Mercurial > ecos

comparison examples/simple-alarm.c @ 168:ead06911cbae

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Add up-to-date examples
author jlarmour
date Wed, 04 Jul 2001 17:34:09 +0000
parents
children
comparison
equal deleted inserted replaced
167:59f91bb9f684 168:ead06911cbae
1 /* this is a very simple program meant to demonstrate
2 a basic use of time, alarms and alarm-handling functions
3 in eCos */
4
5 #include <cyg/kernel/kapi.h>
6
7 #include <stdio.h>
8
9 #define NTHREADS 1
10 #define STACKSIZE 4096
11
12 static cyg_handle_t thread[NTHREADS];
13
14 static cyg_thread thread_obj[NTHREADS];
15 static char stack[NTHREADS][STACKSIZE];
16
17 static void alarm_prog( cyg_addrword_t data );
18
19 /* we install our own startup routine which sets up
20 threads and starts the scheduler */
21 void cyg_user_start(void)
22 {
23 cyg_thread_create(4, alarm_prog, (cyg_addrword_t) 0,
24 "alarm_thread", (void *) stack[0],
25 STACKSIZE, &thread[0], &thread_obj[0]);
26 cyg_thread_resume(thread[0]);
27 }
28
29 /* we need to declare the alarm handling function (which is
30 defined below), so that we can pass it to
31 cyg_alarm_initialize() */
32 cyg_alarm_t test_alarm_func;
33
34 /* alarm_prog() is a thread which sets up an alarm which is then
35 handled by test_alarm_func() */
36 static void alarm_prog(cyg_addrword_t data)
37 {
38 cyg_handle_t test_counterH, system_clockH, test_alarmH;
39 cyg_tick_count_t ticks;
40 cyg_alarm test_alarm;
41 unsigned how_many_alarms = 0, prev_alarms = 0, tmp_how_many;
42
43 system_clockH = cyg_real_time_clock();
44 cyg_clock_to_counter(system_clockH, &test_counterH);
45 cyg_alarm_create(test_counterH, test_alarm_func,
46 (cyg_addrword_t) &how_many_alarms,
47 &test_alarmH, &test_alarm);
48 cyg_alarm_initialize(test_alarmH, cyg_current_time()+200, 200);
49
50 /* get in a loop in which we read the current time and
51 print it out, just to have something scrolling by */
52 for (;;) {
53 ticks = cyg_current_time();
54 printf("Time is %llu\n", ticks);
55 /* note that we must lock access to how_many_alarms, since the
56 alarm handler might change it. this involves using the
57 annoying temporary variable tmp_how_many so that I can keep the
58 critical region short */
59 cyg_scheduler_lock();
60 tmp_how_many = how_many_alarms;
61 cyg_scheduler_unlock();
62 if (prev_alarms != tmp_how_many) {
63 printf(" ---> alarm calls so far: %u\n", tmp_how_many);
64 prev_alarms = tmp_how_many;
65 }
66 cyg_thread_delay(30);
67 }
68 }
69
70 /* test_alarm_func() is invoked as an alarm handler, so
71 it should be quick and simple. in this case it increments
72 the data that is passed to it. */
73 void test_alarm_func(cyg_handle_t alarmH, cyg_addrword_t data)
74 {
75 ++*((unsigned *) data);
76 }