void Lock::CollectionLock::relockWithMode(LockMode mode, Lock::DBLock& dbLock ) {
if (supportsDocLocking() || enableCollectionLocking) {
_lockState->unlock(_id);
}
dbLock.relockWithMode( mode );
if (supportsDocLocking() || enableCollectionLocking) {
_lockState->lock(_id, mode);
}
}
void Lock::CollectionLock::relockAsDatabaseExclusive(Lock::DBLock& dbLock) {
if (supportsDocLocking() || enableCollectionLocking) {
_lockState->unlock(_id);
}
dbLock.relockWithMode(MODE_X);
if (supportsDocLocking() || enableCollectionLocking) {
// don't need the lock, but need something to unlock in the destructor
_lockState->lock(_id, MODE_IX);
}
}
bool PlanYieldPolicy::yield(RecordFetcher* fetcher) {
invariant(_planYielding);
OperationContext* opCtx = _planYielding->getOpCtx();
invariant(opCtx);
// All YIELD_AUTO plans will get here eventually when the elapsed tracker triggers that it's
// time to yield. Whether or not we will actually yield (doc-level locking systems won't),
// we need to check if this operation has been interrupted. Throws if the interrupt flag is
// set.
opCtx->checkForInterrupt();
if (supportsDocLocking()) {
// Doc-level locking is supported, so no need to release locks.
return true;
}
// No need to yield if the collection is NULL.
if (NULL == _planYielding->collection()) {
return true;
}
_planYielding->saveState();
// Release and reacquire locks.
QueryYield::yieldAllLocks(opCtx, fetcher);
_elapsedTracker.resetLastTime();
return _planYielding->restoreState(opCtx);
}
void AutoGetCollectionForRead::_init() {
massert(28535, "need a non-empty collection name", !_nss.coll().empty());
// TODO: Client::Context legacy, needs to be removed
_txn->getCurOp()->ensureStarted();
_txn->getCurOp()->setNS(_nss.toString());
// Lock both the DB and the collection (DB is locked in the constructor), because this is
// necessary in order to to shard version checking.
const ResourceId resId(RESOURCE_COLLECTION, _nss);
const LockMode collLockMode = supportsDocLocking() ? MODE_IS : MODE_S;
invariant(LOCK_OK == _txn->lockState()->lock(resId, collLockMode));
// Shard version check needs to be performed under the collection lock
ensureShardVersionOKOrThrow(_nss);
// 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.
_db = dbHolder().get(_txn, _nss.db());
if (_db != NULL) {
// TODO: Client::Context legacy, needs to be removed
_txn->getCurOp()->enter(_nss.toString().c_str(), _db->getProfilingLevel());
_coll = _db->getCollection(_txn, _nss);
}
}
Lock::CollectionLock::CollectionLock(Locker* lockState, StringData ns, LockMode mode)
: _id(RESOURCE_COLLECTION, ns), _lockState(lockState) {
massert(28538, "need a non-empty collection name", nsIsFull(ns));
dassert(_lockState->isDbLockedForMode(nsToDatabaseSubstring(ns),
isSharedLockMode(mode) ? MODE_IS : MODE_IX));
if (supportsDocLocking()) {
_lockState->lock(_id, mode);
} else {
_lockState->lock(_id, isSharedLockMode(mode) ? MODE_S : MODE_X);
}
}
void WorkingSetCommon::prepareForSnapshotChange(WorkingSet* workingSet) {
dassert(supportsDocLocking());
for (WorkingSet::iterator it = workingSet->begin(); it != workingSet->end(); ++it) {
if (it->state == WorkingSetMember::LOC_AND_IDX) {
it->isSuspicious = true;
}
else if (it->state == WorkingSetMember::LOC_AND_UNOWNED_OBJ) {
// We already have the data so convert directly to owned state.
