gistfile1.c

/* <MYSQL_ROOT>/vio/vio.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 */

/*
  Note that we can't have assertion on file descriptors;  The reason for
  this is that during mysql shutdown, another thread can close a file
  we are working on.  In this case we should just return read errors from
  the file descriptior.
*/

#include "vio_priv.h"

/*
 * Helper to fill most of the Vio* with defaults.
 */

static void vio_init(Vio* vio, enum enum_vio_type type,
                     my_socket sd, HANDLE hPipe, uint flags)
{
  DBUG_ENTER("vio_init");
  DBUG_PRINT("enter", ("type: %d  sd: %d  flags: %d", type, sd, flags));

#ifndef HAVE_VIO_READ_BUFF
  flags&= ~VIO_BUFFERED_READ;
#endif
  bzero((char*) vio, sizeof(*vio));
  vio->type	= type;
  vio->sd	= sd;
  vio->hPipe	= hPipe;
  vio->localhost= flags & VIO_LOCALHOST;
  if ((flags & VIO_BUFFERED_READ) &&
      !(vio->read_buffer= (char*)my_malloc(VIO_READ_BUFFER_SIZE, MYF(MY_WME))))
    flags&= ~VIO_BUFFERED_READ;
#ifdef __WIN__ 
  if (type == VIO_TYPE_NAMEDPIPE)
  {
    vio->viodelete	=vio_delete;
    vio->vioerrno	=vio_errno;
    vio->read           =vio_read_pipe;
    vio->write          =vio_write_pipe;
    vio->fastsend	=vio_fastsend;
    vio->viokeepalive	=vio_keepalive;
    vio->should_retry	=vio_should_retry;
    vio->was_interrupted=vio_was_interrupted;
    vio->vioclose	=vio_close_pipe;
    vio->peer_addr	=vio_peer_addr;
    vio->in_addr	=vio_in_addr;
    vio->vioblocking	=vio_blocking;
    vio->is_blocking	=vio_is_blocking;
    vio->timeout	=vio_ignore_timeout;
  }
  else					/* default is VIO_TYPE_TCPIP */
#endif
#ifdef HAVE_SMEM 
  if (type == VIO_TYPE_SHARED_MEMORY)
  {
    vio->viodelete	=vio_delete;
    vio->vioerrno	=vio_errno;
    vio->read           =vio_read_shared_memory;
    vio->write          =vio_write_shared_memory;
    vio->fastsend	=vio_fastsend;
    vio->viokeepalive	=vio_keepalive;
    vio->should_retry	=vio_should_retry;
    vio->was_interrupted=vio_was_interrupted;
    vio->vioclose	=vio_close_shared_memory;
    vio->peer_addr	=vio_peer_addr;
    vio->in_addr	=vio_in_addr;
    vio->vioblocking	=vio_blocking;
    vio->is_blocking	=vio_is_blocking;
    vio->timeout	=vio_ignore_timeout;
  }
  else
#endif   
#ifdef HAVE_OPENSSL 
  if (type == VIO_TYPE_SSL)
  {
    vio->viodelete	=vio_ssl_delete;
    vio->vioerrno	=vio_errno;
    vio->read		=vio_ssl_read;
    vio->write		=vio_ssl_write;
    vio->fastsend	=vio_fastsend;
    vio->viokeepalive	=vio_keepalive;
    vio->should_retry	=vio_should_retry;
    vio->was_interrupted=vio_was_interrupted;
    vio->vioclose	=vio_ssl_close;
    vio->peer_addr	=vio_peer_addr;
    vio->in_addr	=vio_in_addr;
    vio->vioblocking	=vio_ssl_blocking;
    vio->is_blocking	=vio_is_blocking;
    vio->timeout	=vio_timeout;
  }
  else					/* default is VIO_TYPE_TCPIP */
#endif /* HAVE_OPENSSL */
  {
    vio->viodelete	=vio_delete;
    vio->vioerrno	=vio_errno;
    vio->read= (flags & VIO_BUFFERED_READ) ? vio_read_buff : vio_read;
    vio->write		=vio_write;
    vio->fastsend	=vio_fastsend;
    vio->viokeepalive	=vio_keepalive;
    vio->should_retry	=vio_should_retry;
    vio->was_interrupted=vio_was_interrupted;
    vio->vioclose	=vio_close;
    vio->peer_addr	=vio_peer_addr;
    vio->in_addr	=vio_in_addr;
    vio->vioblocking	=vio_blocking;
    vio->is_blocking	=vio_is_blocking;
    vio->timeout	=vio_timeout;
  }
  DBUG_VOID_RETURN;
}


