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- /****************************************************************************
- * libs/libc/aio/aio_suspend.c
- *
- * 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.
- *
- ****************************************************************************/
- /****************************************************************************
- * Included Files
- ****************************************************************************/
- #include <nuttx/config.h>
- #include <sched.h>
- #include <signal.h>
- #include <aio.h>
- #include <assert.h>
- #include <errno.h>
- #ifdef CONFIG_FS_AIO
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: aio_suspend
- *
- * Description:
- * The aio_suspend() function suspends 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 returns without suspending the calling thread.
- *
- * Each aiocb structure pointed to must have 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.
- *
- * Input Parameters:
- * list - An array of pointers to asynchronous I/O control blocks.
- * nent - The number of elements in the array.
- * aiocbp - A pointer to an array
- * timeout - If not NULL, this parameter is pointer to a timespec
- * structure that determines a timeout on the operation. If
- * the time referred to timeout passes before any of the I/O
- * operations referenced by list are completed, then
- * aio_suspend() returns with an error.
- *
- * Returned Value:
- * If the aio_suspend() function returns after one or more asynchronous
- * I/O operations have completed, the function returns zero. Otherwise,
- * the function returns a value of -1 and sets errno to indicate the
- * error. The application may determine which asynchronous I/O completed
- * by scanning the associated error and return status using aio_error()
- * and aio_return(), respectively.
- *
- * The aio_suspend() function will fail if:
- *
- * EAGAIN - No asynchronous I/O indicated in the list referenced by
- * list completed in the time interval indicated by timeout.
- * EINTR - A signal interrupted the aio_suspend() function.
- *
- ****************************************************************************/
- int aio_suspend(FAR const struct aiocb * const list[], int nent,
- FAR const struct timespec *timeout)
- {
- sigset_t set;
- int ret;
- int i;
- DEBUGASSERT(list);
- /* Lock the scheduler so that no I/O events can complete on the worker
- * thread until we set our wait set up. Pre-emption will, of course, be
- * re-enabled while we are waiting for the signal.
- */
- sched_lock();
- /* Check each entry in the list. Break out of the loop if any entry
- * has completed.
- */
- for (i = 0; i < nent; i++)
- {
- /* Check if the I/O has completed */
- if (list[i] && list[i]->aio_result != -EINPROGRESS)
- {
- /* Yes, return success */
- sched_unlock();
- return OK;
- }
- }
- /* Then wait for SIGPOLL. On success sigtimedwait() will return the
- * signal number that cause the error (SIGPOLL). It will set errno
- * appropriately for this function on errors.
- *
- * NOTE: If completion of the I/O causes other signals to be generated
- * first, then this will wake up and return EINTR instead of success.
- */
- sigemptyset(&set);
- sigaddset(&set, SIGPOLL);
- ret = sigtimedwait(&set, NULL, timeout);
- sched_unlock();
- return ret >= 0 ? OK : ERROR;
- }
- #endif /* CONFIG_FS_AIO */
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