it->obj.setValue(it->obj.value().getOwned());
it->state = WorkingSetMember::LOC_AND_OWNED_OBJ;
}
}
}
void Lock::DBLock::lockDB() {
const bool isRead = (_mode == newlm::MODE_S || _mode == newlm::MODE_IS);
TrackLockAcquireTime a(isRead ? 'r' : 'w');
_lockState->lockGlobal(isRead ? newlm::MODE_IS : newlm::MODE_IX);
if (supportsDocLocking() || isRead) {
_lockState->lock(_id, _mode);
}
else {
_lockState->lock(_id, newlm::MODE_X);
}
resetTime();
}
Lock::CollectionLock::CollectionLock(Locker* lockState,
const StringData& ns,
LockMode mode)
: _id(RESOURCE_COLLECTION, ns),
_lockState(lockState) {
const bool isRead = (mode == MODE_S || mode == MODE_IS);
massert(28538, "need a non-empty collection name", nsIsFull(ns));
dassert(_lockState->isDbLockedForMode(nsToDatabaseSubstring(ns),
isRead ? MODE_IS : MODE_IX));
if (supportsDocLocking()) {
_lockState->lock(_id, mode);
} else if (enableCollectionLocking) {
_lockState->lock(_id, isRead ? MODE_S : MODE_X);
}
}
void Lock::DBLock::relockWithMode(LockMode newMode) {
// 2PL would delay the unlocking
invariant(!_locker->inAWriteUnitOfWork());
// Not allowed to change global intent
invariant(!isSharedLockMode(_mode) || isSharedLockMode(newMode));
_locker->unlock(_id);
_mode = newMode;
if (supportsDocLocking() || enableCollectionLocking) {
invariant(LOCK_OK == _locker->lock(_id, _mode));
} else {
invariant(LOCK_OK == _locker->lock(_id, isSharedLockMode(_mode) ? MODE_S : MODE_X));
}
}
Lock::CollectionLock::CollectionLock(Locker* lockState,
StringData ns,
LockMode mode,
Date_t deadline)
: _id(RESOURCE_COLLECTION, ns), _result(LOCK_INVALID), _lockState(lockState) {
massert(28538, "need a non-empty collection name", nsIsFull(ns));
dassert(_lockState->isDbLockedForMode(nsToDatabaseSubstring(ns),
isSharedLockMode(mode) ? MODE_IS : MODE_IX));
LockMode actualLockMode = mode;
if (!supportsDocLocking()) {
actualLockMode = isSharedLockMode(mode) ? MODE_S : MODE_X;
}
_result = _lockState->lock(_id, actualLockMode, deadline);
invariant(_result == LOCK_OK || deadline != Date_t::max());
}
void Lock::DBRead::unlockDB() {
if (supportsDocLocking()) {
if (nsIsFull(_ns)) {
const newlm::ResourceId resIdCollection(newlm::RESOURCE_COLLECTION, _ns);
_lockState->unlock(resIdCollection);
}
}
const StringData db = nsToDatabaseSubstring(_ns);
const newlm::ResourceId resIdDb(newlm::RESOURCE_DATABASE, db);
_lockState->unlock(resIdDb);
// The last release reports time the lock was held
if (_lockState->unlockGlobal()) {
recordTime();
}
}
Lock::DBLock::DBLock(Locker* lockState, const StringData& db, LockMode mode)
: ScopedLock(lockState),
_id(RESOURCE_DATABASE, db),
_lockState(lockState),
_mode(mode) {
massert(28539, "need a valid database name", !db.empty() && nsIsDbOnly(db));
const bool isRead = (_mode == MODE_S || _mode == MODE_IS);
_lockState->lockGlobal(isRead ? MODE_IS : MODE_IX);
if (supportsDocLocking() || enableCollectionLocking) {
_lockState->lock(_id, _mode);
}
else {
_lockState->lock(_id, isRead ? MODE_S : MODE_X);
}
}
Lock::CollectionLock::CollectionLock(Locker* lockState,
const StringData& ns,
newlm::LockMode mode)
: _id(newlm::RESOURCE_COLLECTION, ns),
_lockState(lockState) {
const bool isRead = (mode == newlm::MODE_S || mode == newlm::MODE_IS);
dassert(!ns.empty());
dassert(nsIsFull(ns));
dassert(_lockState->isLockHeldForMode(newlm::ResourceId(newlm::RESOURCE_DATABASE,
nsToDatabaseSubstring(ns)),
isRead ? newlm::MODE_IS : newlm::MODE_IX));
if (supportsDocLocking()) {
_lockState->lock(_id, mode);
}
else {
_lockState->lock(_id, isRead ? newlm::MODE_S : newlm::MODE_X);
}
}
void WorkingSetCommon::prepareForSnapshotChange(WorkingSet* workingSet) {
dassert(supportsDocLocking());
for (auto id : workingSet->getAndClearYieldSensitiveIds()) {
if (workingSet->isFree(id)) {
continue;
}
// We may see the same member twice, so anything we do here should be idempotent.