/* Reset initialized VIO to use with another transport type */

void vio_reset(Vio* vio, enum enum_vio_type type,
               my_socket sd, HANDLE hPipe, uint flags)
{
  my_free(vio->read_buffer, MYF(MY_ALLOW_ZERO_PTR));
  vio_init(vio, type, sd, hPipe, flags);
}


/* Open the socket or TCP/IP connection and read the fnctl() status */

Vio *vio_new(my_socket sd, enum enum_vio_type type, uint flags)
{
  Vio *vio;
  DBUG_ENTER("vio_new");
  DBUG_PRINT("enter", ("sd: %d", sd));
  if ((vio = (Vio*) my_malloc(sizeof(*vio),MYF(MY_WME))))
  {
    vio_init(vio, type, sd, 0, flags);
    sprintf(vio->desc,
	    (vio->type == VIO_TYPE_SOCKET ? "socket (%d)" : "TCP/IP (%d)"),
	    vio->sd);
#if !defined(__WIN__) && !defined(__EMX__) && !defined(OS2)
#if !defined(NO_FCNTL_NONBLOCK)
    /*
      We call fcntl() to set the flags and then immediately read them back
      to make sure that we and the system are in agreement on the state of
      things.

      An example of why we need to do this is FreeBSD (and apparently some
      other BSD-derived systems, like Mac OS X), where the system sometimes
      reports that the socket is set for non-blocking when it really will
      block.
    */
    fcntl(sd, F_SETFL, 0);
    vio->fcntl_mode= fcntl(sd, F_GETFL);
#elif defined(HAVE_SYS_IOCTL_H)			/* hpux */
    /* Non blocking sockets doesn't work good on HPUX 11.0 */
    (void) ioctl(sd,FIOSNBIO,0);
    vio->fcntl_mode &= ~O_NONBLOCK;
#endif
#else /* !defined(__WIN__) && !defined(__EMX__) */
    {
      /* set to blocking mode by default */
      ulong arg=0, r;
      r = ioctlsocket(sd,FIONBIO,(void*) &arg);
      vio->fcntl_mode &= ~O_NONBLOCK;
    }
#endif
  }
  DBUG_RETURN(vio);
}


#ifdef __WIN__

Vio *vio_new_win32pipe(HANDLE hPipe)
{
  Vio *vio;
  DBUG_ENTER("vio_new_handle");
  if ((vio = (Vio*) my_malloc(sizeof(Vio),MYF(MY_WME))))
  {
    vio_init(vio, VIO_TYPE_NAMEDPIPE, 0, hPipe, VIO_LOCALHOST);
    strmov(vio->desc, "named pipe");
  }
  DBUG_RETURN(vio);
}

#ifdef HAVE_SMEM
Vio *vio_new_win32shared_memory(NET *net,HANDLE handle_file_map, HANDLE handle_map,
                                HANDLE event_server_wrote, HANDLE event_server_read,
                                HANDLE event_client_wrote, HANDLE event_client_read,
                                HANDLE event_conn_closed)
{
  Vio *vio;
  DBUG_ENTER("vio_new_win32shared_memory");
  if ((vio = (Vio*) my_malloc(sizeof(Vio),MYF(MY_WME))))
  {
    vio_init(vio, VIO_TYPE_SHARED_MEMORY, 0, 0, VIO_LOCALHOST);
    vio->handle_file_map= handle_file_map;
    vio->handle_map= handle_map;
    vio->event_server_wrote= event_server_wrote;
    vio->event_server_read= event_server_read;
    vio->event_client_wrote= event_client_wrote;
    vio->event_client_read= event_client_read;
    vio->event_conn_closed= event_conn_closed;
    vio->shared_memory_remain= 0;
    vio->shared_memory_pos= handle_map;
    vio->net= net;
    strmov(vio->desc, "shared memory");
  }
  DBUG_RETURN(vio);
}
#endif
#endif


void vio_delete(Vio* vio)
{
  if (!vio)
    return; /* It must be safe to delete null pointers. */

  if (vio->type != VIO_CLOSED)
    vio->vioclose(vio);
  my_free((gptr) vio->read_buffer, MYF(MY_ALLOW_ZERO_PTR));
  my_free((gptr) vio,MYF(0));
}


