path: root/mysys/my_wincond.c

/* 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 */

/*****************************************************************************
** The following is a simple implementation of posix conditions
*****************************************************************************/

#include <my_global.h>
#undef SAFE_MUTEX			/* Avoid safe_mutex redefinitions */
#include "mysys_priv.h"
#if defined(THREAD) && defined(__WIN__)
#include <m_string.h>
#undef getpid
#include <process.h>
#include <sys/timeb.h>

int pthread_cond_init(pthread_cond_t *cond, const pthread_condattr_t *attr)
{
  cond->waiting= 0;
  InitializeCriticalSection(&cond->lock_waiting);
    
  cond->events[SIGNAL]= CreateEvent(NULL,  /* no security */
                                    FALSE, /* auto-reset event */
                                    FALSE, /* non-signaled initially */
                                    NULL); /* unnamed */

  /* Create a manual-reset event. */
  cond->events[BROADCAST]= CreateEvent(NULL,  /* no security */
                                       TRUE,  /* manual-reset */
                                       FALSE, /* non-signaled initially */
                                       NULL); /* unnamed */


  cond->broadcast_block_event= CreateEvent(NULL,  /* no security */
                                           TRUE,  /* manual-reset */
                                           TRUE,  /* signaled initially */
                                           NULL); /* unnamed */
  
  if( cond->events[SIGNAL] == NULL ||
      cond->events[BROADCAST] == NULL ||
      cond->broadcast_block_event == NULL )
    return ENOMEM;
  return 0;
}

int pthread_cond_destroy(pthread_cond_t *cond)
{
  DeleteCriticalSection(&cond->lock_waiting);

  if (CloseHandle(cond->events[SIGNAL]) == 0 ||
      CloseHandle(cond->events[BROADCAST]) == 0 ||
      CloseHandle(cond->broadcast_block_event) == 0)
    return EINVAL;
  return 0;
}


int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
{
  return pthread_cond_timedwait(cond,mutex,NULL);
}


int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex,
                           struct timespec *abstime)
{
  int result;
  long timeout; 
  union ft64 now;

  if( abstime != NULL )
  {
    GetSystemTimeAsFileTime(&now.ft);

    /*
      Calculate time left to abstime
      - subtract start time from current time(values are in 100ns units)
      - convert to millisec by dividing with 10000
    */
    timeout= (long)((abstime->tv.i64 - now.i64) / 10000);
    
    /* Don't allow the timeout to be negative */
    if (timeout < 0)
      timeout= 0L;

    /*
      Make sure the calucated timeout does not exceed original timeout
      value which could cause "wait for ever" if system time changes
    */
    if (timeout > abstime->max_timeout_msec)
      timeout= abstime->max_timeout_msec;

  }
  else
  {
    /* No time specified; don't expire */
    timeout= INFINITE;
  }

  /* 
    Block access if previous broadcast hasn't finished.
    This is just for safety and should normally not
    affect the total time spent in this function.
  */
  WaitForSingleObject(cond->broadcast_block_event, INFINITE);

  EnterCriticalSection(&cond->lock_waiting);
  cond->waiting++;
  LeaveCriticalSection(&cond->lock_waiting);

  LeaveCriticalSection(mutex);
  result= WaitForMultipleObjects(2, cond->events, FALSE, timeout);
  
  EnterCriticalSection(&cond->lock_waiting);
  cond->waiting--;
  
  if (cond->waiting == 0)
  {
    /*
      We're the last waiter to be notified or to stop waiting, so
      reset the manual event. 
    */
    /* Close broadcast gate */
    ResetEvent(cond->events[BROADCAST]);
    /* Open block gate */
    SetEvent(cond->broadcast_block_event);
  }
  LeaveCriticalSection(&cond->lock_waiting);
  
  EnterCriticalSection(mutex);

  return result == WAIT_TIMEOUT ? ETIMEDOUT : 0;
}

int pthread_cond_signal(pthread_cond_t *cond)
{
  EnterCriticalSection(&cond->lock_waiting);
  
  if(cond->waiting > 0)
    SetEvent(cond->events[SIGNAL]);

  LeaveCriticalSection(&cond->lock_waiting);
  
  return 0;
}


int pthread_cond_broadcast(pthread_cond_t *cond)
{
  EnterCriticalSection(&cond->lock_waiting);
  /*
     The mutex protect us from broadcasting if
     there isn't any thread waiting to open the
     block gate after this call has closed it.
   */
  if(cond->waiting > 0)
  {
    /* Close block gate */
    ResetEvent(cond->broadcast_block_event); 
    /* Open broadcast gate */
    SetEvent(cond->events[BROADCAST]);
  }

  LeaveCriticalSection(&cond->lock_waiting);  

  return 0;
}


int pthread_attr_init(pthread_attr_t *connect_att)
{
  connect_att->dwStackSize	= 0;
  connect_att->dwCreatingFlag	= 0;
  connect_att->priority		= 0;
  return 0;
}

int pthread_attr_setstacksize(pthread_attr_t *connect_att,DWORD stack)
{
  connect_att->dwStackSize=stack;
  return 0;
}

int pthread_attr_setprio(pthread_attr_t *connect_att,int priority)
{
  connect_att->priority=priority;
  return 0;
}

int pthread_attr_destroy(pthread_attr_t *connect_att)
{
  bzero((uchar*) connect_att,sizeof(*connect_att));
  return 0;
}

/****************************************************************************
** Fix localtime_r() to be a bit safer
****************************************************************************/

struct tm *localtime_r(const time_t *timep,struct tm *tmp)
{
  if (*timep == (time_t) -1)			/* This will crash win32 */
  {
    bzero(tmp,sizeof(*tmp));
  }
  else
  {
    struct tm *res=localtime(timep);
    if (!res)                                   /* Wrong date */
    {
      bzero(tmp,sizeof(*tmp));                  /* Keep things safe */
      return 0;
    }
    *tmp= *res;
  }
  return tmp;
}
#endif /* __WIN__ */