| /**************************************************************************** |
| * libs/libc/aio/lio_listio.c |
| * |
| * 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. |
| * |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Included Files |
| ****************************************************************************/ |
| |
| #include <nuttx/config.h> |
| |
| #include <unistd.h> |
| #include <signal.h> |
| #include <aio.h> |
| #include <assert.h> |
| #include <debug.h> |
| #include <errno.h> |
| |
| #include <nuttx/signal.h> |
| #include <nuttx/sched.h> |
| |
| #include "libc.h" |
| #include "aio/aio.h" |
| |
| #ifdef CONFIG_FS_AIO |
| |
| /**************************************************************************** |
| * Private Types |
| ****************************************************************************/ |
| |
| struct lio_sighand_s |
| { |
| FAR struct aiocb * const *list; /* List of I/O operations */ |
| FAR struct sigevent sig; /* Describes how to signal the caller */ |
| int nent; /* Number or elements in list[] */ |
| pid_t pid; /* ID of client */ |
| sigset_t oprocmask; /* sigprocmask to restore */ |
| struct sigaction oact; /* Signal handler to restore */ |
| }; |
| |
| /**************************************************************************** |
| * Private Functions |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Name: lio_checkio |
| * |
| * Description: |
| * Check if all I/O operations in the list are complete. |
| * |
| * Input Parameters: |
| * list - The list of I/O operations to be performed |
| * nent - The number of elements in the list |
| * |
| * Returned Value: |
| * Zero (OK) is returned if all I/O completed successfully. |
| * -EINPROGRESS is returned if one or more I/Os have not yet completed. |
| * The negated errno value if first error noted in the case where all I/O |
| * completed but one or more I/Os completed with an error. |
| * |
| * Assumptions: |
| * The scheduler is locked and no I/O can complete asynchronously with |
| * the logic in this function. |
| * |
| ****************************************************************************/ |
| |
| static int lio_checkio(FAR struct aiocb * const *list, int nent) |
| { |
| FAR struct aiocb *aiocbp; |
| int ret; |
| int i; |
| |
| ret = OK; /* Assume success */ |
| |
| /* Check each entry in the list. Break out of the loop if any entry |
| * has not completed. |
| */ |
| |
| for (i = 0; i < nent; i++) |
| { |
| /* Skip over NULL entries */ |
| |
| aiocbp = list[i]; |
| if (aiocbp) |
| { |
| /* Check if the I/O has completed */ |
| |
| if (aiocbp->aio_result == -EINPROGRESS) |
| { |
| /* No.. return -EINPROGRESS */ |
| |
| return -EINPROGRESS; |
| } |
| |
| /* Check for an I/O error */ |
| |
| else if (aiocbp->aio_result < 0 && ret == OK) |
| { |
| /* Some other error other than -EINPROGRESS */ |
| |
| ret = aiocbp->aio_result; |
| } |
| } |
| } |
| |
| /* All of the I/Os have completed */ |
| |
| return ret; |
| } |
| |
| /**************************************************************************** |
| * Name: lio_sighandler |
| * |
| * Description: |
| * Handle the SIGPOLL signal. |
| * |
| * Input Parameters: |
| * signo - The number of the signal that we caught (SIGPOLL) |
| * info - Information accompanying the signal |
| * context - Not used in NuttX |
| * |
| * Returned Value: |
| * None |
| * |
| ****************************************************************************/ |
| |
| static void lio_sighandler(int signo, siginfo_t *info, void *ucontext) |
| { |
| FAR struct aiocb *aiocbp; |
| FAR struct lio_sighand_s *sighand; |
| int ret; |
| |
| DEBUGASSERT(signo == SIGPOLL && info); |
