StdLib/LibC: Fix transcription error from submitted patch.

[mirror_edk2.git] / StdLib / LibC / Uefi / select.c

/*\r
 * Copyright (c) 1982, 1986, 1989, 1993\r
 *  The Regents of the University of California.  All rights reserved.\r
 * (c) UNIX System Laboratories, Inc.\r
 * All or some portions of this file are derived from material licensed\r
 * to the University of California by American Telephone and Telegraph\r
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with\r
 * the permission of UNIX System Laboratories, Inc.\r
 *\r
 * Portions copyright (c) 1999, 2000\r
 * Intel Corporation.\r
 * All rights reserved.\r
 *\r
 * Redistribution and use in source and binary forms, with or without\r
 * modification, are permitted provided that the following conditions\r
 * are met:\r
 *\r
 * 1. Redistributions of source code must retain the above copyright\r
 *    notice, this list of conditions and the following disclaimer.\r
 *\r
 * 2. Redistributions in binary form must reproduce the above copyright\r
 *    notice, this list of conditions and the following disclaimer in the\r
 *    documentation and/or other materials provided with the distribution.\r
 *\r
 * 3. All advertising materials mentioning features or use of this software\r
 *    must display the following acknowledgement:\r
 *\r
 *    This product includes software developed by the University of\r
 *    California, Berkeley, Intel Corporation, and its contributors.\r
 *\r
 * 4. Neither the name of University, Intel Corporation, or their respective\r
 *    contributors may be used to endorse or promote products derived from\r
 *    this software without specific prior written permission.\r
 *\r
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS, INTEL CORPORATION AND\r
 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,\r
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS\r
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS,\r
 * INTEL CORPORATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,\r
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT\r
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,\r
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY\r
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT\r
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF\r
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.\r
 *\r
 *  @(#)sys_generic.c 8.5 (Berkeley) 1/21/94\r
 * $Id: select.c,v 1.1.1.1 2003/11/19 01:50:30 kyu3 Exp $\r
 */\r
#include <Library/UefiBootServicesTableLib.h>\r
\r
#include  <LibConfig.h>\r
\r
#include <stdlib.h>\r
#include <unistd.h>\r
#include <string.h>\r
#include <sys/poll.h>\r
#include <sys/param.h>\r
#include <sys/time.h>\r
#include  <extern.h>      /* For ffs() */\r
#ifndef KERNEL\r
#define KERNEL\r
#include <errno.h>\r
#undef KERNEL\r
#else\r
#include <errno.h>\r
#endif\r
\r
#ifdef  EFI_NT_EMULATOR\r
#define _SELECT_DELAY_  10000\r
#else\r
#define _SELECT_DELAY_  1000\r
#endif\r
\r
#define MAX_SLEEP_DELAY 0xfffffffe\r
\r
/** Sleep for the specified number of Microseconds.\r
\r
    Implements the usleep(3) function.\r
\r
    @param[in]    Microseconds    Number of microseconds to sleep.\r
\r
    @retval   0   Always returns zero.\r
**/\r
int\r
usleep( useconds_t Microseconds )\r
{\r
  while ( MAX_SLEEP_DELAY < Microseconds ) {\r
    gBS->Stall ( MAX_SLEEP_DELAY );\r
    Microseconds -= MAX_SLEEP_DELAY;\r
  }\r
  gBS->Stall((UINTN)Microseconds );\r
  return (0);\r
}\r
\r
unsigned int\r
sleep( unsigned int Seconds )\r
{\r
  return (usleep( (useconds_t)(Seconds * 1000000) ));\r
