xref: /btstack/platform/posix/btstack_run_loop_posix.c (revision 2c455dad9a589f886e28f6a5d10bb735305e4f1b)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 /*
39  *  btstack_run_loop.c
40  *
41  *  Created by Matthias Ringwald on 6/6/09.
42  */
43 
44 #include "btstack_run_loop.h"
45 #include "btstack_run_loop_posix.h"
46 #include "btstack_linked_list.h"
47 #include "btstack_debug.h"
48 
49 #ifdef _WIN32
50 #include "Winsock2.h"
51 #else
52 #include <sys/select.h>
53 #endif
54 #include <stdio.h>
55 #include <stdlib.h>
56 
57 static void btstack_run_loop_posix_dump_timer(void);
58 static int  btstack_run_loop_posix_timeval_compare(struct timeval *a, struct timeval *b);
59 static int  btstack_run_loop_posix_timer_compare(btstack_timer_source_t *a, btstack_timer_source_t *b);
60 
61 // the run loop
62 static btstack_linked_list_t data_sources;
63 static int data_sources_modified;
64 static btstack_linked_list_t timers;
65 static struct timeval init_tv;
66 
67 /**
68  * Add data_source to run_loop
69  */
70 static void btstack_run_loop_posix_add_data_source(btstack_data_source_t *ds){
71     data_sources_modified = 1;
72     // log_info("btstack_run_loop_posix_add_data_source %x with fd %u\n", (int) ds, ds->fd);
73     btstack_linked_list_add(&data_sources, (btstack_linked_item_t *) ds);
74 }
75 
76 /**
77  * Remove data_source from run loop
78  */
79 static int btstack_run_loop_posix_remove_data_source(btstack_data_source_t *ds){
80     data_sources_modified = 1;
81     // log_info("btstack_run_loop_posix_remove_data_source %x\n", (int) ds);
82     return btstack_linked_list_remove(&data_sources, (btstack_linked_item_t *) ds);
83 }
84 
85 /**
86  * Add timer to run_loop (keep list sorted)
87  */
88 static void btstack_run_loop_posix_add_timer(btstack_timer_source_t *ts){
89     btstack_linked_item_t *it;
90     for (it = (btstack_linked_item_t *) &timers; it->next ; it = it->next){
91         if ((btstack_timer_source_t *) it->next == ts){
92             log_error( "btstack_run_loop_timer_add error: timer to add already in list!");
93             return;
94         }
95         if (btstack_run_loop_posix_timer_compare( (btstack_timer_source_t *) it->next, ts) > 0) {
96             break;
97         }
98     }
99     ts->item.next = it->next;
100     it->next = (btstack_linked_item_t *) ts;
101     // log_info("Added timer %x at %u\n", (int) ts, (unsigned int) ts->timeout.tv_sec);
102     // btstack_run_loop_posix_dump_timer();
103 }
104 
105 /**
106  * Remove timer from run loop
107  */
108 static int btstack_run_loop_posix_remove_timer(btstack_timer_source_t *ts){
109     // log_info("Removed timer %x at %u\n", (int) ts, (unsigned int) ts->timeout.tv_sec);
110     // btstack_run_loop_posix_dump_timer();
111     return btstack_linked_list_remove(&timers, (btstack_linked_item_t *) ts);
112 }
113 
114 static void btstack_run_loop_posix_dump_timer(void){
115     btstack_linked_item_t *it;
116     int i = 0;
117     for (it = (btstack_linked_item_t *) timers; it ; it = it->next){
118         btstack_timer_source_t *ts = (btstack_timer_source_t*) it;
119         log_info("timer %u, timeout %u\n", i, (unsigned int) ts->timeout.tv_sec);
120     }
121 }
122 
123 static void btstack_run_loop_posix_enable_data_source_callbacks(btstack_data_source_t * ds, uint16_t callback_types){
124     ds->flags |= callback_types;
125 }
126 
127 static void btstack_run_loop_posix_disable_data_source_callbacks(btstack_data_source_t * ds, uint16_t callback_types){
128     ds->flags &= ~callback_types;
129 }
130 
131 /**
132  * Execute run_loop
133  */
134 static void btstack_run_loop_posix_execute(void) {
135     fd_set descriptors_read;
136     fd_set descriptors_write;
137 
138     btstack_timer_source_t       *ts;
139     struct timeval current_tv;
140     struct timeval next_tv;
141     struct timeval *timeout;
142     btstack_linked_list_iterator_t it;
143 
144     while (1) {
145         // collect FDs
146         FD_ZERO(&descriptors_read);
147         FD_ZERO(&descriptors_write);
148         int highest_fd = 0;
149         btstack_linked_list_iterator_init(&it, &data_sources);
150         while (btstack_linked_list_iterator_has_next(&it)){
151             btstack_data_source_t *ds = (btstack_data_source_t*) btstack_linked_list_iterator_next(&it);
152             if (ds->fd < 0) continue;
153             if (ds->flags & DATA_SOURCE_CALLBACK_READ){
154                 FD_SET(ds->fd, &descriptors_read);
155                 if (ds->fd > highest_fd) {
156                     highest_fd = ds->fd;
157                 }
158             }
159             if (ds->flags & DATA_SOURCE_CALLBACK_WRITE){
160                 FD_SET(ds->fd, &descriptors_write);
161                 if (ds->fd > highest_fd) {
162                     highest_fd = ds->fd;
163                 }
164             }
165         }
166 
167         // get next timeout
168         // pre: 0 <= tv_usec < 1000000
169         timeout = NULL;
170         if (timers) {
171             gettimeofday(&current_tv, NULL);
172             ts = (btstack_timer_source_t *) timers;
173             next_tv.tv_usec = ts->timeout.tv_usec - current_tv.tv_usec;
