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Diffstat (limited to 'src/mongo/db/query/plan_yield_policy_impl.h')
-rw-r--r-- | src/mongo/db/query/plan_yield_policy_impl.h | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/src/mongo/db/query/plan_yield_policy_impl.h b/src/mongo/db/query/plan_yield_policy_impl.h new file mode 100644 index 00000000000..fcc92669fe7 --- /dev/null +++ b/src/mongo/db/query/plan_yield_policy_impl.h @@ -0,0 +1,63 @@ +/** + * Copyright (C) 2020-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. + */ + +#pragma once + +#include "mongo/db/query/plan_executor.h" +#include "mongo/db/query/plan_yield_policy.h" + +namespace mongo { + +class PlanYieldPolicyImpl final : public PlanYieldPolicy { +public: + PlanYieldPolicyImpl(PlanExecutor* exec, PlanYieldPolicy::YieldPolicy policy); + +private: + Status yield(OperationContext* opCtx, std::function<void()> whileYieldingFn = nullptr) override; + + void preCheckInterruptOnly(OperationContext* opCtx) override; + + /** + * If not in a nested context, unlocks all locks, suggests to the operating system to switch to + * another thread, and then reacquires all locks. + * + * If in a nested context (eg DBDirectClient), does nothing. + * + * The whileYieldingFn will be executed after unlocking the locks and before re-acquiring them. + */ + void _yieldAllLocks(OperationContext* opCtx, + std::function<void()> whileYieldingFn, + const NamespaceString& planExecNS); + + // The plan executor which this yield policy is responsible for yielding. Must not outlive the + // plan executor. + PlanExecutor* const _planYielding; +}; + +} // namespace mongo |