1 /* Auxiliary code for filtering of data through a subprocess.
2 Copyright (C) 2001-2003, 2008-2013 Free Software Foundation, Inc.
3 Written by Bruno Haible <haible@clisp.cons.org>, 2009.
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.
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.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18 #ifndef _GL_INLINE_HEADER_BEGIN
19 #error "Please include config.h first."
21 _GL_INLINE_HEADER_BEGIN
22 #ifndef PIPE_FILTER_AUX_INLINE
23 # define PIPE_FILTER_AUX_INLINE _GL_INLINE
27 # define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2))
30 /* We use a child process, and communicate through a bidirectional pipe.
31 To avoid deadlocks, let the child process decide when it wants to read
32 or to write, and let the parent behave accordingly. The parent uses
33 select() to know whether it must write or read. On platforms without
34 select(), we use non-blocking I/O. (This means the parent is busy
35 looping while waiting for the child. Not good. But hardly any platform
36 lacks select() nowadays.) */
38 /* On BeOS select() works only on sockets, not on normal file descriptors. */
45 /* EINTR handling for close(), read(), write(), select().
46 These functions can return -1/EINTR even though we don't have any
47 signal handlers set up, namely when we get interrupted via SIGSTOP. */
49 PIPE_FILTER_AUX_INLINE int
50 nonintr_close (int fd)
56 while (retval < 0 && errno == EINTR);
60 #undef close /* avoid warning related to gnulib module unistd */
61 #define close nonintr_close
63 PIPE_FILTER_AUX_INLINE ssize_t
64 nonintr_read (int fd, void *buf, size_t count)
69 retval = read (fd, buf, count);
70 while (retval < 0 && errno == EINTR);
74 #define read nonintr_read
76 PIPE_FILTER_AUX_INLINE ssize_t
77 nonintr_write (int fd, const void *buf, size_t count)
82 retval = write (fd, buf, count);
83 while (retval < 0 && errno == EINTR);
87 #undef write /* avoid warning on VMS */
88 #define write nonintr_write
92 PIPE_FILTER_AUX_INLINE int
93 nonintr_select (int n, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
94 struct timeval *timeout)
99 retval = select (n, readfds, writefds, exceptfds, timeout);
100 while (retval < 0 && errno == EINTR);
104 # undef select /* avoid warning on VMS */
105 # define select nonintr_select
111 /* Non-blocking I/O. */
113 # define IS_EAGAIN(errcode) 0
116 # define IS_EAGAIN(errcode) ((errcode) == EAGAIN || (errcode) == EWOULDBLOCK)
118 # define IS_EAGAIN(errcode) ((errcode) == EAGAIN)
122 _GL_INLINE_HEADER_END