void IndexBuildInterceptor::_tryYield(OperationContext* opCtx) {
// Never yield while holding locks that prevent writes to the collection: only yield while
// holding intent locks. This check considers all locks in the hierarchy that would cover this
// mode.
const NamespaceString nss(_indexCatalogEntry->ns());
if (opCtx->lockState()->isCollectionLockedForMode(nss, MODE_S)) {
return;
}
DEV {
invariant(!opCtx->lockState()->isCollectionLockedForMode(nss, MODE_X));
invariant(!opCtx->lockState()->isDbLockedForMode(nss.db(), MODE_X));
}
// Releasing locks means a new snapshot should be acquired when restored.
opCtx->recoveryUnit()->abandonSnapshot();
auto locker = opCtx->lockState();
Locker::LockSnapshot snapshot;
invariant(locker->saveLockStateAndUnlock(&snapshot));
// Track the number of yields in CurOp.
CurOp::get(opCtx)->yielded();
MONGO_FAIL_POINT_BLOCK(hangDuringIndexBuildDrainYield, config) {
StringData ns{config.getData().getStringField("namespace")};
if (ns == _indexCatalogEntry->ns()) {
log() << "Hanging index build during drain yield";
MONGO_FAIL_POINT_PAUSE_WHILE_SET(hangDuringIndexBuildDrainYield);
}
}
bool LockerImpl::releaseWriteUnitOfWork(LockSnapshot* stateOut) {
// Only the global WUOW can be released.
invariant(_wuowNestingLevel == 1);
--_wuowNestingLevel;
invariant(!isGlobalLockedRecursively());
// All locks should be pending to unlock.
invariant(_requests.size() == _numResourcesToUnlockAtEndUnitOfWork);
for (auto it = _requests.begin(); it; it.next()) {
// No converted lock so we don't need to unlock more than once.
invariant(it->unlockPending == 1);
}
_numResourcesToUnlockAtEndUnitOfWork = 0;
return saveLockStateAndUnlock(stateOut);
}
