1b5e9d7e1b
* include/bits/stl_threads.h (_Atomic_swap): Only enable path
when platform supports __GTHREAD_MUTEX_INIT.
From-SVN: r46725
564 lines
19 KiB
C++
564 lines
19 KiB
C++
// Threading support -*- C++ -*-
|
|
|
|
// Copyright (C) 2001 Free Software Foundation, Inc.
|
|
//
|
|
// This file is part of the GNU ISO C++ Library. This library 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, or (at your option)
|
|
// any later version.
|
|
|
|
// This library 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 library; see the file COPYING. If not, write to the Free
|
|
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
|
|
// 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.
|
|
|
|
/*
|
|
* Copyright (c) 1997-1999
|
|
* Silicon Graphics Computer Systems, Inc.
|
|
*
|
|
* Permission to use, copy, modify, distribute and sell this software
|
|
* and its documentation for any purpose is hereby granted without fee,
|
|
* provided that the above copyright notice appear in all copies and
|
|
* that both that copyright notice and this permission notice appear
|
|
* in supporting documentation. Silicon Graphics makes no
|
|
* representations about the suitability of this software for any
|
|
* purpose. It is provided "as is" without express or implied warranty.
|
|
*/
|
|
|
|
/** @file stl_threads.h
|
|
* This is an internal header file, included by other library headers.
|
|
* You should not attempt to use it directly.
|
|
*/
|
|
|
|
#ifndef __SGI_STL_INTERNAL_THREADS_H
|
|
#define __SGI_STL_INTERNAL_THREADS_H
|
|
|
|
// Supported threading models are native SGI, pthreads, uithreads
|
|
// (similar to pthreads, but based on an earlier draft of the Posix
|
|
// threads standard), and Win32 threads. Uithread support by Jochen
|
|
// Schlick, 1999.
|
|
|
|
// GCC extension begin
|
|
// In order to present a stable threading configuration, in all cases,
|
|
// gcc looks for it's own abstraction layer before all others. All
|
|
// modifications to this file are marked to allow easier importation of
|
|
// STL upgrades.
|
|
#if defined(__STL_GTHREADS)
|
|
#include "bits/gthr.h"
|
|
#else
|
|
// GCC extension end
|
|
#if defined(__STL_SGI_THREADS)
|
|
#include <mutex.h>
|
|
#include <time.h>
|
|
#elif defined(__STL_PTHREADS)
|
|
#include <pthread.h>
|
|
#elif defined(__STL_UITHREADS)
|
|
#include <thread.h>
|
|
#include <synch.h>
|
|
#elif defined(__STL_WIN32THREADS)
|
|
#include <windows.h>
|
|
#endif
|
|
// GCC extension begin
|
|
#endif
|
|
// GCC extension end
|
|
|
|
namespace std
|
|
{
|
|
|
|
// Class _Refcount_Base provides a type, _RC_t, a data member,
|
|
// _M_ref_count, and member functions _M_incr and _M_decr, which perform
|
|
// atomic preincrement/predecrement. The constructor initializes
|
|
// _M_ref_count.
|
|
|
|
// Hack for SGI o32 compilers.
|
|
#if defined(__STL_SGI_THREADS) && !defined(__add_and_fetch) && \
|
|
(__mips < 3 || !(defined (_ABIN32) || defined(_ABI64)))
|
|
# define __add_and_fetch(__l,__v) add_then_test((unsigned long*)__l,__v)
|
|
# define __test_and_set(__l,__v) test_and_set(__l,__v)
|
|
#endif /* o32 */
|
|
|
|
struct _Refcount_Base
|
|
{
|
|
// The type _RC_t
|
|
# ifdef __STL_WIN32THREADS
|
|
typedef long _RC_t;
|
|
# else
|
|
typedef size_t _RC_t;
|
|
#endif
|
|
|
|
// The data member _M_ref_count
|
|
volatile _RC_t _M_ref_count;
|
|
|
|
// Constructor
|
|
// GCC extension begin
|
|
#ifdef __STL_GTHREADS
|
|
__gthread_mutex_t _M_ref_count_lock;
|
|
_Refcount_Base(_RC_t __n) : _M_ref_count(__n)
|
|
{
|
|
#ifdef __GTHREAD_MUTEX_INIT
|
|
__gthread_mutex_t __tmp = __GTHREAD_MUTEX_INIT;
|
|
_M_ref_count_lock = __tmp;
|
|
#elif defined(__GTHREAD_MUTEX_INIT_FUNCTION)
|
|
__GTHREAD_MUTEX_INIT_FUNCTION (&_M_ref_count_lock);
|
|
#else
|
|
#error __GTHREAD_MUTEX_INIT or __GTHREAD_MUTEX_INIT_FUNCTION should be defined by gthr.h abstraction layer, report problem to libstdc++@gcc.gnu.org.
