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arangodb/lib/Basics/WorkMonitor.cpp

608 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
////////////////////////////////////////////////////////////////////////////////
#include "WorkMonitor.h"
#include <velocypack/Dumper.h>
#include <velocypack/Sink.h>
#include <velocypack/velocypack-aliases.h>
#include "Logger/Logger.h"
#include "Basics/Mutex.h"
#include "Basics/MutexLocker.h"
#include "Basics/tri-strings.h"
#include <boost/lockfree/queue.hpp>
using namespace arangodb;
using namespace arangodb::basics;
////////////////////////////////////////////////////////////////////////////////
/// @brief list of free descriptions
////////////////////////////////////////////////////////////////////////////////
static boost::lockfree::queue<WorkDescription*> EMPTY_WORK_DESCRIPTION(128);
////////////////////////////////////////////////////////////////////////////////
/// @brief list of freeable descriptions
////////////////////////////////////////////////////////////////////////////////
static boost::lockfree::queue<WorkDescription*> FREEABLE_WORK_DESCRIPTION(128);
////////////////////////////////////////////////////////////////////////////////
/// @brief tasks that want an overview
////////////////////////////////////////////////////////////////////////////////
static boost::lockfree::queue<uint64_t> WORK_OVERVIEW(128);
////////////////////////////////////////////////////////////////////////////////
/// @brief stopped flag
////////////////////////////////////////////////////////////////////////////////
static std::atomic<bool> WORK_MONITOR_STOPPED(true);
////////////////////////////////////////////////////////////////////////////////
/// @brief guard for THREADS
///
/// The order in this file must be: WORK_DESCRIPTION, THREADS_LOCK, THREADS,
/// WORK_MONITOR.
////////////////////////////////////////////////////////////////////////////////
static Mutex THREADS_LOCK;
////////////////////////////////////////////////////////////////////////////////
/// @brief all known threads
////////////////////////////////////////////////////////////////////////////////
static std::set<Thread*> THREADS;
////////////////////////////////////////////////////////////////////////////////
/// @brief singleton
////////////////////////////////////////////////////////////////////////////////
static WorkMonitor WORK_MONITOR;
////////////////////////////////////////////////////////////////////////////////
/// @brief lock for canceled ids
////////////////////////////////////////////////////////////////////////////////
static Mutex CANCEL_LOCK;
////////////////////////////////////////////////////////////////////////////////
/// @brief list of canceled ids
////////////////////////////////////////////////////////////////////////////////
static std::set<uint64_t> CANCEL_IDS;
////////////////////////////////////////////////////////////////////////////////
/// @brief current work description as thread local variable
////////////////////////////////////////////////////////////////////////////////
static thread_local WorkDescription* CURRENT_WORK_DESCRIPTION = nullptr;
////////////////////////////////////////////////////////////////////////////////
/// @brief vpack representation of a work description
////////////////////////////////////////////////////////////////////////////////
namespace {
std::atomic<uint64_t> NEXT_DESC_ID(static_cast<uint64_t>(0));
}
WorkDescription::WorkDescription(WorkType type, WorkDescription* prev)
: _type(type), _prev(prev), _id(0), _destroy(true), _canceled(false) {}
WorkMonitor::WorkMonitor() : Thread("WorkMonitor") {}
////////////////////////////////////////////////////////////////////////////////
/// @brief frees a work description
////////////////////////////////////////////////////////////////////////////////
void WorkMonitor::freeWorkDescription(WorkDescription* desc) {
if (WORK_MONITOR_STOPPED.load()) {
deleteWorkDescription(desc, true);
} else {
FREEABLE_WORK_DESCRIPTION.push(desc);
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief pushes a thread
////////////////////////////////////////////////////////////////////////////////
bool WorkMonitor::pushThread(Thread* thread) {
if (WORK_MONITOR_STOPPED.load()) {
return false;
}
TRI_ASSERT(thread != nullptr);
TRI_ASSERT(Thread::CURRENT_THREAD == nullptr);
Thread::CURRENT_THREAD = thread;
try {
WorkDescription* desc = createWorkDescription(WorkType::THREAD);
desc->_data.thread = thread;
activateWorkDescription(desc);
{
MUTEX_LOCKER(guard, THREADS_LOCK);
THREADS.insert(thread);
}
} catch (...) {
throw;
}
return true;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief pops a thread
////////////////////////////////////////////////////////////////////////////////
void WorkMonitor::popThread(Thread* thread) {
if (WORK_MONITOR_STOPPED.load()) {
return;
}
TRI_ASSERT(thread != nullptr);
WorkDescription* desc = deactivateWorkDescription();
TRI_ASSERT(desc->_type == WorkType::THREAD);
TRI_ASSERT(desc->_data.thread == thread);
try {
freeWorkDescription(desc);
{
MUTEX_LOCKER(guard, THREADS_LOCK);
THREADS.erase(thread);
}
} catch (...) {
// just to prevent throwing exceptions from here, as this method
// will be called in destructors...
