Imported Upstream version 8.17upstream/8.17

1 files changed, 37 insertions, 0 deletions

diff --git a/lib/safe-write.h b/lib/safe-write.h
new file mode 100644
index 00000000..5c4ef381
--- /dev/null
+++ b/lib/safe-write.h
@@ -0,0 +1,37 @@
+/* An interface to write() that retries after interrupts.
+   Copyright (C) 2002, 2009-2012 Free Software Foundation, Inc.
+
+   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 <http://www.gnu.org/licenses/>.  */
+
+/* Some system calls may be interrupted and fail with errno = EINTR in the
+   following situations:
+     - The process is stopped and restarted (signal SIGSTOP and SIGCONT, user
+       types Ctrl-Z) on some platforms: MacOS X.
+     - The process receives a signal for which a signal handler was installed
+       with sigaction() with an sa_flags field that does not contain
+       SA_RESTART.
+     - The process receives a signal for which a signal handler was installed
+       with signal() and for which no call to siginterrupt(sig,0) was done,
+       on some platforms: AIX, HP-UX, IRIX, OSF/1, Solaris.
+
+   This module provides a wrapper around write() that handles EINTR.  */
+
+#include <stddef.h>
+
+#define SAFE_WRITE_ERROR ((size_t) -1)
+
+/* Write up to COUNT bytes at BUF to descriptor FD, retrying if interrupted.
+   Return the actual number of bytes written, zero for EOF, or SAFE_WRITE_ERROR
+   upon error.  */
+extern size_t safe_write (int fd, const void *buf, size_t count);