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Diffstat (limited to 'src/debug/fast_mutex.h')
| -rw-r--r-- | src/debug/fast_mutex.h | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/src/debug/fast_mutex.h b/src/debug/fast_mutex.h new file mode 100644 index 000000000..a6adb2db3 --- /dev/null +++ b/src/debug/fast_mutex.h @@ -0,0 +1,314 @@ +// -*- Mode: C++; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- +// vim:tabstop=4:shiftwidth=4:expandtab: + +/* + * Copyright (C) 2004-2008 Wu Yongwei <adah at users dot sourceforge dot net> + * + * This software is provided 'as-is', without any express or implied + * warranty. In no event will the authors be held liable for any + * damages arising from the use of this software. + * + * Permission is granted to anyone to use this software for any purpose, + * including commercial applications, and to alter it and redistribute + * it freely, subject to the following restrictions: + * + * 1. The origin of this software must not be misrepresented; you must + * not claim that you wrote the original software. If you use this + * software in a product, an acknowledgement in the product + * documentation would be appreciated but is not required. + * 2. Altered source versions must be plainly marked as such, and must + * not be misrepresented as being the original software. + * 3. This notice may not be removed or altered from any source + * distribution. + * + * This file is part of Stones of Nvwa: + * http://sourceforge.net/projects/nvwa + * + * original version changed for ManaPlus + * + * Copyright (C) 2011 ManaPlus developers + */ + +/** + * @file fast_mutex.h + * + * A fast mutex implementation for POSIX and Win32. + * + * @version 1.18, 2005/05/06 + * @author Wu Yongwei + * + */ + +#ifndef _FAST_MUTEX_H +#define _FAST_MUTEX_H + +# if !defined(_NOTHREADS) +# if !defined(_WIN32THREADS) && \ + (defined(_WIN32) && defined(_MT)) +// Automatically use _WIN32THREADS when specifying -MT/-MD in MSVC, +// or -mthreads in MinGW GCC. +# define _WIN32THREADS +# elif !defined(_PTHREADS) && \ + defined(_REENTRANT) +// Automatically use _PTHREADS when specifying -pthread in GCC. +// N.B. I do not detect on _PTHREAD_H since libstdc++-v3 under +// Linux will silently include <pthread.h> anyway. +# define _PTHREADS +# endif +# endif + +# if !defined(_PTHREADS) && !defined(_WIN32THREADS) && !defined(_NOTHREADS) +# define _NOTHREADS +# endif + +# if defined(_NOTHREADS) +# if defined(_PTHREADS) || defined(_WIN32THREADS) +# undef _NOTHREADS +# error "Cannot define multi-threaded mode with -D_NOTHREADS" +# if defined(__MINGW32__) && defined(_WIN32THREADS) && !defined(_MT) +# error "Be sure to specify -mthreads with -D_WIN32THREADS" +# endif +# endif +# endif + +# ifndef _FAST_MUTEX_CHECK_INITIALIZATION +/** + * Macro to control whether to check for initialization status for each + * lock/unlock operation. Defining it to a non-zero value will enable + * the check, so that the construction/destruction of a static object + * using a static fast_mutex not yet constructed or already destroyed + * will work (with lock/unlock operations ignored). Defining it to zero + * will disable to check. + */ +# define _FAST_MUTEX_CHECK_INITIALIZATION 1 +# endif + +# if defined(_PTHREADS) && defined(_WIN32THREADS) +// Some C++ libraries have _PTHREADS defined even on Win32 platforms. +// Thus this hack. +# undef _PTHREADS +# endif + +# ifdef _DEBUG +# include <stdio.h> +# include <stdlib.h> +/** Macro for fast_mutex assertions. Real version (for debug mode). */ +# define _FAST_MUTEX_ASSERT(_Expr, _Msg) \ + if (!(_Expr)) { \ + fprintf(stderr, "fast_mutex::%s\n", _Msg); \ + abort(); \ + } +# else +/** Macro for fast_mutex assertions. Fake version (for release mode). */ +# define _FAST_MUTEX_ASSERT(_Expr, _Msg) \ + ((void)0) +# endif + +# ifdef _PTHREADS +# include <pthread.h> +/** + * Macro alias to `volatile' semantics. Here it is truly volatile since + * it is in a multi-threaded (POSIX threads) environment. + */ +# define __VOLATILE volatile + /** + * Class for non-reentrant fast mutexes. This is the implementation + * for POSIX threads. + */ + class fast_mutex + { + pthread_mutex_t _M_mtx_impl; +# if _FAST_MUTEX_CHECK_INITIALIZATION + bool _M_initialized; +# endif +# ifdef _DEBUG + bool _M_locked; +# endif + public: + fast_mutex() +# ifdef _DEBUG + : _M_locked(false) +# endif + { + ::pthread_mutex_init(&_M_mtx_impl, NULL); +# if _FAST_MUTEX_CHECK_INITIALIZATION + _M_initialized = true; +# endif + } + ~fast_mutex() + { + _FAST_MUTEX_ASSERT(!