| |
| /* The info structure should contain a pointer to the AIO control block */ |
| |
| aiocbp = (FAR struct aiocb *)info->si_value.sival_ptr; |
| DEBUGASSERT(aiocbp && aiocbp->aio_result != -EINPROGRESS); |
| |
| /* Recover our private data from the AIO control block */ |
| |
| sighand = (FAR struct lio_sighand_s *)aiocbp->aio_priv; |
| DEBUGASSERT(sighand && sighand->list); |
| aiocbp->aio_priv = NULL; |
| |
| /* Prevent any asynchronous I/O completions while the signal handler runs */ |
| |
| sched_lock(); |
| |
| /* Check if all of the pending I/O has completed */ |
| |
| ret = lio_checkio(sighand->list, sighand->nent); |
| if (ret != -EINPROGRESS) |
| { |
| /* All pending I/O has completed */ |
| |
| /* Restore the signal handler */ |
| |
| sigaction(SIGPOLL, &sighand->oact, NULL); |
| |
| /* Restore the sigprocmask */ |
| |
| sigprocmask(SIG_SETMASK, &sighand->oprocmask, NULL); |
| |
| /* Signal the client */ |
| |
| DEBUGVERIFY(nxsig_notification(sighand->pid, &sighand->sig, |
| SI_ASYNCIO, &aiocbp->aio_sigwork)); |
| |
| /* And free the container */ |
| |
| lib_free(sighand); |
| } |
| |
| sched_unlock(); |
| } |
| |
| /**************************************************************************** |
| * Name: lio_sigsetup |
| * |
| * Description: |
| * Setup a signal handler to detect when until all I/O completes. |
| * |
| * Input Parameters: |
| * list - The list of I/O operations to be performed |
| * nent - The number of elements in the list |
| * |
| * Returned Value: |
| * Zero (OK) is returned if all I/O completed successfully; Otherwise, a |
| * negated errno value is returned corresponding to the first error |
| * detected. |
| * |
| * Assumptions: |
| * The scheduler is locked and no I/O can complete asynchronously with |
| * the logic in this function. |
| * |
| ****************************************************************************/ |
| |
| static int lio_sigsetup(FAR struct aiocb * const *list, int nent, |
| FAR struct sigevent *sig) |
| { |
| FAR struct aiocb *aiocbp; |
| struct lio_sighand_s sighand; |
| sigset_t set; |
| struct sigaction act; |
| int status; |
| int i; |
| |
| /* Initialize the allocated structure */ |
| |
| memset(&sighand, 0, sizeof(struct lio_sighand_s)); |
| sighand.list = list; |
| sighand.sig = *sig; |
| sighand.nent = nent; |
| sighand.pid = _SCHED_GETPID(); |
| |
| /* Make sure that SIGPOLL is not blocked */ |
| |
| sigemptyset(&set); |
| sigaddset(&set, SIGPOLL); |
| status = sigprocmask(SIG_UNBLOCK, &set, &sighand.oprocmask); |
| if (status != OK) |
| { |
| int errcode = get_errno(); |
| ferr("ERROR sigprocmask failed: %d\n", errcode); |
| DEBUGASSERT(errcode > 0); |
| return -errcode; |
| } |
| |
| /* Attach our signal handler */ |
| |
| finfo("Registering signal handler\n"); |
| |
| act.sa_sigaction = lio_sighandler; |
| act.sa_flags = SA_SIGINFO; |
| |
| sigfillset(&act.sa_mask); |
| sigdelset(&act.sa_mask, SIGPOLL); |
| |
| status = sigaction(SIGPOLL, &act, &sighand.oact); |
| if (status != OK) |
| { |
| int errcode = get_errno(); |
| |
| ferr("ERROR sigaction failed: %d\n", errcode); |
| |
| DEBUGASSERT(errcode > 0); |
| return -errcode; |
| } |
| |
| /* Save this structure as the private data attached to each aiocb */ |
| |
| for (i = 0; i < nent; i++) |
| { |
| /* Skip over NULL entries in the list */ |
| |
| aiocbp = list[i]; |
| if (aiocbp) |
| { |
| FAR void *priv = NULL; |
| |
| /* Check if I/O is pending for this entry */ |
| |
| if (aiocbp->aio_result == -EINPROGRESS) |
| { |
| priv = lib_zalloc(sizeof(struct lio_sighand_s)); |
| if (!priv) |
| { |
| ferr("ERROR: lib_zalloc failed\n"); |
| return -ENOMEM; |
| } |
| |
| memcpy(priv, (FAR void *)&sighand, |
