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/* Copyright (C) 2000 MySQL AB
This program 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; version 2 of the License.
This program 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 program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/*****************************************************************************
** Simulation of posix threads calls for WIN95 and NT
*****************************************************************************/
/* SAFE_MUTEX will not work until the thread structure is up to date */
#include <my_global.h>
#undef SAFE_MUTEX
#include "mysys_priv.h"
#if defined(THREAD) && defined(__WIN__)
#include <m_string.h>
#undef getpid
#include <process.h>
static pthread_mutex_t THR_LOCK_thread;
struct pthread_map
{
HANDLE pthreadself;
pthread_handler func;
void *param;
};
void win_pthread_init(void)
{
pthread_mutex_init(&THR_LOCK_thread,MY_MUTEX_INIT_FAST);
}
/**
Adapter to @c pthread_mutex_trylock()
@retval 0 Mutex was acquired
@retval EBUSY Mutex was already locked by a thread
*/
int
win_pthread_mutex_trylock(pthread_mutex_t *mutex)
{
if (TryEnterCriticalSection(mutex))
{
/* Don't allow recursive lock */
if (mutex->RecursionCount > 1){
LeaveCriticalSection(mutex);
return EBUSY;
}
return 0;
}
return EBUSY;
}
/*
** We have tried to use '_beginthreadex' instead of '_beginthread' here
** but in this case the program leaks about 512 characters for each
** created thread !
** As we want to save the created thread handler for other threads to
** use and to be returned by pthread_self() (instead of the Win32 pseudo
** handler), we have to go trough pthread_start() to catch the returned handler
** in the new thread.
*/
pthread_handler_t pthread_start(void *param)
{
pthread_handler func=((struct pthread_map *) param)->func;
void *func_param=((struct pthread_map *) param)->param;
void *result;
my_thread_init(); /* Will always succeed in windows */
pthread_mutex_lock(&THR_LOCK_thread); /* Wait for beginthread to return */
win_pthread_self=((struct pthread_map *) param)->pthreadself;
pthread_mutex_unlock(&THR_LOCK_thread);
free((char*) param); /* Free param from create */
result= (void*) (*func)(func_param);
my_thread_end();
pthread_exit(result);
return 0; /* Safety */
}
int pthread_create(pthread_t *thread_id, pthread_attr_t *attr,
pthread_handler func, void *param)
{
HANDLE hThread;
struct pthread_map *map;
DWORD StackSize= 0;
int priority= 0;
DBUG_ENTER("pthread_create");
if (!(map=malloc(sizeof(*map))))
DBUG_RETURN(-1);
map->func=func;
map->param=param;
if (attr != NULL)
{
StackSize= attr->dwStackSize;
priority= attr->priority;
}
if (StackSize == 0)
StackSize= PTHREAD_STACK_MIN;
pthread_mutex_lock(&THR_LOCK_thread);
#ifdef __BORLANDC__
hThread=(HANDLE)_beginthread((void(_USERENTRY *)(void *)) pthread_start,
StackSize, (void*) map);
#else
hThread=(HANDLE)_beginthread((void( __cdecl *)(void *)) pthread_start,
StackSize, (void*) map);
#endif
DBUG_PRINT("info", ("hThread=%lu",(long) hThread));
*thread_id=map->pthreadself=hThread;
pthread_mutex_unlock(&THR_LOCK_thread);
if (hThread == (HANDLE) -1)
{
int error=errno;
DBUG_PRINT("error",
("Can't create thread to handle request (error %d)",error));
DBUG_RETURN(error ? error : -1);
}
VOID(SetThreadPriority(hThread, priority)) ;
DBUG_RETURN(0);
}
void pthread_exit(void *a)
{
_endthread();
}
/* This is neaded to get the macro pthread_setspecific to work */
int win_pthread_setspecific(void *a,void *b,uint length)
{
memcpy(a,b,length);
return 0;
}
/*
One time initialization. For simplicity, we assume initializer thread
does not exit within init_routine().
*/
int my_pthread_once(my_pthread_once_t *once_control,
void (*init_routine)(void))
{
LONG state= InterlockedCompareExchange(once_control, MY_PTHREAD_ONCE_INPROGRESS,
MY_PTHREAD_ONCE_INIT);
switch(state)
{
case MY_PTHREAD_ONCE_INIT:
/* This is initializer thread */
(*init_routine)();
*once_control= MY_PTHREAD_ONCE_DONE;
break;
case MY_PTHREAD_ONCE_INPROGRESS:
/* init_routine in progress. Wait for its completion */
while(*once_control == MY_PTHREAD_ONCE_INPROGRESS)
{
Sleep(1);
}
break;
case MY_PTHREAD_ONCE_DONE:
/* Nothing to do */
break;
}
return 0;
}
#endif
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