_M_locked, "~fast_mutex(): still locked"); +# if _FAST_MUTEX_CHECK_INITIALIZATION + _M_initialized = false; +# endif + ::pthread_mutex_destroy(&_M_mtx_impl); + } + void lock() + { +# if _FAST_MUTEX_CHECK_INITIALIZATION + if (!_M_initialized) + return; +# endif + ::pthread_mutex_lock(&_M_mtx_impl); +# ifdef _DEBUG + // The following assertion should _always_ be true for a + // real `fast' pthread_mutex. However, this assertion can + // help sometimes, when people forget to use `-lpthread' and + // glibc provides an empty implementation. Having this + // assertion is also more consistent. + _FAST_MUTEX_ASSERT(!_M_locked, "lock(): already locked"); + _M_locked = true; +# endif + } + void unlock() + { +# if _FAST_MUTEX_CHECK_INITIALIZATION + if (!_M_initialized) + return; +# endif +# ifdef _DEBUG + _FAST_MUTEX_ASSERT(_M_locked, "unlock(): not locked"); + _M_locked = false; +# endif + ::pthread_mutex_unlock(&_M_mtx_impl); + } + private: + fast_mutex(const fast_mutex&); + fast_mutex& operator=(const fast_mutex&); + }; +# endif // _PTHREADS + +# ifdef _WIN32THREADS +# include <windows.h> +/** + * Macro alias to `volatile' semantics. Here it is truly volatile since + * it is in a multi-threaded (Win32 threads) environment. + */ +# define __VOLATILE volatile + /** + * Class for non-reentrant fast mutexes. This is the implementation + * for Win32 threads. + */ + class fast_mutex + { + CRITICAL_SECTION _M_mtx_impl; +# if _FAST_MUTEX_CHECK_INITIALIZATION + bool _M_initialized; +# endif +# ifdef _DEBUG + bool _M_locked; +# endif + public: + fast_mutex() +# ifdef _DEBUG + : _M_locked(false) +# endif + { + ::InitializeCriticalSection(&_M_mtx_impl); +# if _FAST_MUTEX_CHECK_INITIALIZATION + _M_initialized = true; +# endif + } + ~fast_mutex() + { + _FAST_MUTEX_ASSERT(!_M_locked, "~fast_mutex(): still locked"); +# if _FAST_MUTEX_CHECK_INITIALIZATION + _M_initialized = false; +# endif + ::DeleteCriticalSection(&_M_mtx_impl); + } + void lock() + { +# if _FAST_MUTEX_CHECK_INITIALIZATION + if (!_M_initialized) + return; +# endif + ::EnterCriticalSection(&_M_mtx_impl); +# ifdef _DEBUG + _FAST_MUTEX_ASSERT(!_M_locked, "lock(): already locked"); + _M_locked = true; +# endif + } + void unlock() + { +# if _FAST_MUTEX_CHECK_INITIALIZATION + if (!_M_initialized) + return; +# endif +# ifdef _DEBUG + _FAST_MUTEX_ASSERT(_M_locked, "unlock(): not locked"); + _M_locked = false; +# endif + ::LeaveCriticalSection(&_M_mtx_impl); + } + private: + fast_mutex(const fast_mutex&); + fast_mutex& operator=(const fast_mutex&); + }; +# endif // _WIN32THREADS + +# ifdef _NOTHREADS +/** + * Macro alias to `volatile' semantics. Here it is not truly volatile + * since it is in a single-threaded environment. + */ +# define __VOLATILE + /** + * Class for non-reentrant fast mutexes. This is the null + * implementation for single-threaded environments. + */ + class fast_mutex + { +# ifdef _DEBUG + bool _M_locked; +# endif + public: + fast_mutex() +# ifdef _DEBUG + : _M_locked(false) +# endif + { + } + ~fast_mutex() + { + _FAST_MUTEX_ASSERT(!_M_locked, "~fast_mutex(): still locked"); + } + void lock() + { +# ifdef _DEBUG + _FAST_MUTEX_ASSERT(!_M_locked, "lock(): already locked"); + _M_locked = true; +# endif + } + void unlock() + { +# ifdef _DEBUG + _FAST_MUTEX_ASSERT(_M_locked, "unlock(): not locked"); + _M_locked = false; +# endif + } + private: + fast_mutex(const fast_mutex&); + fast_mutex& operator=(const fast_mutex&); + }; +# endif // _NOTHREADS + +/** An acquistion-on-initialization lock class based on fast_mutex. */ +class fast_mutex_autolock +{ + fast_mutex& _M_mtx; +public: + explicit fast_mutex_autolock(fast_mutex& __mtx) : _M_mtx(__mtx) + { + _M_mtx.lock(); + } + ~fast_mutex_autolock() + { + _M_mtx.unlock(); + } +private: + fast_mutex_autolock(const fast_mutex_autolock&); + fast_mutex_autolock& operator=(const fast_mutex_autolock&); +}; + +#endif // _FAST_MUTEX_H |