/* * File : posix_aio.c * This file is part of RT-Thread RTOS * COPYRIGHT (C) 2017, RT-Thread Development Team * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * * Change Logs: * Date Author Notes * 2017/12/30 Bernard The first version. */ #include #include #include #include #include #include #include "posix_aio.h" struct rt_workqueue* aio_queue = NULL; /** * The aio_cancel() function shall attempt to cancel one or more asynchronous I/O * requests currently outstanding against file descriptor fildes. The aiocbp * argument points to the asynchronous I/O control block for a particular request * to be canceled. If aiocbp is NULL, then all outstanding cancelable asynchronous * I/O requests against fildes shall be canceled. * * Normal asynchronous notification shall occur for asynchronous I/O operations * that are successfully canceled. If there are requests that cannot be canceled, * then the normal asynchronous completion process shall take place for those * requests when they are completed. * * For requested operations that are successfully canceled, the associated error * status shall be set to [ECANCELED] and the return status shall be -1. For * requested operations that are not successfully canceled, the aiocbp shall not * be modified by aio_cancel(). * * If aiocbp is not NULL, then if fildes does not have the same value as the file * descriptor with which the asynchronous operation was initiated, unspecified results occur. * * Which operations are cancelable is implementation-defined. */ int aio_cancel(int fd, struct aiocb *cb) { rt_err_t ret; if (!cb) return -EINVAL; if (cb->aio_fildes != fd) return -EINVAL; ret = rt_workqueue_cancel_work_sync(aio_queue, &(cb->aio_work)); if (ret == RT_EOK) { errno = -ECANCELED; return -1; } return 0; } /** * The aio_error() function shall return the error status associated with the * aiocb structure referenced by the aiocbp argument. The error status for an * asynchronous I/O operation is the errno value that would be set by the corresponding * read(), write(), */ int aio_error (const struct aiocb *cb) { if (cb) { return cb->aio_result; } return -EINVAL; } /** * The aio_fsync() function shall asynchronously perform a file synchronization * operation, as specified by the op argument, for I/O operations associated with * the file indicated by the file descriptor aio_fildes member of the aiocb * structure referenced by the aiocbp argument and queued at the time of the * call to aio_fsync(). The function call shall return when the synchronization * request has been initiated or queued to the file or device (even when the data * cannot be synchronized immediately). * * option: If op is O_DSYNC, all currently queued I/O operations shall be completed * as if by a call to fdatasync(); that is, as defined for synchronized I/O data * integrity completion. * * option: If op is O_SYNC, all currently queued I/O operations shall be completed * as if by a call to fsync(); that is, as defined for synchronized I/O file integrity * completion. If the aio_fsync() function fails, or if the operation queued by * aio_fsync() fails, then outstanding I/O operations are not guaranteed to have * been completed. * * If aio_fsync() succeeds, then it is only the I/O that was queued at the time * of the call to aio_fsync() that is guaranteed to be forced to the relevant * completion state. The completion of subsequent I/O on the file descriptor is * not guaranteed to be completed in a synchronized fashion. * * The aiocbp argument refers to an asynchronous I/O control block. The aiocbp * value may be used as an argument to aio_error() and aio_return() in order to * determine the error status and return status, respectively, of the asynchronous * operation while it is proceeding. When the request is queued, the error status * for the operation is [EINPROGRESS]. When all data has been successfully transferred, * the error status shall be reset to reflect the success or failure of the operation. * If the operation does not complete successfully, the error status for the * operation shall be set to indicate the error. The aio_sigevent member determines * the asynchronous notification to occur as specified in Signal Generation and * Delivery when all operations have achieved synchronized I/O completion. All * other members of the structure referenced by aiocbp are ignored. If the control * block referenced by aiocbp becomes an illegal address prior to asynchronous * I/O completion, then the behavior