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arangodb/lib/Basics/Thread.cpp

356 lines
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C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 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 Achim Brandt
////////////////////////////////////////////////////////////////////////////////
#include "Thread.h"
#include <errno.h>
#include <signal.h>
#include "Basics/ConditionLocker.h"
#include "Basics/Exceptions.h"
#include "Basics/Logger.h"
#include "Basics/WorkMonitor.h"
#include <velocypack/Builder.h>
#include <velocypack/velocypack-aliases.h>
using namespace arangodb;
using namespace arangodb::basics;
////////////////////////////////////////////////////////////////////////////////
/// @brief local thread number
////////////////////////////////////////////////////////////////////////////////
static thread_local uint64_t LOCAL_THREAD_NUMBER = 0;
#if !defined(ARANGODB_HAVE_GETTID) && !defined(_WIN32)
namespace {
std::atomic<uint64_t> NEXT_THREAD_ID(1);
}
#endif
////////////////////////////////////////////////////////////////////////////////
/// @brief current work description as thread local variable
////////////////////////////////////////////////////////////////////////////////
thread_local Thread* Thread::CURRENT_THREAD = nullptr;
////////////////////////////////////////////////////////////////////////////////
/// @brief static started with access to the private variables
////////////////////////////////////////////////////////////////////////////////
void Thread::startThread(void* arg) {
#if defined(ARANGODB_HAVE_GETTID)
LOCAL_THREAD_NUMBER = (uint64_t)gettid();
#elif defined(_WIN32)
LOCAL_THREAD_NUMBER = (uint64_t)GetCurrentThreadId();
#else
LOCAL_THREAD_NUMBER = NEXT_THREAD_ID.fetch_add(1, std::memory_order_seq_cst);
#endif
Thread* ptr = static_cast<Thread*>(arg);
ptr->_threadNumber = LOCAL_THREAD_NUMBER;
WorkMonitor::pushThread(ptr);
try {
ptr->runMe();
} catch (...) {
WorkMonitor::popThread(ptr);
throw;
}
WorkMonitor::popThread(ptr);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the process id
////////////////////////////////////////////////////////////////////////////////
TRI_pid_t Thread::currentProcessId() {
#ifdef _WIN32
return _getpid();
#else
return getpid();
#endif
}
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the thread process id
////////////////////////////////////////////////////////////////////////////////
uint64_t Thread::currentThreadNumber() { return LOCAL_THREAD_NUMBER; }
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the thread id
////////////////////////////////////////////////////////////////////////////////
TRI_tid_t Thread::currentThreadId() {
#ifdef TRI_HAVE_WIN32_THREADS
return GetCurrentThreadId();
#else
#ifdef TRI_HAVE_POSIX_THREADS
return pthread_self();
#else
#error "Thread::currentThreadId not implemented"
#endif
#endif
}
////////////////////////////////////////////////////////////////////////////////
/// @brief constructs a thread
////////////////////////////////////////////////////////////////////////////////
Thread::Thread(std::string const& name)
: _name(name),
_thread(),
_threadNumber(0),
_threadId(),
_finishedCondition(nullptr),
_state(ThreadState::CREATED),
_affinity(-1),
_workDescription(nullptr) {
TRI_InitThread(&_thread);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief deletes the thread
////////////////////////////////////////////////////////////////////////////////
Thread::~Thread() {
LOG_TOPIC(TRACE, Logger::THREADS) << "delete(" << _name << ")";
if (_state.load() == ThreadState::STOPPED) {
#ifdef TRI_HAVE_POSIX_THREADS
int res = pthread_detach(_thread);
if (res != 0) {
LOG_TOPIC(INFO, Logger::THREADS) << "cannot detach thread";
}
_state.store(ThreadState::DETACHED);
#endif
}
if (_state.load() != ThreadState::DETACHED) {
LOG(FATAL) << "thread is not detached, hard shutdown";
FATAL_ERROR_EXIT();
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief flags the tread as stopping
////////////////////////////////////////////////////////////////////////////////
void Thread::beginShutdown() {
LOG_TOPIC(TRACE, Logger::THREADS) << "beginShutdown(" << _name << ")";
ThreadState state = _state.load();
while (state != ThreadState::STOPPING && state != ThreadState::STOPPED &&
state != ThreadState::DETACHED) {
_state.compare_exchange_strong(state, ThreadState::STOPPING);
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief called from the destructor
