// .............................................................................
options["Server Options:help-admin"]
#ifdef _WIN32
// ...........................................................................
// since we are trying to use libev, then only select is available
// no point in allowing this to be configured at this stage. Perhaps if we
// eventually write a native libev we can offer something.
// ...........................................................................
//("scheduler.backend", &_backend, "1: select, 2: poll, 4: epoll")
#else
("scheduler.backend", &_backend, "1: select, 2: poll, 4: epoll")
#endif
("scheduler.report-interval", &_reportInterval, "scheduler report interval")
#ifdef TRI_HAVE_GETRLIMIT
("server.descriptors-minimum", &_descriptorMinimum, "minimum number of file descriptors needed to start")
#endif
;
if (_multiSchedulerAllowed) {
options["Server Options:help-admin"]
("scheduler.threads", &_nrSchedulerThreads, "number of threads for I/O scheduler")
;
}
}
////////////////////////////////////////////////////////////////////////////////
/// {@inheritDoc}
////////////////////////////////////////////////////////////////////////////////
bool ApplicationScheduler::parsePhase1 (triagens::basics::ProgramOptions& options) {
// show io backends
if (options.has("show-io-backends")) {
cout << "available io backends are: " << SchedulerLibev::availableBackends() << endl;
TRI_EXIT_FUNCTION(EXIT_SUCCESS, NULL);
}
return true;
}
////////////////////////////////////////////////////////////////////////////////
/// {@inheritDoc}
////////////////////////////////////////////////////////////////////////////////
bool ApplicationScheduler::parsePhase2 (triagens::basics::ProgramOptions& options) {
// adjust file descriptors
adjustFileDescriptors();
return true;
}
////////////////////////////////////////////////////////////////////////////////
/// {@inheritDoc}
////////////////////////////////////////////////////////////////////////////////
bool ApplicationScheduler::prepare () {
if (_disabled) {
return true;
}
buildScheduler();
return true;
}
////////////////////////////////////////////////////////////////////////////////
/// {@inheritDoc}
////////////////////////////////////////////////////////////////////////////////
bool ApplicationScheduler::start () {
if (_disabled) {
return true;
}
buildSchedulerReporter();
buildControlCHandler();
#ifdef TRI_HAVE_GETRLIMIT
struct rlimit rlim;
int res = getrlimit(RLIMIT_NOFILE, &rlim);
if (res == 0) {
LOG_INFO("file-descriptors (nofiles) hard limit is %d, soft limit is %d", (int) rlim.rlim_max, (int) rlim.rlim_cur);
}
#endif
bool ok = _scheduler->start(nullptr);
if (! ok) {
LOG_FATAL_AND_EXIT("the scheduler cannot be started");
}
while (! _scheduler->isStarted()) {
LOG_DEBUG("waiting for scheduler to start");
usleep(500 * 1000);
}
return true;
}
////////////////////////////////////////////////////////////////////////////////
/// {@inheritDoc}
////////////////////////////////////////////////////////////////////////////////
bool ApplicationScheduler::open () {
if (_disabled) {
return true;
}
if (_scheduler != nullptr) {
return _scheduler->open();
}
return false;
}
////////////////////////////////////////////////////////////////////////////////
/// {@inheritDoc}
////////////////////////////////////////////////////////////////////////////////
void ApplicationScheduler::stop () {
if (_disabled) {
return;
}
if (_scheduler != nullptr) {
static size_t const MAX_TRIES = 10;
// remove all helper tasks
for (auto& task : _tasks) {
_scheduler->destroyTask(task);
}
_tasks.clear();
// shutdown the scheduler
_scheduler->beginShutdown();
for (size_t count = 0; count < MAX_TRIES && _scheduler->isRunning(); ++count) {
LOG_TRACE("waiting for scheduler to stop");
usleep(100000);
}
_scheduler->shutdown();
// delete the scheduler
delete _scheduler;
