source: rtems/cpukit/libcsupport/src/read.c @ 53da07e

4.11
Last change on this file since 53da07e was 53da07e, checked in by Sebastian Huber <sebastian.huber@…>, on May 14, 2012 at 1:21:30 PM

Filesystem: PR1255: Move offset update to handlers

It is now the responsibility of the read() and write() handler to update
the offset field of the IO descriptor (rtems_libio_t). This change
makes it possible to protect the IO descriptor from concurrent access by
per file locks.

  • Property mode set to 100644
File size: 1.2 KB
Line 
1/*
2 *  read() - POSIX 1003.1b 6.4.1 - Read From a File
3 *
4 *  COPYRIGHT (c) 1989-2011.
5 *  On-Line Applications Research Corporation (OAR).
6 *
7 *  The license and distribution terms for this file may be
8 *  found in the file LICENSE in this distribution or at
9 *  http://www.rtems.com/license/LICENSE.
10 */
11
12#if HAVE_CONFIG_H
13#include "config.h"
14#endif
15
16#include <rtems/libio_.h>
17#include <rtems/seterr.h>
18
19ssize_t read(
20  int         fd,
21  void       *buffer,
22  size_t      count
23)
24{
25  rtems_libio_t *iop;
26
27  rtems_libio_check_fd( fd );
28  iop = rtems_libio_iop( fd );
29  rtems_libio_check_is_open( iop );
30  rtems_libio_check_buffer( buffer );
31  rtems_libio_check_count( count );
32  rtems_libio_check_permissions_with_error( iop, LIBIO_FLAGS_READ, EBADF );
33
34  /*
35   *  Now process the read().
36   */
37  return (*iop->pathinfo.handlers->read_h)( iop, buffer, count );
38}
39
40/*
41 *  _read_r
42 *
43 *  This is the Newlib dependent reentrant version of read().
44 */
45
46#if defined(RTEMS_NEWLIB) && !defined(HAVE__READ_R)
47
48#include <reent.h>
49
50ssize_t _read_r(
51  struct _reent *ptr __attribute__((unused)),
52  int            fd,
53  void          *buf,
54  size_t         nbytes
55)
56{
57  return read( fd, buf, nbytes );
58}
59#endif
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