| sizeof(struct lio_sighand_s)); |
| } |
| |
| aiocbp->aio_priv = priv; |
| } |
| } |
| |
| return OK; |
| } |
| |
| /**************************************************************************** |
| * Name: lio_waitall |
| * |
| * Description: |
| * Wait for all I/O operations in the list to be complete. |
| * |
| * Input Parameters: |
| * list - The list of I/O operations to be performed |
| * nent - The number of elements in the list |
| * |
| * Returned Value: |
| * Zero (OK) is returned if all I/O completed successfully; Otherwise, a |
| * negated errno value is returned corresponding to the first error |
| * detected. |
| * |
| * Assumptions: |
| * The scheduler is locked and no I/O can complete asynchronously with |
| * the logic in this function. |
| * |
| ****************************************************************************/ |
| |
| static int lio_waitall(FAR struct aiocb * const *list, int nent) |
| { |
| sigset_t set; |
| int ret; |
| |
| /* Loop until all I/O completes */ |
| |
| for (; ; ) |
| { |
| /* Check if all I/O has completed */ |
| |
| ret = lio_checkio(list, nent); |
| if (ret != -EINPROGRESS) |
| { |
| /* All I/O has completed.. We are finished. */ |
| |
| return ret; |
| } |
| |
| /* Then wait for SIGPOLL -- indefinitely. |
| * |
| * 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 = sigwaitinfo(&set, NULL); |
| if (ret < 0) |
| { |
| int errcode = get_errno(); |
| |
| /* The most likely reason that we would get here is because some |
| * unrelated signal has been received. |
| */ |
| |
| ferr("ERROR: sigwaitinfo failed: %d\n", errcode); |
| DEBUGASSERT(errcode > 0); |
| return -errcode; |
| } |
| } |
| } |
| |
| /**************************************************************************** |
| * Public Functions |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Name: lio_listio |
| * |
| * Description: |
| * The lio_listio() function initiates 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 <aio.h> 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 will |
| * wait until all I/O is complete and the 'sig' argument will be ignored. |
| * |
| * If the 'mode' argument is LIO_NOWAIT, the function will return |
| * immediately, and asynchronous notification will occur, according to the |
| * 'sig' argument, when all the I/O operations complete. If 'sig' is NULL, |
| * then no asynchronous notification will occur. If 'sig' is not NULL, |
| * asynchronous notification occurs 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 will 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 <aio.h>. 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. |
| * |
| * Input Parameters: |
| * mode - Either LIO_WAIT or LIO_NOWAIT |
| * list - The list of I/O operations to be performed |
| * nent - The number of elements in the list |
| * sig - Used to notify the caller when the I/O is performed |
| * asynchronously. |
| * |
| * Returned Value: |
| * If the mode argument has the value LIO_NOWAIT, the lio_listio() |
| * function will return the value zero if the I/O operations are |
| * successfully queued; otherwise, the function will return the value |
| * -1 and set errno to indicate the error. |
| * |
| * If the mode argument has the value LIO_WAIT, the lio_listio() function |
| * will return the value zero when all the indicated I/O has completed |
| * successfully. Otherwise, lio_listio() will return a value of -1 and |
| * set errno to indicate the error. |
| * |
| * In either case, the return value only indicates the success or failure |
| * of the lio_listio() call itself, not the status of the individual I/O |
| * requests. In some cases one or more of the I/O requests contained in |
