LockResult LockerImpl::_lockGlobalBegin(OperationContext* opCtx, LockMode mode, Date_t deadline) {
dassert(isLocked() == (_modeForTicket != MODE_NONE));
if (_modeForTicket == MODE_NONE) {
auto acquireTicketResult = _acquireTicket(opCtx, mode, deadline);
if (acquireTicketResult != LOCK_OK) {
return acquireTicketResult;
}
_modeForTicket = mode;
}
LockMode actualLockMode = mode;
if (opCtx) {
auto storageEngine = opCtx->getServiceContext()->getStorageEngine();
if (storageEngine && !storageEngine->supportsDBLocking()) {
actualLockMode = isSharedLockMode(mode) ? MODE_S : MODE_X;
}
}
const LockResult result = lockBegin(opCtx, resourceIdGlobal, actualLockMode);
if (result == LOCK_OK)
return LOCK_OK;
invariant(result == LOCK_WAITING);
return result;
}
LockResult LockerImpl<IsForMMAPV1>::_lockGlobalBegin(OperationContext* opCtx,
LockMode mode,
Date_t deadline) {
dassert(isLocked() == (_modeForTicket != MODE_NONE));
if (_modeForTicket == MODE_NONE) {
auto acquireTicketResult = _acquireTicket(opCtx, mode, deadline);
if (acquireTicketResult != LOCK_OK) {
return acquireTicketResult;
}
_modeForTicket = mode;
}
const LockResult result = lockBegin(opCtx, resourceIdGlobal, mode);
if (result == LOCK_OK)
return LOCK_OK;
// Currently, deadlock detection does not happen inline with lock acquisition so the only
// unsuccessful result that the lock manager would return is LOCK_WAITING.
invariant(result == LOCK_WAITING);
return result;
}
void LockerImpl::reacquireTicket(OperationContext* opCtx) {
invariant(_modeForTicket != MODE_NONE);
auto clientState = _clientState.load();
const bool reader = isSharedLockMode(_modeForTicket);
// Ensure that either we don't have a ticket, or the current ticket mode matches the lock mode.
invariant(clientState == kInactive || (clientState == kActiveReader && reader) ||
(clientState == kActiveWriter && !reader));
// If we already have a ticket, there's nothing to do.
if (clientState != kInactive)
return;
auto acquireTicketResult = _acquireTicket(opCtx, _modeForTicket, Date_t::max());
uassert(ErrorCodes::LockTimeout,
str::stream() << "Unable to acquire ticket with mode '" << _modeForTicket
<< "' within a max lock request timeout of '"
<< _maxLockTimeout.get()
<< "' milliseconds.",
acquireTicketResult == LOCK_OK || !_maxLockTimeout);
// If no deadline is specified we should always get a ticket.
invariant(acquireTicketResult == LOCK_OK);
}
void LockerImpl<IsForMMAPV1>::reacquireTicket(OperationContext* opCtx) {
invariant(_modeForTicket != MODE_NONE);
auto acquireTicketResult = _acquireTicket(opCtx, _modeForTicket, Date_t::max());
invariant(acquireTicketResult == LOCK_OK);
}
