| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License. |
| |
| |
| #ifndef IMPALA_RUNTIME_QUERY_EXEC_MGR_H |
| #define IMPALA_RUNTIME_QUERY_EXEC_MGR_H |
| |
| #include <boost/thread/mutex.hpp> |
| #include <unordered_map> |
| |
| #include "common/status.h" |
| #include "gen-cpp/Types_types.h" |
| #include "util/sharded-query-map-util.h" |
| |
| namespace impala { |
| |
| class QueryState; |
| class Thread; |
| class TExecPlanFragmentParams; |
| class TQueryCtx; |
| class TUniqueId; |
| class FragmentInstanceState; |
| |
| /// A daemon-wide registry and manager of QueryStates. This is the central |
| /// entry point for gaining refcounted access to a QueryState. It also initiates |
| /// query execution. |
| /// Thread-safe. |
| class QueryExecMgr : public CacheLineAligned { |
| public: |
| /// Creates QueryState if it doesn't exist and initiates execution of all fragment |
| /// instance for this query. All fragment instances hold a reference to their |
| /// QueryState for the duration of their execution. |
| /// |
| /// Returns an error if there was some unrecoverable problem before any instance |
| /// was started (like low memory). In that case, no QueryState is created. |
| /// After this function returns, it is legal to call QueryState::Cancel(), regardless of |
| /// the return value of this function. |
| Status StartQuery(const ExecQueryFInstancesRequestPB* request, |
| const TQueryCtx& query_ctx, const TExecPlanFragmentInfo& fragment_info); |
| |
| /// Creates a QueryState for the given query with the provided parameters. Only valid |
| /// to call if the QueryState does not already exist. The caller must call |
| /// ReleaseQueryState() with the returned QueryState to decrement the refcount. |
| QueryState* CreateQueryState(const TQueryCtx& query_ctx, int64_t mem_limit); |
| |
| /// If a QueryState for the given query exists, increments that refcount and returns |
| /// the QueryState, otherwise returns nullptr. |
| QueryState* GetQueryState(const TUniqueId& query_id); |
| |
| /// Decrements the refcount for the given QueryState. |
| void ReleaseQueryState(QueryState* qs); |
| |
| private: |
| |
| typedef ShardedQueryMap<QueryState*> QueryStateMap; |
| QueryStateMap qs_map_; |
| |
| /// Gets the existing QueryState or creates a new one if not present. |
| /// 'created' is set to true if it was created, false otherwise. |
| /// Increments the refcount. |
| QueryState* GetOrCreateQueryState( |
| const TQueryCtx& query_ctx, int64_t mem_limit, bool* created); |
| |
| /// Execute instances and decrement refcount (acquire ownership of qs). |
| /// Return only after all fragments complete unless an instances hit |
| /// an error or the query is cancelled. |
| void ExecuteQueryHelper(QueryState* qs); |
| }; |
| } |
| |
| #endif |