|
|
#endif
|
|
}
|
|
#else
|
|
// GCC extension end
|
|
# ifdef __STL_PTHREADS
|
|
pthread_mutex_t _M_ref_count_lock;
|
|
_Refcount_Base(_RC_t __n) : _M_ref_count(__n)
|
|
{ pthread_mutex_init(&_M_ref_count_lock, 0); }
|
|
# elif defined(__STL_UITHREADS)
|
|
mutex_t _M_ref_count_lock;
|
|
_Refcount_Base(_RC_t __n) : _M_ref_count(__n)
|
|
{ mutex_init(&_M_ref_count_lock, USYNC_THREAD, 0); }
|
|
# else
|
|
_Refcount_Base(_RC_t __n) : _M_ref_count(__n) {}
|
|
# endif
|
|
// GCC extension begin
|
|
#endif
|
|
// GCC extension end
|
|
|
|
// GCC extension begin
|
|
#ifdef __STL_GTHREADS
|
|
void _M_incr() {
|
|
__gthread_mutex_lock(&_M_ref_count_lock);
|
|
++_M_ref_count;
|
|
__gthread_mutex_unlock(&_M_ref_count_lock);
|
|
}
|
|
_RC_t _M_decr() {
|
|
__gthread_mutex_lock(&_M_ref_count_lock);
|
|
volatile _RC_t __tmp = --_M_ref_count;
|
|
__gthread_mutex_unlock(&_M_ref_count_lock);
|
|
return __tmp;
|
|
}
|
|
#else
|
|
// GCC extension end
|
|
// _M_incr and _M_decr
|
|
# ifdef __STL_SGI_THREADS
|
|
void _M_incr() { __add_and_fetch(&_M_ref_count, 1); }
|
|
_RC_t _M_decr() { return __add_and_fetch(&_M_ref_count, (size_t) -1); }
|
|
# elif defined (__STL_WIN32THREADS)
|
|
void _M_incr() { InterlockedIncrement((_RC_t*)&_M_ref_count); }
|
|
_RC_t _M_decr() { return InterlockedDecrement((_RC_t*)&_M_ref_count); }
|
|
# elif defined(__STL_PTHREADS)
|
|
void _M_incr() {
|
|
pthread_mutex_lock(&_M_ref_count_lock);
|
|
++_M_ref_count;
|
|
pthread_mutex_unlock(&_M_ref_count_lock);
|
|
}
|
|
_RC_t _M_decr() {
|
|
pthread_mutex_lock(&_M_ref_count_lock);
|
|
volatile _RC_t __tmp = --_M_ref_count;
|
|
pthread_mutex_unlock(&_M_ref_count_lock);
|
|
return __tmp;
|
|
}
|
|
# elif defined(__STL_UITHREADS)
|
|
void _M_incr() {
|
|
mutex_lock(&_M_ref_count_lock);
|
|
++_M_ref_count;
|
|
mutex_unlock(&_M_ref_count_lock);
|
|
}
|
|
_RC_t _M_decr() {
|
|
mutex_lock(&_M_ref_count_lock);
|
|
/*volatile*/ _RC_t __tmp = --_M_ref_count;
|
|
mutex_unlock(&_M_ref_count_lock);
|
|
return __tmp;
|
|
}
|
|
# else /* No threads */
|
|
void _M_incr() { ++_M_ref_count; }
|
|
_RC_t _M_decr() { return --_M_ref_count; }
|
|
# endif
|
|
// GCC extension begin
|
|
#endif
|
|
// GCC extension end
|
|
};
|
|
|
|
// Atomic swap on unsigned long
|
|
// This is guaranteed to behave as though it were atomic only if all
|
|
// possibly concurrent updates use _Atomic_swap.
|
|
// In some cases the operation is emulated with a lock.
