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/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kDefault
#include "mongo/platform/basic.h"
#include "mongo/db/service_context.h"
#include <list>
#include <memory>
#include "mongo/base/init.h"
#include "mongo/bson/bsonobj.h"
#include "mongo/db/client.h"
#include "mongo/db/concurrency/locker_noop.h"
#include "mongo/db/default_baton.h"
#include "mongo/db/op_observer.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/storage/recovery_unit_noop.h"
#include "mongo/logv2/log.h"
#include "mongo/transport/service_entry_point.h"
#include "mongo/transport/session.h"
#include "mongo/transport/transport_layer.h"
#include "mongo/util/assert_util.h"
#include "mongo/util/log.h"
#include "mongo/util/str.h"
#include "mongo/util/system_clock_source.h"
#include "mongo/util/system_tick_source.h"
#include <iostream>
namespace mongo {
namespace {
using ConstructorActionList = std::list<ServiceContext::ConstructorDestructorActions>;
ServiceContext* globalServiceContext = nullptr;
AtomicWord<int> _numCurrentOps{0};
} // namespace
LockedClient::LockedClient(Client* client) : _lk{*client}, _client{client} {}
bool hasGlobalServiceContext() {
return globalServiceContext;
}
ServiceContext* getGlobalServiceContext() {
fassert(17508, globalServiceContext);
return globalServiceContext;
}
ServiceContext* getCurrentServiceContext() {
auto client = Client::getCurrent();
if (client) {
return client->getServiceContext();
}
return nullptr;
}
void setGlobalServiceContext(ServiceContext::UniqueServiceContext&& serviceContext) {
if (globalServiceContext) {
// Make sure that calling getGlobalServiceContext() during the destructor results in
// nullptr. Decorations might try and do this.
ServiceContext::UniqueServiceContext oldServiceContext{globalServiceContext};
globalServiceContext = nullptr;
}
globalServiceContext = serviceContext.release();
}
bool _supportsDocLocking = false;
bool supportsDocLocking() {
return _supportsDocLocking;
}
ServiceContext::ServiceContext()
: _tickSource(std::make_unique<SystemTickSource>()),
_fastClockSource(std::make_unique<SystemClockSource>()),
_preciseClockSource(std::make_unique<SystemClockSource>()) {}
ServiceContext::~ServiceContext() {
stdx::lock_guard<Latch> lk(_mutex);
for (const auto& client : _clients) {
LOGV2_FATAL(23828,
"Client {client_desc} still exists while destroying "
"ServiceContext@{reinterpret_cast_uint64_t_this}",
"client_desc"_attr = client->desc(),
"reinterpret_cast_uint64_t_this"_attr = reinterpret_cast<uint64_t>(this));
}
invariant(_clients.empty());
}
namespace {
//
// These onDestroy and onCreate functions are utilities for correctly executing supplemental
// constructor and destructor methods for the ServiceContext, Client and OperationContext types.
//
// Note that destructors run in reverse order of constructors, and that failed construction
// leads to corresponding destructors to run, similarly to how member variable construction and
// destruction behave.