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief pushes a custom task
////////////////////////////////////////////////////////////////////////////////
void WorkMonitor::pushAql(TRI_vocbase_t* vocbase, uint64_t queryId,
char const* text, size_t length) {
TRI_ASSERT(vocbase != nullptr);
TRI_ASSERT(text != nullptr);
WorkDescription* desc = createWorkDescription(WorkType::AQL_STRING);
TRI_ASSERT(desc != nullptr);
desc->_identifier._id = queryId;
desc->_vocbase = vocbase;
if (sizeof(desc->_data.text) - 1 < length) {
length = sizeof(desc->_data.text) - 1;
}
TRI_CopyString(desc->_data.text, text, length);
activateWorkDescription(desc);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief pushes a custom task
////////////////////////////////////////////////////////////////////////////////
void WorkMonitor::pushAql(TRI_vocbase_t* vocbase, uint64_t queryId) {
TRI_ASSERT(vocbase != nullptr);
WorkDescription* desc = createWorkDescription(WorkType::AQL_ID);
TRI_ASSERT(desc != nullptr);
desc->_identifier._id = queryId;
desc->_vocbase = vocbase;
activateWorkDescription(desc);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief pops a custom task
////////////////////////////////////////////////////////////////////////////////
void WorkMonitor::popAql() {
WorkDescription* desc = deactivateWorkDescription();
TRI_ASSERT(desc != nullptr);
TRI_ASSERT(desc->_type == WorkType::AQL_STRING ||
desc->_type == WorkType::AQL_ID);
try {
freeWorkDescription(desc);
} catch (...) {
// just to prevent throwing exceptions from here, as this method
// will be called in destructors...
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief pushes a custom task
////////////////////////////////////////////////////////////////////////////////
void WorkMonitor::pushCustom(char const* type, char const* text,
size_t length) {
TRI_ASSERT(type != nullptr);
TRI_ASSERT(text != nullptr);
WorkDescription* desc = createWorkDescription(WorkType::CUSTOM);
TRI_ASSERT(desc != nullptr);
TRI_CopyString(desc->_identifier._customType, type,
sizeof(desc->_identifier._customType) - 1);
if (sizeof(desc->_data.text) - 1 < length) {
length = sizeof(desc->_data.text) - 1;
}
TRI_CopyString(desc->_data.text, text, length);
activateWorkDescription(desc);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief pushes a custom task
////////////////////////////////////////////////////////////////////////////////
void WorkMonitor::pushCustom(char const* type, uint64_t id) {
TRI_ASSERT(type != nullptr);
WorkDescription* desc = createWorkDescription(WorkType::CUSTOM);
TRI_ASSERT(desc != nullptr);
TRI_CopyString(desc->_identifier._customType, type,
sizeof(desc->_identifier._customType) - 1);
std::string idString(std::to_string(id));
TRI_CopyString(desc->_data.text, idString.c_str(), idString.size());
activateWorkDescription(desc);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief pops a custom task
////////////////////////////////////////////////////////////////////////////////
void WorkMonitor::popCustom() {
WorkDescription* desc = deactivateWorkDescription();
TRI_ASSERT(desc != nullptr);
TRI_ASSERT(desc->_type == WorkType::CUSTOM);
try {
freeWorkDescription(desc);
} catch (...) {
// just to prevent throwing exceptions from here, as this method
// will be called in destructors...
