/**************************************************************************** * fs/aio/aio.h * * Copyright (C) 2014 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include /**************************************************************************** * 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 aio_container_s { dq_entry_t aioc_link; /* Supports a doubly linked list */ FAR struct aiocb *aioc_aiocbp; /* The contained AIO control block */ struct work_s aioc_work; /* Used to defer I/O to the work thread */ pid_t aioc_pid; /* ID of the waiting task */ uint8_t aioc_prio; /* Priority of the waiting task */ }; /**************************************************************************** * 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 * * 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_lock(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. * ****************************************************************************/ 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_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 */