| /*************************************************************************** |
| * |
| * _mutex.h - definitions of classes for thread safety |
| * |
| * This is an internal header file used to implement the C++ Standard |
| * Library. It should never be #included directly by a program. |
| * |
| * $Id$ |
| * |
| *************************************************************************** |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed |
| * with this work for additional information regarding copyright |
| * ownership. The ASF licenses this file to you under the Apache |
| * License, Version 2.0 (the "License"); you may not use this file |
| * except in compliance with the License. You may obtain a copy of |
| * the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or |
| * implied. See the License for the specific language governing |
| * permissions and limitations under the License. |
| * |
| * Copyright 1994-2008 Rogue Wave Software, Inc. |
| * |
| **************************************************************************/ |
| |
| #ifndef _RWSTD_RW_MUTEX_H_INCLUDED |
| #define _RWSTD_RW_MUTEX_H_INCLUDED |
| |
| |
| #if __GNUG__ >= 3 |
| # pragma GCC system_header |
| #endif // gcc >= 3 |
| |
| |
| #ifndef _RWSTD_RW_DEFS_H_INCLUDED |
| # include <rw/_defs.h> |
| #endif // _RWSTD_RW_DEFS_H_INCLUDED |
| |
| |
| #ifndef _RWSTD_RW_ATOMIC_H_INCLUDED |
| # include <rw/_atomic.h> |
| #endif // _RWSTD_RW_ATOMIC_H_INCLUDED |
| |
| |
| #ifdef _RWSTD_REENTRANT |
| |
| # ifndef _RWSTD_RW_EXCEPTION_H_INCLUDED |
| # include <rw/_exception.h> |
| # endif // _RWSTD_RW_EXCEPTION_INCLUDED |
| |
| # ifndef _RWSTD_RW_ERROR_H_INCLUDED |
| # include <rw/_error.h> |
| # endif // _RWSTD_RW_ERROR_H_INCLUDED |
| |
| |
| // work around SunOS 5.{8,9}/SunPro bug (see PR #26255) |
| # if defined (__SunOS_5_8) || defined (__SunOS_5_9) |
| # undef _TIME_T |
| # endif // __SunOS_5_{8,9} |
| |
| # if defined (_RWSTD_SOLARIS_THREADS) // assuming Solaris 2.1 or greater |
| # include <rw/_mutex-solaris.h> |
| # elif defined (_RWSTD_POSIX_THREADS) |
| # include <rw/_mutex-pthread.h> |
| # elif defined (_RWSTD_DCE_THREADS) |
| # include <rw/_mutex-dce.h> |
| # elif defined (_WIN32) |
| # include <rw/_mutex-win32.h> |
| # elif defined (__OS2__) |
| # include <rw/_mutex-os2.h> |
| # else |
| # error unknown thread environment |
| # endif |
| |
| |
| # if defined(_RWSTD_NO_STATIC_MUTEX_INIT) |
| # include <new> |
| # endif //_RWSTD_NO_STATIC_MUTEX_INIT |
| |
| |
| _RWSTD_NAMESPACE (__rw) { |
| |
| // a using declaration (rather than a directive) |
| // used to work around yet another MSVC 6.0 bug |
| _USING (std::exception); |
| |
| class __rw_thread_error : public exception |
| { |
| public: |
| __rw_thread_error () _THROWS (()) |
| : exception () { } |
| |
| virtual const char* what () const _THROWS (()) { |
| return "thread synchronization error"; |
| } |
| }; |
| |
| |
| // POD type with no user-defined ctor or dtor facilitates static |
| // initialization of mutex objects with static storage duration |
| // (important during library initialziation time) |
| class _RWSTD_EXPORT __rw_mutex_base |
| { |
| public: |
| |
| void _C_acquire () { |
