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/************************************************************
* lib_init.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.
*
************************************************************/
/************************************************************
* Included Files
************************************************************/
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs.h>
#include <nuttx/os_external.h>
#include "lib_internal.h"
/************************************************************
* Definitions
************************************************************/
/************************************************************
* Private Variables
************************************************************/
/************************************************************
* Private Functions
************************************************************/
#if CONFIG_NFILE_STREAMS > 0
static void _lib_semtake(FAR struct streamlist *list)
{
/* Take the semaphore (perhaps waiting) */
while (sem_wait(&list->sl_sem) != 0)
{
/* The only case that an error should occr here is if
* the wait was awakened by a signal.
*/
ASSERT(*get_errno_ptr() == EINTR);
}
}
# define _lib_semgive(list) sem_post(&list->sl_sem)
#else
# define _lib_semtake(list)
# define _lib_semgive(list)
#endif
/************************************************************
* Public Functions
************************************************************/
/************************************************************
* lib_initialize
************************************************************/
/* General library initialization hook */
void weak_const_function lib_initialize(void)
{
}
#if CONFIG_NFILE_STREAMS > 0
/* The following function is called when a new TCB is allocated. It
* creates the streamlist instance that is stored in the TCB.
*/
FAR struct streamlist *lib_alloclist(void)
{
FAR struct streamlist *list;
list = (FAR struct streamlist*)kzmalloc(sizeof(struct streamlist));
if (list)
{
int i;
/* Start with a reference count of one */
list->sl_crefs = 1;
/* Initialize the list access mutex */
(void)sem_init(&list->sl_sem, 0, 1);
/* Initialize each FILE structure */
for (i = 0; i < CONFIG_NFILE_STREAMS; i++)
{
/* Clear the IOB */
memset(&list->sl_streams[i], 0, sizeof(FILE));
/* Indicate not opened */
list->sl_streams[i].fs_filedes = -1;
/* Initialize the stream semaphore to one to support one-at-
* a-time access to private data sets.
*/
lib_sem_initialize(&list->sl_streams[i]);
}
}
return list;
}
/* This function is called when a TCB is closed (such as with
* pthread_create(). It increases the reference count on the stream
* list.
*/
void lib_addreflist(FAR struct streamlist *list)
{
if (list)
{
/* Increment the reference count on the list.
* NOTE: that we disable interrupts to do this
* (vs. taking the list semaphore). We do this
* because file cleanup operations often must be
* done from the IDLE task which cannot wait
* on semaphores.
*/
register irqstate_t flags = irqsave();
list->sl_crefs++;
irqrestore(flags);
}
}
/* this function is called when a TCB is destroyed. Note that is
* does not close the file by release this inode. This happens
* separately when the file descriptor list is freed.
*/
void lib_releaselist(FAR struct streamlist *list)
{
int crefs;
if (list)
{
/* Decrement the reference count on the list.
* NOTE: that we disable interrupts to do this
* (vs. taking the list semaphore). We do this
* because file cleanup operations often must be
* done from the IDLE task which cannot wait
* on semaphores.
*/
register irqstate_t flags = irqsave();
crefs = --(list->sl_crefs);
irqrestore(flags);
/* If the count decrements to zero, then there is no reference
* to the structure and it should be deallocated. Since there
* are references, it would be an error if any task still held
* a reference to the list's semaphore.
*/
if (crefs <= 0)
{
int i;
/* Destroy the semaphore and release the filelist */
(void)sem_destroy(&list->sl_sem);
sched_free(list);
/* Initialize each FILE structure */
#if CONFIG_STDIO_BUFFER_SIZE > 0
for (i = 0; i < CONFIG_NFILE_STREAMS; i++)
{
/* Destroy the semaphore that protects the IO buffer */
(void)sem_destroy(&list->sl_streams[i].fs_sem);
/* Release the IO buffer */
if (&list->sl_streams[i].fs_bufstart)
{
free(list->sl_streams[i].fs_bufstart);
}
}
#endif
}
}
}
#endif /* CONFIG_NFILE_STREAMS */
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