/*
  Cleanup memory allocated by vio or the
  components below it when application finish

*/
void vio_end(void)
{
#ifdef HAVE_YASSL
  yaSSL_CleanUp();
#endif
}

gistfile2.c

/* <MYSQL_ROOT>/vio/viosocket.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 */

/*
  Note that we can't have assertion on file descriptors;  The reason for
  this is that during mysql shutdown, another thread can close a file
  we are working on.  In this case we should just return read errors from
  the file descriptior.
*/

#include "vio_priv.h"

int vio_errno(Vio *vio __attribute__((unused)))
{
  return socket_errno;		/* On Win32 this mapped to WSAGetLastError() */
}


int vio_read(Vio * vio, gptr buf, int size)
{
  int r;
  DBUG_ENTER("vio_read");
  DBUG_PRINT("enter", ("sd: %d  buf: 0x%lx  size: %d", vio->sd, (long) buf, size));

  /* Ensure nobody uses vio_read_buff and vio_read simultaneously */
  DBUG_ASSERT(vio->read_end == vio->read_pos);
#ifdef __WIN__
  r = recv(vio->sd, buf, size,0);
#else
  errno=0;					/* For linux */
  r = read(vio->sd, buf, size);
#endif /* __WIN__ */
#ifndef DBUG_OFF
  if (r < 0)
  {
    DBUG_PRINT("vio_error", ("Got error %d during read",errno));
  }
#endif /* DBUG_OFF */
  DBUG_PRINT("exit", ("%d", r));
  DBUG_RETURN(r);
}


/*
  Buffered read: if average read size is small it may
  reduce number of syscalls.
*/

int vio_read_buff(Vio *vio, gptr buf, int size)
{
  int rc;
#define VIO_UNBUFFERED_READ_MIN_SIZE 2048
  DBUG_ENTER("vio_read_buff");
  DBUG_PRINT("enter", ("sd: %d  buf: 0x%lx  size: %d", vio->sd, (long) buf, size));

  if (vio->read_pos < vio->read_end)
  {
    rc= min(vio->read_end - vio->read_pos, size);
    memcpy(buf, vio->read_pos, rc);
    vio->read_pos+= rc;
    /*
      Do not try to read from the socket now even if rc < size:
      vio_read can return -1 due to an error or non-blocking mode, and
      the safest way to handle it is to move to a separate branch.
    */
  }
  else if (size < VIO_UNBUFFERED_READ_MIN_SIZE)
  {
    rc= vio_read(vio, vio->read_buffer, VIO_READ_BUFFER_SIZE);
    if (rc > 0)
    {
      if (rc > size)
      {
        vio->read_pos= vio->read_buffer + size;
        vio->read_end= vio->read_buffer + rc;
        rc= size;
      }
      memcpy(buf, vio->read_buffer, rc);
    }
  }
  else
    rc= vio_read(vio, buf, size);
  DBUG_RETURN(rc);
#undef VIO_UNBUFFERED_READ_MIN_SIZE
}


int vio_write(Vio * vio, const gptr buf, int size)
{
  int r;
  DBUG_ENTER("vio_write");
  DBUG_PRINT("enter", ("sd: %d  buf: 0x%lx  size: %d", vio->sd, (long) buf, size));
#ifdef __WIN__
  r = send(vio->sd, buf, size,0);
#else
  r = write(vio->sd, buf, size);
#endif /* __WIN__ */
#ifndef DBUG_OFF
  if (r < 0)
  {
    DBUG_PRINT("vio_error", ("Got error on write: %d",socket_errno));
  }
#endif /* DBUG_OFF */
  DBUG_PRINT("exit", ("%d", r));
  DBUG_RETURN(r);
}

int vio_blocking(Vio * vio __attribute__((unused)), my_bool set_blocking_mode,
		 my_bool *old_mode)
{
  int r=0;
  DBUG_ENTER("vio_blocking");

