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