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