91 lines
3.2 KiB
C++
91 lines
3.2 KiB
C++
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// This file is part of OpenCV project.
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// It is subject to the license terms in the LICENSE file found in the top-level directory
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// of this distribution and at http://opencv.org/license.html.
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#ifndef OPENCV_CORE_PARALLEL_BACKEND_HPP
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#define OPENCV_CORE_PARALLEL_BACKEND_HPP
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#include "opencv2/core/cvdef.h"
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#include <memory>
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namespace cv { namespace parallel {
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#ifndef CV_API_CALL
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#define CV_API_CALL
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#endif
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/** @addtogroup core_parallel_backend
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* @{
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* API below is provided to resolve problem of CPU resource over-subscription by multiple thread pools from different multi-threading frameworks.
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* This is common problem for cases when OpenCV compiled threading framework is different from the Users Applications framework.
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*
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* Applications can replace OpenCV `parallel_for()` backend with own implementation (to reuse Application's thread pool).
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*
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*
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* ### Backend API usage examples
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*
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* #### Intel TBB
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*
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* - include header with simple implementation of TBB backend:
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* @snippet parallel_backend/example-tbb.cpp tbb_include
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* - execute backend replacement code:
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* @snippet parallel_backend/example-tbb.cpp tbb_backend
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* - configuration of compiler/linker options is responsibility of Application's scripts
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*
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* #### OpenMP
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*
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* - include header with simple implementation of OpenMP backend:
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* @snippet parallel_backend/example-openmp.cpp openmp_include
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* - execute backend replacement code:
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* @snippet parallel_backend/example-openmp.cpp openmp_backend
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* - Configuration of compiler/linker options is responsibility of Application's scripts
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*
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*
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* ### Plugins support
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*
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* Runtime configuration options:
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* - change backend priority: `OPENCV_PARALLEL_PRIORITY_<backend>=9999`
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* - disable backend: `OPENCV_PARALLEL_PRIORITY_<backend>=0`
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* - specify list of backends with high priority (>100000): `OPENCV_PARALLEL_PRIORITY_LIST=TBB,OPENMP`. Unknown backends are registered as new plugins.
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*
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*/
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/** Interface for parallel_for backends implementations
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*
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* @sa setParallelForBackend
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*/
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class CV_EXPORTS ParallelForAPI
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{
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public:
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virtual ~ParallelForAPI();
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typedef void (CV_API_CALL *FN_parallel_for_body_cb_t)(int start, int end, void* data);
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virtual void parallel_for(int tasks, FN_parallel_for_body_cb_t body_callback, void* callback_data) = 0;
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virtual int getThreadNum() const = 0;
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virtual int getNumThreads() const = 0;
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virtual int setNumThreads(int nThreads) = 0;
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virtual const char* getName() const = 0;
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};
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/** @brief Replace OpenCV parallel_for backend
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*
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* Application can replace OpenCV `parallel_for()` backend with own implementation.
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*
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* @note This call is not thread-safe. Consider calling this function from the `main()` before any other OpenCV processing functions (and without any other created threads).
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*/
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CV_EXPORTS void setParallelForBackend(const std::shared_ptr<ParallelForAPI>& api, bool propagateNumThreads = true);
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/** @brief Change OpenCV parallel_for backend
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*
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* @note This call is not thread-safe. Consider calling this function from the `main()` before any other OpenCV processing functions (and without any other created threads).
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*/
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CV_EXPORTS_W bool setParallelForBackend(const std::string& backendName, bool propagateNumThreads = true);
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//! @}
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}} // namespace
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#endif // OPENCV_CORE_PARALLEL_BACKEND_HPP
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