| /* Suspend until termination of a requests. |
| Copyright (C) 1997-2018 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, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| |
| /* We use an UGLY hack to prevent gcc from finding us cheating. The |
| implementations of aio_suspend and aio_suspend64 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_suspend64 has no prototype. */ |
| #define aio_suspend64 XXX |
| #include <aio.h> |
| /* And undo the hack. */ |
| #undef aio_suspend64 |
| |
| #include <assert.h> |
| #include <errno.h> |
| #include <stdbool.h> |
| #include <stdlib.h> |
| #include <sys/time.h> |
| |
| #include <libc-lock.h> |
| #include <aio_misc.h> |
| |
| |
| struct clparam |
| { |
| const struct aiocb *const *list; |
| struct waitlist *waitlist; |
| struct requestlist **requestlist; |
| #ifndef DONT_NEED_AIO_MISC_COND |
| pthread_cond_t *cond; |
| #endif |
| int nent; |
| }; |
| |
| |
| static void |
| cleanup (void *arg) |
| { |
| #ifdef DONT_NEED_AIO_MISC_COND |
| /* Acquire the mutex. If pthread_cond_*wait is used this would |
| happen implicitly. */ |
| pthread_mutex_lock (&__aio_requests_mutex); |
| #endif |
| |
| const struct clparam *param = (const struct clparam *) arg; |
| |
| /* Now remove the entry in the waiting list for all requests |
| which didn't terminate. */ |
| int cnt = param->nent; |
| while (cnt-- > 0) |
| if (param->list[cnt] != NULL |
| && param->list[cnt]->__error_code == EINPROGRESS) |
| { |
| struct waitlist **listp; |
| |
| assert (param->requestlist[cnt] != NULL); |
| |
| /* There is the chance that we cannot find our entry anymore. This |
| could happen if the request terminated and restarted again. */ |
| listp = ¶m->requestlist[cnt]->waiting; |
| while (*listp != NULL && *listp != ¶m->waitlist[cnt]) |
| listp = &(*listp)->next; |
| |
| if (*listp != NULL) |
| *listp = (*listp)->next; |
| } |
| |
| #ifndef DONT_NEED_AIO_MISC_COND |
| /* Release the conditional variable. */ |
| (void) pthread_cond_destroy (param->cond); |
| #endif |
| |
| /* Release the mutex. */ |
| pthread_mutex_unlock (&__aio_requests_mutex); |
| } |
| |
| #ifdef DONT_NEED_AIO_MISC_COND |
| static int |
| __attribute__ ((noinline)) |
| do_aio_misc_wait (unsigned int *cntr, const struct timespec *timeout) |
| { |
| int result = 0; |
| |
| AIO_MISC_WAIT (result, *cntr, timeout, 1); |
| |
| return result; |
| } |
| #endif |
| |
| int |
| aio_suspend (const struct aiocb *const list[], int nent, |
| const struct timespec *timeout) |
| { |
| if (__glibc_unlikely (nent < 0)) |
| { |
| __set_errno (EINVAL); |
| return -1; |
| } |
| |
| struct waitlist waitlist[nent]; |
| struct requestlist *requestlist[nent]; |
| #ifndef DONT_NEED_AIO_MISC_COND |
| pthread_cond_t cond = PTHREAD_COND_INITIALIZER; |
| #endif |
| int cnt; |
| bool any = false; |
| int result = 0; |
| unsigned int cntr = 1; |
| |
| /* Request the mutex. */ |
| pthread_mutex_lock (&__aio_requests_mutex); |
| |
| /* There is not yet a finished request. Signal the request that |
| we are working for it. */ |
| for (cnt = 0; cnt < nent; ++cnt) |
| if (list[cnt] != NULL) |
| { |
| if (list[cnt]->__error_code == EINPROGRESS) |
| { |
| requestlist[cnt] = __aio_find_req ((aiocb_union *) list[cnt]); |
| |
| if (requestlist[cnt] != NULL) |
| { |
| #ifndef DONT_NEED_AIO_MISC_COND |
| waitlist[cnt].cond = &cond; |
| #endif |
| waitlist[cnt].result = NULL; |
| waitlist[cnt].next = requestlist[cnt]->waiting; |
| waitlist[cnt].counterp = &cntr; |
| waitlist[cnt].sigevp = NULL; |
| requestlist[cnt]->waiting = &waitlist[cnt]; |
| any = true; |
| } |
| else |
| /* We will never suspend. */ |
| break; |
| } |
| else |
| /* We will never suspend. */ |
| break; |
| } |
| |
| |
| /* Only if none of the entries is NULL or finished to be wait. */ |
| if (cnt == nent && any) |
| { |
| struct clparam clparam = |
| { |
| .list = list, |
| .waitlist = waitlist, |
| .requestlist = requestlist, |
| #ifndef DONT_NEED_AIO_MISC_COND |
| .cond = &cond, |
| #endif |
| .nent = nent |
| }; |
| |
| pthread_cleanup_push (cleanup, &clparam); |
| |
| #ifdef DONT_NEED_AIO_MISC_COND |
| result = do_aio_misc_wait (&cntr, timeout); |
| #else |
| if (timeout == NULL) |
| result = pthread_cond_wait (&cond, &__aio_requests_mutex); |
| else |
| { |
| /* We have to convert the relative timeout value into an |
| absolute time value with pthread_cond_timedwait expects. */ |
| struct timeval now; |
| struct timespec abstime; |
| |
| __gettimeofday (&now, NULL); |
| abstime.tv_nsec = timeout->tv_nsec + now.tv_usec * 1000; |
| abstime.tv_sec = timeout->tv_sec + now.tv_sec; |
| if (abstime.tv_nsec >= 1000000000) |
| { |
| abstime.tv_nsec -= 1000000000; |
| abstime.tv_sec += 1; |
| } |
| |
| result = pthread_cond_timedwait (&cond, &__aio_requests_mutex, |
| &abstime); |
| } |
| #endif |
| |
| pthread_cleanup_pop (0); |
| } |
| |
| /* Now remove the entry in the waiting list for all requests |
| which didn't terminate. */ |
| while (cnt-- > 0) |
| if (list[cnt] != NULL && list[cnt]->__error_code == EINPROGRESS) |
| { |
| struct waitlist **listp; |
| |
| assert (requestlist[cnt] != NULL); |
| |
| /* There is the chance that we cannot find our entry anymore. This |
| could happen if the request terminated and restarted again. */ |
| listp = &requestlist[cnt]->waiting; |
| while (*listp != NULL && *listp != &waitlist[cnt]) |
| listp = &(*listp)->next; |
| |
| if (*listp != NULL) |
| *listp = (*listp)->next; |
| } |
| |
| #ifndef DONT_NEED_AIO_MISC_COND |
| /* Release the conditional variable. */ |
| if (__glibc_unlikely (pthread_cond_destroy (&cond) != 0)) |
| /* This must never happen. */ |
| abort (); |
| #endif |
| |
| if (result != 0) |
| { |
| #ifndef DONT_NEED_AIO_MISC_COND |
| /* An error occurred. Possibly it's ETIMEDOUT. We have to translate |
| the timeout error report of `pthread_cond_timedwait' to the |
| form expected from `aio_suspend'. */ |
| if (result == ETIMEDOUT) |
| __set_errno (EAGAIN); |
| else |
| #endif |
| __set_errno (result); |
| |
| result = -1; |
| } |
| |
| /* Release the mutex. */ |
| pthread_mutex_unlock (&__aio_requests_mutex); |
| |
| return result; |
| } |
| |
| weak_alias (aio_suspend, aio_suspend64) |