1 /* POSIX compatible read() function.
2 Copyright (C) 2008-2020 Free Software Foundation, Inc.
3 Written by Bruno Haible <bruno@clisp.org>, 2011.
4
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
9
10 This program 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 General Public License for more details.
14
15 You should have received a copy of the GNU 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
read_nothrow(int fd,void * buf,size_t count)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
rpl_read(int fd,void * buf,size_t count)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
96