util/u_queue: fix a use-before-initialization race for queue->threads
[mesa.git] / src / util / u_queue.h
1 /*
2 * Copyright © 2016 Advanced Micro Devices, Inc.
3 * All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining
6 * a copy of this software and associated documentation files (the
7 * "Software"), to deal in the Software without restriction, including
8 * without limitation the rights to use, copy, modify, merge, publish,
9 * distribute, sub license, and/or sell copies of the Software, and to
10 * permit persons to whom the Software is furnished to do so, subject to
11 * the following conditions:
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
14 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
15 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
16 * NON-INFRINGEMENT. IN NO EVENT SHALL THE COPYRIGHT HOLDERS, AUTHORS
17 * AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
20 * USE OR OTHER DEALINGS IN THE SOFTWARE.
21 *
22 * The above copyright notice and this permission notice (including the
23 * next paragraph) shall be included in all copies or substantial portions
24 * of the Software.
25 */
26
27 /* Job queue with execution in a separate thread.
28 *
29 * Jobs can be added from any thread. After that, the wait call can be used
30 * to wait for completion of the job.
31 */
32
33 #ifndef U_QUEUE_H
34 #define U_QUEUE_H
35
36 #include <string.h>
37
38 #include "util/list.h"
39 #include "util/u_thread.h"
40
41 #ifdef __cplusplus
42 extern "C" {
43 #endif
44
45 #define UTIL_QUEUE_INIT_USE_MINIMUM_PRIORITY (1 << 0)
46
47 /* Job completion fence.
48 * Put this into your job structure.
49 */
50 struct util_queue_fence {
51 mtx_t mutex;
52 cnd_t cond;
53 int signalled;
54 };
55
56 typedef void (*util_queue_execute_func)(void *job, int thread_index);
57
58 struct util_queue_job {
59 void *job;
60 struct util_queue_fence *fence;
61 util_queue_execute_func execute;
62 util_queue_execute_func cleanup;
63 };
64
65 /* Put this into your context. */
66 struct util_queue {
67 const char *name;
68 mtx_t lock;
69 cnd_t has_queued_cond;
70 cnd_t has_space_cond;
71 thrd_t *threads;
72 int num_queued;
73 unsigned num_threads;
74 int kill_threads;
75 int max_jobs;
76 int write_idx, read_idx; /* ring buffer pointers */
77 struct util_queue_job *jobs;
78
79 /* for cleanup at exit(), protected by exit_mutex */
80 struct list_head head;
81 };
82
83 bool util_queue_init(struct util_queue *queue,
84 const char *name,
85 unsigned max_jobs,
86 unsigned num_threads,
87 unsigned flags);
88 void util_queue_destroy(struct util_queue *queue);
89 void util_queue_fence_init(struct util_queue_fence *fence);
90 void util_queue_fence_destroy(struct util_queue_fence *fence);
91
92 /* optional cleanup callback is called after fence is signaled: */
93 void util_queue_add_job(struct util_queue *queue,
94 void *job,
95 struct util_queue_fence *fence,
96 util_queue_execute_func execute,
97 util_queue_execute_func cleanup);
98 void util_queue_drop_job(struct util_queue *queue,
99 struct util_queue_fence *fence);
100
101 void util_queue_fence_wait(struct util_queue_fence *fence);
102 int64_t util_queue_get_thread_time_nano(struct util_queue *queue,
103 unsigned thread_index);
104
105 /* util_queue needs to be cleared to zeroes for this to work */
106 static inline bool
107 util_queue_is_initialized(struct util_queue *queue)
108 {
109 return queue->threads != NULL;
110 }
111
112 static inline bool
113 util_queue_fence_is_signalled(struct util_queue_fence *fence)
114 {
115 return fence->signalled != 0;
116 }
117
118 #ifdef __cplusplus
119 }
120 #endif
121
122 #endif