| # if !defined (__HP_aCC) || __HP_aCC > 32700 |
| if (0 != _RWSTD_MUTEX_LOCK (_C_mutex)) |
| _RW::__rw_throw (_RWSTD_ERROR_RUNTIME_ERROR, |
| "synchronization error"); |
| # else |
| // working around an HP aCC 3.27 bug JAGac88738 |
| _RWSTD_MUTEX_LOCK (_C_mutex); |
| # endif // !defined (__HP_aCC) || __HP_aCC > 32700 |
| } |
| |
| void _C_release (); |
| |
| # ifdef _RWSTD_NO_STATIC_MUTEX_INIT |
| |
| // static initialization not an option, define ctor and dtor |
| // and make member mutex private |
| |
| __rw_mutex_base (); |
| |
| ~__rw_mutex_base (); |
| |
| private: |
| |
| // not defined |
| __rw_mutex_base (const __rw_mutex_base&); |
| __rw_mutex_base& operator= (const __rw_mutex_base&); |
| |
| # endif // _RWSTD_NO_STATIC_MUTEX_INIT |
| |
| _RWSTD_MUTEX_T _C_mutex; // the real thing |
| }; |
| |
| |
| inline void __rw_mutex_base::_C_release () |
| { |
| // we should NOT throw from here as _C_release will typically be called |
| // during the destruction of local objects such as __rw_guard (perhaps |
| // due to another exception) |
| _RWSTD_MUTEX_UNLOCK (_C_mutex); |
| } |
| |
| |
| // non-POD type, always initializes mutex data member via a function call |
| class _RWSTD_EXPORT __rw_mutex: public __rw_mutex_base |
| { |
| public: |
| |
| # ifndef _RWSTD_NO_STATIC_MUTEX_INIT |
| |
| __rw_mutex (); |
| |
| ~__rw_mutex (); |
| |
| private: |
| |
| // not defined |
| __rw_mutex (const __rw_mutex&); |
| __rw_mutex& operator= (const __rw_mutex&); |
| |
| # endif // _RWSTD_NO_STATIC_MUTEX_INIT |
| |
| }; |
| |
| |
| # ifndef _RWSTD_NO_STATIC_MUTEX_INIT |
| |
| // helper factory class - static member is guranteed to be constructed |
| // during static initialization; objects of this POD class are not |
| // destroyed during program termination (important to allow them |
| // to be used in dtors of other objects with static storage duration) |
| template <class _TypeT> |
| struct __rw_static_mutex |
| { |
| static __rw_mutex_base _C_mutex; |
| }; |
| |
| |
| template <class _TypeT> |
| __rw_mutex_base __rw_static_mutex<_TypeT>::_C_mutex |
| |
| # ifdef _RWSTD_MUTEX_INITIALIZER |
| |
| = { _RWSTD_MUTEX_INITIALIZER } |
| |
| # undef _RWSTD_MUTEX_INITIALIZER |
| # endif // _RWSTD_MUTEX_INITIALIZER |
| ; |
| |
| # if _RWSTD_INSTANTIATE (_STATIC_MUTEX, _INT) |
| |
| // explicitly instantiated to work around a g++ 2.95.2 bug on COFF systems |
| // (such as IBM AIX or DEC OSF1) where it "forgets" to do so implicitly for |
| // explicitly initialized static data members |
| _RWSTD_INSTANTIATE_1 (class _RWSTD_TI_EXPORT __rw_static_mutex<int>); |
| _RWSTD_INSTANTIATE_1 (class _RWSTD_TI_EXPORT __rw_static_mutex<size_t>); |
| |
| # endif // _RWSTD_INSTANTIATE (_STATIC_MUTEX, _INT) |
| |
| |
| inline __rw_mutex::__rw_mutex () |
| |
| # else // if defined (_RWSTD_NO_STATIC_MUTEX_INIT) |
| |
| inline __rw_mutex_base::__rw_mutex_base () |
| |
| # endif // _RWSTD_NO_STATIC_MUTEX_INIT |
| { |
| if (0 != _RWSTD_MUTEX_INIT (_C_mutex)) |
| _RW::__rw_throw (_RWSTD_ERROR_RUNTIME_ERROR, "synchronization error"); |
| } |
| |
| # ifndef _RWSTD_NO_STATIC_MUTEX_INIT |
| |
| inline __rw_mutex::~__rw_mutex () |
| |
