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C Library: Add a very limited, first step implementation of setvbuf(). This is a collaborative effort. Alan Carvalho de Assis did the initial prototype.

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This commit is contained in:
Gregory Nutt 2017-02-08 10:33:18 -06:00
parent 4700499b59
commit 51a14c9b2f
7 changed files with 308 additions and 30 deletions
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12
fs/vfs/fs_stat.c
View file

@ -66,6 +66,14 @@
# define RESET_BUF(b) memset((b), 0, sizeof(struct stat));
#endif
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static inline int statpseudo(FAR struct inode *inode, FAR struct stat *buf);
static inline int statroot(FAR struct stat *buf);
int stat_recursive(FAR const char *path, FAR struct stat *buf);
/****************************************************************************
* Private Functions
****************************************************************************/
@ -129,7 +137,7 @@ static inline int statpseudo(FAR struct inode *inode, FAR struct stat *buf)
return -ELOOP;
}
DEBUGASSERT(buff->st_count > 0); /* Check for unsigned integer overflow */
DEBUGASSERT(buf->st_count > 0); /* Check for unsigned integer overflow */
/* stat() the target of the soft link. */
@ -307,8 +315,6 @@ errout_with_inode:
errout_with_search:
RELEASE_SEARCH(&desc);
errout:
set_errno(ret);
return ERROR;
}

1
include/nuttx/fs/fs.h
View file

@ -65,6 +65,7 @@
#define __FS_FLAG_EOF (1 << 0) /* EOF detected by a read operation */
#define __FS_FLAG_ERROR (1 << 1) /* Error detected by any operation */
#define __FS_FLAG_UBF (1 << 2) /* Buffer allocated by caller of setvbuf */
/* Inode i_flag values:
*

17
include/stdio.h
View file

@ -64,15 +64,21 @@
# define BUFSIZ CONFIG_STDIO_BUFFER_SIZE
#endif
/* The following three definitions are for ANSI C, used by setvbuf */
#define _IOFBF 0 /* Fully buffered */
#define _IOLBF 1 /* Line buffered */
#define _IONBF 2 /* Unbuffered */
/* File system error values */
#define EOF (-1)
/* The first three _iob entries are reserved for standard I/O */
#define stdin (&sched_getstreams()->sl_streams[0])
#define stdout (&sched_getstreams()->sl_streams[1])
#define stderr (&sched_getstreams()->sl_streams[2])
#define stdin (&sched_getstreams()->sl_streams[0])
#define stdout (&sched_getstreams()->sl_streams[1])
#define stderr (&sched_getstreams()->sl_streams[2])
/* These APIs are not implemented and/or can be synthesized from
* supported APIs.
@ -90,7 +96,7 @@
# define CONFIG_LIBC_TMPDIR "/tmp"
#endif
#define P_tmpdir CONFIG_LIBC_TMPDIR
#define P_tmpdir CONFIG_LIBC_TMPDIR
/* Maximum size of character array to hold tmpnam() output. */
@ -98,7 +104,7 @@
# define CONFIG_LIBC_MAX_TMPFILE 32
#endif
#define L_tmpnam CONFIG_LIBC_MAX_TMPFILE
#define L_tmpnam CONFIG_LIBC_MAX_TMPFILE
/* The maximum number of unique temporary file names that can be generated */
@ -156,6 +162,7 @@ size_t fwrite(FAR const void *ptr, size_t size, size_t n_items,
FAR FILE *stream);
FAR char *gets(FAR char *s);
FAR char *gets_s(FAR char *s, rsize_t n);
int setvbuf(FAR FILE *stream, FAR char *buffer, int mode, size_t size);
int ungetc(int c, FAR FILE *stream);
/* Operations on the stdout stream, buffers, paths, and the whole printf-family */

