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Diffstat (limited to 'sysdeps/posix/preadv.c')
-rw-r--r--sysdeps/posix/preadv.c91
1 files changed, 7 insertions, 84 deletions
diff --git a/sysdeps/posix/preadv.c b/sysdeps/posix/preadv.c
index fb7586c0a6..f944ec746e 100644
--- a/sysdeps/posix/preadv.c
+++ b/sysdeps/posix/preadv.c
@@ -1,4 +1,5 @@
-/* Copyright (C) 2009-2016 Free Software Foundation, Inc.
+/* Read data into multiple buffers. Generic version.
+ Copyright (C) 2009-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@@ -15,93 +16,15 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
-#include <errno.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <string.h>
-#include <limits.h>
-#include <stdbool.h>
-#include <sys/param.h>
-#if __WORDSIZE == 64 && !defined PREADV
-/* Hide the preadv64 declaration. */
-# define preadv64 __redirect_preadv64
-#endif
-#include <sys/uio.h>
-#include <bits/wordsize.h>
+#include <sys/types.h>
+
+#ifndef __OFF_T_MATCHES_OFF64_T
-#ifndef PREADV
# define PREADV preadv
# define PREAD __pread
# define OFF_T off_t
-#endif
-
-
-static void
-ifree (char **ptrp)
-{
- free (*ptrp);
-}
-
-
-/* Read data from file descriptor FD at the given position OFFSET
- without change the file pointer, and put the result in the buffers
- described by VECTOR, which is a vector of COUNT 'struct iovec's.
- The buffers are filled in the order specified. Operates just like
- 'pread' (see <unistd.h>) except that data are put in VECTOR instead
- of a contiguous buffer. */
-ssize_t
-PREADV (int fd, const struct iovec *vector, int count, OFF_T offset)
-{
- /* Find the total number of bytes to be read. */
- size_t bytes = 0;
- for (int i = 0; i < count; ++i)
- {
- /* Check for ssize_t overflow. */
- if (SSIZE_MAX - bytes < vector[i].iov_len)
- {
- __set_errno (EINVAL);
- return -1;
- }
- bytes += vector[i].iov_len;
- }
-
- /* Allocate a temporary buffer to hold the data. We should normally
- use alloca since it's faster and does not require synchronization
- with other threads. But we cannot if the amount of memory
- required is too large. */
- char *buffer;
- char *malloced_buffer __attribute__ ((__cleanup__ (ifree))) = NULL;
- if (__libc_use_alloca (bytes))
- buffer = (char *) __alloca (bytes);
- else
- {
- malloced_buffer = buffer = (char *) malloc (bytes);
- if (buffer == NULL)
- return -1;
- }
-
- /* Read the data. */
- ssize_t bytes_read = PREAD (fd, buffer, bytes, offset);
- if (bytes_read < 0)
- return -1;
-
- /* Copy the data from BUFFER into the memory specified by VECTOR. */
- bytes = bytes_read;
- for (int i = 0; i < count; ++i)
- {
- size_t copy = MIN (vector[i].iov_len, bytes);
-
- (void) memcpy ((void *) vector[i].iov_base, (void *) buffer, copy);
+# include <sysdeps/posix/preadv_common.c>
- buffer += copy;
- bytes -= copy;
- if (bytes == 0)
- break;
- }
+libc_hidden_def (preadv)
- return bytes_read;
-}
-#if __WORDSIZE == 64 && defined preadv64
-# undef preadv64
-strong_alias (preadv, preadv64)
#endif