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NuttX RTOS
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3 42af7a65-404d-4744-a932-0658087f49c3
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/************************************************************
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* lib_init.c
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*
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* Copyright (C) 2007 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name Gregory Nutt nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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************************************************************/
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/************************************************************
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* Included Files
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************************************************************/
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#include <stdio.h>
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#include <string.h>
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#include <errno.h>
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#include <nuttx/kmalloc.h>
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#include <nuttx/fs.h>
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#include <nuttx/os_external.h>
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#include "lib_internal.h"
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/************************************************************
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* Definitions
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************************************************************/
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/************************************************************
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* Private Variables
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************************************************************/
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/************************************************************
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* Private Functions
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************************************************************/
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static void _lib_semtake(struct streamlist *list)
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{
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/* Take the semaphore (perhaps waiting) */
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while (sem_wait(&list->sl_sem) != 0)
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{
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/* The only case that an error should occr here is if
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* the wait was awakened by a signal.
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*/
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ASSERT(*get_errno_ptr() == EINTR);
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}
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}
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static inline void _lib_semgive(struct streamlist *list)
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{
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sem_post(&list->sl_sem);
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}
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/************************************************************
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* Public Functions
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************************************************************/
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/************************************************************
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* lib_initialize
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************************************************************/
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/* General library initialization hook */
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void weak_const_function lib_initialize(void)
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{
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}
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#if CONFIG_NFILE_STREAMS > 0
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/* The following function is called when a new TCB is allocated. It
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* creates the streamlist instance that is stored in the TCB.
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*/
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struct streamlist *lib_alloclist(void)
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{
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struct streamlist *list;
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list = (struct streamlist*)kzmalloc(sizeof(struct streamlist));
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if (list)
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{
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int i;
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/* Start with a reference count of one */
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list->sl_crefs = 1;
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/* Initialize the list access mutex */
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(void)sem_init(&list->sl_sem, 0, 1);
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/* Initialize each FILE structure */
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for (i = 0; i < CONFIG_NFILE_STREAMS; i++)
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{
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/* Clear the IOB */
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memset(&list->sl_streams[i], 0, sizeof(FILE));
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/* Indicate not opened */
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list->sl_streams[i].fs_filedes = -1;
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/* Initialize the stream semaphore to one to support one-at-
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* a-time access to private data sets.
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*/
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lib_sem_initialize(&list->sl_streams[i]);
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}
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}
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return list;
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}
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/* This function is called when a TCB is closed (such as with
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* pthread_create(). It increases the reference count on the stream
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* list.
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*/
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void lib_addreflist(struct streamlist *list)
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{
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if (list)
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{
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/* Increment the reference count on the list */
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_lib_semtake(list);
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list->sl_crefs++;
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_lib_semgive(list);
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}
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}
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/* this function is called when a TCB is destroyed. Note that is
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* does not close the file by release this inode. This happens
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* separately when the file descriptor list is freed.
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*/
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void lib_releaselist(struct streamlist *list)
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{
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int crefs;
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if (list)
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{
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/* Decrement the reference count */
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_lib_semtake(list);
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crefs = --list->sl_crefs;
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_lib_semgive(list);
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/* If the count decrements to zero, then there is no reference
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* to the structure and it should be deallocated.
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*/
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if (crefs <= 0)
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{
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int i;
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/* Destroy the semaphore and release the filelist */
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(void)sem_destroy(&list->sl_sem);
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sched_free(list);
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/* Initialize each FILE structure */
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for (i = 0; i < CONFIG_NFILE_STREAMS; i++)
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{
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/* Destroy the semaphore that protects the IO buffer */
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(void)sem_destroy(&list->sl_streams[i].fs_sem);
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/* Release the IO buffer */
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if (&list->sl_streams[i].fs_bufstart)
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{
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free(list->sl_streams[i].fs_bufstart);
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}
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}
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}
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}
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}
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#endif /* CONFIG_NFILE_STREAMS */
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