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9b36a80c | 1 | /* POSIX compatible write() function. |
5e69ceb7 | 2 | Copyright (C) 2008-2014 Free Software Foundation, Inc. |
9b36a80c LC |
3 | Written by Bruno Haible <bruno@clisp.org>, 2008. |
4 | ||
5 | This program is free software: you can redistribute it and/or modify | |
6 | it under the terms of the GNU Lesser 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 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 <http://www.gnu.org/licenses/>. */ | |
17 | ||
18 | #include <config.h> | |
19 | ||
20 | /* Specification. */ | |
21 | #include <unistd.h> | |
22 | ||
9b36a80c LC |
23 | /* On native Windows platforms, SIGPIPE does not exist. When write() is |
24 | called on a pipe with no readers, WriteFile() fails with error | |
25 | GetLastError() = ERROR_NO_DATA, and write() in consequence fails with | |
26 | error EINVAL. */ | |
27 | ||
35428fb6 LC |
28 | #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ |
29 | ||
30 | # include <errno.h> | |
31 | # include <signal.h> | |
32 | # include <io.h> | |
33 | ||
34 | # define WIN32_LEAN_AND_MEAN /* avoid including junk */ | |
35 | # include <windows.h> | |
36 | ||
37 | # include "msvc-inval.h" | |
38 | # include "msvc-nothrow.h" | |
9b36a80c | 39 | |
35428fb6 LC |
40 | # undef write |
41 | ||
42 | # if HAVE_MSVC_INVALID_PARAMETER_HANDLER | |
af07e104 | 43 | static ssize_t |
35428fb6 LC |
44 | write_nothrow (int fd, const void *buf, size_t count) |
45 | { | |
46 | ssize_t result; | |
47 | ||
48 | TRY_MSVC_INVAL | |
49 | { | |
50 | result = write (fd, buf, count); | |
51 | } | |
52 | CATCH_MSVC_INVAL | |
53 | { | |
54 | result = -1; | |
55 | errno = EBADF; | |
56 | } | |
57 | DONE_MSVC_INVAL; | |
9b36a80c | 58 | |
35428fb6 LC |
59 | return result; |
60 | } | |
61 | # else | |
62 | # define write_nothrow write | |
63 | # endif | |
9b36a80c LC |
64 | |
65 | ssize_t | |
66 | rpl_write (int fd, const void *buf, size_t count) | |
9b36a80c | 67 | { |
dd7d0148 | 68 | for (;;) |
9b36a80c | 69 | { |
35428fb6 | 70 | ssize_t ret = write_nothrow (fd, buf, count); |
dd7d0148 LC |
71 | |
72 | if (ret < 0) | |
1cd4fffc | 73 | { |
35428fb6 | 74 | # if GNULIB_NONBLOCKING |
dd7d0148 LC |
75 | if (errno == ENOSPC) |
76 | { | |
77 | HANDLE h = (HANDLE) _get_osfhandle (fd); | |
78 | if (GetFileType (h) == FILE_TYPE_PIPE) | |
79 | { | |
80 | /* h is a pipe or socket. */ | |
81 | DWORD state; | |
82 | if (GetNamedPipeHandleState (h, &state, NULL, NULL, NULL, | |
83 | NULL, 0) | |
84 | && (state & PIPE_NOWAIT) != 0) | |
85 | { | |
86 | /* h is a pipe in non-blocking mode. | |
87 | We can get here in four situations: | |
88 | 1. When the pipe buffer is full. | |
89 | 2. When count <= pipe_buf_size and the number of | |
90 | free bytes in the pipe buffer is < count. | |
91 | 3. When count > pipe_buf_size and the number of free | |
92 | bytes in the pipe buffer is > 0, < pipe_buf_size. | |
93 | 4. When count > pipe_buf_size and the pipe buffer is | |
94 | entirely empty. | |
95 | The cases 1 and 2 are POSIX compliant. In cases 3 and | |
96 | 4 POSIX specifies that write() must split the request | |
97 | and succeed with a partial write. We fix case 4. | |
98 | We don't fix case 3 because it is not essential for | |
99 | programs. */ | |
100 | DWORD out_size; /* size of the buffer for outgoing data */ | |
101 | DWORD in_size; /* size of the buffer for incoming data */ | |
102 | if (GetNamedPipeInfo (h, NULL, &out_size, &in_size, NULL)) | |
103 | { | |
104 | size_t reduced_count = count; | |
105 | /* In theory we need only one of out_size, in_size. | |
106 | But I don't know which of the two. The description | |
107 | is ambiguous. */ | |
108 | if (out_size != 0 && out_size < reduced_count) | |
109 | reduced_count = out_size; | |
110 | if (in_size != 0 && in_size < reduced_count) | |
111 | reduced_count = in_size; | |
112 | if (reduced_count < count) | |
113 | { | |
114 | /* Attempt to write only the first part. */ | |
115 | count = reduced_count; | |
116 | continue; | |
117 | } | |
118 | } | |
119 | /* Change errno from ENOSPC to EAGAIN. */ | |
120 | errno = EAGAIN; | |
121 | } | |
122 | } | |
123 | } | |
124 | else | |
35428fb6 | 125 | # endif |
dd7d0148 | 126 | { |
35428fb6 | 127 | # if GNULIB_SIGPIPE |
dd7d0148 LC |
128 | if (GetLastError () == ERROR_NO_DATA |
129 | && GetFileType ((HANDLE) _get_osfhandle (fd)) | |
130 | == FILE_TYPE_PIPE) | |
131 | { | |
132 | /* Try to raise signal SIGPIPE. */ | |
133 | raise (SIGPIPE); | |
134 | /* If it is currently blocked or ignored, change errno from | |
135 | EINVAL to EPIPE. */ | |
136 | errno = EPIPE; | |
137 | } | |
35428fb6 | 138 | # endif |
dd7d0148 | 139 | } |
1cd4fffc | 140 | } |
dd7d0148 | 141 | return ret; |
9b36a80c | 142 | } |
9b36a80c LC |
143 | } |
144 | ||
9b36a80c | 145 | #endif |