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| author | Joakim Verona | 2013-07-14 11:04:49 +0200 |
|---|---|---|
| committer | Joakim Verona | 2013-07-14 11:04:49 +0200 |
| commit | 0bb9bb0841d89fff09820a57369df4cb01b16b43 (patch) | |
| tree | 832bf9fa8415eef0ce464d22b3ee1300cfa90bb1 /lib/pipe2.c | |
| parent | 3718127221fbbc31f8ebd027ab7c95403dbe9118 (diff) | |
| parent | 3af1c8684ed6e48fbc21481d129e9aa164752c6e (diff) | |
| download | emacs-0bb9bb0841d89fff09820a57369df4cb01b16b43.tar.gz emacs-0bb9bb0841d89fff09820a57369df4cb01b16b43.zip | |
Merge branch 'trunk' into xwidget
Conflicts:
src/xdisp.c
Diffstat (limited to 'lib/pipe2.c')
| -rw-r--r-- | lib/pipe2.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/lib/pipe2.c b/lib/pipe2.c new file mode 100644 index 00000000000..211d75545c0 --- /dev/null +++ b/lib/pipe2.c | |||
| @@ -0,0 +1,168 @@ | |||
| 1 | /* Create a pipe, with specific opening flags. | ||
| 2 | Copyright (C) 2009-2013 Free Software Foundation, Inc. | ||
| 3 | |||
| 4 | This program is free software; you can redistribute it and/or modify | ||
| 5 | it under the terms of the GNU General Public License as published by | ||
| 6 | the Free Software Foundation; either version 3, or (at your option) | ||
| 7 | any later version. | ||
| 8 | |||
| 9 | This program is distributed in the hope that it will be useful, | ||
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
| 12 | GNU General Public License for more details. | ||
| 13 | |||
| 14 | You should have received a copy of the GNU General Public License along | ||
| 15 | with this program; if not, see <http://www.gnu.org/licenses/>. */ | ||
| 16 | |||
| 17 | #include <config.h> | ||
| 18 | |||
| 19 | /* Specification. */ | ||
| 20 | #include <unistd.h> | ||
| 21 | |||
| 22 | #include <errno.h> | ||
| 23 | #include <fcntl.h> | ||
| 24 | |||
| 25 | #include "binary-io.h" | ||
| 26 | #include "verify.h" | ||
| 27 | |||
| 28 | #if GNULIB_defined_O_NONBLOCK | ||
| 29 | # include "nonblocking.h" | ||
| 30 | #endif | ||
| 31 | |||
| 32 | #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ | ||
| 33 | /* Native Windows API. */ | ||
| 34 | |||
| 35 | # include <io.h> | ||
| 36 | |||
| 37 | #endif | ||
| 38 | |||
| 39 | int | ||
| 40 | pipe2 (int fd[2], int flags) | ||
| 41 | { | ||
| 42 | /* Mingw _pipe() corrupts fd on failure; also, if we succeed at | ||
| 43 | creating the pipe but later fail at changing fcntl, we want | ||
| 44 | to leave fd unchanged: http://austingroupbugs.net/view.php?id=467 */ | ||
| 45 | int tmp[2]; | ||
| 46 | tmp[0] = fd[0]; | ||
| 47 | tmp[1] = fd[1]; | ||
| 48 | |||
| 49 | #if HAVE_PIPE2 | ||
| 50 | # undef pipe2 | ||
| 51 | /* Try the system call first, if it exists. (We may be running with a glibc | ||
| 52 | that has the function but with an older kernel that lacks it.) */ | ||
| 53 | { | ||
| 54 | /* Cache the information whether the system call really exists. */ | ||
| 55 | static int have_pipe2_really; /* 0 = unknown, 1 = yes, -1 = no */ | ||
| 56 | if (have_pipe2_really >= 0) | ||
| 57 | { | ||
| 58 | int result = pipe2 (fd, flags); | ||
| 59 | if (!(result < 0 && errno == ENOSYS)) | ||
| 60 | { | ||
| 61 | have_pipe2_really = 1; | ||
| 62 | return result; | ||
| 63 | } | ||
| 64 | have_pipe2_really = -1; | ||
| 65 | } | ||