//
template <typename T, typename ObserversIterator>
void onDestroy(T* object,
const ObserversIterator& observerBegin,
const ObserversIterator& observerEnd) {
try {
auto observer = observerEnd;
while (observer != observerBegin) {
--observer;
observer->onDestroy(object);
}
} catch (...) {
std::terminate();
}
}
template <typename T, typename ObserversContainer>
void onDestroy(T* object, const ObserversContainer& observers) {
onDestroy(object, observers.cbegin(), observers.cend());
}
template <typename T, typename ObserversIterator>
void onCreate(T* object,
const ObserversIterator& observerBegin,
const ObserversIterator& observerEnd) {
auto observer = observerBegin;
try {
for (; observer != observerEnd; ++observer) {
observer->onCreate(object);
}
} catch (...) {
onDestroy(object, observerBegin, observer);
throw;
}
}
template <typename T, typename ObserversContainer>
void onCreate(T* object, const ObserversContainer& observers) {
onCreate(object, observers.cbegin(), observers.cend());
}
} // namespace
ServiceContext::UniqueClient ServiceContext::makeClient(std::string desc,
transport::SessionHandle session) {
std::unique_ptr<Client> client(new Client(std::move(desc), this, std::move(session)));
onCreate(client.get(), _clientObservers);
{
stdx::lock_guard<Latch> lk(_mutex);
invariant(_clients.insert(client.get()).second);
}
return UniqueClient(client.release());
}
void ServiceContext::setPeriodicRunner(std::unique_ptr<PeriodicRunner> runner) {
invariant(!_runner);
_runner = std::move(runner);
}
PeriodicRunner* ServiceContext::getPeriodicRunner() const {
return _runner.get();
}
transport::TransportLayer* ServiceContext::getTransportLayer() const {
return _transportLayer.get();
}
ServiceEntryPoint* ServiceContext::getServiceEntryPoint() const {
return _serviceEntryPoint.get();
}
transport::ServiceExecutor* ServiceContext::getServiceExecutor() const {
return _serviceExecutor.get();
}
void ServiceContext::setStorageEngine(std::unique_ptr<StorageEngine> engine) {
invariant(engine);
invariant(!_storageEngine);
_storageEngine = std::move(engine);
}
void ServiceContext::setOpObserver(std::unique_ptr<OpObserver> opObserver) {
_opObserver = std::move(opObserver);
}
void ServiceContext::setTickSource(std::unique_ptr<TickSource> newSource) {
_tickSource = std::move(newSource);
}
void ServiceContext::setFastClockSource(std::unique_ptr<ClockSource> newSource) {
_fastClockSource = std::move(newSource);
}
void ServiceContext::setPreciseClockSource(std::unique_ptr<ClockSource> newSource) {
_preciseClockSource = std::move(newSource);
}
void ServiceContext::setServiceEntryPoint(std::unique_ptr<ServiceEntryPoint> sep) {
_serviceEntryPoint = std::move(sep);
}
void ServiceContext::setTransportLayer(std::unique_ptr<transport::TransportLayer> tl) {
_transportLayer = std::move(tl);
}
void ServiceContext::setServiceExecutor(std::unique_ptr<transport::ServiceExecutor> exec) {
_serviceExecutor = std::move(exec);
}
void ServiceContext::ClientDeleter::operator()(Client* client) const {
ServiceContext* const service = client->getServiceContext();
{
stdx::lock_guard<Latch> lk(service->_mutex);
invariant(service->_clients.erase(client));
}
onDestroy(client, service->_clientObservers);
delete client;
}
ServiceContext::UniqueOperationContext ServiceContext::makeOperationContext(Client* client) {
auto opCtx = std::make_unique<OperationContext>(client, _nextOpId.fetchAndAdd(1));
if (client->session()) {
_numCurrentOps.addAndFetch(1);
}
onCreate(opCtx.get(), _clientObservers);
if (!opCtx->lockState()) {
opCtx->setLockState(std::make_unique<LockerNoop>());
}
if (!opCtx->recoveryUnit()) {
opCtx->setRecoveryUnit(std::make_unique<RecoveryUnitNoop>(),
WriteUnitOfWork::RecoveryUnitState::kNotInUnitOfWork);
}
// The baton must be attached before attaching to a client
if (_transportLayer) {
_transportLayer->makeBaton(opCtx.get());
} else {
makeBaton(opCtx.get());
}
{
stdx::lock_guard<Client> lk(*client);
client->setOperationContext(opCtx.get());
}
{
stdx::lock_guard lk(_mutex);
_clientByOperationId.emplace(opCtx->getOpID(), client);
}
return UniqueOperationContext(opCtx.release());
};
void ServiceContext::OperationContextDeleter::operator()(OperationContext* opCtx) const {
auto client = opCtx->getClient();
if (client->session()) {
_numCurrentOps.subtractAndFetch(1);
}