| * the list may fail. Failure of an individual request does not prevent |
| * completion of any other individual request. To determine the outcome |
| * of each I/O request, the application must examine the error status |
| * associated with each aiocb control block. The error statuses so |
| * returned are identical to those returned as the result of an aio_read() |
| * or aio_write() function. |
| * |
| * The lio_listio() function will fail if: |
| * |
| * EAGAIN - The resources necessary to queue all the I/O requests were |
| * not available. The application may check the error status for each |
| * aiocb to determine the individual request(s) that failed. |
| * EAGAIN - The number of entries indicated by 'nent' would cause the |
| * system-wide limit {AIO_MAX} to be exceeded. |
| * EINVAL - The mode argument is not a proper value, or the value of |
| * 'nent' was greater than {AIO_LISTIO_MAX}. |
| * EINTR - A signal was delivered while waiting for all I/O requests to |
| * complete during an LIO_WAIT operation. Note that, since each I/O |
| * operation invoked by lio_listio() may possibly provoke a signal when |
| * it completes, this error return may be caused by the completion of |
| * one (or more) of the very I/O operations being awaited. Outstanding |
| * I/O requests are not cancelled, and the application will examine |
| * each list element to determine whether the request was initiated, |
| * cancelled, or completed. |
| * EIO - One or more of the individual I/O operations failed. The |
| * application may check the error status for each aiocb structure to |
| * determine the individual request(s) that failed. |
| * |
| * In addition to the errors returned by the lio_listio() function, if the |
| * lio_listio() function succeeds or fails with errors of EAGAIN, EINTR, or |
| * EIO, then some of the I/O specified by the list may have been initiated. |
| * If the lio_listio() function fails with an error code other than EAGAIN, |
| * EINTR, or EIO, no operations from the list will have been initiated. The |
| * I/O operation indicated by each list element can encounter errors |
| * specific to the individual read or write function being performed. In |
| * this event, the error status for each aiocb control block contains the |
| * associated error code. The error codes that can be set are the same as |
| * would be set by a read() or write() function, with the following |
| * additional error codes possible: |
| * |
| * EAGAIN - The requested I/O operation was not queued due to resource |
| * limitations. |
| * ECANCELED - The requested I/O was cancelled before the I/O completed |
| * due to an explicit aio_cancel() request. |
| * EFBIG - The aiocbp->aio_lio_opcode is LIO_WRITE, the file is a |
| * regular file, aiocbp->aio_nbytes is greater than 0, and the |
| * aiocbp->aio_offset is greater than or equal to the offset maximum |
| * in the open file description associated with aiocbp->aio_fildes. |
| * EINPROGRESS - The requested I/O is in progress. |
| * EOVERFLOW - The aiocbp->aio_lio_opcode is LIO_READ, the file is a |
| * regular file, aiocbp->aio_nbytes is greater than 0, and the |
| * aiocbp->aio_offset is before the end-of-file and is greater than |
| * or equal to the offset maximum in the open file description |
| * associated with aiocbp->aio_fildes. |
| * |
| ****************************************************************************/ |
| |
| int lio_listio(int mode, FAR struct aiocb * const list[], int nent, |
| FAR struct sigevent *sig) |
| { |
| FAR struct aiocb *aiocbp = NULL; |
| int nqueued; |
| int errcode; |
| int retcode; |
| int status; |