is undefined. * * If the aio_fsync() function fails or aiocbp indicates an error condition, * data is not guaranteed to have been successfully transferred. */ static void aio_fync_work(struct rt_work* work, void* work_data) { int result; rt_ubase_t level; struct aiocb *cb = (struct aiocb*)work_data; RT_ASSERT(cb != RT_NULL); result = fsync(cb->aio_fildes); /* modify result */ level = rt_hw_interrupt_disable(); if (result < 0) cb->aio_result = errno; else cb->aio_result = 0; rt_hw_interrupt_enable(level); return ; } int aio_fsync(int op, struct aiocb *cb) { rt_ubase_t level; if (!cb) return -EINVAL; level = rt_hw_interrupt_disable(); cb->aio_result = -EINPROGRESS; rt_hw_interrupt_enable(level); rt_work_init(&(cb->aio_work), aio_fync_work, cb); rt_workqueue_dowork(aio_queue, &(cb->aio_work)); return 0; } static void aio_read_work(struct rt_work* work, void* work_data) { int len; rt_ubase_t level; uint8_t *buf_ptr; struct aiocb *cb = (struct aiocb*)work_data; buf_ptr = (uint8_t*)cb->aio_buf; /* seek to offset */ lseek(cb->aio_fildes, cb->aio_offset, SEEK_SET); len = read(cb->aio_fildes, &buf_ptr[cb->aio_offset], cb->aio_nbytes); /* modify result */ level = rt_hw_interrupt_disable(); if (len <= 0) cb->aio_result = errno; else cb->aio_result = 0; rt_hw_interrupt_enable(level); return ; } /** * The aio_read() function shall read aiocbp->aio_nbytes from the file associated * with aiocbp->aio_fildes into the buffer pointed to by aiocbp->aio_buf. The * function call shall return when the read request has been initiated or queued * to the file or device (even when the data cannot be delivered immediately). * * If prioritized I/O is supported for this file, then the asynchronous operation * shall be submitted at a priority equal to a base scheduling priority minus * aiocbp->aio_reqprio. If Thread Execution Scheduling is not supported, then * the base scheduling priority is that of the calling process; * * otherwise, the base scheduling priority is that of the calling thread. * * The aiocbp value may be used as an argument to aio_error() and aio_return() * in order to determine the error status and return status, respectively, of * the asynchronous operation while it is proceeding. If an error condition is * encountered during queuing, the function call shall return without having * initiated or queued the request. The requested operation takes place at the * absolute position in the file as given by aio_offset, as if lseek() were called * immediately prior to the operation with an offset equal to aio_offset and a * whence equal to SEEK_SET. After a successful call to enqueue an asynchronous * I/O operation, the value of the file offset for the file is unspecified. * * The aio_sigevent member specifies the notification which occurs when the * request is completed. * * The aiocbp->aio_lio_opcode field shall be ignored by aio_read(). * * The aiocbp argument points to an aiocb structure. If the buffer pointed to by * aiocbp->aio_buf or the control block pointed to by aiocbp becomes an illegal * address prior to asynchronous I/O completion, then the behavior is undefined. * * Simultaneous asynchronous operations using the same aiocbp produce undefined * results. * * If synchronized I/O is enabled on the file associated with aiocbp->aio_fildes, * the behavior of this function shall be according to the definitions of synchronized * I/O data integrity completion and synchronized I/O file integrity completion. * * For any system action that changes the process memory space while an asynchronous * I/O is outstanding to the address range being changed, the result of that action * is undefined. * * For regular files, no data transfer shall occur past the offset maximum * established in the open file description associated with aiocbp->aio_fildes. * */ int aio_read(struct aiocb *cb) { rt_ubase_t level; if (!cb) return -EINVAL; if (cb->aio_offset < 0) return -EINVAL; level = rt_hw_interrupt_disable(); cb->aio_result = -EINPROGRESS; rt_hw_interrupt_enable(level); /* en-queue read work */ rt_work_init(&(cb->aio_work), aio_read_work, cb); rt_workqueue_dowork(aio_queue, &(cb->aio_work)); return 0; } /** * The aio_return() function shall return the return status associated with the * aiocb structure referenced by the aiocbp argument. The return status for an * asynchronous I/O operation is the value that would be returned by the corresponding * read(), write(), or fsync() function call. If the error status for the operation * is