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/* this is a very simple program meant to demonstrate
a basic use of time, alarms and alarm-handling functions
in eCos */
#include <cyg/kernel/kapi.h>
#include <stdio.h>
#define NTHREADS 1
#define STACKSIZE 4096
static cyg_handle_t thread[NTHREADS];
static cyg_thread thread_obj[NTHREADS];
static char stack[NTHREADS][STACKSIZE];
static void alarm_prog( cyg_addrword_t data );
/* we install our own startup routine which sets up
threads and starts the scheduler */
void cyg_user_start(void)
{
cyg_thread_create(4, alarm_prog, (cyg_addrword_t) 0,
"alarm_thread", (void *) stack[0],
STACKSIZE, &thread[0], &thread_obj[0]);
cyg_thread_resume(thread[0]);
}
/* we need to declare the alarm handling function (which is
defined below), so that we can pass it to
cyg_alarm_initialize() */
cyg_alarm_t test_alarm_func;
/* alarm_prog() is a thread which sets up an alarm which is then
handled by test_alarm_func() */
static void alarm_prog(cyg_addrword_t data)
{
cyg_handle_t test_counterH, system_clockH, test_alarmH;
cyg_tick_count_t ticks;
cyg_alarm test_alarm;
unsigned how_many_alarms = 0, prev_alarms = 0, tmp_how_many;
system_clockH = cyg_real_time_clock();
cyg_clock_to_counter(system_clockH, &test_counterH);
cyg_alarm_create(test_counterH, test_alarm_func,
(cyg_addrword_t) &how_many_alarms,
&test_alarmH, &test_alarm);
cyg_alarm_initialize(test_alarmH, cyg_current_time()+200, 200);
/* get in a loop in which we read the current time and
print it out, just to have something scrolling by */
for (;;) {
ticks = cyg_current_time();
printf("Time is %llu\n", ticks);
/* note that we must lock access to how_many_alarms, since the
alarm handler might change it. this involves using the
annoying temporary variable tmp_how_many so that I can keep the
critical region short */
cyg_scheduler_lock();
tmp_how_many = how_many_alarms;
cyg_scheduler_unlock();
if (prev_alarms != tmp_how_many) {
printf(" ---> alarm calls so far: %u\n", tmp_how_many);
prev_alarms = tmp_how_many;
}
cyg_thread_delay(30);
}
}
/* test_alarm_func() is invoked as an alarm handler, so
it should be quick and simple. in this case it increments
the data that is passed to it. */
void test_alarm_func(cyg_handle_t alarmH, cyg_addrword_t data)
{
++*((unsigned *) data);
}
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