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief requests a work overview
////////////////////////////////////////////////////////////////////////////////
void WorkMonitor::requestWorkOverview(uint64_t taskId) {
WORK_OVERVIEW.push(taskId);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief requests cancel of work
////////////////////////////////////////////////////////////////////////////////
void WorkMonitor::cancelWork(uint64_t id) {
MUTEX_LOCKER(guard, CANCEL_LOCK);
CANCEL_IDS.insert(id);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief the main event loop, wait for requests and delete old descriptions
////////////////////////////////////////////////////////////////////////////////
void WorkMonitor::run() {
uint32_t const maxSleep = 100 * 1000;
uint32_t const minSleep = 100;
uint32_t s = minSleep;
// clean old entries and create summary if requested
while (!isStopping()) {
try {
bool found = false;
WorkDescription* desc;
while (FREEABLE_WORK_DESCRIPTION.pop(desc)) {
found = true;
if (desc != nullptr) {
deleteWorkDescription(desc, false);
}
}
if (found) {
s = minSleep;
} else if (s < maxSleep) {
s *= 2;
}
uint64_t taskId;
{
MUTEX_LOCKER(guard, CANCEL_LOCK);
if (!CANCEL_IDS.empty()) {
for (auto thread : THREADS) {
cancelWorkDescriptions(thread);
}
CANCEL_IDS.clear();
}
}
while (WORK_OVERVIEW.pop(taskId)) {
VPackBuilder builder;
builder.add(VPackValue(VPackValueType::Object));
builder.add("time", VPackValue(TRI_microtime()));
builder.add("work", VPackValue(VPackValueType::Array));
{
MUTEX_LOCKER(guard, THREADS_LOCK);
for (auto& thread : THREADS) {
WorkDescription* desc = thread->workDescription();
if (desc != nullptr) {
builder.add(VPackValue(VPackValueType::Object));
vpackWorkDescription(&builder, desc);
builder.close();
}
}
}
b.close();
b.close();
sendWorkOverview(taskId, b);
}
} catch (...) {
// must prevent propagation of exceptions from here
}
usleep(s);
}
// indicate that we stopped the work monitor, freeWorkDescription
// should directly delete old entries
WORK_MONITOR_STOPPED.store(true);
// cleanup old entries
WorkDescription* desc;
while (FREEABLE_WORK_DESCRIPTION.pop(desc)) {
if (desc != nullptr) {
deleteWorkDescription(desc, false);
}
}
while (EMPTY_WORK_DESCRIPTION.pop(desc)) {
if (desc != nullptr) {
delete desc;
}
}
}
WorkDescription* WorkMonitor::createWorkDescription(WorkType type) {
WorkDescription* desc = nullptr;
WorkDescription* prev = (Thread::CURRENT_THREAD == nullptr)
? CURRENT_WORK_DESCRIPTION
: Thread::CURRENT_THREAD->workDescription();
if (EMPTY_WORK_DESCRIPTION.pop(desc) && desc != nullptr) {
desc->_type = type;
desc->_prev.store(prev);
desc->_destroy = true;
} else {
desc = new WorkDescription(type, prev);
}
desc->_id = NEXT_DESC_ID.fetch_add(1, std::memory_order_seq_cst);
desc->_data.handler = nullptr;
return desc;
}
void WorkMonitor::deleteWorkDescription(WorkDescription* desc, bool stopped) {
if (desc->_destroy) {
switch (desc->_type) {
case WorkType::THREAD:
case WorkType::CUSTOM:
case WorkType::AQL_ID:
case WorkType::AQL_STRING:
break;
case WorkType::HANDLER:
deleteHandler(desc);
break;
}
}
if (stopped) {
// we'll be getting here if the work monitor thread is already shut down
// and cannot delete anything anymore. this means we ourselves are
// responsible for cleaning up!