| 66 | } | ||
| 67 | #endif | ||
| 68 | |||
| 69 | /* Check the supported flags. */ | ||
| 70 | if ((flags & ~(O_CLOEXEC | O_NONBLOCK | O_BINARY | O_TEXT)) != 0) | ||
| 71 | { | ||
| 72 | errno = EINVAL; | ||
| 73 | return -1; | ||
| 74 | } | ||
| 75 | |||
| 76 | #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ | ||
| 77 | /* Native Windows API. */ | ||
| 78 | |||
| 79 | if (_pipe (fd, 4096, flags & ~O_NONBLOCK) < 0) | ||
| 80 | { | ||
| 81 | fd[0] = tmp[0]; | ||
| 82 | fd[1] = tmp[1]; | ||
| 83 | return -1; | ||
| 84 | } | ||
| 85 | |||
| 86 | /* O_NONBLOCK handling. | ||
| 87 | On native Windows platforms, O_NONBLOCK is defined by gnulib. Use the | ||
| 88 | functions defined by the gnulib module 'nonblocking'. */ | ||
| 89 | # if GNULIB_defined_O_NONBLOCK | ||
| 90 | if (flags & O_NONBLOCK) | ||
| 91 | { | ||
| 92 | if (set_nonblocking_flag (fd[0], true) != 0 | ||
| 93 | || set_nonblocking_flag (fd[1], true) != 0) | ||
| 94 | goto fail; | ||
| 95 | } | ||
| 96 | # else | ||
| 97 | { | ||
| 98 | verify (O_NONBLOCK == 0); | ||
| 99 | } | ||
| 100 | # endif | ||
| 101 | |||
| 102 | return 0; | ||
| 103 | |||
| 104 | #else | ||
| 105 | /* Unix API. */ | ||
| 106 | |||
| 107 | if (pipe (fd) < 0) | ||
| 108 | return -1; | ||
| 109 | |||
| 110 | /* POSIX <http://www.opengroup.org/onlinepubs/9699919799/functions/pipe.html> | ||
| 111 | says that initially, the O_NONBLOCK and FD_CLOEXEC flags are cleared on | ||
| 112 | both fd[0] and fd[1]. */ | ||
| 113 | |||
| 114 | /* O_NONBLOCK handling. | ||
| 115 | On Unix platforms, O_NONBLOCK is defined by the system. Use fcntl(). */ | ||
| 116 | if (flags & O_NONBLOCK) | ||
| 117 | { | ||
| 118 | int fcntl_flags; | ||
| 119 | |||
| 120 | if ((fcntl_flags = fcntl (fd[1], F_GETFL, 0)) < 0 | ||
| 121 | || fcntl (fd[1], F_SETFL, fcntl_flags | O_NONBLOCK) == -1 | ||
| 122 | || (fcntl_flags = fcntl (fd[0], F_GETFL, 0)) < 0 | ||
| 123 | || fcntl (fd[0], F_SETFL, fcntl_flags | O_NONBLOCK) == -1) | ||
| 124 | goto fail; | ||
| 125 | } | ||
| 126 | |||
| 127 | if (flags & O_CLOEXEC) | ||
| 128 | { | ||
| 129 | int fcntl_flags; | ||
| 130 | |||
| 131 | if ((fcntl_flags = fcntl (fd[1], F_GETFD, 0)) < 0 | ||
| 132 | || fcntl (fd[1], F_SETFD, fcntl_flags | FD_CLOEXEC) == -1 | ||
| 133 | || (fcntl_flags = fcntl (fd[0], F_GETFD, 0)) < 0 | ||
| 134 | || fcntl (fd[0], F_SETFD, fcntl_flags | FD_CLOEXEC) == -1) | ||
| 135 | goto fail; | ||
| 136 | } | ||
| 137 | |||
| 138 | # if O_BINARY | ||
| 139 | if (flags & O_BINARY) | ||
| 140 | { | ||
| 141 | set_binary_mode (fd[1], O_BINARY); | ||
| 142 | set_binary_mode (fd[0], O_BINARY); | ||
| 143 | } | ||
| 144 | else if (flags & O_TEXT) | ||
| 145 | { | ||
| 146 | set_binary_mode (fd[1], O_TEXT); | ||
| 147 | set_binary_mode (fd[0], O_TEXT); | ||
| 148 | } | ||
| 149 | # endif | ||
| 150 | |||
| 151 | return 0; | ||
| 152 | |||
| 153 | #endif | ||
| 154 | |||
| 155 | #if GNULIB_defined_O_NONBLOCK || \ | ||
| 156 | !((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__) | ||
| 157 | fail: | ||
| 158 | { | ||
| 159 | int saved_errno = errno; | ||
| 160 | close (fd[0]); | ||
| 161 | close (fd[1]); | ||
| 162 | fd[0] = tmp[0]; | ||
| 163 | fd[1] = tmp[1]; | ||
| 164 | errno = saved_errno; | ||
| 165 | return -1; | ||
| 166 | } | ||
| 167 | #endif | ||
| 168 | } | ||