451ab91e |
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 | } |