174             next_tv.tv_sec  = ts->timeout.tv_sec  - current_tv.tv_sec;
175             while (next_tv.tv_usec < 0){
176                 next_tv.tv_usec += 1000000;
177                 next_tv.tv_sec--;
178             }
179             if (next_tv.tv_sec < 0){
180                 next_tv.tv_sec  = 0;
181                 next_tv.tv_usec = 0;
182             }
183             timeout = &next_tv;
184         }
185 
186         // wait for ready FDs
187         select( highest_fd+1 , &descriptors_read, &descriptors_write, NULL, timeout);
188 
189         // process data sources very carefully
190         // bt_control.close() triggered from a client can remove a different data source
191 
192         // log_info("btstack_run_loop_posix_execute: before ds check\n");
193         data_sources_modified = 0;
194         btstack_linked_list_iterator_init(&it, &data_sources);
195         while (btstack_linked_list_iterator_has_next(&it) && !data_sources_modified){
196             btstack_data_source_t *ds = (btstack_data_source_t*) btstack_linked_list_iterator_next(&it);
197             // log_info("btstack_run_loop_posix_execute: check %x with fd %u\n", (int) ds, ds->fd);
198             if (FD_ISSET(ds->fd, &descriptors_read)) {
199                 // log_info("btstack_run_loop_posix_execute: process read %x with fd %u\n", (int) ds, ds->fd);
200                 ds->process(ds, DATA_SOURCE_CALLBACK_READ);
201             }
202             if (FD_ISSET(ds->fd, &descriptors_write)) {
203                 // log_info("btstack_run_loop_posix_execute: process write %x with fd %u\n", (int) ds, ds->fd);
204                 ds->process(ds, DATA_SOURCE_CALLBACK_WRITE);
205             }
206         }
207         // log_info("btstack_run_loop_posix_execute: after ds check\n");
208 
209         // process timers
210         // pre: 0 <= tv_usec < 1000000
211         while (timers) {
212             gettimeofday(&current_tv, NULL);
213             ts = (btstack_timer_source_t *) timers;
214             if (ts->timeout.tv_sec  > current_tv.tv_sec) break;
215             if (ts->timeout.tv_sec == current_tv.tv_sec && ts->timeout.tv_usec > current_tv.tv_usec) break;
216             // log_info("btstack_run_loop_posix_execute: process times %x\n", (int) ts);
217 
218             // remove timer before processing it to allow handler to re-register with run loop
219             btstack_run_loop_remove_timer(ts);
220             ts->process(ts);
221         }
222     }
223 }
224 
225 // set timer
226 static void btstack_run_loop_posix_set_timer(btstack_timer_source_t *a, uint32_t timeout_in_ms){
227     gettimeofday(&a->timeout, NULL);
228     a->timeout.tv_sec  +=  timeout_in_ms / 1000;
229     a->timeout.tv_usec += (timeout_in_ms % 1000) * 1000;
230     if (a->timeout.tv_usec  > 1000000) {
231         a->timeout.tv_usec -= 1000000;
232         a->timeout.tv_sec++;
233     }
234 }
235 
236 // compare timers - NULL is assumed to be before the Big Bang
237 // pre: 0 <= tv_usec < 1000000
238 static int btstack_run_loop_posix_timeval_compare(struct timeval *a, struct timeval *b){
239     if (!a && !b) return 0;
240     if (!a) return -1;
241     if (!b) return 1;
242 
243     if (a->tv_sec < b->tv_sec) {
244         return -1;
245     }
246     if (a->tv_sec > b->tv_sec) {
247         return 1;
248     }
249 
250     if (a->tv_usec < b->tv_usec) {
251         return -1;
252     }
253     if (a->tv_usec > b->tv_usec) {
254         return 1;
255     }
256 
257     return 0;
258 
259 }
260 
261 // compare timers - NULL is assumed to be before the Big Bang
262 // pre: 0 <= tv_usec < 1000000
263 static int btstack_run_loop_posix_timer_compare(btstack_timer_source_t *a, btstack_timer_source_t *b){
264     if (!a && !b) return 0;
265     if (!a) return -1;
266     if (!b) return 1;
267     return btstack_run_loop_posix_timeval_compare(&a->timeout, &b->timeout);
268 }
269 
270 static void btstack_run_loop_posix_init(void){
271     data_sources = NULL;
272     timers = NULL;
273     gettimeofday(&init_tv, NULL);
274 }
275 
276 /**
277  * @brief Queries the current time in ms since start
278  */
279 static uint32_t btstack_run_loop_posix_get_time_ms(void){
280     struct timeval current_tv;
281     gettimeofday(&current_tv, NULL);
282     return (current_tv.tv_sec  - init_tv.tv_sec)  * 1000
283          + (current_tv.tv_usec - init_tv.tv_usec) / 1000;
284 }
285 
286 
287 static const btstack_run_loop_t btstack_run_loop_posix = {
288     &btstack_run_loop_posix_init,
289     &btstack_run_loop_posix_add_data_source,
290     &btstack_run_loop_posix_remove_data_source,
291     &btstack_run_loop_posix_enable_data_source_callbacks,
292     &btstack_run_loop_posix_disable_data_source_callbacks,
293     &btstack_run_loop_posix_set_timer,
294     &btstack_run_loop_posix_add_timer,
295     &btstack_run_loop_posix_remove_timer,
296     &btstack_run_loop_posix_execute,
297     &btstack_run_loop_posix_dump_timer,
298     &btstack_run_loop_posix_get_time_ms,
299 };
300 
301 /**
302  * Provide btstack_run_loop_posix instance
303  */
304 const btstack_run_loop_t * btstack_run_loop_posix_get_instance(void){
305     return &btstack_run_loop_posix;
306 }
307 
308