_scheduler = nullptr;
}
}
// -----------------------------------------------------------------------------
// --SECTION-- private methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief builds the scheduler
////////////////////////////////////////////////////////////////////////////////
void ApplicationScheduler::buildScheduler () {
if (_scheduler != nullptr) {
LOG_FATAL_AND_EXIT("a scheduler has already been created");
}
_scheduler = new SchedulerLibev(_nrSchedulerThreads, _backend);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief builds the scheduler reporter
////////////////////////////////////////////////////////////////////////////////
void ApplicationScheduler::buildSchedulerReporter () {
if (_scheduler == nullptr) {
LOG_FATAL_AND_EXIT("no scheduler is known, cannot create control-c handler");
}
if (0.0 < _reportInterval) {
Task* reporter = new SchedulerReporterTask(_scheduler, _reportInterval);
_scheduler->registerTask(reporter);
_tasks.emplace_back(reporter);
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief quits on control-c signal
////////////////////////////////////////////////////////////////////////////////
void ApplicationScheduler::buildControlCHandler () {
if (_scheduler == nullptr) {
LOG_FATAL_AND_EXIT("no scheduler is known, cannot create control-c handler");
}
if (! _disableControlCHandler) {
// control C handler
Task* controlC = new ControlCTask(_applicationServer);
_scheduler->registerTask(controlC);
_tasks.emplace_back(controlC);
}
// hangup handler
Task* hangup = new HangupTask();
_scheduler->registerTask(hangup);
_tasks.emplace_back(hangup);
// sigusr handler
Task* sigusr = new Sigusr1Task(this);
_scheduler->registerTask(sigusr);
_tasks.emplace_back(sigusr);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief adjusts the file descriptor limits
////////////////////////////////////////////////////////////////////////////////
void ApplicationScheduler::adjustFileDescriptors () {
#ifdef TRI_HAVE_GETRLIMIT
if (0 < _descriptorMinimum) {
struct rlimit rlim;
int res = getrlimit(RLIMIT_NOFILE, &rlim);
if (res != 0) {
LOG_FATAL_AND_EXIT("cannot get the file descriptor limit: %s", strerror(errno));
}
LOG_DEBUG("file-descriptors (nofiles) hard limit is %d, soft limit is %d", (int) rlim.rlim_max, (int) rlim.rlim_cur);
bool changed = false;
if (rlim.rlim_max < _descriptorMinimum) {
LOG_DEBUG("hard limit %d is too small, trying to raise", (int) rlim.rlim_max);
rlim.rlim_max = _descriptorMinimum;
rlim.rlim_cur = _descriptorMinimum;
res = setrlimit(RLIMIT_NOFILE, &rlim);
if (res < 0) {
LOG_FATAL_AND_EXIT("cannot raise the file descriptor limit to %d: %s", (int) _descriptorMinimum, strerror(errno));
}
changed = true;
}
else if (rlim.rlim_cur < _descriptorMinimum) {
LOG_DEBUG("soft limit %d is too small, trying to raise", (int) rlim.rlim_cur);
rlim.rlim_cur = _descriptorMinimum;
res = setrlimit(RLIMIT_NOFILE, &rlim);
if (res < 0) {
LOG_FATAL_AND_EXIT("cannot raise the file descriptor limit to %d: %s", (int) _descriptorMinimum, strerror(errno));
}
changed = true;
}
if (changed) {
res = getrlimit(RLIMIT_NOFILE, &rlim);
if (res != 0) {
LOG_FATAL_AND_EXIT("cannot get the file descriptor limit: %s", strerror(errno));
}
LOG_INFO("file-descriptors (nofiles) new hard limit is %d, new soft limit is %d", (int) rlim.rlim_max, (int) rlim.rlim_cur);
}
// the select backend has more restrictions
if (_backend == 1) {
if (FD_SETSIZE < _descriptorMinimum) {
LOG_FATAL_AND_EXIT("i/o backend 'select' has been selected, which supports only %d descriptors, but %d are required",
(int) FD_SETSIZE,
(int) _descriptorMinimum);
}
}
}
#endif
}
// -----------------------------------------------------------------------------
// --SECTION-- END-OF-FILE
// -----------------------------------------------------------------------------
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