auto service = client->getServiceContext();
{
stdx::lock_guard lk(service->_mutex);
service->_clientByOperationId.erase(opCtx->getOpID());
}
{
stdx::lock_guard<Client> lk(*client);
client->resetOperationContext();
}
opCtx->getBaton()->detach();
onDestroy(opCtx, service->_clientObservers);
delete opCtx;
}
LockedClient ServiceContext::getLockedClient(OperationId id) {
stdx::lock_guard lk(_mutex);
auto it = _clientByOperationId.find(id);
if (it == _clientByOperationId.end()) {
return {};
}
return LockedClient(it->second);
}
void ServiceContext::registerClientObserver(std::unique_ptr<ClientObserver> observer) {
_clientObservers.emplace_back(std::move(observer));
}
ServiceContext::LockedClientsCursor::LockedClientsCursor(ServiceContext* service)
: _lock(service->_mutex), _curr(service->_clients.cbegin()), _end(service->_clients.cend()) {}
Client* ServiceContext::LockedClientsCursor::next() {
if (_curr == _end)
return nullptr;
Client* result = *_curr;
++_curr;
return result;
}
void ServiceContext::setKillAllOperations() {
stdx::lock_guard<Latch> clientLock(_mutex);
// Ensure that all newly created operation contexts will immediately be in the interrupted state
_globalKill.store(true);
// Interrupt all active operations
for (auto&& client : _clients) {
stdx::lock_guard<Client> lk(*client);
auto opCtxToKill = client->getOperationContext();
if (opCtxToKill) {
killOperation(lk, opCtxToKill, ErrorCodes::InterruptedAtShutdown);
}
}
// Notify any listeners who need to reach to the server shutting down
for (const auto listener : _killOpListeners) {
try {
listener->interruptAll();
} catch (...) {
std::terminate();
}
}
}
void ServiceContext::killOperation(WithLock, OperationContext* opCtx, ErrorCodes::Error killCode) {
opCtx->markKilled(killCode);
for (const auto listener : _killOpListeners) {
try {
listener->interrupt(opCtx->getOpID());
} catch (...) {
std::terminate();
}
}
}
void ServiceContext::unsetKillAllOperations() {
_globalKill.store(false);
}
void ServiceContext::registerKillOpListener(KillOpListenerInterface* listener) {
stdx::lock_guard<Latch> clientLock(_mutex);
_killOpListeners.push_back(listener);
}
void ServiceContext::waitForStartupComplete() {
stdx::unique_lock<Latch> lk(_mutex);
_startupCompleteCondVar.wait(lk, [this] { return _startupComplete; });
}
void ServiceContext::notifyStartupComplete() {
stdx::unique_lock<Latch> lk(_mutex);
_startupComplete = true;
lk.unlock();
_startupCompleteCondVar.notify_all();
}
int ServiceContext::getActiveClientOperations() {
return _numCurrentOps.load();
}
namespace {
/**
* Accessor function to get the global list of ServiceContext constructor and destructor
* functions.
*/
ConstructorActionList& registeredConstructorActions() {
static ConstructorActionList cal;
return cal;
}
} // namespace
ServiceContext::ConstructorActionRegisterer::ConstructorActionRegisterer(
std::string name, ConstructorAction constructor, DestructorAction destructor)
: ConstructorActionRegisterer(
std::move(name), {}, std::move(constructor), std::move(destructor)) {}
ServiceContext::ConstructorActionRegisterer::ConstructorActionRegisterer(
std::string name,
std::vector<std::string> prereqs,
ConstructorAction constructor,
DestructorAction destructor) {
if (!destructor)
destructor = [](ServiceContext*) {};
_registerer.emplace(std::move(name),
[this, constructor, destructor](InitializerContext* context) {
_iter = registeredConstructorActions().emplace(
registeredConstructorActions().end(),
std::move(constructor),
std::move(destructor));
return Status::OK();
},
[this](DeinitializerContext* context) {
registeredConstructorActions().erase(_iter);
return Status::OK();
},
std::move(prereqs));
}
ServiceContext::UniqueServiceContext ServiceContext::make() {
auto service = std::make_unique<ServiceContext>();
onCreate(service.get(), registeredConstructorActions());
return UniqueServiceContext{service.release()};
}
void ServiceContext::ServiceContextDeleter::operator()(ServiceContext* service) const {
onDestroy(service, registeredConstructorActions());
delete service;
}
BatonHandle ServiceContext::makeBaton(OperationContext* opCtx) const {
invariant(!opCtx->getBaton());
auto baton = std::make_shared<DefaultBaton>(opCtx);
opCtx->setBaton(baton);
return baton;
}
} // namespace mongo
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