| /* Copyright (C) 2006-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| 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 define a special synchronization primitive for AIO. POSIX |
| conditional variables would be ideal but the pthread_cond_*wait |
| operations do not return on EINTR. This is a requirement for |
| correct aio_suspend and lio_listio implementations. */ |
| |
| #include <assert.h> |
| #include <nptl/pthreadP.h> |
| #include <futex-internal.h> |
| |
| #define DONT_NEED_AIO_MISC_COND 1 |
| |
| #define AIO_MISC_NOTIFY(waitlist) \ |
| do { \ |
| if (*waitlist->counterp > 0 && --*waitlist->counterp == 0) \ |
| futex_wake ((unsigned int *) waitlist->counterp, 1, FUTEX_PRIVATE); \ |
| } while (0) |
| |
| #define AIO_MISC_WAIT(result, futex, timeout, cancel) \ |
| do { \ |
| volatile unsigned int *futexaddr = &futex; \ |
| unsigned int oldval = futex; \ |
| \ |
| if (oldval != 0) \ |
| { \ |
| pthread_mutex_unlock (&__aio_requests_mutex); \ |
| \ |
| int oldtype; \ |
| if (cancel) \ |
| oldtype = LIBC_CANCEL_ASYNC (); \ |
| \ |
| int status; \ |
| do \ |
| { \ |
| status = futex_reltimed_wait ((unsigned int *) futexaddr, oldval, \ |
| timeout, FUTEX_PRIVATE); \ |
| if (status != EAGAIN) \ |
| break; \ |
| \ |
| oldval = *futexaddr; \ |
| } \ |
| while (oldval != 0); \ |
| \ |
| if (cancel) \ |
| LIBC_CANCEL_RESET (oldtype); \ |
| \ |
| if (status == EINTR) \ |
| result = EINTR; \ |
| else if (status == ETIMEDOUT) \ |
| result = EAGAIN; \ |
| else \ |
| assert (status == 0 || status == EAGAIN); \ |
| \ |
| pthread_mutex_lock (&__aio_requests_mutex); \ |
| } \ |
| } while (0) |
| |
| #include_next <aio_misc.h> |