31
libc/misc/lib_stream.c
View file

@ -53,18 +53,6 @@
#if (!defined(CONFIG_BUILD_PROTECTED) && !defined(CONFIG_BUILD_KERNEL)) || \
defined(__KERNEL__)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
@ -101,13 +89,15 @@ void lib_stream_initialize(FAR struct task_group_s *group)
for (i = 0; i < CONFIG_NFILE_STREAMS; i++)
{
/* Clear the IOB */
FAR struct file_struct *stream = &list->sl_streams[i];
memset(&list->sl_streams[i], 0, sizeof(FILE));
/* Clear the IOB */
memset(stream, 0, sizeof(FILE));
/* Indicate not opened */
list->sl_streams[i].fs_fd = -1;
stream->fs_fd = -1;
/* Initialize the stream semaphore to one to support one-at-
* a-time access to private data sets.
@ -154,18 +144,21 @@ void lib_stream_release(FAR struct task_group_s *group)
#if CONFIG_STDIO_BUFFER_SIZE > 0
for (i = 0; i < CONFIG_NFILE_STREAMS; i++)
{
FAR struct file_struct *stream = &list->sl_streams[i];
/* Destroy the semaphore that protects the IO buffer */
(void)sem_destroy(&list->sl_streams[i].fs_sem);
(void)sem_destroy(&stream->fs_sem);
/* Release the IO buffer */
if (list->sl_streams[i].fs_bufstart)
if (stream->fs_bufstart != NULL &&
(stream->fs_flags & __FS_FLAG_UBF) == 0)
{
#ifndef CONFIG_BUILD_KERNEL
/* Release memory from the user heap */
sched_ufree(list->sl_streams[i].fs_bufstart);
sched_ufree(stream->fs_bufstart);
#else
/* If the exiting group is unprivileged, then it has an address
* environment. Don't bother to release the memory in this case...
@ -177,7 +170,7 @@ void lib_stream_release(FAR struct task_group_s *group)
if ((group->tg_flags & GROUP_FLAG_PRIVILEGED) != 0)
{
sched_kfree(list->sl_streams[i].fs_bufstart);
sched_kfree(stream->fs_bufstart);
}
#endif
}

2
libc/stdio/Make.defs
View file

@ -65,7 +65,7 @@ CSRCS += lib_rdflush.c lib_wrflush.c lib_fputc.c lib_puts.c lib_fputs.c
CSRCS += lib_ungetc.c lib_vprintf.c lib_fprintf.c lib_vfprintf.c
CSRCS += lib_stdinstream.c lib_stdoutstream.c lib_stdsistream.c
CSRCS += lib_stdsostream.c lib_perror.c lib_feof.c lib_ferror.c
CSRCS += lib_clearerr.c
CSRCS += lib_clearerr.c lib_setvbuf.c
endif

5
libc/stdio/lib_fclose.c
View file

@ -1,7 +1,7 @@
/****************************************************************************
* libc/stdio/lib_fclose.c
*
* Copyright (C) 2007-2009, 2011, 3013 Gregory Nutt. All rights reserved.
* Copyright (C) 2007-2009, 2011, 2013, 2017 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
@ -114,7 +114,8 @@ int fclose(FAR FILE *stream)
/* Release the buffer */
if (stream->fs_bufstart)
if (stream->fs_bufstart != NULL &&
(stream->fs_flags & __FS_FLAG_UBF) == 0)
{
lib_free(stream->fs_bufstart);
}