|
|
// GCC extension begin
|
|
#if defined (__STL_GTHREADS) && defined (__GTHREAD_MUTEX_INIT)
|
|
// We don't provide an _Atomic_swap in this configuration. This only
|
|
// affects the use of ext/rope with threads. Someone could add this
|
|
// later, if required. You can start by cloning the __STL_PTHREADS
|
|
// path while making the obvious changes. Later it could be optimized
|
|
// to use the atomicity.h abstraction layer from libstdc++-v3.
|
|
// vyzo: simple _Atomic_swap implementation following the guidelines above
|
|
// We use a template here only to get a unique initialized instance.
|
|
template<int __dummy>
|
|
struct _Swap_lock_struct {
|
|
static __gthread_mutex_t _S_swap_lock;
|
|
};
|
|
|
|
template<int __dummy>
|
|
__gthread_mutex_t
|
|
_Swap_lock_struct<__dummy>::_S_swap_lock = __GTHREAD_MUTEX_INIT;
|
|
|
|
// This should be portable, but performance is expected
|
|
// to be quite awful. This really needs platform specific
|
|
// code.
|
|
inline unsigned long _Atomic_swap(unsigned long * __p, unsigned long __q) {
|
|
__gthread_mutex_lock(&_Swap_lock_struct<0>::_S_swap_lock);
|
|
unsigned long __result = *__p;
|
|
*__p = __q;
|
|
__gthread_mutex_unlock(&_Swap_lock_struct<0>::_S_swap_lock);
|
|
return __result;
|
|
}
|
|
|
|
#else
|
|
// GCC extension end
|
|
# ifdef __STL_SGI_THREADS
|
|
inline unsigned long _Atomic_swap(unsigned long * __p, unsigned long __q) {
|
|
# if __mips < 3 || !(defined (_ABIN32) || defined(_ABI64))
|
|
return test_and_set(__p, __q);
|
|
# else
|
|
return __test_and_set(__p, (unsigned long)__q);
|
|
# endif
|
|
}
|
|
# elif defined(__STL_WIN32THREADS)
|
|
inline unsigned long _Atomic_swap(unsigned long * __p, unsigned long __q) {
|
|
return (unsigned long) InterlockedExchange((LPLONG)__p, (LONG)__q);
|
|
}
|
|
# elif defined(__STL_PTHREADS)
|
|
// We use a template here only to get a unique initialized instance.
|
|
template<int __dummy>
|
|
struct _Swap_lock_struct {
|
|
static pthread_mutex_t _S_swap_lock;
|
|
};
|
|
|
|
template<int __dummy>
|
|
pthread_mutex_t
|
|
_Swap_lock_struct<__dummy>::_S_swap_lock = PTHREAD_MUTEX_INITIALIZER;
|
|
|
|
// This should be portable, but performance is expected
|
|
// to be quite awful. This really needs platform specific
|
|
// code.
|
|
inline unsigned long _Atomic_swap(unsigned long * __p, unsigned long __q) {
|
|
pthread_mutex_lock(&_Swap_lock_struct<0>::_S_swap_lock);
|
|
unsigned long __result = *__p;
|
|
*__p = __q;
|
|
pthread_mutex_unlock(&_Swap_lock_struct<0>::_S_swap_lock);
|
|
return __result;
|
|
}
|
|
# elif defined(__STL_UITHREADS)
|
|
// We use a template here only to get a unique initialized instance.
|
|
template<int __dummy>
|
|
struct _Swap_lock_struct {
|
|
static mutex_t _S_swap_lock;
|
|
};
|
|
|
|
template<int __dummy>
|
|
mutex_t
|
|
_Swap_lock_struct<__dummy>::_S_swap_lock = DEFAULTMUTEX;
|
|
|
|
// This should be portable, but performance is expected
|
|
// to be quite awful. This really needs platform specific
|
|
// code.
|
|
inline unsigned long _Atomic_swap(unsigned long * __p, unsigned long __q) {
|
|
mutex_lock(&_Swap_lock_struct<0>::_S_swap_lock);
|
|
unsigned long __result = *__p;
|
|
*__p = __q;
|
|
mutex_unlock(&_Swap_lock_struct<0>::_S_swap_lock);
|
|
return __result;
|
|
}
|
|
# elif defined (__STL_SOLARIS_THREADS)
|
|
// any better solutions ?
|
|
// We use a template here only to get a unique initialized instance.
