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/**
* Copyright (C) 2014 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* 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 GNU Affero General 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.
*/
#include "mongo/platform/basic.h"
#include "mongo/db/db_raii.h"
#include "mongo/db/catalog/collection.h"
#include "mongo/db/catalog/database.h"
#include "mongo/db/catalog/database_holder.h"
#include "mongo/db/client.h"
#include "mongo/db/curop.h"
#include "mongo/db/repl/replication_coordinator_global.h"
#include "mongo/db/s/collection_sharding_state.h"
#include "mongo/db/stats/top.h"
namespace mongo {
AutoGetDb::AutoGetDb(OperationContext* txn, StringData ns, LockMode mode)
: _dbLock(txn->lockState(), ns, mode), _db(dbHolder().get(txn, ns)) {}
AutoGetCollection::AutoGetCollection(OperationContext* txn,
const NamespaceString& nss,
LockMode modeAll)
: AutoGetCollection(txn, nss, modeAll, modeAll) {}
AutoGetCollection::AutoGetCollection(OperationContext* txn,
const NamespaceString& nss,
LockMode modeDB,
LockMode modeColl)
: _autoDb(txn, nss.db(), modeDB),
_collLock(txn->lockState(), nss.ns(), modeColl),
_coll(_autoDb.getDb() ? _autoDb.getDb()->getCollection(nss) : nullptr) {}
AutoGetOrCreateDb::AutoGetOrCreateDb(OperationContext* txn, StringData ns, LockMode mode)
: _transaction(txn, MODE_IX),
_dbLock(txn->lockState(), ns, mode),
_db(dbHolder().get(txn, ns)) {
invariant(mode == MODE_IX || mode == MODE_X);
_justCreated = false;
// If the database didn't exist, relock in MODE_X
if (_db == NULL) {
if (mode != MODE_X) {
_dbLock.relockWithMode(MODE_X);
}
_db = dbHolder().openDb(txn, ns);
_justCreated = true;
}
}
AutoGetCollectionForRead::AutoGetCollectionForRead(OperationContext* txn, const std::string& ns)
: AutoGetCollectionForRead(txn, NamespaceString(ns)) {}
AutoGetCollectionForRead::AutoGetCollectionForRead(OperationContext* txn,
const NamespaceString& nss)
: _txn(txn), _transaction(txn, MODE_IS) {
{
_autoColl.emplace(txn, nss, MODE_IS);
auto curOp = CurOp::get(_txn);
stdx::lock_guard<Client> lk(*_txn->getClient());
// TODO: OldClientContext legacy, needs to be removed
curOp->ensureStarted();
curOp->setNS_inlock(nss.ns());
// At this point, we are locked in shared mode for the database by the DB lock in the
// constructor, so it is safe to load the DB pointer.
if (_autoColl->getDb()) {
// TODO: OldClientContext legacy, needs to be removed
curOp->enter_inlock(nss.ns().c_str(), _autoColl->getDb()->getProfilingLevel());
}
}
// Note: this can yield.
_ensureMajorityCommittedSnapshotIsValid(nss);
// We have both the DB and collection locked, which is the prerequisite to do a stable shard
// version check, but we'd like to do the check after we have a satisfactory snapshot.
auto css = CollectionShardingState::get(txn, nss);
css->checkShardVersionOrThrow(txn);
}
AutoGetCollectionForRead::~AutoGetCollectionForRead() {
// Report time spent in read lock
auto currentOp = CurOp::get(_txn);
Top::get(_txn->getClient()->getServiceContext())
.record(currentOp->getNS(),
currentOp->getLogicalOp(),
-1, // "read locked"
_timer.micros(),
currentOp->isCommand());
}
void AutoGetCollectionForRead::_ensureMajorityCommittedSnapshotIsValid(const NamespaceString& nss) {
while (true) {
auto coll = _autoColl->getCollection();
if (!coll) {
return;
}
auto minSnapshot = coll->getMinimumVisibleSnapshot();
if (!minSnapshot) {
return;
}
auto mySnapshot = _txn->recoveryUnit()->getMajorityCommittedSnapshot();
if (!mySnapshot) {
return;
}
if (mySnapshot >= minSnapshot) {
return;
}
// Yield locks.
_autoColl = boost::none;
repl::ReplicationCoordinator::get(_txn)->waitUntilSnapshotCommitted(_txn, *minSnapshot);
uassertStatusOK(_txn->recoveryUnit()->setReadFromMajorityCommittedSnapshot());
{
stdx::lock_guard<Client> lk(*_txn->getClient());
CurOp::get(_txn)->yielded();
}
// Relock.
_autoColl.emplace(_txn, nss, MODE_IS);
}
}
OldClientContext::OldClientContext(OperationContext* txn,
const std::string& ns,
Database* db,
bool justCreated)
: _justCreated(justCreated), _doVersion(true), _ns(ns), _db(db), _txn(txn) {
_finishInit();
}
OldClientContext::OldClientContext(OperationContext* txn,
const std::string& ns,
bool doVersion)
: _justCreated(false), // set for real in finishInit
_doVersion(doVersion),
_ns(ns),
_db(NULL),
_txn(txn) {
_finishInit();
}
void OldClientContext::_finishInit() {
_db = dbHolder().get(_txn, _ns);
if (_db) {
_justCreated = false;
} else {
invariant(_txn->lockState()->isDbLockedForMode(nsToDatabaseSubstring(_ns), MODE_X));
_db = dbHolder().openDb(_txn, _ns, &_justCreated);
invariant(_db);
}
if (_doVersion) {
_checkNotStale();
}
stdx::lock_guard<Client> lk(*_txn->getClient());
CurOp::get(_txn)->enter_inlock(_ns.c_str(), _db->getProfilingLevel());
}
void OldClientContext::_checkNotStale() const {
switch (CurOp::get(_txn)->getNetworkOp()) {
case dbGetMore: // getMore is special and should be handled elsewhere.
case dbUpdate: // update & delete check shard version in instance.cpp, so don't check
case dbDelete: // here as well.
break;
default:
auto css = CollectionShardingState::get(_txn, _ns);
css->checkShardVersionOrThrow(_txn);
}
}
OldClientContext::~OldClientContext() {
// Lock must still be held
invariant(_txn->lockState()->isLocked());
auto currentOp = CurOp::get(_txn);
Top::get(_txn->getClient()->getServiceContext())
.record(currentOp->getNS(),
currentOp->getLogicalOp(),
_txn->lockState()->isWriteLocked() ? 1 : -1,
_timer.micros(),
currentOp->isCommand());
}
OldClientWriteContext::OldClientWriteContext(OperationContext* opCtx, const std::string& ns)
: _txn(opCtx),
_nss(ns),
_autodb(opCtx, _nss.db(), MODE_IX),
_collk(opCtx->lockState(), ns, MODE_IX),
_c(opCtx, ns, _autodb.getDb(), _autodb.justCreated()) {
_collection = _c.db()->getCollection(ns);
if (!_collection && !_autodb.justCreated()) {
// relock database in MODE_X to allow collection creation
_collk.relockAsDatabaseExclusive(_autodb.lock());
Database* db = dbHolder().get(_txn, ns);
invariant(db == _c.db());
}
}
} // namespace mongo
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