| 1 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * |
| 2 | * Mupen64plus - util.h * |
| 3 | * Mupen64Plus homepage: http://code.google.com/p/mupen64plus/ * |
| 4 | * Copyright (C) 2012 Mupen64plus development team * |
| 5 | * * |
| 6 | * This program is free software; you can redistribute it and/or modify * |
| 7 | * it under the terms of the GNU General Public License as published by * |
| 8 | * the Free Software Foundation; either version 2 of the License, or * |
| 9 | * (at your option) any later version. * |
| 10 | * * |
| 11 | * This program is distributed in the hope that it will be useful, * |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of * |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * |
| 14 | * GNU General Public License for more details. * |
| 15 | * * |
| 16 | * You should have received a copy of the GNU General Public License * |
| 17 | * along with this program; if not, write to the * |
| 18 | * Free Software Foundation, Inc., * |
| 19 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. * |
| 20 | * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ |
| 21 | |
| 22 | #include "workqueue.h" |
| 23 | #include "api/callbacks.h" |
| 24 | |
| 25 | #include <SDL.h> |
| 26 | #include <SDL_thread.h> |
| 27 | |
| 28 | #define WORKQUEUE_THREADS 1 |
| 29 | |
| 30 | struct workqueue_mgmt_globals { |
| 31 | struct list_head work_queue; |
| 32 | struct list_head thread_queue; |
| 33 | struct list_head thread_list; |
| 34 | SDL_mutex *lock; |
| 35 | }; |
| 36 | |
| 37 | struct workqueue_thread { |
| 38 | SDL_Thread *thread; |
| 39 | SDL_cond *work_avail; |
| 40 | struct list_head list; |
| 41 | struct list_head list_mgmt; |
| 42 | }; |
| 43 | |
| 44 | static struct workqueue_mgmt_globals workqueue_mgmt; |
| 45 | |
| 46 | static void workqueue_dismiss(struct work_struct *work) |
| 47 | { |
| 48 | } |
| 49 | |
| 50 | static struct work_struct *workqueue_get_work(struct workqueue_thread *thread) |
| 51 | { |
| 52 | int found = 0; |
| 53 | struct work_struct *work; |
| 54 | |
| 55 | while (1) { |
| 56 | SDL_LockMutex(workqueue_mgmt.lock); |
| 57 | list_del_init(&thread->list); |
| 58 | if (!list_empty(&workqueue_mgmt.work_queue)) { |
| 59 | found = 1; |
| 60 | work = list_first_entry(&workqueue_mgmt.work_queue, struct work_struct, list); |
| 61 | list_del_init(&work->list); |
| 62 | } else { |
| 63 | list_add(&thread->list, &workqueue_mgmt.thread_queue); |
| 64 | SDL_CondWait(thread->work_avail, workqueue_mgmt.lock); |
| 65 | } |
| 66 | SDL_UnlockMutex(workqueue_mgmt.lock); |
| 67 | |
| 68 | if (found) |
| 69 | break; |
| 70 | } |
| 71 | |
| 72 | return work; |
| 73 | } |
| 74 | |
| 75 | static int workqueue_thread_handler(void *data) |
| 76 | { |
| 77 | struct workqueue_thread *thread = data; |
| 78 | struct work_struct *work; |
| 79 | |
| 80 | while (1) { |
| 81 | work = workqueue_get_work(thread); |
| 82 | if (work->func == workqueue_dismiss) { |
| 83 | free(work); |
| 84 | break; |
| 85 | } |
| 86 | |
| 87 | work->func(work); |
| 88 | } |
| 89 | |
| 90 | return 0; |
| 91 | } |
| 92 | |
| 93 | int workqueue_init(void) |
| 94 | { |
| 95 | size_t i; |
| 96 | struct workqueue_thread *thread; |
| 97 | |
| 98 | memset(&workqueue_mgmt, 0, sizeof(workqueue_mgmt)); |