  *old_mode= test(!(vio->fcntl_mode & O_NONBLOCK));
  DBUG_PRINT("enter", ("set_blocking_mode: %d  old_mode: %d",
		       (int) set_blocking_mode, (int) *old_mode));

#if !defined(__WIN__) && !defined(__EMX__)
#if !defined(NO_FCNTL_NONBLOCK)
  if (vio->sd >= 0)
  {
    int old_fcntl=vio->fcntl_mode;
    if (set_blocking_mode)
      vio->fcntl_mode &= ~O_NONBLOCK; /* clear bit */
    else
      vio->fcntl_mode |= O_NONBLOCK; /* set bit */
    if (old_fcntl != vio->fcntl_mode)
    {
      r= fcntl(vio->sd, F_SETFL, vio->fcntl_mode);
      if (r == -1)
      {
        DBUG_PRINT("info", ("fcntl failed, errno %d", errno));
        vio->fcntl_mode= old_fcntl;
      }
    }
  }
#else
  r= set_blocking_mode ? 0 : 1;
#endif /* !defined(NO_FCNTL_NONBLOCK) */
#else /* !defined(__WIN__) && !defined(__EMX__) */
#ifndef __EMX__
  if (vio->type != VIO_TYPE_NAMEDPIPE && vio->type != VIO_TYPE_SHARED_MEMORY)
#endif
  { 
    ulong arg;
    int old_fcntl=vio->fcntl_mode;
    if (set_blocking_mode)
    {
      arg = 0;
      vio->fcntl_mode &= ~O_NONBLOCK; /* clear bit */
    }
    else
    {
      arg = 1;
      vio->fcntl_mode |= O_NONBLOCK; /* set bit */
    }
    if (old_fcntl != vio->fcntl_mode)
      r = ioctlsocket(vio->sd,FIONBIO,(void*) &arg);
  }
#ifndef __EMX__
  else
    r=  test(!(vio->fcntl_mode & O_NONBLOCK)) != set_blocking_mode;
#endif /* __EMX__ */
#endif /* !defined(__WIN__) && !defined(__EMX__) */
  DBUG_PRINT("exit", ("%d", r));
  DBUG_RETURN(r);
}

my_bool
vio_is_blocking(Vio * vio)
{
  my_bool r;
  DBUG_ENTER("vio_is_blocking");
  r = !(vio->fcntl_mode & O_NONBLOCK);
  DBUG_PRINT("exit", ("%d", (int) r));
  DBUG_RETURN(r);
}


int vio_fastsend(Vio * vio __attribute__((unused)))
{
  int r=0;
  DBUG_ENTER("vio_fastsend");

#if defined(IPTOS_THROUGHPUT) && !defined(__EMX__)
  {
    int tos = IPTOS_THROUGHPUT;
    r= setsockopt(vio->sd, IPPROTO_IP, IP_TOS, (void *) &tos, sizeof(tos));
  }
#endif                                    /* IPTOS_THROUGHPUT && !__EMX__ */
  if (!r)
  {
#ifdef __WIN__
    BOOL nodelay= 1;
#else
    int nodelay = 1;
#endif

    r= setsockopt(vio->sd, IPPROTO_TCP, TCP_NODELAY,
                  IF_WIN(const char*, void*) &nodelay,
                  sizeof(nodelay));