WorkingSetMember* member = workingSet->get(id);
if (member->getState() == WorkingSetMember::LOC_AND_IDX) {
member->isSuspicious = true;
} else if (member->getState() == WorkingSetMember::LOC_AND_OBJ) {
// Need to make sure that the data is owned, as underlying storage can change during a
// yield.
member->makeObjOwned();
}
}
}
void Lock::DBLock::relockWithMode(const LockMode newMode) {
const bool wasRead = (_mode == MODE_S || _mode == MODE_IS);
const bool isRead = (newMode == MODE_S || newMode == MODE_IS);
invariant (!_lockState->inAWriteUnitOfWork()); // 2PL would delay the unlocking
invariant(!wasRead || isRead); // Not allowed to change global intent
_lockState->unlock(_id);
_mode = newMode;
if (supportsDocLocking() || enableCollectionLocking) {
_lockState->lock(_id, _mode);
dassert(_lockState->isLockHeldForMode(_id, _mode));
}
else {
LockMode effectiveMode = isRead ? MODE_S : MODE_X;
_lockState->lock(_id, effectiveMode);
dassert(_lockState->isLockHeldForMode(_id, effectiveMode));
}
}
void run() {
if ( supportsDocLocking() ) {
return;
}
auto_ptr<PlanExecutor> run(getCollscan());
BSONObj obj;
// Read some of it.
for (int i = 0; i < 10; ++i) {
ASSERT_EQUALS(PlanExecutor::ADVANCED, run->getNext(&obj, NULL));
ASSERT_EQUALS(i, obj["foo"].numberInt());
}
// Register it.
run->saveState();
registerExecutor(run.get());
// At this point it's safe to yield. forceYield would do that. Let's now simulate some
// stuff going on in the yield.
// Delete some data, namely the next 2 things we'd expect.
_client.remove(ns(), BSON("foo" << 10));
_client.remove(ns(), BSON("foo" << 11));
// At this point, we're done yielding. We recover our lock.
// Unregister the runner.
deregisterExecutor(run.get());
// And clean up anything that happened before.
run->restoreState(&_opCtx);
// Make sure that the runner moved forward over the deleted data. We don't see foo==10
// or foo==11.
for (int i = 12; i < N(); ++i) {
ASSERT_EQUALS(PlanExecutor::ADVANCED, run->getNext(&obj, NULL));
ASSERT_EQUALS(i, obj["foo"].numberInt());
}
ASSERT_EQUALS(PlanExecutor::IS_EOF, run->getNext(&obj, NULL));
}
void WorkingSetCommon::prepareForSnapshotChange(WorkingSet* workingSet) {
if (!supportsDocLocking()) {
// Non doc-locking storage engines use invalidations, so we don't need to examine the
// buffered working set ids. But we do need to clear the set of ids in order to keep our
// memory utilization in check.
workingSet->getAndClearYieldSensitiveIds();
return;
}
for (auto id : workingSet->getAndClearYieldSensitiveIds()) {
if (workingSet->isFree(id)) {
continue;
}
// We may see the same member twice, so anything we do here should be idempotent.
WorkingSetMember* member = workingSet->get(id);
if (member->getState() == WorkingSetMember::RID_AND_IDX) {
member->isSuspicious = true;
}
}
}
void Lock::DBRead::lockDB() {
TrackLockAcquireTime a('r');
const StringData db = nsToDatabaseSubstring(_ns);
const newlm::ResourceId resIdDb(newlm::RESOURCE_DATABASE, db);
_lockState->lockGlobal(newlm::MODE_IS);
if (supportsDocLocking()) {
_lockState->lock(resIdDb, newlm::MODE_IS);
if (nsIsFull(_ns)) {
const newlm::ResourceId resIdCollection(newlm::RESOURCE_COLLECTION, _ns);
_lockState->lock(resIdCollection, newlm::MODE_IS);
}
}
else {
_lockState->lock(resIdDb, newlm::MODE_S);
}
resetTime();
}
Lock::DBLock::DBLock(Locker* locker, StringData db, LockMode mode)
: _id(RESOURCE_DATABASE, db),
_locker(locker),
_mode(mode),
_globalLock(locker, isSharedLockMode(_mode) ? MODE_IS : MODE_IX, UINT_MAX) {
massert(28539, "need a valid database name", !db.empty() && nsIsDbOnly(db));
// Need to acquire the flush lock
_locker->lockMMAPV1Flush();
if (supportsDocLocking() || enableCollectionLocking) {
// The check for the admin db is to ensure direct writes to auth collections
// are serialized (see SERVER-16092).
if ((_id == resourceIdAdminDB) && !isSharedLockMode(_mode)) {
_mode = MODE_X;
}
invariant(LOCK_OK == _locker->lock(_id, _mode));
} else {
invariant(LOCK_OK == _locker->lock(_id, isSharedLockMode(_mode) ? MODE_S : MODE_X));
}
}
void Lock::OplogIntentWriteLock::serializeIfNeeded() {
if (!supportsDocLocking() && !_serialized) {
oplogSerialization.lock();
_serialized = true;
}
}
Lock::CollectionLock::~CollectionLock() {
if (supportsDocLocking() || enableCollectionLocking) {
_lockState->unlock(_id);
}
}