diff options
Diffstat (limited to 'rtkaio/sysdeps/unix/sysv/linux/kaio_cancel.c')
| -rw-r--r-- | rtkaio/sysdeps/unix/sysv/linux/kaio_cancel.c | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/rtkaio/sysdeps/unix/sysv/linux/kaio_cancel.c b/rtkaio/sysdeps/unix/sysv/linux/kaio_cancel.c new file mode 100644 index 0000000000..7d2738d5bc --- /dev/null +++ b/rtkaio/sysdeps/unix/sysv/linux/kaio_cancel.c @@ -0,0 +1,238 @@ +/* Cancel requests associated with given file descriptor. + Copyright (C) 1997, 1998, 2000, 2002, 2003, 2005 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +/* We use an UGLY hack to prevent gcc from finding us cheating. The + implementation of aio_cancel and aio_cancel64 are identical and so + we want to avoid code duplication by using aliases. But gcc sees + the different parameter lists and prints a warning. We define here + a function so that aio_cancel64 has no prototype. */ +#ifndef aio_cancel +#define aio_cancel64 XXX +#include <aio.h> +/* And undo the hack. */ +#undef aio_cancel64 +#endif + +#include <kaio_misc.h> + +#ifndef USE_KAIO +#include <aio_cancel.c> +#else + +#include <assert.h> +#include <errno.h> + +int +aio_cancel (fildes, aiocbp) + int fildes; + struct aiocb *aiocbp; +{ + struct requestlist *req = NULL; + int result = AIO_ALLDONE; + + /* If fildes is invalid, error. */ + if (fcntl (fildes, F_GETFL) < 0) + { + __set_errno (EBADF); + return -1; + } + + /* Request the mutex. */ + pthread_mutex_lock (&__aio_requests_mutex); + + /* We are asked to cancel a specific AIO request. */ + 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) + { + pthread_mutex_unlock (&__aio_requests_mutex); + __set_errno (EINVAL); + return -1; + } + else if (aiocbp->__error_code == EINPROGRESS) + { + struct requestlist *last = NULL; + + req = __aio_find_req_fd (fildes); + + if (req != NULL) + while (req->aiocbp != (aiocb_union *) aiocbp) + { + last = req; + req = req->next_prio; + if (req == NULL) + break; + } + + if (req != NULL) + { + /* Don't remove the entry if a thread is already working on + it. */ + if (req->running == allocated) + { + result = AIO_NOTCANCELED; + req = NULL; + } + else + { + /* We can remove the entry. */ + __aio_remove_request (last, req, 0); + + result = AIO_CANCELED; + + req->next_prio = NULL; + } + } + else + { + /* Try kernel requests. */ + req = __aio_find_req ((aiocb_union *) aiocbp); + + if (req == NULL) + { + pthread_mutex_unlock (&__aio_requests_mutex); + __set_errno (EINVAL); + return -1; + } + + assert (req->kioctx != KCTX_NONE); + + /* If kernel is working on it, try cancelling it. */ + if (req->running == allocated) + { + struct kio_event ev; + INTERNAL_SYSCALL_DECL (err); + int res; + + res = INTERNAL_SYSCALL (io_cancel, err, 3, __aio_kioctx, + &req->kiocb, &ev); + if (INTERNAL_SYSCALL_ERROR_P (res, err)) + { + result = AIO_NOTCANCELED; + req = NULL; + } + else + req->running = queued; + } + if (req != NULL) + { + /* We can remove the entry. */ + __aio_remove_krequest (req); + result = AIO_CANCELED; + 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; + + if (req != NULL) + __aio_remove_request (old, req, 1); + } + else + { + result = AIO_CANCELED; + + /* We can remove the entry. */ + __aio_remove_request (NULL, req, 1); + } + } + + if (result != AIO_NOTCANCELED) + { + /* Try to cancel kernel requests. */ + struct requestlist *kreq = __aio_find_kreq_fd (fildes); + + while (kreq) + { + struct requestlist *next; + + /* If kernel is working on it, try cancelling it. */ + if (kreq->running == allocated) + { + struct kio_event ev; + INTERNAL_SYSCALL_DECL (err); + int res; + + res = INTERNAL_SYSCALL (io_cancel, err, 3, __aio_kioctx, + &kreq->kiocb, &ev); + if (INTERNAL_SYSCALL_ERROR_P (res, err)) + { + result = AIO_NOTCANCELED; + break; + } + else + kreq->running = queued; + } + next = kreq->next_prio; + __aio_remove_krequest (kreq); + result = AIO_CANCELED; + kreq->next_prio = NULL; + assert (kreq->running == yes || kreq->running == queued); + kreq->aiocbp->aiocb.__error_code = ECANCELED; + kreq->aiocbp->aiocb.__return_value = -1; + __aio_notify (kreq); + __aio_free_request (kreq); + kreq = next; + } + } + } + + /* Mark requests as canceled and send signal. */ + while (req != NULL) + { + struct requestlist *old = req; + assert (req->running == yes || req->running == queued); + 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 mutex. */ + pthread_mutex_unlock (&__aio_requests_mutex); + + return result; +} + +#ifndef aio_cancel +weak_alias (aio_cancel, aio_cancel64) +#endif + +#endif |