equal to [EINPROGRESS], then the return status for the operation is undefined. * The aio_return() function may be called exactly once to retrieve the return * status of a given asynchronous operation; thereafter, if the same aiocb structure * is used in a call to aio_return() or aio_error(), an error may be returned. * When the aiocb structure referred to by aiocbp is used to submit another asynchronous * operation, then aio_return() may be successfully used to retrieve the return * status of that operation. */ ssize_t aio_return(struct aiocb *cb) { if (cb) { if (cb->aio_result < 0) rt_set_errno(cb->aio_result); return cb->aio_result; } return -EINVAL; } /** * The aio_suspend() function shall suspend the calling thread until at least * one of the asynchronous I/O operations referenced by the list argument has * completed, until a signal interrupts the function, or, if timeout is not NULL, * until the time interval specified by timeout has passed. If any of the aiocb * structures in the list correspond to completed asynchronous I/O operations * (that is, the error status for the operation is not equal to [EINPROGRESS]) * at the time of the call, the function shall return without suspending the * calling thread. The list argument is an array of pointers to asynchronous I/O * control blocks. The nent argument indicates the number of elements in the * array. Each aiocb structure pointed to has been used in initiating an asynchronous * I/O request via aio_read(), aio_write(), or lio_listio(). This array may * contain null pointers, which are ignored. If this array contains pointers * that refer to aiocb structures that have not been used in submitting asynchronous * I/O, the effect is undefined. * * If the time interval indicated in the timespec structure pointed to by timeout * passes before any of the I/O operations referenced by list are completed, then * aio_suspend() shall return with an error. */ int aio_suspend(const struct aiocb *const list[], int nent, const struct timespec *timeout) { return -ENOSYS; } static void aio_write_work(struct rt_work* work, void* work_data) { int len, oflags, level; uint8_t *buf_ptr; struct aiocb *cb = (struct aiocb*)work_data; buf_ptr = (uint8_t*)cb->aio_buf; /* whether seek offset */ oflags = fcntl(cb->aio_fildes, F_GETFL, 0); if ((oflags & O_APPEND) == 0) { lseek(cb->aio_fildes, SEEK_SET, cb->aio_offset); } /* write data */ len = write(cb->aio_fildes, buf_ptr, cb->aio_nbytes); /* modify result */ level = rt_hw_interrupt_disable(); if (len <= 0) cb->aio_result = errno; else cb->aio_result = len; rt_hw_interrupt_enable(level); return; } /** * The aio_write() function shall write aiocbp->aio_nbytes to the file associated * with aiocbp->aio_fildes from the buffer pointed to by aiocbp->aio_buf. The * function shall return when the write request has been initiated or, at a minimum, * queued to the file or device. * * The aiocbp argument may be used as an argument to aio_error() and aio_return() * in order to determine the error status and return status, respectively, of the * asynchronous operation while it is proceeding. * * The aiocbp argument points to an aiocb structure. If the buffer pointed to by * aiocbp->aio_buf or the control block pointed to by aiocbp becomes an illegal * address prior to asynchronous I/O completion, then the behavior is undefined. * * If O_APPEND is not set for the file descriptor aio_fildes, then the requested * operation shall take place at the absolute position in the file as given by * aio_offset, as if lseek() were called immediately prior to the operation with * an offset equal to aio_offset and a whence equal to SEEK_SET. If O_APPEND is * set for the file descriptor, or if aio_fildes is associated with a device that * is incapable of seeking, write operations append to the file in the same order * as the calls were made, except under circumstances described in Asynchronous * I/O. After a successful call to enqueue an asynchronous I/O operation, the value * of the file offset for the file is unspecified. * * The aio_sigevent member specifies the notification which occurs when the request * is completed. * * The aiocbp->aio_lio_opcode field shall be ignored by aio_write(). * * Simultaneous asynchronous operations using the same aiocbp produce undefined * results. * * If synchronized I/O is enabled on the file associated with aiocbp->aio_fildes, * the behavior of this function shall be according to the definitions of synchronized * I/O data