}\r
\r
static int\r
selscan(\r
  fd_mask **ibits,\r
  fd_mask **obits,\r
  int nfd,\r
  int *nselected\r
  )\r
{\r
  int   msk;\r
  int i;\r
  int j;\r
  int fd;\r
  int n;\r
  struct pollfd pfd;\r
  int FdCount;\r
  fd_mask   bits;\r
  /* Note: backend also returns POLLHUP/POLLERR if appropriate. */\r
  static int16_t  flag[3] = { POLLRDNORM, POLLWRNORM, POLLRDBAND };\r
\r
  for (msk = 0, n = 0; msk < 3; msk++) {\r
    if (ibits[msk] == NULL)\r
      continue;\r
    for (i = 0; i < nfd; i += NFDBITS) {\r
      bits = ibits[ msk ][ i / NFDBITS ];\r
      while (( 0 != (j = ffs(bits))) && ((fd = i + --j) < nfd)) {\r
        bits &= ~(1 << j);\r
\r
        pfd.fd = fd;\r
        pfd.events = flag[msk];\r
        pfd.revents = 0;\r
        FdCount = poll ( &pfd, 1, 0 );\r
        if ( -1 == FdCount ) {\r
          return errno;\r
        }\r
        if ( 0 != FdCount ) {\r
          obits[msk][(fd)/NFDBITS] |=\r
            (1 << ((fd) % NFDBITS));\r
          n++;\r
          break;\r
        }\r
      }\r
    }\r
  }\r
  *nselected = n;\r
  return (0);\r
}\r
\r
int\r
select(\r
  int nd,\r
  fd_set  *in,\r
  fd_set *ou,\r
  fd_set *ex,\r
  struct  timeval *tv\r
  )\r
{\r
  fd_mask *ibits[3], *obits[3], *selbits, *sbp;\r
  int error, forever, nselected;\r
  u_int nbufbytes, ncpbytes, nfdbits;\r
  int64_t timo;\r
\r
  if (nd < 0)\r
    return (EINVAL);\r
\r
  /*\r
   * Allocate just enough bits for the non-null fd_sets.  Use the\r
   * preallocated auto buffer if possible.\r
   */\r
  nfdbits = roundup(nd, NFDBITS);\r
  ncpbytes = nfdbits / NBBY;\r
  nbufbytes = 0;\r
  if (in != NULL)\r
    nbufbytes += 2 * ncpbytes;\r
  if (ou != NULL)\r
    nbufbytes += 2 * ncpbytes;\r
  if (ex != NULL)\r
    nbufbytes += 2 * ncpbytes;\r
  selbits = malloc(nbufbytes);\r
\r
  /*\r
   * Assign pointers into the bit buffers and fetch the input bits.\r
   * Put the output buffers together so that they can be bzeroed\r
   * together.\r
   */\r
  sbp = selbits;\r
#define getbits(name, x) \\r
  do {                \\r
    if (name == NULL)         \\r
      ibits[x] = NULL;        \\r
    else {              \\r
      ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \\r
      obits[x] = sbp;         \\r
      sbp += ncpbytes / sizeof *sbp;      \\r
      bcopy(name, ibits[x], ncpbytes);    \\r
    }             \\r
  } while (0)\r
  getbits(in, 0);\r
  getbits(ou, 1);\r
  getbits(ex, 2);\r
#undef  getbits\r
  if (nbufbytes != 0)\r
    memset(selbits, 0, nbufbytes / 2);\r
\r
  if (tv) {\r
    timo = tv->tv_usec + (tv->tv_sec * 1000000);\r
    forever = 0;\r
  } else {\r
    timo = 0;\r
    forever = 1;\r
  }\r
\r
  /*\r
   *  Poll for I/O events\r
   */\r
  nselected = 0;\r
  do {\r
    /*\r
     *  Scan for pending I/O\r
     */\r
    error = selscan(ibits, obits, nd, &nselected);\r
    if (error || nselected)\r
      break;\r
\r
    /*\r
     *  Adjust timeout is needed\r
     */\r
    if (timo)  {\r
      /*\r
       *  Give it a rest\r
       */\r
      usleep( _SELECT_DELAY_ );\r
      timo -= _SELECT_DELAY_;\r
    }\r
\r
  } while (timo > 0 || forever);\r
\r
  /* select is not restarted after signals... */\r
  if (error == ERESTART)\r
    error = EINTR;\r
  else if (error == EWOULDBLOCK)\r
    error = 0;\r
\r
#define putbits(name, x)  if (name) bcopy(obits[x], name, ncpbytes)\r
  if (error == 0) {\r
    putbits(in, 0);\r
    putbits(ou, 1);\r
    putbits(ex, 2);\r
#undef putbits\r
  } else {\r
    errno = error;\r
    nselected = -1;\r
  }\r
\r
  free( selbits );\r
  return ( nselected );\r
}\r