wehub-resource-sync
137 lines
3.6 KiB
C++
137 lines
3.6 KiB
C++
/*!
|
|
* Copyright (c) 2017-2026 Microsoft Corporation. All rights reserved.
|
|
* Copyright (c) 2017-2026 The LightGBM developers. All rights reserved.
|
|
* Licensed under the MIT License. See LICENSE file in the project root for license information.
|
|
*/
|
|
#ifndef LIGHTGBM_INCLUDE_LIGHTGBM_UTILS_OPENMP_WRAPPER_H_
|
|
#define LIGHTGBM_INCLUDE_LIGHTGBM_UTILS_OPENMP_WRAPPER_H_
|
|
|
|
#include <LightGBM/export.h>
|
|
|
|
// this can only be changed by LGBM_SetMaxThreads()
|
|
LIGHTGBM_EXTERN_C int LGBM_MAX_NUM_THREADS;
|
|
|
|
// this is modified by OMP_SET_NUM_THREADS(), for example
|
|
// by passing num_thread through params
|
|
LIGHTGBM_EXTERN_C int LGBM_DEFAULT_NUM_THREADS;
|
|
|
|
#ifdef _OPENMP
|
|
|
|
#include <LightGBM/utils/log.h>
|
|
|
|
#include <omp.h>
|
|
|
|
#include <exception>
|
|
#include <memory>
|
|
#include <mutex>
|
|
#include <stdexcept>
|
|
#include <vector>
|
|
|
|
/*
|
|
Get number of threads to use in OpenMP parallel regions.
|
|
|
|
By default, this will return the result of omp_get_max_threads(),
|
|
which is OpenMP-implementation dependent but generally can be controlled
|
|
by environment variable OMP_NUM_THREADS.
|
|
|
|
ref:
|
|
- https://www.openmp.org/spec-html/5.0/openmpsu112.html
|
|
- https://gcc.gnu.org/onlinedocs/libgomp/omp_005fget_005fmax_005fthreads.html
|
|
*/
|
|
LIGHTGBM_EXTERN_C int OMP_NUM_THREADS();
|
|
|
|
/*
|
|
Update the default number of threads that'll be used in OpenMP parallel
|
|
regions for LightGBM routines where the number of threads aren't directly
|
|
supplied.
|
|
*/
|
|
LIGHTGBM_EXTERN_C void OMP_SET_NUM_THREADS(int num_threads);
|
|
|
|
class ThreadExceptionHelper {
|
|
public:
|
|
ThreadExceptionHelper() {
|
|
ex_ptr_ = nullptr;
|
|
}
|
|
|
|
~ThreadExceptionHelper() {
|
|
ReThrow();
|
|
}
|
|
void ReThrow() {
|
|
if (ex_ptr_ != nullptr) {
|
|
std::rethrow_exception(ex_ptr_);
|
|
}
|
|
}
|
|
void CaptureException() {
|
|
// only catch first exception.
|
|
if (ex_ptr_ != nullptr) {
|
|
return;
|
|
}
|
|
std::unique_lock<std::mutex> guard(lock_);
|
|
if (ex_ptr_ != nullptr) {
|
|
return;
|
|
}
|
|
ex_ptr_ = std::current_exception();
|
|
}
|
|
|
|
private:
|
|
std::exception_ptr ex_ptr_;
|
|
std::mutex lock_;
|
|
};
|
|
|
|
#define OMP_INIT_EX() ThreadExceptionHelper omp_except_helper
|
|
#define OMP_LOOP_EX_BEGIN() try {
|
|
#define OMP_LOOP_EX_END() \
|
|
} \
|
|
catch (std::exception & ex) { \
|
|
Log::Warning(ex.what()); \
|
|
omp_except_helper.CaptureException(); \
|
|
} \
|
|
catch (...) { \
|
|
omp_except_helper.CaptureException(); \
|
|
}
|
|
#define OMP_THROW_EX() omp_except_helper.ReThrow()
|
|
|
|
#else
|
|
|
|
/*
|
|
* To be compatible with OpenMP, define a nothrow macro which is used by gcc
|
|
* openmp, but not by clang.
|
|
* See also https://github.com/dmlc/dmlc-core/blob/3106c1cbdcc9fc9ef3a2c1d2196a7a6f6616c13d/include/dmlc/omp.h#L14
|
|
*/
|
|
#if defined(__clang__)
|
|
#undef __GOMP_NOTHROW
|
|
#define __GOMP_NOTHROW
|
|
#elif defined(__cplusplus)
|
|
#undef __GOMP_NOTHROW
|
|
#define __GOMP_NOTHROW throw()
|
|
#else
|
|
#undef __GOMP_NOTHROW
|
|
#define __GOMP_NOTHROW __attribute__((__nothrow__))
|
|
#endif
|
|
|
|
#ifdef _MSC_VER
|
|
#pragma warning(disable : 4068) // disable unknown pragma warning
|
|
#endif
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
/** Fall here if no OPENMP support, so just
|
|
simulate a single thread running.
|
|
All #pragma omp should be ignored by the compiler **/
|
|
inline void OMP_SET_NUM_THREADS(int) __GOMP_NOTHROW {}
|
|
inline int omp_get_thread_num() __GOMP_NOTHROW {return 0;}
|
|
inline int OMP_NUM_THREADS() __GOMP_NOTHROW { return 1; }
|
|
#ifdef __cplusplus
|
|
} // extern "C"
|
|
#endif
|
|
|
|
#define OMP_INIT_EX()
|
|
#define OMP_LOOP_EX_BEGIN()
|
|
#define OMP_LOOP_EX_END()
|
|
#define OMP_THROW_EX()
|
|
|
|
#endif
|
|
|
|
#endif // LIGHTGBM_INCLUDE_LIGHTGBM_UTILS_OPENMP_WRAPPER_H_
|