  }
  if (r)
  {
    DBUG_PRINT("warning", ("Couldn't set socket option for fast send"));
    r= -1;
  }
  DBUG_PRINT("exit", ("%d", r));
  DBUG_RETURN(r);
}

int vio_keepalive(Vio* vio, my_bool set_keep_alive)
{
  int r=0;
  uint opt = 0;
  DBUG_ENTER("vio_keepalive");
  DBUG_PRINT("enter", ("sd: %d  set_keep_alive: %d", vio->sd, (int)
		       set_keep_alive));
  if (vio->type != VIO_TYPE_NAMEDPIPE)
  {
    if (set_keep_alive)
      opt = 1;
    r = setsockopt(vio->sd, SOL_SOCKET, SO_KEEPALIVE, (char *) &opt,
		   sizeof(opt));
  }
  DBUG_RETURN(r);
}


my_bool
vio_should_retry(Vio * vio __attribute__((unused)))
{
  int en = socket_errno;
  return (en == SOCKET_EAGAIN || en == SOCKET_EINTR ||
	  en == SOCKET_EWOULDBLOCK);
}


my_bool
vio_was_interrupted(Vio *vio __attribute__((unused)))
{
  int en= socket_errno;
  return (en == SOCKET_EAGAIN || en == SOCKET_EINTR ||
	  en == SOCKET_EWOULDBLOCK || en == SOCKET_ETIMEDOUT);
}


int vio_close(Vio * vio)
{
  int r=0;
  DBUG_ENTER("vio_close");
#ifdef __WIN__
  if (vio->type == VIO_TYPE_NAMEDPIPE)
  {
#if defined(__NT__) && defined(MYSQL_SERVER)
    CancelIo(vio->hPipe);
    DisconnectNamedPipe(vio->hPipe);
#endif
    r=CloseHandle(vio->hPipe);
  }
  else
#endif /* __WIN__ */
 if (vio->type != VIO_CLOSED)
  {
    DBUG_ASSERT(vio->sd >= 0);
    if (shutdown(vio->sd, SHUT_RDWR))
      r= -1;
    if (closesocket(vio->sd))
      r= -1;
  }
  if (r)
  {
    DBUG_PRINT("vio_error", ("close() failed, error: %d",socket_errno));
    /* FIXME: error handling (not critical for MySQL) */
  }
  vio->type= VIO_CLOSED;
  vio->sd=   -1;
  DBUG_RETURN(r);
}


const char *vio_description(Vio * vio)
{
  return vio->desc;
}

enum enum_vio_type vio_type(Vio* vio)
{
  return vio->type;
}

my_socket vio_fd(Vio* vio)
{
  return vio->sd;
}


my_bool vio_peer_addr(Vio * vio, char *buf, uint16 *port)
{
  DBUG_ENTER("vio_peer_addr");
  DBUG_PRINT("enter", ("sd: %d", vio->sd));
  if (vio->localhost)
  {
    strmov(buf,"127.0.0.1");
    *port= 0;
  }
  else
  {
    size_socket addrLen = sizeof(vio->remote);
    if (getpeername(vio->sd, (struct sockaddr *) (&vio->remote),
		    &addrLen) != 0)
    {
      DBUG_PRINT("exit", ("getpeername gave error: %d", socket_errno));
      DBUG_RETURN(1);
    }
    my_inet_ntoa(vio->remote.sin_addr,buf);
    *port= ntohs(vio->remote.sin_port);
  }
  DBUG_PRINT("exit", ("addr: %s", buf));
  DBUG_RETURN(0);
}


/*
  Get in_addr for a TCP/IP connection

  SYNOPSIS
    vio_in_addr()
    vio		vio handle
    in		put in_addr here

  NOTES
    one must call vio_peer_addr() before calling this one
*/

void vio_in_addr(Vio *vio, struct in_addr *in)
{
  DBUG_ENTER("vio_in_addr");
  if (vio->localhost)
    bzero((char*) in, sizeof(*in));
  else
    *in=vio->remote.sin_addr;
  DBUG_VOID_RETURN;
}


/* Return 0 if there is data to be read */

my_bool vio_poll_read(Vio *vio,uint timeout)
{
#ifndef HAVE_POLL
  return 0;
#else
  struct pollfd fds;
  int res;
  DBUG_ENTER("vio_poll");
  fds.fd=vio->sd;
  fds.events=POLLIN;
  fds.revents=0;
  if ((res=poll(&fds,1,(int) timeout*1000)) <= 0)
  {
    DBUG_RETURN(res < 0 ? 0 : 1);		/* Don't return 1 on errors */
  }
  DBUG_RETURN(fds.revents & POLLIN ? 0 : 1);
#endif
}


void vio_timeout(Vio *vio, uint which, uint timeout)
{
#if defined(SO_SNDTIMEO) && defined(SO_RCVTIMEO)
  int r;
  DBUG_ENTER("vio_timeout");

