| // 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. |
| #pragma once |
| |
| #include <cstdint> |
| #include <memory> |
| |
| #include "kudu/codegen/code_generator.h" |
| #include "kudu/codegen/code_cache.h" |
| #include "kudu/gutil/macros.h" |
| #include "kudu/gutil/ref_counted.h" |
| #include "kudu/gutil/singleton.h" |
| #include "kudu/util/atomic.h" |
| #include "kudu/util/status.h" |
| |
| namespace kudu { |
| |
| class MetricEntity; |
| class Schema; |
| class ThreadPool; |
| |
| namespace codegen { |
| |
| class RowProjector; |
| |
| // The compilation manager is a top-level class which manages the actual |
| // delivery of a code generator's output by maintaining its own |
| // threadpool and code cache. It accepts requests to compile various classes |
| // (all the ones that the CodeGenerator offers) and attempts to retrieve a |
| // cached copy. If no such copy exists, it adds a request to generate it. |
| // |
| // Class is thread safe. |
| // |
| // The compilation manager is available as a global singleton only because |
| // it is intended to be used on a per-tablet-server basis. While in |
| // certain unit tests (that don't depend on compilation performance), |
| // there may be multiple TSs per processes, this will not occur in a |
| // distributed enviornment, where each TS has its own process. |
| // Furthermore, using a singleton ensures that lower-level classes which |
| // depend on code generation need not depend on a top-level class which |
| // instantiates them to provide a compilation manager. This avoids many |
| // unnecessary dependencies on state and lifetime of top-level and |
| // intermediary classes which should not be aware of the code generation's |
| // use in the first place. |
| class CompilationManager { |
| public: |
| // Waits for all async tasks to finish. |
| ~CompilationManager(); |
| |
| static CompilationManager* GetSingleton() { |
| return Singleton<CompilationManager>::get(); |
| } |
| |
| // If a codegenned row projector with compatible schemas (see |
| // codegen::JITSchemaPair::ProjectionsCompatible) is ready, |
| // then it is written to 'out' and true is returned. |
| // Otherwise, this enqueues a compilation task for the parameter |
| // schemas in the CompilationManager's thread pool and returns |
| // false. Upon any failure, false is returned. |
| // Does not write to 'out' if false is returned. |
| bool RequestRowProjector(const Schema* base_schema, |
| const Schema* projection, |
| std::unique_ptr<RowProjector>* out); |
| |
| // Waits for all asynchronous compilation tasks to finish. |
| void Wait(); |
| |
| // Sets up a metric registry to observe the compilation manager's metrics. |
| // This method is used instead of registering a counter with a given |
| // registry because the CompilationManager is a singleton and there would |
| // be lifetime issues if the manager was dependent on a single registry. |
| Status StartInstrumentation(const scoped_refptr<MetricEntity>& metric_entity); |
| |
| private: |
| friend class Singleton<CompilationManager>; |
| CompilationManager(); |
| |
| static void Shutdown(); |
| |
| CodeGenerator generator_; |
| CodeCache cache_; |
| std::unique_ptr<ThreadPool> pool_; |
| |
| AtomicInt<int64_t> hit_counter_; |
| AtomicInt<int64_t> query_counter_; |
| |
| static const int kThreadTimeoutMs = 100; |
| |
| DISALLOW_COPY_AND_ASSIGN(CompilationManager); |
| }; |
| |
| } // namespace codegen |
| } // namespace kudu |
| |