173 lines
4.9 KiB
C
173 lines
4.9 KiB
C
/*
|
|
*
|
|
*
|
|
* Copyright (c) 1994
|
|
* Hewlett-Packard Company
|
|
*
|
|
* Copyright (c) 1996,1997
|
|
* Silicon Graphics Computer Systems, Inc.
|
|
*
|
|
* Copyright (c) 1997
|
|
* Moscow Center for SPARC Technology
|
|
*
|
|
* Copyright (c) 1999
|
|
* Boris Fomitchev
|
|
*
|
|
* This material is provided "as is", with absolutely no warranty expressed
|
|
* or implied. Any use is at your own risk.
|
|
*
|
|
* Permission to use or copy this software for any purpose is hereby granted
|
|
* without fee, provided the above notices are retained on all copies.
|
|
* Permission to modify the code and to distribute modified code is granted,
|
|
* provided the above notices are retained, and a notice that the code was
|
|
* modified is included with the above copyright notice.
|
|
*
|
|
*/
|
|
#ifndef _STLP_THREADS_C
|
|
#define _STLP_THREADS_C
|
|
|
|
#ifndef _STLP_INTERNAL_THREADS_H
|
|
# include <stl/_threads.h>
|
|
#endif
|
|
|
|
# if defined (_STLP_EXPOSE_GLOBALS_IMPLEMENTATION)
|
|
|
|
# if defined(_STLP_SGI_THREADS)
|
|
# include <time.h>
|
|
# elif defined (_STLP_UNIX)
|
|
# include <ctime>
|
|
# if defined (_STLP_USE_NAMESPACES) && ! defined (_STLP_VENDOR_GLOBAL_CSTD)
|
|
using _STLP_VENDOR_CSTD::time_t;
|
|
# endif
|
|
# include <sys/time.h>
|
|
# endif
|
|
|
|
_STLP_BEGIN_NAMESPACE
|
|
|
|
# if (_STLP_STATIC_TEMPLATE_DATA > 0)
|
|
|
|
# ifdef _STLP_THREADS
|
|
# if !defined(_STLP_ATOMIC_EXCHANGE) && (defined(_STLP_PTHREADS) || defined(_STLP_UITHREADS) || defined(_STLP_OS2THREADS) || defined(_STLP_USE_PTHREAD_SPINLOCK))
|
|
template<int __dummy>
|
|
_STLP_STATIC_MUTEX
|
|
_Swap_lock_struct<__dummy>::_S_swap_lock _STLP_MUTEX_INITIALIZER;
|
|
# endif
|
|
# endif //_STLP_THREADS
|
|
|
|
# ifndef _STLP_USE_PTHREAD_SPINLOCK
|
|
template <int __inst>
|
|
unsigned _STLP_mutex_spin<__inst>::__max = _STLP_mutex_spin<__inst>::__low_max;
|
|
|
|
template <int __inst>
|
|
unsigned _STLP_mutex_spin<__inst>::__last = 0;
|
|
# endif // _STLP_USE_PTHREAD_SPINLOCK
|
|
|
|
# else /* ( _STLP_STATIC_TEMPLATE_DATA > 0 ) */
|
|
|
|
# if defined(_STLP_PTHREADS) || defined(_STLP_UITHREADS) || defined(_STLP_OS2THREADS)
|
|
__DECLARE_INSTANCE(_STLP_STATIC_MUTEX, _Swap_lock_struct<0>::_S_swap_lock,
|
|
_STLP_MUTEX_INITIALIZER );
|
|
# endif /* _STLP_PTHREADS */
|
|
|
|
# ifndef _STLP_USE_PTHREAD_SPINLOCK
|
|
__DECLARE_INSTANCE(unsigned, _STLP_mutex_spin<0>::__max, =30);
|
|
__DECLARE_INSTANCE(unsigned, _STLP_mutex_spin<0>::__last, =0);
|
|
# endif // _STLP_USE_PTHREAD_SPINLOCK
|
|
|
|
# endif /* ( _STLP_STATIC_TEMPLATE_DATA > 0 ) */
|
|
|
|
#ifndef _STLP_USE_PTHREAD_SPINLOCK
|
|
|
|
#ifdef _STLP_SPARC_SOLARIS_THREADS
|
|
// underground function in libc.so; we do not want dependance on librt
|
|
extern "C" int __nanosleep(const struct timespec*, struct timespec*);
|
|
# define _STLP_NANOSLEEP __nanosleep
|
|
#else
|
|
# define _STLP_NANOSLEEP nanosleep
|
|
#endif
|
|
|
|
template <int __inst>
|
|
void _STLP_CALL
|
|
_STLP_mutex_spin<__inst>::_S_nsec_sleep(int __log_nsec) {
|
|
# if defined(_STLP_WIN32THREADS)
|
|
if (__log_nsec <= 20) {
|
|
// Note from boost (www.boost.org):
|
|
// Changed to Sleep(1) from Sleep(0).
|
|
// According to MSDN, Sleep(0) will never yield
|
|
// to a lower-priority thread, whereas Sleep(1)
|
|
// will. Performance seems not to be affected.
|
|
Sleep(1);
|
|
} else {
|
|
Sleep(1 << (__log_nsec - 20));
|
|
}
|
|
# elif defined(_STLP_OS2THREADS)
|
|
if (__log_nsec <= 20) {
|
|
DosSleep(0);
|
|
} else {
|
|
DosSleep(1 << (__log_nsec - 20));
|
|
}
|
|
# elif defined (_STLP_UNIX)
|
|
timespec __ts;
|
|
/* Max sleep is 2**27nsec ~ 60msec */
|
|
__ts.tv_sec = 0;
|
|
__ts.tv_nsec = 1 << __log_nsec;
|
|
_STLP_NANOSLEEP(&__ts, 0);
|
|
# endif
|
|
}
|
|
|
|
|
|
template <int __inst>
|
|
void _STLP_CALL
|
|
_STLP_mutex_spin<__inst>::_M_do_lock(volatile __stl_atomic_t* __lock)
|
|
{
|
|
#if defined(_STLP_ATOMIC_EXCHANGE)
|
|
if (_Atomic_swap(__lock, 1)) {
|
|
unsigned __my_spin_max = _STLP_mutex_spin<0>::__max;
|
|
unsigned __my_last_spins = _STLP_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;
|
|
} else {
|
|
if (!_Atomic_swap(__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.
|
|
_STLP_mutex_spin<0>::__last = __i;
|
|
_STLP_mutex_spin<0>::__max = _STLP_mutex_spin<0>::__high_max;
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
// We are probably being scheduled against the other process. Sleep.
|
|
_STLP_mutex_spin<0>::__max = _STLP_mutex_spin<0>::__low_max;
|
|
|
|
for (__i = 0 ;; ++__i) {
|
|
int __log_nsec = __i + 6;
|
|
|
|
if (__log_nsec > 27) __log_nsec = 27;
|
|
if (!_Atomic_swap(__lock, 1)) {
|
|
break;
|
|
}
|
|
_S_nsec_sleep(__log_nsec);
|
|
}
|
|
|
|
} /* first _Atomic_swap */
|
|
# endif
|
|
}
|
|
#endif // _STLP_USE_PTHREAD_SPINLOCK
|
|
|
|
_STLP_END_NAMESPACE
|
|
|
|
# endif /* BUILDING_STLPORT */
|
|
#endif /* _STLP_THREADS_C */
|
|
|
|
// Local Variables:
|
|
// mode:C++
|
|
// End:
|