|
|
template<int __dummy>
|
|
struct _Swap_lock_struct {
|
|
static mutex_t _S_swap_lock;
|
|
};
|
|
|
|
# if ( __STL_STATIC_TEMPLATE_DATA > 0 )
|
|
template<int __dummy>
|
|
mutex_t
|
|
_Swap_lock_struct<__dummy>::_S_swap_lock = DEFAULTMUTEX;
|
|
# else
|
|
__DECLARE_INSTANCE(mutex_t, _Swap_lock_struct<__dummy>::_S_swap_lock,
|
|
=DEFAULTMUTEX);
|
|
# endif /* ( __STL_STATIC_TEMPLATE_DATA > 0 ) */
|
|
|
|
// This should be portable, but performance is expected
|
|
// to be quite awful. This really needs platform specific
|
|
// code.
|
|
inline unsigned long _Atomic_swap(unsigned long * __p, unsigned long __q) {
|
|
mutex_lock(&_Swap_lock_struct<0>::_S_swap_lock);
|
|
unsigned long __result = *__p;
|
|
*__p = __q;
|
|
mutex_unlock(&_Swap_lock_struct<0>::_S_swap_lock);
|
|
return __result;
|
|
}
|
|
# else
|
|
static inline unsigned long _Atomic_swap(unsigned long * __p, unsigned long __q) {
|
|
unsigned long __result = *__p;
|
|
*__p = __q;
|
|
return __result;
|
|
}
|
|
# endif
|
|
// GCC extension begin
|
|
#endif
|
|
// GCC extension end
|
|
|
|
// Locking class. Note that this class *does not have a constructor*.
|
|
// It must be initialized either statically, with __STL_MUTEX_INITIALIZER,
|
|
// or dynamically, by explicitly calling the _M_initialize member function.
|
|
// (This is similar to the ways that a pthreads mutex can be initialized.)
|
|
// There are explicit member functions for acquiring and releasing the lock.
|
|
|
|
// There is no constructor because static initialization is essential for
|
|
// some uses, and only a class aggregate (see section 8.5.1 of the C++
|
|
// standard) can be initialized that way. That means we must have no
|
|
// constructors, no base classes, no virtual functions, and no private or
|
|
// protected members.
|
|
|
|
// Helper struct. This is a workaround for various compilers that don't
|
|
// handle static variables in inline functions properly.
|
|
template <int __inst>
|
|
struct _STL_mutex_spin {
|
|
enum { __low_max = 30, __high_max = 1000 };
|
|
// Low if we suspect uniprocessor, high for multiprocessor.
|
|
|
|
static unsigned __max;
|
|
static unsigned __last;
|
|
};
|
|
|
|
template <int __inst>
|
|
unsigned _STL_mutex_spin<__inst>::__max = _STL_mutex_spin<__inst>::__low_max;
|
|
|
|
template <int __inst>
|
|
unsigned _STL_mutex_spin<__inst>::__last = 0;
|
|
|
|
// GCC extension begin
|
|
#if defined(__STL_GTHREADS)
|
|
#if !defined(__GTHREAD_MUTEX_INIT) && defined(__GTHREAD_MUTEX_INIT_FUNCTION)
|
|
extern __gthread_mutex_t _GLIBCPP_mutex;
|
|
extern __gthread_mutex_t *_GLIBCPP_mutex_address;
|
|
extern __gthread_once_t _GLIBCPP_once;
|
|
extern void _GLIBCPP_mutex_init (void);
|
|
extern void _GLIBCPP_mutex_address_init (void);
|
|
#endif
|
|
#endif
|
|
// GCC extension end
|
|
|
|
struct _STL_mutex_lock
|
|
{
|
|
// GCC extension begin
|
|
#if defined(__STL_GTHREADS)
|
|
// The class must be statically initialized with __STL_MUTEX_INITIALIZER.
|
|
#if !defined(__GTHREAD_MUTEX_INIT) && defined(__GTHREAD_MUTEX_INIT_FUNCTION)
|
|
volatile int _M_init_flag;
|
|
__gthread_once_t _M_once;
|
|
#endif
|
|
__gthread_mutex_t _M_lock;
|
|
void _M_initialize() {
|
|
#ifdef __GTHREAD_MUTEX_INIT
|
|
// There should be no code in this path given the usage rules above.
|
|
#elif defined(__GTHREAD_MUTEX_INIT_FUNCTION)
|
|
if (_M_init_flag) return;
|
|
if (__gthread_once (&_GLIBCPP_once, _GLIBCPP_mutex_init) != 0
|
|
&& __gthread_active_p ())
|
|
abort ();
|
|
__gthread_mutex_lock (&_GLIBCPP_mutex);
|
|
if (!_M_init_flag) {
|
|
// Even though we have a global lock, we use __gthread_once to be
|
|
// absolutely certain the _M_lock mutex is only initialized once on
|
|
// multiprocessor systems.
