/****************************************************************************
* fs/aio/aio.h
*
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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 NuttX 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.
*
****************************************************************************/
#ifndef __FS_AIO_AIO_H
#define __FS_AIO_AIO_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <string.h>
#include <aio.h>
#include <queue.h>
#include <nuttx/wqueue.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
/* Number of pre-allocated AIO Control block containers */
#ifndef CONFIG_FS_NAIOC
# define CONFIG_FS_NAIOC 8
#endif
/****************************************************************************
* Public Types
****************************************************************************/
/* This structure contains one AIO control block and appends information
* needed by the logic running on the worker thread. These structures are
* pre-allocated, the number pre-allocated controlled by CONFIG_FS_NAIOC.
*/
struct file;
struct aio_container_s
{
dq_entry_t aioc_link; /* Supports a doubly linked list */
FAR struct aiocb *aioc_aiocbp; /* The contained AIO control block */
FAR struct file *aioc_filep; /* File structure to use with the I/O */
struct work_s aioc_work; /* Used to defer I/O to the work thread */
pid_t aioc_pid; /* ID of the waiting task */
#ifdef CONFIG_PRIORITY_INHERITANCE
uint8_t aioc_prio; /* Priority of the waiting task */
#endif
};
/****************************************************************************
* Public Data
****************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/* This is a list of pending asynchronous I/O. The user must hold the
* lock on this list in order to access the list.
*/
EXTERN dq_queue_t g_aio_pending;
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: aio_initialize
*
* Description:
* Perform one-time initialization of the asynchronous I/O sub-system
*
* Input Parameters:
* None
*
* Returned Value:
* None
*
****************************************************************************/
void aio_initialize(void);
/****************************************************************************
* Name: aio_lock/aio_unlock
*
* Description:
* Take/give the lock on the pending asynchronous I/O list. These locks
* are implemented with re-entrant semaphores -- deadlocks will not occur
* if the lock is taken multiple times on the same thread.
*
* Input Parameters:
* None
*
* Returned Value:
* None
*
****************************************************************************/
void aio_lock(void);
void aio_unlock(void);
/****************************************************************************
* Name: aioc_alloc
*
* Description:
* Allocate a new AIO container by taking the next, pre-allocated
* container from the free list. This function will wait until
* aioc_free() is called in the event that there is no free container
* available in the free list.
*
* Input Parameters:
* None
*
* Returned Value:
* A reference to the allocated AIO container. This allocation never
* fails because the logic will wait in the event that there is no free
* container.
*
****************************************************************************/
FAR struct aio_container_s *aioc_alloc(void);
/****************************************************************************
* Name: aioc_free
*
* Description:
* Free an AIO container by returning it to the free list and, perhaps,
* awakening any threads waiting for that resource
*
* Input Parameters:
* aioc - The AIO container to be free
*
* Returned Value:
* None
*
****************************************************************************/
void aioc_free(FAR struct aio_container_s *aioc);
/****************************************************************************
* Name: aio_contain
*
* Description:
* Create and initialize a container for the provided AIO control block
*
* Input Parameters:
* aiocbp - The AIO control block pointer
*
* Returned Value:
* A reference to the new AIO control block container. This function
* will not fail but will wait if necessary for the resources to perform
* this operation. NULL will be returned on certain errors with the
* errno value already set appropriately.
*
****************************************************************************/
FAR struct aio_container_s *aio_contain(FAR struct aiocb *aiocbp);
/****************************************************************************
* Name: aioc_decant
*
* Description:
* Remove the AIO control block from the container and free all resources
* used by the container.
*
* Input Parameters:
* aioc - Pointer to the AIO control block container
*
* Returned Value:
* A pointer to the no-longer contained AIO control block.
*
****************************************************************************/
FAR struct aiocb *aioc_decant(FAR struct aio_container_s *aioc);
/****************************************************************************
* Name: aio_queue
*
* Description:
* Schedule the asynchronous I/O on the low priority work queue
*
* Input Parameters:
* arg - Worker argument. In this case, a pointer to an instance of
* struct aiocb cast to void *.
*
* Returned Value:
* Zero (OK) on success. Otherwise, -1 is returned and the errno is set
* appropriately.
*
****************************************************************************/
int aio_queue(FAR struct aio_container_s *aioc, worker_t worker);
/****************************************************************************
* Name: aio_signal
*
* Description:
* Signal the client that an I/O has completed.
*
* Input Parameters:
* pid - ID of the task to signal
* aiocbp - Pointer to the asynchronous I/O state structure that includes
* information about how to signal the client
*
* Returned Value:
* Zero (OK) if the client was successfully signalled. Otherwise, a
* negated errno value is returned.
*
****************************************************************************/
int aio_signal(pid_t pid, FAR struct aiocb *aiocbp);
#endif /* __FS_AIO_AIO_H */
