nuttx/mm/iob/iob.h
Xiang Xiao 9e4a1be8d4 mm/iob: Replace the critical section with spin lock
Base on discusion: https://github.com/apache/nuttx/issues/10981

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
2023-10-30 11:18:34 +02:00

151 lines
5.1 KiB
C

/****************************************************************************
* mm/iob/iob.h
*
* 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.
*
****************************************************************************/
#ifndef __MM_IOB_IOB_H
#define __MM_IOB_IOB_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <debug.h>
#include <nuttx/mm/iob.h>
#include <nuttx/spinlock.h>
#include <nuttx/semaphore.h>
#ifdef CONFIG_MM_IOB
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#if defined(CONFIG_DEBUG_FEATURES) && defined(CONFIG_IOB_DEBUG)
# define ioberr _err
# define iobwarn _warn
# define iobinfo _info
#else
# define ioberr _none
# define iobwarn _none
# define iobinfo _none
#endif /* CONFIG_DEBUG_FEATURES && CONFIG_IOB_DEBUG */
/****************************************************************************
* Public Data
****************************************************************************/
/* A list of all free, unallocated I/O buffers */
extern FAR struct iob_s *g_iob_freelist;
/* A list of I/O buffers that are committed for allocation */
extern FAR struct iob_s *g_iob_committed;
#if CONFIG_IOB_NCHAINS > 0
/* A list of all free, unallocated I/O buffer queue containers */
extern FAR struct iob_qentry_s *g_iob_freeqlist;
/* A list of I/O buffer queue containers that are committed for allocation */
extern FAR struct iob_qentry_s *g_iob_qcommitted;
#endif
/* Counting semaphores that tracks the number of free IOBs/qentries */
extern sem_t g_iob_sem; /* Counts free I/O buffers */
#if CONFIG_IOB_THROTTLE > 0
extern sem_t g_throttle_sem; /* Counts available I/O buffers when throttled */
#endif
#if CONFIG_IOB_NCHAINS > 0
extern sem_t g_qentry_sem; /* Counts free I/O buffer queue containers */
#endif
extern spinlock_t g_iob_lock;
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: iob_alloc_qentry
*
* Description:
* Allocate an I/O buffer chain container by taking the buffer at the head
* of the free list. This function is intended only for internal use by
* the IOB module.
*
****************************************************************************/
FAR struct iob_qentry_s *iob_alloc_qentry(void);
/****************************************************************************
* Name: iob_tryalloc_qentry
*
* Description:
* Try to allocate an I/O buffer chain container by taking the buffer at
* the head of the free list without waiting for the container to become
* free. This function is intended only for internal use by the IOB module.
*
****************************************************************************/
FAR struct iob_qentry_s *iob_tryalloc_qentry(void);
/****************************************************************************
* Name: iob_free_qentry
*
* Description:
* Free the I/O buffer chain container by returning it to the free list.
* The link to the next I/O buffer in the chain is return.
*
****************************************************************************/
FAR struct iob_qentry_s *iob_free_qentry(FAR struct iob_qentry_s *iobq);
/****************************************************************************
* Name: iob_notifier_signal
*
* Description:
* An IOB has become available. Signal all threads waiting for an IOB
* that an IOB is available.
*
* When an IOB becomes available, *all* of the waiters in this thread will
* be signaled. If there are multiple waiters then only the highest
* priority thread will get the IOB. Lower priority threads will need to
* call iob_notifier_setup() once again.
*
* Input Parameters:
* None.
*
* Returned Value:
* None.
*
****************************************************************************/
#ifdef CONFIG_IOB_NOTIFIER
void iob_notifier_signal(void);
#endif
#endif /* CONFIG_MM_IOB */
#endif /* __MM_IOB_IOB_H */