| int ret; |
| int i; |
| |
| if (mode != LIO_WAIT && mode != LIO_NOWAIT) |
| { |
| set_errno(EINVAL); |
| return ERROR; |
| } |
| |
| DEBUGASSERT(list); |
| |
| nqueued = 0; /* No I/O operations yet queued */ |
| ret = OK; /* Assume success */ |
| |
| /* 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(); |
| |
| /* Submit each asynchronous I/O operation in the list, skipping over NULL |
| * entries. |
| */ |
| |
| for (i = 0; i < nent; i++) |
| { |
| /* Skip over NULL entries */ |
| |
| aiocbp = list[i]; |
| if (aiocbp) |
| { |
| /* Submit the operation according to its opcode */ |
| |
| status = OK; |
| switch (aiocbp->aio_lio_opcode) |
| { |
| case LIO_NOP: |
| { |
| /* Mark the do-nothing operation complete */ |
| |
| aiocbp->aio_result = OK; |
| } |
| break; |
| |
| case LIO_READ: |
| case LIO_WRITE: |
| { |
| if (aiocbp->aio_lio_opcode == LIO_READ) |
| { |
| /* Submit the asynchronous read operation */ |
| |
| status = aio_read(aiocbp); |
| } |
| else |
| { |
| /* Submit the asynchronous write operation */ |
| |
| status = aio_write(aiocbp); |
| } |
| |
| if (status < 0) |
| { |
| /* Failed to queue the I/O. Set up the error return. */ |
| |
| errcode = get_errno(); |
| ferr("ERROR: aio_read/write failed: %d\n", errcode); |
| DEBUGASSERT(errcode > 0); |
| aiocbp->aio_result = -errcode; |
| ret = ERROR; |
| } |
| else |
| { |
| /* Increment the count of successfully queue operations */ |
| |
| nqueued++; |
| } |
| } |
| break; |
| |
| default: |
| { |
| /* Make the invalid operation complete with an error */ |
| |
| ferr("ERROR: Unrecognized opcode: %d\n", |
| aiocbp->aio_lio_opcode); |
| aiocbp->aio_result = -EINVAL; |
| ret = ERROR; |
| } |
| break; |
| } |
| } |
| } |
| |
| /* If there was any failure in queuing the I/O, EIO will be returned */ |
| |
| retcode = EIO; |
| |
| /* Now what? Three possibilities: |
| * |
| * Case 1: mode == LIO_WAIT |
| * |
| * Ignore the sig argument; Do no return until all I/O completes. |
| */ |
| |
| if (mode == LIO_WAIT) |
| { |
| /* Don't wait if all if no I/O was queue */ |
| |
| if (nqueued > 0) |
| { |
| /* Wait until all I/O completes. The scheduler will be unlocked |
| * while we are waiting. |
| */ |
| |
| status = lio_waitall(list, nent); |
| if (status < 0 && ret == OK) |
| { |
| /* Something bad happened while waiting and this is the first |
| * error to be reported. |
| */ |
| |
| retcode = -status; |
| ret = ERROR; |
| } |
| } |
| } |
| |
| /* Case 2: mode == LIO_NOWAIT and sig != NULL |
| * |
| * If any I/O was queued, then setup to signal the caller when all of |
| * the transfers complete. |
| * |
| * If no I/O was queue, then we I suppose that we need to signal the |
| * caller ourself? |
| */ |
| |
| else if (sig != NULL) |
| { |
| if (nqueued > 0) |
| { |
| /* Setup a signal handler to detect when until all I/O completes. */ |
| |
| status = lio_sigsetup(list, nent, sig); |
| if (status < 0 && ret == OK) |
| { |
| /* Something bad happened while setting up the signal and this |
| * is the first error to be reported. |
| */ |
| |
| retcode = -status; |
| ret = ERROR; |
| } |
| } |
| else |
| { |
| status = nxsig_notification(_SCHED_GETPID(), sig, |
| SI_ASYNCIO, &aiocbp->aio_sigwork); |
| if (status < 0 && ret == OK) |
| { |
| /* Something bad happened while performing the notification |
| * and this is the first error to be reported. |
| */ |
| |
| retcode = -status; |
| ret = ERROR; |
| } |
| } |
| } |
| |
| /* Case 3: mode == LIO_NOWAIT and sig == NULL |
| * |
| * Just return now. |
| */ |
| |
| sched_unlock(); |
| if (ret < 0) |
| { |
| set_errno(retcode); |
| return ERROR; |
| } |
| |
| return OK; |
| } |
| |
| #endif /* CONFIG_FS_AIO */ |