|
|
_GLIBCPP_mutex_address = &_M_lock;
|
|
if (__gthread_once (&_M_once, _GLIBCPP_mutex_address_init) != 0
|
|
&& __gthread_active_p ())
|
|
abort ();
|
|
_M_init_flag = 1;
|
|
}
|
|
__gthread_mutex_unlock (&_GLIBCPP_mutex);
|
|
#endif
|
|
}
|
|
void _M_acquire_lock() {
|
|
#if !defined(__GTHREAD_MUTEX_INIT) && defined(__GTHREAD_MUTEX_INIT_FUNCTION)
|
|
if (!_M_init_flag) _M_initialize();
|
|
#endif
|
|
__gthread_mutex_lock(&_M_lock);
|
|
}
|
|
void _M_release_lock() {
|
|
#if !defined(__GTHREAD_MUTEX_INIT) && defined(__GTHREAD_MUTEX_INIT_FUNCTION)
|
|
if (!_M_init_flag) _M_initialize();
|
|
#endif
|
|
__gthread_mutex_unlock(&_M_lock);
|
|
}
|
|
#else
|
|
// GCC extension end
|
|
#if defined(__STL_SGI_THREADS) || defined(__STL_WIN32THREADS)
|
|
// It should be relatively easy to get this to work on any modern Unix.
|
|
volatile unsigned long _M_lock;
|
|
void _M_initialize() { _M_lock = 0; }
|
|
static void _S_nsec_sleep(int __log_nsec) {
|
|
# ifdef __STL_SGI_THREADS
|
|
struct timespec __ts;
|
|
/* Max sleep is 2**27nsec ~ 60msec */
|
|
__ts.tv_sec = 0;
|
|
__ts.tv_nsec = 1L << __log_nsec;
|
|
nanosleep(&__ts, 0);
|
|
# elif defined(__STL_WIN32THREADS)
|
|
if (__log_nsec <= 20) {
|
|
Sleep(0);
|
|
} else {
|
|
Sleep(1 << (__log_nsec - 20));
|
|
}
|
|
# else
|
|
# error unimplemented
|
|
# endif
|
|
}
|
|
void _M_acquire_lock() {
|
|
volatile unsigned long* __lock = &this->_M_lock;
|
|
|
|
if (!_Atomic_swap((unsigned long*)__lock, 1)) {
|
|
return;
|
|
}
|
|
unsigned __my_spin_max = _STL_mutex_spin<0>::__max;
|
|
unsigned __my_last_spins = _STL_mutex_spin<0>::__last;
|
|
volatile unsigned __junk = 17; // Value doesn't matter.
|
|
unsigned __i;
|
|
for (__i = 0; __i < __my_spin_max; __i++) {
|
|
if (__i < __my_last_spins/2 || *__lock) {
|
|
__junk *= __junk; __junk *= __junk;
|
|
__junk *= __junk; __junk *= __junk;
|
|
continue;
|
|
}
|
|
if (!_Atomic_swap((unsigned long*)__lock, 1)) {
|
|
// got it!
|
|
// Spinning worked. Thus we're probably not being scheduled
|
|
// against the other process with which we were contending.
|
|
// Thus it makes sense to spin longer the next time.
|
|
_STL_mutex_spin<0>::__last = __i;
|
|
_STL_mutex_spin<0>::__max = _STL_mutex_spin<0>::__high_max;
|
|
return;
|
|
}
|
|
}
|
|
// We are probably being scheduled against the other process. Sleep.
|
|
_STL_mutex_spin<0>::__max = _STL_mutex_spin<0>::__low_max;
|
|
for (__i = 0 ;; ++__i) {
|
|
int __log_nsec = __i + 6;
|
|
|
|
if (__log_nsec > 27) __log_nsec = 27;
|
|
if (!_Atomic_swap((unsigned long *)__lock, 1)) {
|
|
return;
|
|
}
|
|
_S_nsec_sleep(__log_nsec);
|
|
}
|
|
}
|
|
void _M_release_lock() {
|
|
volatile unsigned long* __lock = &_M_lock;
|
|
# if defined(__STL_SGI_THREADS) && defined(__GNUC__) && __mips >= 3
|
|
asm("sync");
|
|
*__lock = 0;
|
|
# elif defined(__STL_SGI_THREADS) && __mips >= 3 \
|
|
&& (defined (_ABIN32) || defined(_ABI64))
|
|
__lock_release(__lock);
|
|
# else
|
|
*__lock = 0;
|
|
// This is not sufficient on many multiprocessors, since
|
|
// writes to protected variables and the lock may be reordered.
