| /* Enqueue and list of read or write 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/>. */ |
| |
| #ifndef lio_listio |
| #include <aio.h> |
| #include <assert.h> |
| #include <errno.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| |
| #include <aio_misc.h> |
| |
| #define LIO_OPCODE_BASE 0 |
| #endif |
| |
| #include <shlib-compat.h> |
| |
| |
| /* We need this special structure to handle asynchronous I/O. */ |
| struct async_waitlist |
| { |
| unsigned int counter; |
| struct sigevent sigev; |
| struct waitlist list[0]; |
| }; |
| |
| |
| /* The code in glibc 2.1 to glibc 2.4 issued only one event when all |
| requests submitted with lio_listio finished. The existing practice |
| is to issue events for the individual requests as well. This is |
| what the new code does. */ |
| #if SHLIB_COMPAT (librt, GLIBC_2_1, GLIBC_2_4) |
| # define LIO_MODE(mode) ((mode) & 127) |
| # define NO_INDIVIDUAL_EVENT_P(mode) ((mode) & 128) |
| #else |
| # define LIO_MODE(mode) mode |
| # define NO_INDIVIDUAL_EVENT_P(mode) 0 |
| #endif |
| |
| |
| static int |
| lio_listio_internal (int mode, struct aiocb *const list[], int nent, |
| struct sigevent *sig) |
| { |
| struct sigevent defsigev; |
| struct requestlist *requests[nent]; |
| int cnt; |
| volatile unsigned int total = 0; |
| int result = 0; |
| |
| if (sig == NULL) |
| { |
| defsigev.sigev_notify = SIGEV_NONE; |
| sig = &defsigev; |
| } |
| |
| /* Request the mutex. */ |
| pthread_mutex_lock (&__aio_requests_mutex); |
| |
| /* Now we can enqueue all requests. Since we already acquired the |
| mutex the enqueue function need not do this. */ |
| for (cnt = 0; cnt < nent; ++cnt) |
| if (list[cnt] != NULL && list[cnt]->aio_lio_opcode != LIO_NOP) |
| { |
| if (NO_INDIVIDUAL_EVENT_P (mode)) |
| list[cnt]->aio_sigevent.sigev_notify = SIGEV_NONE; |
| |
| requests[cnt] = __aio_enqueue_request ((aiocb_union *) list[cnt], |
| (list[cnt]->aio_lio_opcode |
| | LIO_OPCODE_BASE)); |
| |
| if (requests[cnt] != NULL) |
| /* Successfully enqueued. */ |
| ++total; |
| else |
| /* Signal that we've seen an error. `errno' and the error code |
| of the aiocb will tell more. */ |
| result = -1; |
| } |
| else |
| requests[cnt] = NULL; |
| |
| if (total == 0) |
| { |
| /* We don't have anything to do except signalling if we work |
| asynchronously. */ |
| |
| /* Release the mutex. We do this before raising a signal since the |
| signal handler might do a `siglongjmp' and then the mutex is |
| locked forever. */ |
| pthread_mutex_unlock (&__aio_requests_mutex); |
| |
| if (LIO_MODE (mode) == LIO_NOWAIT) |
| __aio_notify_only (sig); |
| |
| return result; |
| } |
| else if (LIO_MODE (mode) == LIO_WAIT) |
| { |
| #ifndef DONT_NEED_AIO_MISC_COND |
| pthread_cond_t cond = PTHREAD_COND_INITIALIZER; |
| int oldstate; |
| #endif |
| struct waitlist waitlist[nent]; |
| |
| total = 0; |
| for (cnt = 0; cnt < nent; ++cnt) |
| { |
| assert (requests[cnt] == NULL || list[cnt] != NULL); |
| |
| if (requests[cnt] != NULL && list[cnt]->aio_lio_opcode != LIO_NOP) |
| { |
| #ifndef DONT_NEED_AIO_MISC_COND |
