diff options
Diffstat (limited to 'rt/aio_cancel.c')
| -rw-r--r-- | rt/aio_cancel.c | 195 |
1 files changed, 86 insertions, 109 deletions
diff --git a/rt/aio_cancel.c b/rt/aio_cancel.c index f2d9389650..e802a8533f 100644 --- a/rt/aio_cancel.c +++ b/rt/aio_cancel.c @@ -30,7 +30,6 @@ #undef aio_cancel64 #include <errno.h> -#include <pthread.h> #include "aio_misc.h" @@ -43,128 +42,106 @@ aio_cancel (fildes, aiocbp) int fildes; struct aiocb *aiocbp; { - struct aiocb *firstp; + struct requestlist *req = NULL; int result = AIO_ALLDONE; - /* Request the semaphore. */ - sem_wait (&__aio_requests_sema); + /* Request the mutex. */ + pthread_mutex_lock (&__aio_requests_mutex); - /* Search for the list of requests associated with the given file - descriptor. */ - for (firstp = (struct aiocb *) __aio_requests; firstp != NULL; - firstp = firstp->__next_fd) - if (firstp->aio_fildes == fildes) - break; - - /* If the file descriptor is not found all work seems to done - already. Otherwise try to cancel the request(s). */ - if (firstp != NULL) + /* We are asked to cancel a specific AIO request. */ + if (aiocbp != NULL) { - if (aiocbp != NULL) + /* If the AIO request is not for this descriptor it has no value + to look for the request block. */ + if (aiocbp->aio_fildes == fildes) { - /* Locate the entry corresponding to the AIOCBP parameter. */ - if (aiocbp == firstp) - /* The requests is currently handled, therefore don't - cancel it and signal this to the user. */ - result = AIO_NOTCANCELED; - else + struct requestlist *last = NULL; + + req = __aio_find_req_fd (fildes); + + while (req->aiocbp != (aiocb_union *) aiocbp) { - while (firstp->__next_prio != NULL - && aiocbp != firstp->__next_prio) - firstp = firstp->__next_prio; - - if (firstp->__next_prio != NULL) - { - /* The request the user wants to cancel is in the - queue. Simply remove it. */ - firstp->__next_prio = aiocbp->__next_prio; - - /* Mark as canceled. */ - aiocbp->__error_code = ECANCELED; - aiocbp->__return_value = -1; - - /* Send the signal to notify about canceled - processing of the request. */ - if (aiocbp->aio_sigevent.sigev_notify == SIGEV_THREAD) - { - /* We have to start a thread. */ - pthread_t tid; - pthread_attr_t attr, *pattr; - - pattr = (pthread_attr_t *) - aiocbp->aio_sigevent.sigev_notify_attributes; - if (pattr == NULL) - { - pthread_attr_init (&attr); - pthread_attr_setdetachstate (&attr, - PTHREAD_CREATE_DETACHED); - pattr = &attr; - } - - pthread_create (&tid, pattr, - (void *(*) (void *)) - aiocbp->aio_sigevent.sigev_notify_function, - aiocbp->aio_sigevent.sigev_value.sival_ptr); - } - else if (aiocbp->aio_sigevent.sigev_notify == SIGEV_SIGNAL) - /* We have to send a signal. */ - __aio_sigqueue (aiocbp->aio_sigevent.sigev_signo, - aiocbp->aio_sigevent.sigev_value); - - result = AIO_CANCELED; - } + last = req; + req = req->next_prio; } - } - else - { - /* First dequeue all waiting requests. */ - aiocbp = firstp; - while ((firstp = firstp->__next_prio) != NULL) + /* Don't remove the entry if a thread is already working on it. */ + if (req->running == allocated) + result = AIO_NOTCANCELED; + else { - firstp->__error_code = ECANCELED; - firstp->__return_value = -1; - - - /* Send the signal to notify about canceled processing - of the request. */ - if (firstp->aio_sigevent.sigev_notify == SIGEV_THREAD) - { - /* We have to start a thread. */ - pthread_t tid; - pthread_attr_t attr, *pattr; - - pattr = (pthread_attr_t *) - aiocbp->aio_sigevent.sigev_notify_attributes; - if (pattr == NULL) - { - pthread_attr_init (&attr); - pthread_attr_setdetachstate (&attr, - PTHREAD_CREATE_DETACHED); - pattr = &attr; - } - - pthread_create (&tid, pattr, - (void *(*) (void *)) - firstp->aio_sigevent.sigev_notify_function, - firstp->aio_sigevent.sigev_value.sival_ptr); - } - else if (firstp->aio_sigevent.sigev_notify == SIGEV_SIGNAL) - /* We have to send a signal. */ - __aio_sigqueue (firstp->aio_sigevent.sigev_signo, - firstp->aio_sigevent.sigev_value); + /* We can remove the entry. */ + if (last != NULL) + last->next_prio = req->next_prio; + else + if (req->next_prio == NULL) + { + if (req->last_fd != NULL) + req->last_fd->next_fd = req->next_fd; + if (req->next_fd != NULL) + req->next_fd->last_fd = req->last_fd; + } + else + { + if (req->last_fd != NULL) + req->last_fd->next_fd = req->next_prio; + if (req->next_fd != NULL) + req->next_fd->last_fd = req->next_prio; + req->next_prio->last_fd = req->last_fd; + req->next_prio->next_fd = req->next_fd; + + /* Mark this entry as runnable. */ + req->next_prio->running = yes; + } + + result = AIO_CANCELED; } - /* We have to signal that not all requests could be canceled - since the first requests is currently processed. */ - result = AIO_NOTCANCELED; - - aiocbp->__next_prio = NULL; + req->next_prio = NULL; } } + else + { + /* Find the beginning of the list of all requests for this + desriptor. */ + req = __aio_find_req_fd (fildes); + + /* If any request is worked on by a thread it must be the first. + So either we can delete all requests or all but the first. */ + if (req != NULL) + if (req->running == allocated) + { + struct requestlist *old = req; + req = req->next_prio; + old->next_prio = NULL; + + result = AIO_NOTCANCELED; + } + else + { + /* Remove entry from the file descriptor list. */ + if (req->last_fd != NULL) + req->last_fd->next_fd = req->next_fd; + if (req->next_fd != NULL) + req->next_fd->last_fd = req->last_fd; + + result = AIO_CANCELED; + } + } + + /* Mark requests as canceled and send signal. */ + while (req != NULL) + { + struct requestlist *old = req; + req->aiocbp->aiocb.__error_code = ECANCELED; + req->aiocbp->aiocb.__return_value = -1; + __aio_notify (req); + req = req->next_prio; + __aio_free_request (old); + } - /* Release the semaphore. */ - sem_post (&__aio_requests_sema); + /* Release the mutex. */ + pthread_mutex_unlock (&__aio_requests_mutex); return result; } |