Commit | Line | Data |
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90c3a0d4 TM |
1 | /* |
2 | * CFLAGS=-lpthread make pthread_msgqueue | |
3 | */ | |
4 | ||
5 | #include <pthread.h> | |
6 | #include <time.h> | |
7 | #include <string.h> | |
8 | #include <stdio.h> | |
9 | #include <stdbool.h> | |
10 | #include <stdlib.h> | |
774d1b14 | 11 | #include <assert.h> |
63658368 TM |
12 | #include <unistd.h> |
13 | ||
14 | #define PTHREAD_X_NONWAIT (&(struct timespec){ .tv_sec = 0, .tv_nsec = 0 }) | |
15 | #define PTHREAD_X_FOREVER NULL | |
90c3a0d4 TM |
16 | |
17 | typedef struct pthread_mq_t { | |
774d1b14 TM |
18 | pthread_mutex_t lock; |
19 | pthread_cond_t cond_readable; | |
20 | pthread_cond_t cond_writable; | |
90c3a0d4 TM |
21 | void * data; |
22 | size_t msg_size; | |
23 | size_t msg_count; | |
24 | size_t msg_count_max; | |
25 | size_t head_idx; | |
26 | char * name; | |
27 | } pthread_mq_t; | |
28 | ||
774d1b14 TM |
29 | bool pthread_mq_readable(pthread_mq_t *mq) { return (mq->msg_count > 0); } |
30 | bool pthread_mq_writable(pthread_mq_t *mq) { return (mq->msg_count < mq->msg_count_max); } | |
90c3a0d4 TM |
31 | |
32 | bool pthread_mq_init(pthread_mq_t *mq, size_t msg_size, size_t msg_count_max) { | |
774d1b14 TM |
33 | pthread_mutex_init(&mq->lock, NULL); |
34 | pthread_cond_init(&mq->cond_readable, NULL); | |
35 | pthread_cond_init(&mq->cond_writable, NULL); | |
63658368 | 36 | //pthread_mutexattr_setclock(&mq->lock, CLOCK_MONOTONIC); |
90c3a0d4 TM |
37 | mq->data = malloc(msg_size*msg_count_max); |
38 | mq->msg_size = msg_size; | |
39 | mq->msg_count_max = msg_count_max; | |
40 | mq->msg_count = 0; | |
41 | mq->head_idx = 0; | |
42 | mq->name = NULL; | |
43 | ||
44 | if(((msg_size*msg_count_max) > 0) && mq->data == NULL) return false; | |
45 | return true; | |
46 | } | |
47 | ||
48 | void pthread_mq_free(pthread_mq_t *mq) { | |
49 | free(mq->data); | |
50 | } | |
51 | ||
90c3a0d4 TM |
52 | void pthread_mq_cond(pthread_mq_t *mq) { |
53 | if(pthread_mq_readable(mq)) pthread_cond_broadcast(&mq->cond_readable); | |
54 | if(pthread_mq_writable(mq)) pthread_cond_broadcast(&mq->cond_writable); | |
55 | } | |
56 | ||
63658368 TM |
57 | size_t pthread_mq_waiting(pthread_mq_t *mq) { |
58 | return mq->msg_count; | |
59 | } | |
60 | ||
774d1b14 TM |
61 | bool pthread_mq_reset(pthread_mq_t *mq) { |
62 | if(pthread_mutex_lock(&mq->lock)) return false; | |
63 | mq->msg_count = 0; | |
64 | mq->head_idx = 0; | |
65 | pthread_mq_cond(mq); | |
66 | pthread_mutex_unlock(&mq->lock); | |
67 | return true; | |
68 | } | |
69 | ||
63658368 | 70 | bool pthread_mq_send_generic(pthread_mq_t *mq, void * data, bool to_front, const struct timespec *restrict abs_timeout) { |
3297654e TM |
71 | int ret; |
72 | ||
774d1b14 TM |
73 | //Lock queue |
74 | if(pthread_mutex_timedlock(&mq->lock, abs_timeout)) return false; | |
90c3a0d4 | 75 | |
774d1b14 | 76 | //Wait for queue to be in writable condition |
90c3a0d4 | 77 | while(!pthread_mq_writable(mq)) { |
3297654e TM |
78 | if(abs_timeout == NULL) { |
79 | ret = pthread_cond_wait(&mq->cond_writable, &mq->lock); | |
80 | } else { | |
81 | ret = pthread_cond_timedwait(&mq->cond_writable, &mq->lock, abs_timeout); | |
82 | } | |
83 | if(ret) { | |
774d1b14 TM |