270
libc/stdio/lib_setvbuf.c Normal file
View file

@ -0,0 +1,270 @@
/****************************************************************************
* libc/stdio/lib_setvbuf.c
*
* Copyright (C) 2017 Gregory Nutt. All rights reserved.
* Author: Alan Carvalho de Assis <acassis@gmail.com>
* Gregory Nutt <gnutt@nuttx.org>
*
* This code is based on Newlib implementation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT will THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdbool.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <nuttx/fs/fs.h>
#include "libc.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: setvbuf
*
* Description:
* The setvbuf() function may be used after the stream pointed to by
* stream is associated with an open file but before any other operation
* (other than an unsuccessful call to setvbuf()) is performed on the
* stream. The argument type determines how stream will be buffered, as
* follows:
*
* _IOFBF - Will cause input/output to be fully buffered.
* _IOLBF - Will cause input/output to be line buffered.
* _IONBF - Will cause input/output to be unbuffered.
*
* If buf is not a null pointer, the array it points to may be used instead
* of a buffer allocated by setvbuf() and the argument size specifies the size
* of the array; otherwise, size may determine the size of a buffer allocated
* by the setvbuf() function. The contents of the array at any time are
* unspecified.
*
* REVISIT: This initial version of setvbuf has some severe limitations and
* not all features features required by the specification are available.
* These the limitations are the result of hard-coded stream logic based
* the static configuration. This logic cannot support variable behaviors
* without some additional logic. Specifically, we cannot support:
*
* - Any line buffering state that is inconsistent with the configuration
* setting CONFIG_STDIO_LINEBUFFER
* - We cannot support disabling stream buffering if
* CONFIG_STDIO_BUFFER_SIZE > 0
*
* Parmeters:
* stream - the stream to flush
* buffer - the user allocate buffer. If NULL, will allocates a buffer of
* specified size
* mode - specifies a mode for file buffering
* size - size of buffer
*
* Return:
* Upon successful completion, setvbuf() will return 0. Otherwise, it will
* return a non-zero value if an invalid value is given for type or if the
* request cannot be honored, [CX] and may set errno to indicate the error
*
****************************************************************************/
int setvbuf(FAR FILE *stream, FAR char *buffer, int mode, size_t size)
{
#if CONFIG_STDIO_BUFFER_SIZE > 0
uint8_t flags;
int errcode;
int ret = OK;
/* Verify arguments */
if (mode != _IOFBF && mode != _IOLBF && mode != _IONBF)
{
errcode = EINVAL;
goto errout;
}
/* Make sure that the size argument agrees with the mode */
if (((mode == _IOFBF || mode == _IOLBF) && size == 0) ||
(mode == _IONBF && size > 0))
{
errcode = EINVAL;
goto errout;
}
/* Make sure that the buffer argument agrees with mode */
if (mode == _IONBF && buffer != NULL)
{
errcode = EINVAL;
goto errout;
}
/* Make sure that the buffer and size argeuments agree */
if (buffer != NULL && size == 0)
{
errcode = EINVAL;
goto errout;
}
/* Not all features are be available. Without some additional logic,
* we cannot support (1) any line buffering state that is inconsistent
* with CONFIG_STDIO_LINEBUFFER nor can we (2) disable buffering if
* CONFIG_STDIO_BUFFER_SIZE > 0
*/
#ifdef CONFIG_STDIO_LINEBUFFER
if (mode != _IOLBF)
#else
if (mode != _IOFBF)
#endif
{
errcode = ENOSYS;
goto errout;
}
/* Make sure that we have exclusive access to the stream */
lib_take_semaphore(stream);
/* setvbuf() may only be called AFTER the file has been opened and BEFORE
* any operations have been performed on the string.
*/
/* Return EBADF if the file is not open */
if (stream->fs_fd < 0)
{
errcode = EBADF;
goto errout_with_semaphore;
}
/* Return EBUSY if operations have already been performed on the buffer.
* Here we really only verify that there is no valid data in the existing
* buffer.
*/
if (stream->fs_bufpos != stream->fs_bufstart)
{
errcode = EBUSY;
goto errout_with_semaphore;
}
/* Initialize by clearing related flags. We try to avoid any permanent
* changes to the stream structure until we know that we will be
* successful.
*/
flags = stream->fs_flags & ~__FS_FLAG_UBF;
/* Allocate a new buffer if one is needed. We have already verified that:
*
* If a buffer is needed, then size > 0
* If a buffer is NOT needed, then buffer is NULL
* If buffer != NULL, then size > 0
*
* That simplifies the following check:
*/
#if 0 /* size should always be > 0 in the currently supported configurations */
if (size > 0)
#else
DEBUGASSERT(size > 0);
#endif
{
FAR unsigned char *newbuf;
/* A buffer is needed. Did the caller provide the buffer memory? */
DEBUGASSERT(mode == _IOFBF || mode == _IOLBF);
if (buffer != NULL)
{
newbuf = (FAR unsigned char *)buffer;
/* Indicate that we have an I/O buffer managed by the caller of
* setvbuf.
*/
flags |= __FS_FLAG_UBF;
}
else
{
newbuf = (FAR unsigned char *)lib_malloc(size);
if (newbuf == NULL)
{
errcode = ENOMEM;
goto errout_with_semaphore;
}
}
/* Do not release the previous buffer if it was allocated by the user
* on a previous call to setvbuf().
*/
if ((stream->fs_flags & __FS_FLAG_UBF) != 0)
{
lib_free(stream->fs_bufstart);
}
/* Use the new buffer */
stream->fs_bufstart = newbuf;
stream->fs_bufend = newbuf;
stream->fs_bufpos = newbuf;
stream->fs_bufread = newbuf;
}
/* Update the stream flags and return success */
stream->fs_flags = flags;
lib_give_semaphore(stream);
return OK;
errout_with_semaphore:
lib_give_semaphore(stream);
errout:
set_errno(errcode);
return ERROR;
#else
/* Return that setvbuf() is not supported */
set_errno(ENOSYS);
return ERROR;
#endif
}