| waitlist[cnt].cond = &cond; |
| #endif |
| waitlist[cnt].result = &result; |
| waitlist[cnt].next = requests[cnt]->waiting; |
| waitlist[cnt].counterp = &total; |
| waitlist[cnt].sigevp = NULL; |
| requests[cnt]->waiting = &waitlist[cnt]; |
| ++total; |
| } |
| } |
| |
| #ifdef DONT_NEED_AIO_MISC_COND |
| AIO_MISC_WAIT (result, total, NULL, 0); |
| #else |
| /* Since `pthread_cond_wait'/`pthread_cond_timedwait' are cancellation |
| points we must be careful. We added entries to the waiting lists |
| which we must remove. So defer cancellation for now. */ |
| pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &oldstate); |
| |
| while (total > 0) |
| pthread_cond_wait (&cond, &__aio_requests_mutex); |
| |
| /* Now it's time to restore the cancellation state. */ |
| pthread_setcancelstate (oldstate, NULL); |
| |
| /* Release the conditional variable. */ |
| if (pthread_cond_destroy (&cond) != 0) |
| /* This must never happen. */ |
| abort (); |
| #endif |
| |
| /* If any of the I/O requests failed, return -1 and set errno. */ |
| if (result != 0) |
| { |
| __set_errno (result == EINTR ? EINTR : EIO); |
| result = -1; |
| } |
| } |
| else |
| { |
| struct async_waitlist *waitlist; |
| |
| waitlist = (struct async_waitlist *) |
| malloc (sizeof (struct async_waitlist) |
| + (nent * sizeof (struct waitlist))); |
| |
| if (waitlist == NULL) |
| { |
| __set_errno (EAGAIN); |
| result = -1; |
| } |
| else |
| { |
| total = 0; |
| |
| for (cnt = 0; cnt < nent; ++cnt) |
| { |
| assert (requests[cnt] == NULL || list[cnt] != NULL); |
| |
| if (requests[cnt] != NULL |
| && list[cnt]->aio_lio_opcode != LIO_NOP) |
| { |
| #ifndef DONT_NEED_AIO_MISC_COND |
| waitlist->list[cnt].cond = NULL; |
| #endif |
| waitlist->list[cnt].result = NULL; |
| waitlist->list[cnt].next = requests[cnt]->waiting; |
| waitlist->list[cnt].counterp = &waitlist->counter; |
| waitlist->list[cnt].sigevp = &waitlist->sigev; |
| requests[cnt]->waiting = &waitlist->list[cnt]; |
| ++total; |
| } |
| } |
| |
| waitlist->counter = total; |
| waitlist->sigev = *sig; |
| } |
| } |
| |
| /* Release the mutex. */ |
| pthread_mutex_unlock (&__aio_requests_mutex); |
| |
| return result; |
| } |
| |
| |
| #if SHLIB_COMPAT (librt, GLIBC_2_1, GLIBC_2_4) |
| int |
| attribute_compat_text_section |
| __lio_listio_21 (int mode, struct aiocb *const list[], int nent, |
| struct sigevent *sig) |
| { |
| /* Check arguments. */ |
| if (mode != LIO_WAIT && mode != LIO_NOWAIT) |
| { |
| __set_errno (EINVAL); |
| return -1; |
| } |
| |
| return lio_listio_internal (mode | LIO_NO_INDIVIDUAL_EVENT, list, nent, sig); |
| } |
| compat_symbol (librt, __lio_listio_21, lio_listio, GLIBC_2_1); |
| #endif |
| |
| |
| int |
| __lio_listio_item_notify (int mode, struct aiocb *const list[], int nent, |
| struct sigevent *sig) |
| { |
| /* Check arguments. */ |
| if (mode != LIO_WAIT && mode != LIO_NOWAIT) |
| { |
| __set_errno (EINVAL); |
| return -1; |
| } |
| |
| return lio_listio_internal (mode, list, nent, sig); |
| } |
| versioned_symbol (librt, __lio_listio_item_notify, lio_listio, GLIBC_2_4); |