| xf.li | bfc6e71 | 2025-02-07 01:54:34 -0800 | [diff] [blame^] | 1 | /* Copyright (C) 2006-2016 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. |
| 3 | |
| 4 | The GNU C Library is free software; you can redistribute it and/or |
| 5 | modify it under the terms of the GNU Lesser General Public |
| 6 | License as published by the Free Software Foundation; either |
| 7 | version 2.1 of the License, or (at your option) any later version. |
| 8 | |
| 9 | The GNU C Library is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | Lesser General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU Lesser General Public |
| 15 | License along with the GNU C Library; if not, see |
| 16 | <http://www.gnu.org/licenses/>. */ |
| 17 | |
| 18 | /* We define a special synchronization primitive for AIO. POSIX |
| 19 | conditional variables would be ideal but the pthread_cond_*wait |
| 20 | operations do not return on EINTR. This is a requirement for |
| 21 | correct aio_suspend and lio_listio implementations. */ |
| 22 | |
| 23 | #include <assert.h> |
| 24 | #include <nptl/pthreadP.h> |
| 25 | #include <futex-internal.h> |
| 26 | |
| 27 | #define DONT_NEED_AIO_MISC_COND 1 |
| 28 | |
| 29 | #define AIO_MISC_NOTIFY(waitlist) \ |
| 30 | do { \ |
| 31 | if (*waitlist->counterp > 0 && --*waitlist->counterp == 0) \ |
| 32 | futex_wake ((unsigned int *) waitlist->counterp, 1, FUTEX_PRIVATE); \ |
| 33 | } while (0) |
| 34 | |
| 35 | #define AIO_MISC_WAIT(result, futex, timeout, cancel) \ |
| 36 | do { \ |
| 37 | volatile unsigned int *futexaddr = &futex; \ |
| 38 | unsigned int oldval = futex; \ |
| 39 | \ |
| 40 | if (oldval != 0) \ |
| 41 | { \ |
| 42 | pthread_mutex_unlock (&__aio_requests_mutex); \ |
| 43 | \ |
| 44 | int oldtype; \ |
| 45 | if (cancel) \ |
| 46 | oldtype = LIBC_CANCEL_ASYNC (); \ |
| 47 | \ |
| 48 | int status; \ |
| 49 | do \ |
| 50 | { \ |
| 51 | status = futex_reltimed_wait ((unsigned int *) futexaddr, oldval, \ |
| 52 | timeout, FUTEX_PRIVATE); \ |
| 53 | if (status != EAGAIN) \ |
| 54 | break; \ |
| 55 | \ |
| 56 | oldval = *futexaddr; \ |
| 57 | } \ |
| 58 | while (oldval != 0); \ |
| 59 | \ |
| 60 | if (cancel) \ |
| 61 | LIBC_CANCEL_RESET (oldtype); \ |
| 62 | \ |
| 63 | if (status == EINTR) \ |
| 64 | result = EINTR; \ |
| 65 | else if (status == ETIMEDOUT) \ |
| 66 | result = EAGAIN; \ |
| 67 | else \ |
| 68 | assert (status == 0 || status == EAGAIN); \ |
| 69 | \ |
| 70 | pthread_mutex_lock (&__aio_requests_mutex); \ |
| 71 | } \ |
| 72 | } while (0) |
| 73 | |
| 74 | #include_next <aio_misc.h> |