| /* Auxiliary code for filtering of data through a subprocess. |
| Copyright (C) 2001-2003, 2008-2020 Free Software Foundation, Inc. |
| Written by Bruno Haible <haible@clisp.cons.org>, 2009. |
| |
| This program is free software: you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
| |
| #ifndef _GL_INLINE_HEADER_BEGIN |
| #error "Please include config.h first." |
| #endif |
| _GL_INLINE_HEADER_BEGIN |
| #ifndef PIPE_FILTER_AUX_INLINE |
| # define PIPE_FILTER_AUX_INLINE _GL_INLINE |
| #endif |
| |
| #ifndef SSIZE_MAX |
| # define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2)) |
| #endif |
| |
| /* We use a child process, and communicate through a bidirectional pipe. |
| To avoid deadlocks, let the child process decide when it wants to read |
| or to write, and let the parent behave accordingly. The parent uses |
| select() to know whether it must write or read. On platforms without |
| select(), we use non-blocking I/O. (This means the parent is busy |
| looping while waiting for the child. Not good. But hardly any platform |
| lacks select() nowadays.) */ |
| |
| /* On BeOS and OS/2 kLIBC select() works only on sockets, not on normal file |
| descriptors. */ |
| #if defined __BEOS__ || defined __KLIBC__ |
| # undef HAVE_SELECT |
| #endif |
| |
| #ifdef EINTR |
| |
| /* EINTR handling for close(), read(), write(), select(). |
| These functions can return -1/EINTR even though we don't have any |
| signal handlers set up, namely when we get interrupted via SIGSTOP. */ |
| |
| PIPE_FILTER_AUX_INLINE int |
| nonintr_close (int fd) |
| { |
| int retval; |
| |
| do |
| retval = close (fd); |
| while (retval < 0 && errno == EINTR); |
| |
| return retval; |
| } |
| #undef close /* avoid warning related to gnulib module unistd */ |
| #define close nonintr_close |
| |
| PIPE_FILTER_AUX_INLINE ssize_t |
| nonintr_read (int fd, void *buf, size_t count) |
| { |
| ssize_t retval; |
| |
| do |
| retval = read (fd, buf, count); |
| while (retval < 0 && errno == EINTR); |
| |
| return retval; |
| } |
| #undef read /* avoid warning related to gnulib module unistd */ |
| #define read nonintr_read |
| |
| PIPE_FILTER_AUX_INLINE ssize_t |
| nonintr_write (int fd, const void *buf, size_t count) |
| { |
| ssize_t retval; |
| |
| do |
| retval = write (fd, buf, count); |
| while (retval < 0 && errno == EINTR); |
| |
| return retval; |
| } |
| #undef write /* avoid warning on VMS */ |
| #define write nonintr_write |
| |
| #endif |
| |
| /* Non-blocking I/O. */ |
| #if HAVE_SELECT |
| # define IS_EAGAIN(errcode) 0 |
| #else |
| # ifdef EWOULDBLOCK |
| # define IS_EAGAIN(errcode) ((errcode) == EAGAIN || (errcode) == EWOULDBLOCK) |
| # else |
| # define IS_EAGAIN(errcode) ((errcode) == EAGAIN) |
| # endif |
| #endif |
| |
| _GL_INLINE_HEADER_END |