X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fsafe-read.c;h=d9cb3308d0cc887320d33b1c8b609fc59492b9b6;hb=34f19098068439da352e5dbac4e431220557f812;hp=22e705aedb951396850eb374fd0b158c6b199779;hpb=300424a2d37b17d304be2783ed40f2efa4d950c0;p=pspp
diff --git a/lib/safe-read.c b/lib/safe-read.c
index 22e705aedb..d9cb3308d0 100644
--- a/lib/safe-read.c
+++ b/lib/safe-read.c
@@ -1,10 +1,12 @@
-/* safe-read.c -- an interface to read that retries after interrupts
- Copyright (C) 1993, 1994 Free Software Foundation, Inc.
+/* An interface to read and write that retries after interrupts.
- This program is free software; you can redistribute it and/or modify
+ Copyright (C) 1993-1994, 1998, 2002-2006, 2009-2011 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 2, or (at your option)
- any later version.
+ 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
@@ -12,49 +14,64 @@
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, write to the Free Software
- Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
+ along with this program. If not, see . */
-#ifdef HAVE_CONFIG_H
#include
+
+/* Specification. */
+#ifdef SAFE_WRITE
+# include "safe-write.h"
+#else
+# include "safe-read.h"
#endif
+/* Get ssize_t. */
#include
-
-#ifdef HAVE_UNISTD_H
#include
-#endif
#include
-#ifndef STDC_HEADERS
-extern int errno;
+
+#ifdef EINTR
+# define IS_EINTR(x) ((x) == EINTR)
+#else
+# define IS_EINTR(x) 0
#endif
-/* Read LEN bytes at PTR from descriptor DESC, retrying if interrupted.
- Return the actual number of bytes read, zero for EOF, or negative
- for an error. */
+#include
-int
-safe_read (desc, ptr, len)
- int desc;
- char *ptr;
- int len;
-{
- int n_chars;
+#ifdef SAFE_WRITE
+# define safe_rw safe_write
+# define rw write
+#else
+# define safe_rw safe_read
+# define rw read
+# undef const
+# define const /* empty */
+#endif
- if (len <= 0)
- return len;
+/* Read(write) up to COUNT bytes at BUF from(to) descriptor FD, retrying if
+ interrupted. Return the actual number of bytes read(written), zero for EOF,
+ or SAFE_READ_ERROR(SAFE_WRITE_ERROR) upon error. */
+size_t
+safe_rw (int fd, void const *buf, size_t count)
+{
+ /* Work around a bug in Tru64 5.1. Attempting to read more than
+ INT_MAX bytes fails with errno == EINVAL. See
+ .
+ When decreasing COUNT, keep it block-aligned. */
+ enum { BUGGY_READ_MAXIMUM = INT_MAX & ~8191 };
-#ifdef EINTR
- do
+ for (;;)
{
- n_chars = read (desc, ptr, len);
- }
- while (n_chars < 0 && errno == EINTR);
-#else
- n_chars = read (desc, ptr, len);
-#endif
+ ssize_t result = rw (fd, buf, count);
- return n_chars;
+ if (0 <= result)
+ return result;
+ else if (IS_EINTR (errno))
+ continue;
+ else if (errno == EINVAL && BUGGY_READ_MAXIMUM < count)
+ count = BUGGY_READ_MAXIMUM;
+ else
+ return result;
+ }
}