nuttx/libs/libc/misc/lib_stream.c

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/****************************************************************************
* libs/libc/misc/lib_stream.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/kmalloc.h>
#include <nuttx/semaphore.h>
#include <nuttx/sched.h>
#include <nuttx/fs/fs.h>
#include <nuttx/lib/lib.h>
#include "libc.h"
#if defined(CONFIG_BUILD_FLAT) || defined(__KERNEL__)
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: lib_stream_initialize
*
* Description:
* This function is called when a new task is allocated. It initializes
* the streamlist instance that is stored in the task group.
*
****************************************************************************/
#ifdef CONFIG_FILE_STREAM
void lib_stream_initialize(FAR struct task_group_s *group)
{
FAR struct streamlist *list;
#ifdef CONFIG_MM_KERNEL_HEAP
DEBUGASSERT(group && group->tg_streamlist);
list = group->tg_streamlist;
#else
DEBUGASSERT(group);
list = &group->tg_streamlist;
#endif
/* Initialize the list access mutex */
_SEM_INIT(&list->sl_sem, 0, 1);
list->sl_head = NULL;
list->sl_tail = NULL;
/* Initialize stdin, stdout and stderr stream */
list->sl_std[0].fs_fd = -1;
lib_sem_initialize(&list->sl_std[0]);
list->sl_std[1].fs_fd = -1;
lib_sem_initialize(&list->sl_std[1]);
list->sl_std[2].fs_fd = -1;
lib_sem_initialize(&list->sl_std[2]);
}
#endif /* CONFIG_FILE_STREAM */
/****************************************************************************
* Name: lib_stream_release
*
* Description:
* This function is called when a TCB is destroyed. Note that it does not
* close the files by releasing the inode. That happens separately when
* the file descriptor list is freed.
*
****************************************************************************/
#ifdef CONFIG_FILE_STREAM
void lib_stream_release(FAR struct task_group_s *group)
{
FAR struct streamlist *list;
#ifdef CONFIG_MM_KERNEL_HEAP
DEBUGASSERT(group && group->tg_streamlist);
list = group->tg_streamlist;
#else
DEBUGASSERT(group);
list = &group->tg_streamlist;
#endif
/* Destroy the semaphore and release the filelist */
_SEM_DESTROY(&list->sl_sem);
/* Release each stream in the list */
list->sl_tail = NULL;
while (list->sl_head != NULL)
{
FAR struct file_struct *stream = list->sl_head;
list->sl_head = stream->fs_next;
#ifndef CONFIG_STDIO_DISABLE_BUFFERING
/* Destroy the semaphore that protects the IO buffer */
_SEM_DESTROY(&stream->fs_sem);
#endif
/* Release the stream */
#ifdef CONFIG_BUILD_KERNEL
/* If the exiting group is unprivileged, then it has an address
* environment. Don't bother to release the memory in this case...
* There is no point since the memory lies in the user heap which
* will be destroyed anyway. But if this is a privileged group,
* when we still have to release the memory using the kernel
* allocator.
*/
if ((group->tg_flags & GROUP_FLAG_PRIVILEGED) != 0)
#endif
{
group_free(group, stream);
}
}
/* Destroy stdin, stdout and stderr stream */
#ifndef CONFIG_STDIO_DISABLE_BUFFERING
_SEM_DESTROY(&list->sl_std[0].fs_sem);
_SEM_DESTROY(&list->sl_std[1].fs_sem);
_SEM_DESTROY(&list->sl_std[2].fs_sem);
#endif
}
#endif /* CONFIG_FILE_STREAM */
#endif /* CONFIG_BUILD_FLAT || __KERNEL__ */