| # else // if defined (_RWSTD_NO_STATIC_MUTEX_INIT) |
| |
| inline __rw_mutex_base::~__rw_mutex_base () |
| |
| # endif // _RWSTD_NO_STATIC_MUTEX_INIT |
| { |
| _RWSTD_MUTEX_DESTROY (_C_mutex); |
| } |
| |
| // type used in instantiating __rw_get_static_mutex |
| template<class _TypeT, int _IntI> struct __rw_type { }; |
| |
| // mutex factory function avoids problematic initialization dependencies |
| // introduced by definitions of mutexes with static storage duration |
| // instead of defining a static mutex member that may not be initialized |
| // before first use, a non-local class may either declare a unique type |
| // (enum or class) or use itself as this type, and call this template |
| // function with a ptr to that type to obtain an initialized mutex object |
| // that is the same for each unique type passed to the function |
| |
| # ifndef _RWSTD_NO_STATIC_MUTEX_INIT |
| |
| template <class _TypeT> |
| inline |
| __rw_mutex_base& __rw_get_static_mutex (_TypeT*) |
| { |
| // POD mutex already initialized during static initialization |
| return __rw_static_mutex<_TypeT>::_C_mutex; |
| } |
| |
| # else // if defined (_RWSTD_NO_STATIC_MUTEX_INIT) |
| |
| # ifdef _INLINE_WITH_STATICS |
| |
| template <class _TypeT> |
| _INLINE_WITH_STATICS |
| __rw_mutex_base& __rw_get_static_mutex (_TypeT*) |
| |
| # else // if !defined (_INLINE_WITH_STATICS) |
| |
| template <class _TypeT> |
| __rw_mutex_base& __rw_get_static_mutex (_TypeT*) |
| |
| # endif // _INLINE_WITH_STATICS |
| |
| { |
| // allocate properly aligned memory for static mutex (necessary |
| // to prevent static local mutex from being destroyed during |
| // program termination) |
| union __mutex_buf_t { |
| long double __pad; // force alignment (must be first) |
| char __buf [sizeof (__rw_mutex_base)]; |
| }; |
| |
| // using a named union to work around a bug in HP aCC 3.14.10 (JAGad03246) |
| static __mutex_buf_t __mutex_buf; |
| |
| // initialize mutex reference to refer to the static buffer space |
| __rw_mutex_base &__mutex = |
| _RWSTD_REINTERPRET_CAST (__rw_mutex_base&, __mutex_buf); |
| |
| // keep track of number of mutex initialization attempts |
| // although `init' may reach a value greater than 1, `mutex' |
| // will (should) never be multiply initialized |
| |
| // implicit initialization used to prevent a g++ 2.95.2 warning on Tru64 |
| // sorry: semantics of inline function static data are wrong (you'll wind |
| // up with multiple copies) |
| static volatile int __cntr /* = 0 */; // initialization counter |
| |
| # if !defined (_RWSTD_NO_ATOMIC_OPS) && !defined (_RWSTD_NO_INT_ATOMIC_OPS) |
| // MT safe |
| // cast __cntr to int& (see STDCXX-792) |
| // casting should be removed after fixing STDCXX-794 |
| if (0 == __cntr && 1 == _RWSTD_ATOMIC_PREINCREMENT ( |
| _RWSTD_CONST_CAST (int&, __cntr), false)) |
| # else // _RWSTD_NO_ATOMIC_OPS || _RWSTD_NO_INT_ATOMIC_OPS |
| // not so safe (volatile should help) |
| if (0 == __cntr && 1 == ++__cntr) |
| # endif // !_RWSTD_NO_ATOMIC_OPS && !_RWSTD_NO_INT_ATOMIC_OPS |
| |
| { |
| // manually initialize `mutex' via a call to placement new |
| new (&__mutex) __rw_mutex_base (); |
| |