  {
#ifdef __WIN__
  /* Windows expects time in milliseconds as int */
  int wait_timeout= (int) timeout * 1000;
#else
  /* POSIX specifies time as struct timeval. */
  struct timeval wait_timeout;
  wait_timeout.tv_sec= timeout;
  wait_timeout.tv_usec= 0;
#endif

  r= setsockopt(vio->sd, SOL_SOCKET, which ? SO_SNDTIMEO : SO_RCVTIMEO,
                IF_WIN(const char*, const void*)&wait_timeout,
                sizeof(wait_timeout));

  }

#ifndef DBUG_OFF
  if (r != 0)
    DBUG_PRINT("error", ("setsockopt failed: %d, errno: %d", r, socket_errno));
#endif

  DBUG_VOID_RETURN;
#else
/*
  Platforms not suporting setting of socket timeout should either use
  thr_alarm or just run without read/write timeout(s)
*/
#endif
}


#ifdef __WIN__
int vio_read_pipe(Vio * vio, gptr buf, int size)
{
  DWORD length;
  DBUG_ENTER("vio_read_pipe");
  DBUG_PRINT("enter", ("sd: %d  buf: 0x%lx  size: %d", vio->sd, buf, size));

  if (!ReadFile(vio->hPipe, buf, size, &length, NULL))
    DBUG_RETURN(-1);

  DBUG_PRINT("exit", ("%d", length));
  DBUG_RETURN(length);
}


int vio_write_pipe(Vio * vio, const gptr buf, int size)
{
  DWORD length;
  DBUG_ENTER("vio_write_pipe");
  DBUG_PRINT("enter", ("sd: %d  buf: 0x%lx  size: %d", vio->sd, buf, size));

  if (!WriteFile(vio->hPipe, (char*) buf, size, &length, NULL))
    DBUG_RETURN(-1);

  DBUG_PRINT("exit", ("%d", length));
  DBUG_RETURN(length);
}

int vio_close_pipe(Vio * vio)
{
  int r;
  DBUG_ENTER("vio_close_pipe");
#if defined(__NT__) && defined(MYSQL_SERVER)
  CancelIo(vio->hPipe);
  DisconnectNamedPipe(vio->hPipe);
#endif
  r=CloseHandle(vio->hPipe);
  if (r)
  {
    DBUG_PRINT("vio_error", ("close() failed, error: %d",GetLastError()));
    /* FIXME: error handling (not critical for MySQL) */
  }
  vio->type= VIO_CLOSED;
  vio->sd=   -1;
  DBUG_RETURN(r);
}


void vio_ignore_timeout(Vio *vio __attribute__((unused)),
			uint which __attribute__((unused)),
			uint timeout __attribute__((unused)))
{
}


#ifdef HAVE_SMEM

int vio_read_shared_memory(Vio * vio, gptr buf, int size)
{
  int length;
  int remain_local;
  char *current_postion;

  DBUG_ENTER("vio_read_shared_memory");
  DBUG_PRINT("enter", ("sd: %d  buf: 0x%lx  size: %d", vio->sd, buf, size));

  remain_local = size;
  current_postion=buf;
  do
  {
    if (vio->shared_memory_remain == 0)
    {
      HANDLE events[2];
      events[0]= vio->event_server_wrote;
      events[1]= vio->event_conn_closed;
      /*
        WaitForMultipleObjects can return next values:
         WAIT_OBJECT_0+0 - event from vio->event_server_wrote
         WAIT_OBJECT_0+1 - event from vio->event_conn_closed. We can't read anything
         WAIT_ABANDONED_0 and WAIT_TIMEOUT - fail.  We can't read anything
      */
      if (WaitForMultipleObjects(2, (HANDLE*)&events,FALSE,
                                 vio->net->read_timeout*1000) != WAIT_OBJECT_0)
      {
        DBUG_RETURN(-1);
      };

