gettimeofday: port recent C++ fix to Emacs

[gnulib.git] / lib / safe-read.h

diff --git a/lib/safe-read.h b/lib/safe-read.h
index be957a6..992b7a6 100644 (file)
--- a/lib/safe-read.h
+++ b/lib/safe-read.h
@@ -1,10 +1,47 @@
-#ifndef PARAMS
-# if defined PROTOTYPES || (defined __STDC__ && __STDC__)
-#  define PARAMS(Args) Args
-# else
-#  define PARAMS(Args) ()
-# endif
+/* An interface to read() that retries after interrupts.
+   Copyright (C) 2002, 2006, 2009-2013 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: Mac OS 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 read() that handles EINTR.  */
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
 #endif
 
-ssize_t
-safe_read PARAMS ((int desc, char *ptr, size_t len));
+
+#define SAFE_READ_ERROR ((size_t) -1)
+
+/* Read up to COUNT bytes at BUF from descriptor FD, retrying if interrupted.
+   Return the actual number of bytes read, zero for EOF, or SAFE_READ_ERROR
+   upon error.  */
+extern size_t safe_read (int fd, void *buf, size_t count);
+
+
+#ifdef __cplusplus
+}
+#endif