| // indicate that `mutex' has been fully initialized |
| // (unlikely that we'll have more than 1000 threads) |
| __cntr += 1000; |
| } |
| else |
| // busywait until `mutex' has been completely initialized |
| while (__cntr < 1000); |
| |
| return __mutex; |
| } |
| |
| # endif //_RWSTD_NO_STATIC_MUTEX_INIT |
| |
| |
| // clean up |
| # undef _RWSTD_MUTEX_LOCK |
| # undef _RWSTD_MUTEX_UNLOCK |
| # undef _RWSTD_MUTEX_T |
| |
| |
| // allows safe use of a mutex in the presence of exceptions |
| class __rw_guard |
| { |
| __rw_mutex_base *_C_mutex; |
| |
| // undefined |
| __rw_guard& operator= (const __rw_guard&); |
| |
| public: |
| |
| __rw_guard (__rw_guard &__rhs) |
| : _C_mutex (__rhs._C_mutex) { |
| __rhs._C_mutex = 0; |
| } |
| |
| __rw_guard (__rw_mutex_base &__mutex): _C_mutex (&__mutex) { |
| _C_mutex->_C_acquire (); |
| } |
| |
| __rw_guard (__rw_mutex_base *__mutex): _C_mutex (__mutex) { |
| if (_C_mutex) |
| _C_mutex->_C_acquire (); |
| } |
| |
| ~__rw_guard () { |
| if (_C_mutex) |
| _C_mutex->_C_release (); |
| } |
| |
| __rw_mutex_base* _C_set (__rw_mutex_base *__mutex) { |
| __rw_mutex_base *__tmp = _C_mutex; |
| return _C_mutex = __mutex, __tmp; |
| } |
| }; |
| |
| |
| // base class for obects required to guarantee some degree of MT safety |
| struct _RWSTD_EXPORT __rw_synchronized |
| { |
| __rw_mutex _C_mutex; |
| |
| void _C_lock () { |
| _C_mutex._C_acquire (); |
| } |
| |
| void _C_unlock () { |
| _C_mutex._C_release (); |
| } |
| |
| __rw_guard _C_guard () { |
| __rw_guard __guard (_C_mutex); |
| return __guard; |
| } |
| }; |
| |
| } // namespace __rw |
| |
| |
| // include atomic functions using mutex object |
| # ifndef _RWSTD_RW_ATOMIC_MUTEX_H_INCLUDED |
| # include <rw/_atomic-mutex.h> |
| # endif // _RWSTD_RW_ATOMIC_MUTEX_H_INCLUDED |
| |
| |
| #else // if !defined (_RWSTD_REENTRANT) |
| |
| _RWSTD_NAMESPACE (__rw) { |
| |
| // dummy classes used as a base class in single-threaded environments |
| |
| struct __rw_mutex_base |
| { |
| void _C_acquire () { } |
| |
| void _C_release () { } |
| }; |
| |
| |
| struct _RWSTD_EXPORT __rw_mutex: public __rw_mutex_base |
| { |
| }; |
| |
| |
| struct __rw_guard |
| { |
| __rw_guard (__rw_mutex_base&) { } |
| |
| __rw_guard (__rw_mutex_base*) { } |
| |
| __rw_mutex_base* _C_set (__rw_mutex_base*) { |
| return 0; |
| } |
| }; |
| |
| |
| struct __rw_synchronized |
| { |
| // static so that it takes up no space |
| static _RWSTD_EXPORT __rw_mutex _C_mutex; |
| |
| void _C_lock () { } |
| |
| void _C_unlock () { } |
| |
| __rw_guard _C_guard () { |
| return __rw_guard (_C_mutex); |
| } |
| }; |
| |
| |
| } // namespace __rw |
| |
| |
| #endif // _RWSTD_REENTRANT |
| |
| // clean up |
| #ifdef _RWSTD_NO_CHAR_ATOMIC_OPS |
| # undef _RWSTD_NO_CHAR_ATOMIC_OPS |
| #endif |
| |
| #ifdef _RWSTD_NO_SHORT_ATOMIC_OPS |
| # undef _RWSTD_NO_SHORT_ATOMIC_OPS |
| #endif |
| |
| #ifdef _RWSTD_NO_INT_ATOMIC_OPS |
| # undef _RWSTD_NO_INT_ATOMIC_OPS |
| #endif |
| |
| #ifdef _RWSTD_NO_LONG_ATOMIC_OPS |
| # undef _RWSTD_NO_LONG_ATOMIC_OPS |
| #endif |
| |
| #ifdef _RWSTD_NO_LLONG_ATOMIC_OPS |
| # undef _RWSTD_NO_LLONG_ATOMIC_OPS |
| #endif |
| |
| #endif // _RWSTD_RW_MUTEX_H_INCLUDED |