|
|
# endif
|
|
}
|
|
|
|
// We no longer use win32 critical sections.
|
|
// They appear to be slower in the contention-free case,
|
|
// and they appear difficult to initialize without introducing a race.
|
|
|
|
#elif defined(__STL_PTHREADS)
|
|
pthread_mutex_t _M_lock;
|
|
void _M_initialize() { pthread_mutex_init(&_M_lock, NULL); }
|
|
void _M_acquire_lock() { pthread_mutex_lock(&_M_lock); }
|
|
void _M_release_lock() { pthread_mutex_unlock(&_M_lock); }
|
|
#elif defined(__STL_UITHREADS)
|
|
mutex_t _M_lock;
|
|
void _M_initialize() { mutex_init(&_M_lock, USYNC_THREAD, 0); }
|
|
void _M_acquire_lock() { mutex_lock(&_M_lock); }
|
|
void _M_release_lock() { mutex_unlock(&_M_lock); }
|
|
#else /* No threads */
|
|
void _M_initialize() {}
|
|
void _M_acquire_lock() {}
|
|
void _M_release_lock() {}
|
|
#endif
|
|
// GCC extension begin
|
|
#endif
|
|
// GCC extension end
|
|
};
|
|
|
|
// GCC extension begin
|
|
#if defined(__STL_GTHREADS)
|
|
#ifdef __GTHREAD_MUTEX_INIT
|
|
#define __STL_MUTEX_INITIALIZER = { __GTHREAD_MUTEX_INIT }
|
|
#elif defined(__GTHREAD_MUTEX_INIT_FUNCTION)
|
|
#ifdef __GTHREAD_MUTEX_INIT_DEFAULT
|
|
#define __STL_MUTEX_INITIALIZER \
|
|
= { 0, __GTHREAD_ONCE_INIT, __GTHREAD_MUTEX_INIT_DEFAULT }
|
|
#else
|
|
#define __STL_MUTEX_INITIALIZER = { 0, __GTHREAD_ONCE_INIT }
|
|
#endif
|
|
#endif
|
|
#else
|
|
// GCC extension end
|
|
#ifdef __STL_PTHREADS
|
|
// Pthreads locks must be statically initialized to something other than
|
|
// the default value of zero.
|
|
# define __STL_MUTEX_INITIALIZER = { PTHREAD_MUTEX_INITIALIZER }
|
|
#elif defined(__STL_UITHREADS)
|
|
// UIthreads locks must be statically initialized to something other than
|
|
// the default value of zero.
|
|
# define __STL_MUTEX_INITIALIZER = { DEFAULTMUTEX }
|
|
#elif defined(__STL_SGI_THREADS) || defined(__STL_WIN32THREADS)
|
|
# define __STL_MUTEX_INITIALIZER = { 0 }
|
|
#else
|
|
# define __STL_MUTEX_INITIALIZER
|
|
#endif
|
|
// GCC extension begin
|
|
#endif
|
|
// GCC extension end
|
|
|
|
|
|
// A locking class that uses _STL_mutex_lock. The constructor takes a
|
|
// reference to an _STL_mutex_lock, and acquires a lock. The
|
|
// destructor releases the lock. It's not clear that this is exactly
|
|
// the right functionality. It will probably change in the future.
|
|
|
|
struct _STL_auto_lock
|
|
{
|
|
_STL_mutex_lock& _M_lock;
|
|
|
|
_STL_auto_lock(_STL_mutex_lock& __lock) : _M_lock(__lock)
|
|
{ _M_lock._M_acquire_lock(); }
|
|
~_STL_auto_lock() { _M_lock._M_release_lock(); }
|
|
|
|
private:
|
|
void operator=(const _STL_auto_lock&);
|
|
_STL_auto_lock(const _STL_auto_lock&);
|
|
};
|
|
|
|
} // namespace std
|
|
|
|
#endif /* __SGI_STL_INTERNAL_THREADS_H */
|
|
|
|
// Local Variables:
|
|
// mode:C++
|
|
// End:
|
|
|