diff options
Diffstat (limited to 'source/blender/blenlib')
-rw-r--r-- | source/blender/blenlib/BLI_enumerable_thread_specific.hh | 73 | ||||
-rw-r--r-- | source/blender/blenlib/CMakeLists.txt | 1 |
2 files changed, 74 insertions, 0 deletions
diff --git a/source/blender/blenlib/BLI_enumerable_thread_specific.hh b/source/blender/blenlib/BLI_enumerable_thread_specific.hh new file mode 100644 index 00000000000..89be4cad848 --- /dev/null +++ b/source/blender/blenlib/BLI_enumerable_thread_specific.hh @@ -0,0 +1,73 @@ +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * 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 + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#pragma once + +#ifdef WITH_TBB +# include <tbb/enumerable_thread_specific.h> +#endif + +#include <atomic> +#include <mutex> + +#include "BLI_map.hh" +#include "BLI_utility_mixins.hh" + +namespace blender { + +namespace enumerable_thread_specific_utils { +inline std::atomic<int> next_id = 0; +inline thread_local int thread_id = next_id.fetch_add(1, std::memory_order_relaxed); +} // namespace enumerable_thread_specific_utils + +/** + * This is mainly a wrapper for `tbb::enumerable_thread_specific`. The wrapper is needed because we + * want to be able to build without tbb. + * + * More features of the tbb version can be wrapped when they are used. + */ +template<typename T> class EnumerableThreadSpecific : NonCopyable, NonMovable { +#ifdef WITH_TBB + + private: + tbb::enumerable_thread_specific<T> values_; + + public: + T &local() + { + return values_.local(); + } + +#else /* WITH_TBB */ + + private: + std::mutex mutex_; + /* Maps thread ids to their corresponding values. The values are not embedded in the map, so that + * their addresses do not change when the map grows. */ + Map<int, std::unique_ptr<T>> values_; + + public: + T &local() + { + const int thread_id = enumerable_thread_specific_utils::thread_id; + std::lock_guard lock{mutex_}; + return *values_.lookup_or_add_cb(thread_id, []() { return std::make_unique<T>(); }); + } + +#endif /* WITH_TBB */ +}; + +} // namespace blender diff --git a/source/blender/blenlib/CMakeLists.txt b/source/blender/blenlib/CMakeLists.txt index e66049c9bd6..ce3515ac153 100644 --- a/source/blender/blenlib/CMakeLists.txt +++ b/source/blender/blenlib/CMakeLists.txt @@ -185,6 +185,7 @@ set(SRC BLI_edgehash.h BLI_endian_switch.h BLI_endian_switch_inline.h + BLI_enumerable_thread_specific.hh BLI_expr_pylike_eval.h BLI_fileops.h BLI_fileops_types.h |