delete desc;
return;
}
// while the work monitor thread is still active, push the item on the
// work monitor's cleanup list for destruction
EMPTY_WORK_DESCRIPTION.push(desc);
}
void WorkMonitor::activateWorkDescription(WorkDescription* desc) {
if (Thread::CURRENT_THREAD == nullptr) {
CURRENT_WORK_DESCRIPTION = desc;
} else {
Thread::CURRENT_THREAD->setWorkDescription(desc);
}
}
WorkDescription* WorkMonitor::deactivateWorkDescription() {
if (Thread::CURRENT_THREAD == nullptr) {
WorkDescription* desc = CURRENT_WORK_DESCRIPTION;
TRI_ASSERT(desc != nullptr);
CURRENT_WORK_DESCRIPTION = desc->_prev.load();
return desc;
} else {
return Thread::CURRENT_THREAD->setPrevWorkDescription();
}
}
void WorkMonitor::vpackWorkDescription(VPackBuilder* b, WorkDescription* desc) {
switch (desc->_type) {
case WorkType::THREAD:
b->add("type", VPackValue("thread"));
b->add("name", VPackValue(desc->_data.thread->name()));
b->add("number", VPackValue(desc->_data.thread->threadNumber()));
b->add("status", VPackValue(VPackValueType::Object));
desc->_data.thread->addStatus(b);
b->close();
break;
case WorkType::CUSTOM:
b->add("type", VPackValue(desc->_identifier._customType));
b->add("description", VPackValue(desc->_data.text));
break;
case WorkType::AQL_STRING:
b->add("type", VPackValue("AQL query"));
b->add("queryId", VPackValue(desc->_identifier._id));
b->add("description", VPackValue(desc->_data.text));
break;
case WorkType::AQL_ID:
b->add("type", VPackValue("AQL query id"));
b->add("queryId", VPackValue(desc->_identifier._id));
break;
case WorkType::HANDLER:
vpackHandler(b, desc);
break;
}
b->add("id", VPackValue(desc->_id));
auto prev = desc->_prev.load();
if (prev != nullptr) {
b->add("parent", VPackValue(VPackValueType::Object));
vpackWorkDescription(b, prev);
b->close();
}
}
void WorkMonitor::cancelWorkDescriptions(Thread* thread) {
WorkDescription* desc = thread->workDescription();
std::vector<WorkDescription*> path;
while (desc != nullptr && desc->_type != WorkType::THREAD) {
path.push_back(desc);
uint64_t id = desc->_id;
if (CANCEL_IDS.find(id) != CANCEL_IDS.end()) {
for (auto it = path.rbegin(); it < path.rend(); ++it) {
bool descent = true;
WorkDescription* d = *it;
switch (d->_type) {
case WorkType::THREAD:
case WorkType::CUSTOM:
case WorkType::HANDLER:
d->_canceled.store(true);
break;
case WorkType::AQL_STRING:
case WorkType::AQL_ID:
descent = cancelAql(d);
break;
}
if (! descent) {
break;
}
}
return;
}
desc = desc->_prev.load();
}
}
AqlWorkStack::AqlWorkStack(TRI_vocbase_t* vocbase, uint64_t queryId,
char const* text, size_t length) {
WorkMonitor::pushAql(vocbase, queryId, text, length);
}
AqlWorkStack::AqlWorkStack(TRI_vocbase_t* vocbase, uint64_t queryId) {
WorkMonitor::pushAql(vocbase, queryId);
}
AqlWorkStack::~AqlWorkStack() { WorkMonitor::popAql(); }
CustomWorkStack::CustomWorkStack(char const* type, char const* text,
size_t length) {
WorkMonitor::pushCustom(type, text, length);
}
CustomWorkStack::CustomWorkStack(char const* type, uint64_t id) {
WorkMonitor::pushCustom(type, id);
}
CustomWorkStack::~CustomWorkStack() { WorkMonitor::popCustom(); }
////////////////////////////////////////////////////////////////////////////////
/// @brief starts the work monitor
////////////////////////////////////////////////////////////////////////////////
void arangodb::InitializeWorkMonitor() {
WORK_MONITOR_STOPPED.store(false);
WORK_MONITOR.start();
}
////////////////////////////////////////////////////////////////////////////////
/// @brief stops the work monitor
////////////////////////////////////////////////////////////////////////////////
void arangodb::ShutdownWorkMonitor() {
WORK_MONITOR_STOPPED.store(true);
WORK_MONITOR.beginShutdown();
}