84 | pthread_mutex_unlock(&mq->lock); |
85 | return false; | |
86 | } | |
90c3a0d4 TM |
87 | } |
88 | ||
774d1b14 TM |
89 | //Write data to queue |
90 | size_t idx = ( ( mq->msg_count_max + mq->head_idx + (to_front?-1:mq->msg_count) ) % mq->msg_count_max ); | |
90c3a0d4 TM |
91 | void *ptr = mq->data + (idx * mq->msg_size); |
92 | mq->msg_count++; | |
774d1b14 | 93 | if(to_front) mq->head_idx = (mq->msg_count_max + mq->head_idx - 1) % mq->msg_count_max; |
90c3a0d4 TM |
94 | memcpy(ptr, data, mq->msg_size); |
95 | ||
774d1b14 | 96 | //Signal conditions and unlock |
90c3a0d4 TM |
97 | pthread_mq_cond(mq); |
98 | pthread_mutex_unlock(&mq->lock); | |
99 | return true; | |
100 | } | |
101 | ||
63658368 TM |
102 | bool pthread_mq_receive_generic(pthread_mq_t *mq, void * data, bool peek, const struct timespec *restrict abs_timeout) { |
103 | int ret; | |
104 | ||
105 | //Lock queue | |
106 | if(pthread_mutex_timedlock(&mq->lock, abs_timeout)) return false; | |
107 | ||
108 | //Wait for queue to be in readable condition | |
109 | while(!pthread_mq_readable(mq)) { | |
110 | if(abs_timeout == NULL) { | |
111 | ret = pthread_cond_wait(&mq->cond_readable, &mq->lock); | |
112 | } else { | |
113 | ret = pthread_cond_timedwait(&mq->cond_readable, &mq->lock, abs_timeout); | |
114 | } | |
115 | if(ret) { | |
116 | pthread_mutex_unlock(&mq->lock); | |
117 | return false; | |
118 | } | |
119 | } | |
120 | ||
121 | //Read data from queue | |
122 | void *ptr = mq->data + (mq->head_idx * mq->msg_size); | |
123 | memcpy(data, ptr, mq->msg_size); | |
124 | ||
125 | //Delete data from queue if not peeking | |
126 | if(!peek) { | |
127 | mq->msg_count--; | |
128 | mq->head_idx = (mq->head_idx+1) % mq->msg_count_max; | |
129 | } | |
130 | ||
131 | //Signal conditions and unlock | |
132 | pthread_mq_cond(mq); | |
133 | pthread_mutex_unlock(&mq->lock); | |
134 | return true; | |
135 | } | |
136 | ||
137 | ||
138 | ||
139 | ||
140 | ||
141 | ||
142 | ||
143 | ||
144 | ||
145 | ||
146 | pthread_mq_t myq; | |
147 | ||
148 | void *thread_recv(void *args) { | |
149 | char str[128]; | |
150 | while(1) { | |
151 | pthread_mq_receive_generic(&myq, &str, false, NULL); | |
152 | printf("RECVD: %.6s\t\t(waiting %d)\n", str, pthread_mq_waiting(&myq)); | |
153 | sleep(1); | |
154 | } | |
155 | } | |
156 | ||
90c3a0d4 | 157 | int main() { |
63658368 TM |
158 | char tmp[128]; |
159 | ||
3297654e | 160 | pthread_mq_init(&myq, 6, 5); |
63658368 TM |
161 | |
162 | pthread_t t; | |
163 | pthread_create(&t, NULL, thread_recv, NULL); | |
164 | ||
165 | pthread_mq_send_generic(&myq, "AHOJ1", false, NULL); | |
166 | pthread_mq_send_generic(&myq, "AHOJ2", false, NULL); | |
167 | pthread_mq_send_generic(&myq, "AHOJ3", true, NULL); | |
168 | pthread_mq_send_generic(&myq, "AHOJ4", true, NULL); | |
169 | pthread_mq_send_generic(&myq, "AHOJ5", false, NULL); | |
170 | pthread_mq_send_generic(&myq, "AHOJ6", true, NULL); | |
171 | ||
172 | while(1) { | |
173 | pthread_mq_send_generic(&myq, "B", false, NULL); | |
174 | pthread_mq_send_generic(&myq, "A", true, NULL); | |
175 | pthread_mq_send_generic(&myq, " A", false, NULL); | |
176 | pthread_mq_send_generic(&myq, " B", false, NULL); | |
3297654e | 177 | } |
63658368 TM |
178 | |
179 | pthread_join(t, NULL); | |
90c3a0d4 | 180 | } |