| 99 | INIT_LIST_HEAD(&workqueue_mgmt.work_queue); |
| 100 | INIT_LIST_HEAD(&workqueue_mgmt.thread_queue); |
| 101 | INIT_LIST_HEAD(&workqueue_mgmt.thread_list); |
| 102 | |
| 103 | workqueue_mgmt.lock = SDL_CreateMutex(); |
| 104 | if (!workqueue_mgmt.lock) { |
| 105 | DebugMessage(M64MSG_ERROR, "Could not create workqueue management"); |
| 106 | return -1; |
| 107 | } |
| 108 | |
| 109 | SDL_LockMutex(workqueue_mgmt.lock); |
| 110 | for (i = 0; i < WORKQUEUE_THREADS; i++) { |
| 111 | thread = malloc(sizeof(*thread)); |
| 112 | if (!thread) { |
| 113 | DebugMessage(M64MSG_ERROR, "Could not create workqueue thread management data"); |
| 114 | SDL_UnlockMutex(workqueue_mgmt.lock); |
| 115 | return -1; |
| 116 | } |
| 117 | |
| 118 | memset(thread, 0, sizeof(*thread)); |
| 119 | list_add(&thread->list_mgmt, &workqueue_mgmt.thread_list); |
| 120 | INIT_LIST_HEAD(&thread->list); |
| 121 | thread->work_avail = SDL_CreateCond(); |
| 122 | if (!thread->work_avail) { |
| 123 | DebugMessage(M64MSG_ERROR, "Could not create workqueue thread work_avail condition"); |
| 124 | SDL_UnlockMutex(workqueue_mgmt.lock); |
| 125 | return -1; |
| 126 | } |
| 127 | |
| 128 | #if SDL_VERSION_ATLEAST(2,0,0) |
| 129 | thread->thread = SDL_CreateThread(workqueue_thread_handler, "m64pwq", thread); |
| 130 | #else |
| 131 | thread->thread = SDL_CreateThread(workqueue_thread_handler, thread); |
| 132 | #endif |
| 133 | if (!thread->thread) { |
| 134 | DebugMessage(M64MSG_ERROR, "Could not create workqueue thread handler"); |
| 135 | SDL_UnlockMutex(workqueue_mgmt.lock); |
| 136 | return -1; |
| 137 | } |
| 138 | } |
| 139 | SDL_UnlockMutex(workqueue_mgmt.lock); |
| 140 | |
| 141 | return 0; |
| 142 | } |
| 143 | |
| 144 | void workqueue_shutdown(void) |
| 145 | { |
| 146 | size_t i; |
| 147 | int status; |
| 148 | struct work_struct *work; |
| 149 | struct workqueue_thread *thread, *safe; |
| 150 | |
| 151 | for (i = 0; i < WORKQUEUE_THREADS; i++) { |
| 152 | work = malloc(sizeof(*work)); |
| 153 | init_work(work, workqueue_dismiss); |
| 154 | queue_work(work); |
| 155 | } |
| 156 | |
| 157 | list_for_each_entry_safe(thread, safe, &workqueue_mgmt.thread_list, struct workqueue_thread, list_mgmt) { |
| 158 | list_del(&thread->list_mgmt); |
| 159 | SDL_WaitThread(thread->thread, &status); |
| 160 | SDL_DestroyCond(thread->work_avail); |
| 161 | free(thread); |
| 162 | } |
| 163 | |
| 164 | if (!list_empty(&workqueue_mgmt.work_queue)) |
| 165 | DebugMessage(M64MSG_WARNING, "Stopped workqueue with work still pending"); |
| 166 | |
| 167 | SDL_DestroyMutex(workqueue_mgmt.lock); |
| 168 | } |
| 169 | |
| 170 | int queue_work(struct work_struct *work) |
| 171 | { |
| 172 | struct workqueue_thread *thread; |
| 173 | |
| 174 | SDL_LockMutex(workqueue_mgmt.lock); |
| 175 | list_add_tail(&work->list, &workqueue_mgmt.work_queue); |
| 176 | if (!list_empty(&workqueue_mgmt.thread_queue)) { |
| 177 | thread = list_first_entry(&workqueue_mgmt.thread_queue, struct workqueue_thread, list); |
| 178 | list_del_init(&thread->list); |
| 179 | |
| 180 | SDL_CondSignal(thread->work_avail); |
| 181 | } |
| 182 | SDL_UnlockMutex(workqueue_mgmt.lock); |
| 183 | |
| 184 | return 0; |
| 185 | } |