1  /* POSIX compatible read() function.
       2     Copyright (C) 2008-2023 Free Software Foundation, Inc.
       3     Written by Bruno Haible <bruno@clisp.org>, 2011.
       4  
       5     This file is free software: you can redistribute it and/or modify
       6     it under the terms of the GNU Lesser General Public License as
       7     published by the Free Software Foundation; either version 2.1 of the
       8     License, or (at your option) any later version.
       9  
      10     This file is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      13     GNU Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public License
      16     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <config.h>
      19  
      20  /* Specification.  */
      21  #include <unistd.h>
      22  
      23  #if defined _WIN32 && ! defined __CYGWIN__
      24  
      25  # include <errno.h>
      26  # include <io.h>
      27  
      28  # define WIN32_LEAN_AND_MEAN  /* avoid including junk */
      29  # include <windows.h>
      30  
      31  # if HAVE_MSVC_INVALID_PARAMETER_HANDLER
      32  #  include "msvc-inval.h"
      33  # endif
      34  # if GNULIB_MSVC_NOTHROW
      35  #  include "msvc-nothrow.h"
      36  # else
      37  #  include <io.h>
      38  # endif
      39  
      40  /* Don't assume that UNICODE is not defined.  */
      41  # undef GetNamedPipeHandleState
      42  # define GetNamedPipeHandleState GetNamedPipeHandleStateA
      43  
      44  # undef read
      45  
      46  # if HAVE_MSVC_INVALID_PARAMETER_HANDLER
      47  static ssize_t
      48  read_nothrow (int fd, void *buf, size_t count)
      49  {
      50    ssize_t result;
      51  
      52    TRY_MSVC_INVAL
      53      {
      54        result = _read (fd, buf, count);
      55      }
      56    CATCH_MSVC_INVAL
      57      {
      58        result = -1;
      59        errno = EBADF;
      60      }
      61    DONE_MSVC_INVAL;
      62  
      63    return result;
      64  }
      65  # else
      66  #  define read_nothrow _read
      67  # endif
      68  
      69  ssize_t
      70  rpl_read (int fd, void *buf, size_t count)
      71  {
      72    ssize_t ret = read_nothrow (fd, buf, count);
      73  
      74  # if GNULIB_NONBLOCKING
      75    if (ret < 0
      76        && GetLastError () == ERROR_NO_DATA)
      77      {
      78        HANDLE h = (HANDLE) _get_osfhandle (fd);
      79        if (GetFileType (h) == FILE_TYPE_PIPE)
      80          {
      81            /* h is a pipe or socket.  */
      82            DWORD state;
      83            if (GetNamedPipeHandleState (h, &state, NULL, NULL, NULL, NULL, 0)
      84                && (state & PIPE_NOWAIT) != 0)
      85              /* h is a pipe in non-blocking mode.
      86                 Change errno from EINVAL to EAGAIN.  */
      87              errno = EAGAIN;
      88          }
      89      }
      90  # endif
      91  
      92    return ret;
      93  }
      94  
      95  #endif