|
|
/************************************************************
* lib_fflush.c
*
* Copyright (C) 2007 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 Gregory Nutt 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 SHALL 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.
*
************************************************************/
/************************************************************
* Compilation Switches
************************************************************/
/************************************************************
* Included Files
************************************************************/
#include <nuttx/config.h> /* for CONFIG_STDIO_BUFFER_SIZE */
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <nuttx/fs.h>
#include "lib_internal.h"
/************************************************************
* Definitions
************************************************************/
/************************************************************
* Private Type Declarations
************************************************************/
/************************************************************
* Private Function Prototypes
************************************************************/
/************************************************************
* Global Constant Data
************************************************************/
/************************************************************
* Global Variables
************************************************************/
/************************************************************
* Private Constant Data
************************************************************/
/************************************************************
* Private Variables
************************************************************/
/************************************************************
* Global Functions
************************************************************/
/************************************************************
* Name: lib_fflushall
*
* Description:
* Called by the OS when a task exits
************************************************************/
void lib_flushall(FAR struct streamlist *list)
{
/* Make sure that there are streams associated with this thread */
if (list)
{
int i;
/* Process each stream in the thread's stream list */
stream_semtake(list);
for (i = 0; i < CONFIG_NFILE_STREAMS; i++)
{
/* If the stream is open (i.e., assigned a non-
* negative file descriptor), then flush the
* stream.
*/
if (list->sl_streams[i].fs_filedes >= 0)
{
(void)fflush(&list->sl_streams[i]);
}
}
stream_semgive(list);
}
}
/************************************************************
* Name: fflush
************************************************************/
int fflush(FILE *stream)
{
#if CONFIG_STDIO_BUFFER_SIZE > 0
const unsigned char *src;
size_t bytes_written;
size_t nbuffer;
if (stream->fs_filedes < 0 || (stream->fs_oflags & O_WROK) == 0)
{
*get_errno_ptr() = EBADF;
return ERROR;
}
/* Make sure that we have exclusive access to the stream */
lib_take_semaphore(stream);
/* How many bytes are used in the buffer now */
nbuffer = stream->fs_bufpos - stream->fs_bufstart;
/* Try to write that amount */
src = stream->fs_bufstart;
bytes_written = write(stream->fs_filedes, src, nbuffer);
if (bytes_written < 0)
{
lib_give_semaphore(stream);
return bytes_written;
}
/* Update pointers and counts */
src += bytes_written;
nbuffer -= bytes_written;
/* Reset the buffer position to the beginning of the buffer */
stream->fs_bufpos = stream->fs_bufstart;
/* For the case of an incomplete write, nbuffer will be non-zero
* It will hold the number of bytes that were not written.
* Move the data down in the buffer to handle this (rare) case
*/
while (nbuffer)
{
*stream->fs_bufpos++ = *src++;
--nbuffer;
}
/* Return the number of bytes remaining in the buffer */
lib_give_semaphore(stream);
return stream->fs_bufpos - stream->fs_bufstart;
#else
return 0;
#endif
}
|
