| /* |
| Copyright 2005-2010 Intel Corporation. All Rights Reserved. |
| |
| This file is part of Threading Building Blocks. |
| |
| Threading Building Blocks is free software; you can redistribute it |
| and/or modify it under the terms of the GNU General Public License |
| version 2 as published by the Free Software Foundation. |
| |
| Threading Building Blocks 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 Threading Building Blocks; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| |
| As a special exception, you may use this file as part of a free software |
| library without restriction. Specifically, if other files instantiate |
| templates or use macros or inline functions from this file, or you compile |
| this file and link it with other files to produce an executable, this |
| file does not by itself cause the resulting executable to be covered by |
| the GNU General Public License. This exception does not however |
| invalidate any other reasons why the executable file might be covered by |
| the GNU General Public License. |
| */ |
| |
| #ifndef _TBB_tbb_main_H |
| #define _TBB_tbb_main_H |
| |
| #include "tbb/atomic.h" |
| |
| namespace tbb { |
| |
| namespace internal { |
| |
| void DoOneTimeInitializations (); |
| |
| //------------------------------------------------------------------------ |
| // __TBB_InitOnce |
| //------------------------------------------------------------------------ |
| |
| //! Class that supports TBB initialization. |
| /** It handles acquisition and release of global resources (e.g. TLS) during startup and shutdown, |
| as well as synchronization for DoOneTimeInitializations. */ |
| class __TBB_InitOnce { |
| friend void DoOneTimeInitializations(); |
| friend void ITT_DoUnsafeOneTimeInitialization (); |
| |
| static atomic<int> count; |
| |
| //! Platform specific code to acquire resources. |
| static void acquire_resources(); |
| |
| //! Platform specific code to release resources. |
| static void release_resources(); |
| |
| //! Specifies if the one-time initializations has been done. |
| static bool InitializationDone; |
| |
| // Scenarios are possible when tools interop has to be initialized before the |
| // TBB itself. This imposes a requirement that the global initialization lock |
| // has to support valid static initialization, and does not issue any tool |
| // notifications in any build mode. |
| typedef unsigned char mutex_type; |
| |
| // Global initialization lock |
| static mutex_type InitializationLock; |
| |
| public: |
| static void lock() { __TBB_LockByte( InitializationLock ); } |
| |
| static void unlock() { __TBB_store_with_release( InitializationLock, 0 ); } |
| |
| static bool initialization_done() { return __TBB_load_with_acquire(InitializationDone); } |
| |
| //! Add initial reference to resources. |
| /** We assume that dynamic loading of the library prevents any other threads |
| from entering the library until this constructor has finished running. **/ |
| __TBB_InitOnce() { add_ref(); } |
| |
| //! Remove the initial reference to resources. |
| /** This is not necessarily the last reference if other threads are still running. **/ |
| ~__TBB_InitOnce() { |
| remove_ref(); |
| // We assume that InitializationDone is not set after file-scope destructors |
| // start running, and thus no race on InitializationDone is possible. |
| if( initialization_done() ) { |
| // Remove an extra reference that was added in DoOneTimeInitializations. |
| remove_ref(); |
| } |
| } |
| //! Add reference to resources. If first reference added, acquire the resources. |
| static void add_ref(); |
| |
| //! Remove reference to resources. If last reference removed, release the resources. |
| static void remove_ref(); |
| }; // class __TBB_InitOnce |
| |
| |
| } // namespace internal |
| |
| } // namespace tbb |
| |
| #endif /* _TBB_tbb_main_H */ |