Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2008 Travis Geiselbrecht |
| 3 | * |
| 4 | * Permission is hereby granted, free of charge, to any person obtaining |
| 5 | * a copy of this software and associated documentation files |
| 6 | * (the "Software"), to deal in the Software without restriction, |
| 7 | * including without limitation the rights to use, copy, modify, merge, |
| 8 | * publish, distribute, sublicense, and/or sell copies of the Software, |
| 9 | * and to permit persons to whom the Software is furnished to do so, |
| 10 | * subject to the following conditions: |
| 11 | * |
| 12 | * The above copyright notice and this permission notice shall be |
| 13 | * included in all copies or substantial portions of the Software. |
| 14 | * |
| 15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 16 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 17 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| 18 | * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
| 19 | * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| 20 | * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| 21 | * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| 22 | */ |
| 23 | #include <debug.h> |
| 24 | #include <err.h> |
| 25 | #include <kernel/event.h> |
| 26 | |
| 27 | #if DEBUGLEVEL > 1 |
| 28 | #define EVENT_CHECK 1 |
| 29 | #endif |
| 30 | |
| 31 | void event_init(event_t *e, bool initial, uint flags) |
| 32 | { |
| 33 | #if EVENT_CHECK |
| 34 | // ASSERT(e->magic != EVENT_MAGIC); |
| 35 | #endif |
| 36 | |
| 37 | e->magic = EVENT_MAGIC; |
| 38 | e->signalled = initial; |
| 39 | e->flags = flags; |
| 40 | wait_queue_init(&e->wait); |
| 41 | } |
| 42 | |
| 43 | void event_destroy(event_t *e) |
| 44 | { |
| 45 | enter_critical_section(); |
| 46 | |
| 47 | #if EVENT_CHECK |
| 48 | ASSERT(e->magic == EVENT_MAGIC); |
| 49 | #endif |
| 50 | |
| 51 | e->magic = 0; |
| 52 | e->signalled = false; |
| 53 | e->flags = 0; |
| 54 | wait_queue_destroy(&e->wait, true); |
| 55 | |
| 56 | exit_critical_section(); |
| 57 | } |
| 58 | |
| 59 | status_t event_wait_timeout(event_t *e, time_t timeout) |
| 60 | { |
| 61 | status_t ret = NO_ERROR; |
| 62 | |
| 63 | enter_critical_section(); |
| 64 | |
| 65 | #if EVENT_CHECK |
| 66 | ASSERT(e->magic == EVENT_MAGIC); |
| 67 | #endif |
| 68 | |
| 69 | if (e->signalled) { |
| 70 | /* signalled, we're going to fall through */ |
| 71 | if (e->flags & EVENT_FLAG_AUTOUNSIGNAL) { |
| 72 | /* autounsignal flag lets one thread fall through before unsignalling */ |
| 73 | e->signalled = false; |
| 74 | } |
| 75 | } else { |
| 76 | /* unsignalled, block here */ |
| 77 | ret = wait_queue_block(&e->wait, timeout); |
| 78 | if (ret < 0) |
| 79 | goto err; |
| 80 | } |
| 81 | |
| 82 | err: |
| 83 | exit_critical_section(); |
| 84 | |
| 85 | return ret; |
| 86 | } |
| 87 | |
| 88 | status_t event_wait(event_t *e) |
| 89 | { |
| 90 | return event_wait_timeout(e, INFINITE_TIME); |
| 91 | } |
| 92 | |
| 93 | status_t event_signal(event_t *e, bool reschedule) |
| 94 | { |
| 95 | enter_critical_section(); |
| 96 | |
| 97 | #if EVENT_CHECK |
| 98 | ASSERT(e->magic == EVENT_MAGIC); |
| 99 | #endif |
| 100 | |
| 101 | if (!e->signalled) { |
Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 102 | if (e->flags & EVENT_FLAG_AUTOUNSIGNAL) { |
Travis Geiselbrecht | bb777a1 | 2009-01-20 00:24:27 -0800 | [diff] [blame] | 103 | /* try to release one thread and leave unsignalled if successful */ |
| 104 | if (wait_queue_wake_one(&e->wait, reschedule, NO_ERROR) <= 0) { |
| 105 | /* |
| 106 | * if we didn't actually find a thread to wake up, go to |
| 107 | * signalled state and let the next call to event_wait |
| 108 | * unsignal the event. |
| 109 | */ |
| 110 | e->signalled = true; |
| 111 | } |
Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 112 | } else { |
travis geiselbrecht | d98cea1 | 2008-09-18 16:01:03 +0000 | [diff] [blame] | 113 | /* release all threads and remain signalled */ |
Travis Geiselbrecht | bb777a1 | 2009-01-20 00:24:27 -0800 | [diff] [blame] | 114 | e->signalled = true; |
Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 115 | wait_queue_wake_all(&e->wait, reschedule, NO_ERROR); |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | exit_critical_section(); |
| 120 | |
| 121 | return NO_ERROR; |
| 122 | } |
| 123 | |
| 124 | status_t event_unsignal(event_t *e) |
| 125 | { |
| 126 | enter_critical_section(); |
| 127 | |
| 128 | #if EVENT_CHECK |
| 129 | ASSERT(e->magic == EVENT_MAGIC); |
| 130 | #endif |
| 131 | |
| 132 | e->signalled = false; |
| 133 | |
| 134 | exit_critical_section(); |
| 135 | |
| 136 | return NO_ERROR; |
| 137 | } |
| 138 | |