////////////////////////////////////////////////////////////////////////////////
void Thread::shutdown() {
LOG_TOPIC(TRACE, Logger::THREADS) << "shutdown(" << _name << ")";
ThreadState state = _state.load();
while (state == ThreadState::CREATED) {
bool res = _state.compare_exchange_strong(state, ThreadState::DETACHED);
if (res) {
return;
}
}
if (_state.load() == ThreadState::STARTED) {
beginShutdown();
if (!isSilent()) {
LOG_TOPIC(WARN, Logger::THREADS) << "forcefully shutting down thread '"
<< _name << "'";
}
}
size_t n = 10 * 60 * 5; // * 100ms = 1s * 60 * 5
for (size_t i = 0; i < n; ++i) {
if (_state.load() == ThreadState::STOPPED) {
break;
}
usleep(100 * 1000);
}
if (_state.load() != ThreadState::STOPPED) {
LOG(FATAL) << "cannot shutdown threads, giving up";
FATAL_ERROR_EXIT();
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief checks if the current thread was asked to stop
////////////////////////////////////////////////////////////////////////////////
bool Thread::isStopping() const {
auto state = _state.load(std::memory_order_relaxed);
return state == ThreadState::STOPPING || state == ThreadState::STOPPED ||
state == ThreadState::DETACHED;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief starts the thread
////////////////////////////////////////////////////////////////////////////////
bool Thread::start(ConditionVariable* finishedCondition) {
_finishedCondition = finishedCondition;
if (_state.load() != ThreadState::CREATED) {
LOG_TOPIC(FATAL, Logger::THREADS)
<< "called started on an already started thread";
FATAL_ERROR_EXIT();
}
ThreadState expected = ThreadState::CREATED;
bool res = _state.compare_exchange_strong(expected, ThreadState::STARTED);
if (!res) {
LOG_TOPIC(WARN, Logger::THREADS) << "thread died before it could start";
return false;
}
bool ok =
TRI_StartThread(&_thread, &_threadId, _name.c_str(), &startThread, this);
if (ok) {
if (0 <= _affinity) {
TRI_SetProcessorAffinity(&_thread, (size_t)_affinity);
}
} else {
_state.store(ThreadState::STOPPED);
LOG_TOPIC(ERR, Logger::THREADS) << "could not start thread '"
<< _name
<< "': " << strerror(errno);
return false;
}
return ok;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief sets the process affinity
////////////////////////////////////////////////////////////////////////////////
void Thread::setProcessorAffinity(size_t c) { _affinity = (int)c; }
////////////////////////////////////////////////////////////////////////////////
/// @brief sets the current work description
////////////////////////////////////////////////////////////////////////////////
void Thread::setWorkDescription(WorkDescription* desc) {
_workDescription.store(desc);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief sets the previous work description
////////////////////////////////////////////////////////////////////////////////
WorkDescription* Thread::setPrevWorkDescription() {
return _workDescription.exchange(_workDescription.load()->_prev.load());
}
////////////////////////////////////////////////////////////////////////////////
/// @brief sets status
////////////////////////////////////////////////////////////////////////////////
void Thread::addStatus(VPackBuilder* b) {
b->add("affinity", VPackValue(_affinity));
switch (_state.load()) {
case ThreadState::CREATED:
b->add("started", VPackValue("created"));
break;
case ThreadState::STARTED:
b->add("started", VPackValue("started"));
break;
case ThreadState::STOPPING:
b->add("started", VPackValue("stopping"));
break;
case ThreadState::STOPPED:
b->add("started", VPackValue("stopped"));
break;
case ThreadState::DETACHED:
b->add("started", VPackValue("detached"));
break;
}
}
void Thread::runMe() {
try {
run();
_state.store(ThreadState::STOPPED);
} catch (Exception const& ex) {
LOG_TOPIC(ERR, Logger::THREADS) << "exception caught in thread '"
<< _name << "': " << ex.what();
Logger::flush();
_state.store(ThreadState::STOPPED);
throw;
} catch (std::exception const& ex) {
LOG_TOPIC(ERR, Logger::THREADS) << "exception caught in thread '"
<< _name << "': " << ex.what();
Logger::flush();
_state.store(ThreadState::STOPPED);
throw;
} catch (...) {
if (!isSilent()) {
LOG_TOPIC(ERR, Logger::THREADS) << "exception caught in thread '"
<< _name << "'";
Logger::flush();
}
_state.store(ThreadState::STOPPED);
throw;
}
if (_finishedCondition != nullptr) {
CONDITION_LOCKER(locker, *_finishedCondition);
locker.broadcast();
}
}