      vio->shared_memory_pos = vio->handle_map;
      vio->shared_memory_remain = uint4korr((ulong*)vio->shared_memory_pos);
      vio->shared_memory_pos+=4;
    }

    length = size;

    if (vio->shared_memory_remain < length)
       length = vio->shared_memory_remain;
    if (length > remain_local)
       length = remain_local;

    memcpy(current_postion,vio->shared_memory_pos,length);

    vio->shared_memory_remain-=length;
    vio->shared_memory_pos+=length;
    current_postion+=length;
    remain_local-=length;

    if (!vio->shared_memory_remain)
      if (!SetEvent(vio->event_client_read)) DBUG_RETURN(-1);
  } while (remain_local);
  length = size;

  DBUG_PRINT("exit", ("%d", length));
  DBUG_RETURN(length);
}


int vio_write_shared_memory(Vio * vio, const gptr buf, int size)
{
  int length;
  uint remain;
  HANDLE pos;
  int sz;
  char *current_postion;

  DBUG_ENTER("vio_write_shared_memory");
  DBUG_PRINT("enter", ("sd: %d  buf: 0x%lx  size: %d", vio->sd, buf, size));

  remain = size;
  current_postion = buf;
  while (remain != 0)
  {
    if (WaitForSingleObject(vio->event_server_read, vio->net->write_timeout*1000) 
                            != WAIT_OBJECT_0)
    {
      DBUG_RETURN(-1);
    };

    sz = remain > shared_memory_buffer_length ? shared_memory_buffer_length: remain;

    int4store(vio->handle_map,sz);
    pos = vio->handle_map + 4;
    memcpy(pos,current_postion,sz);
    remain-=sz;
    current_postion+=sz;
    if (!SetEvent(vio->event_client_wrote)) DBUG_RETURN(-1);
  }
  length = size;

  DBUG_PRINT("exit", ("%d", length));
  DBUG_RETURN(length);
}


/**
 Close shared memory and DBUG_PRINT any errors that happen on closing.
 @return Zero if all closing functions succeed, and nonzero otherwise.
*/
int vio_close_shared_memory(Vio * vio)
{
  int error_count= 0;
  DBUG_ENTER("vio_close_shared_memory");
  if (vio->type != VIO_CLOSED)
  {
    /*
      Set event_conn_closed for notification of both client and server that
      connection is closed
    */
    SetEvent(vio->event_conn_closed);
    /*
      Close all handlers. UnmapViewOfFile and CloseHandle return non-zero
      result if they are success.
    */
    if (UnmapViewOfFile(vio->handle_map) == 0) 
    {
      error_count++;
      DBUG_PRINT("vio_error", ("UnmapViewOfFile() failed"));
    }
    if (CloseHandle(vio->event_server_wrote) == 0)
    {
      error_count++;
      DBUG_PRINT("vio_error", ("CloseHandle(vio->esw) failed"));
    }
    if (CloseHandle(vio->event_server_read) == 0)
    {
      error_count++;
      DBUG_PRINT("vio_error", ("CloseHandle(vio->esr) failed"));
    }
    if (CloseHandle(vio->event_client_wrote) == 0)
    {
      error_count++;
      DBUG_PRINT("vio_error", ("CloseHandle(vio->ecw) failed"));
    }
    if (CloseHandle(vio->event_client_read) == 0)
    {
      error_count++;
      DBUG_PRINT("vio_error", ("CloseHandle(vio->ecr) failed"));
    }
    if (CloseHandle(vio->handle_file_map) == 0)
    {
      error_count++;
      DBUG_PRINT("vio_error", ("CloseHandle(vio->hfm) failed"));
    }
    if (CloseHandle(vio->event_conn_closed) == 0)
    {
      error_count++;
      DBUG_PRINT("vio_error", ("CloseHandle(vio->ecc) failed"));
    }
  }
  vio->type= VIO_CLOSED;
  vio->sd=   -1;
  DBUG_RETURN(error_count);
}
#endif /* HAVE_SMEM */
#endif /* __WIN__ */