integrity completion, and synchronized I/O file integrity completion. * * For regular files, no data transfer shall occur past the offset maximum established * in the open file description associated with aiocbp->aio_fildes. */ int aio_write(struct aiocb *cb) { int oflags; rt_ubase_t level; if (!cb || (cb->aio_buf == NULL)) return -EINVAL; /* check access mode */ oflags = fcntl(cb->aio_fildes, F_GETFL, 0); if ((oflags & O_ACCMODE) != O_WRONLY || (oflags & O_ACCMODE) != O_RDWR) return -EINVAL; level = rt_hw_interrupt_disable(); cb->aio_result = -EINPROGRESS; rt_hw_interrupt_enable(level); rt_work_init(&(cb->aio_work), aio_write_work, cb); rt_workqueue_dowork(aio_queue, &(cb->aio_work)); return 0; } /** * The lio_listio() function shall initiate a list of I/O requests with a single * function call. * * The mode argument takes one of the values LIO_WAIT or LIO_NOWAIT declared in * and determines whether the function returns when the I/O operations * have been completed, or as soon as the operations have been queued. If the * mode argument is LIO_WAIT, the function shall wait until all I/O is complete * and the sig argument shall be ignored. * * If the mode argument is LIO_NOWAIT, the function shall return immediately, and * asynchronous notification shall occur, according to the sig argument, when all * the I/O operations complete. If sig is NULL, then no asynchronous notification * shall occur. If sig is not NULL, asynchronous notification occurs as specified * in Signal Generation and Delivery when all the requests in list have completed. * * The I/O requests enumerated by list are submitted in an unspecified order. * * The list argument is an array of pointers to aiocb structures. The array contains * nent elements. The array may contain NULL elements, which shall be ignored. * * If the buffer pointed to by list or the aiocb structures pointed to by the * elements of the array list become illegal addresses before all asynchronous I/O * completed and, if necessary, the notification is sent, then the behavior is * undefined. If the buffers pointed to by the aio_buf member of the aiocb structure * pointed to by the elements of the array list become illegal addresses prior to * the asynchronous I/O associated with that aiocb structure being completed, the * behavior is undefined. * * The aio_lio_opcode field of each aiocb structure specifies the operation to be * performed. The supported operations are LIO_READ, LIO_WRITE, and LIO_NOP; these * symbols are defined in . The LIO_NOP operation causes the list entry to * be ignored. If the aio_lio_opcode element is equal to LIO_READ, then an I/O operation * is submitted as if by a call to aio_read() with the aiocbp equal to the address * of the aiocb structure. If the aio_lio_opcode element is equal to LIO_WRITE, then * an I/O operation is submitted as if by a call to aio_write() with the aiocbp equal * to the address of the aiocb structure. * * The aio_fildes member specifies the file descriptor on which the operation is to * be performed. * * The aio_buf member specifies the address of the buffer to or from which the data * is transferred. * * The aio_nbytes member specifies the number of bytes of data to be transferred. * * The members of the aiocb structure further describe the I/O operation to be * performed, in a manner identical to that of the corresponding aiocb structure * when used by the aio_read() and aio_write() functions. * * The nent argument specifies how many elements are members of the list; that is, * the length of the array. * * The behavior of this function is altered according to the definitions of synchronized * I/O data integrity completion and synchronized I/O file integrity completion if * synchronized I/O is enabled on the file associated with aio_fildes. * * For regular files, no data transfer shall occur past the offset maximum established * in the open file description associated with aiocbp->aio_fildes. * * If sig->sigev_notify is SIGEV_THREAD and sig->sigev_notify_attributes is a * non-null pointer and the block pointed to by this pointer becomes an illegal * address prior to all asynchronous I/O being completed, then the behavior is * undefined. */ int lio_listio(int mode, struct aiocb * const list[], int nent, struct sigevent *sig) { return -ENOSYS; } int aio_system_init(void) { aio_queue = rt_workqueue_create("aio", 2048, RT_THREAD_PRIORITY_MAX/2); RT_ASSERT(aio_queue != NULL); return 0; } INIT_COMPONENT_EXPORT(aio_system_init);