1 | /** |
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2 | * @file |
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3 | * |
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4 | * @brief System Generates Signal for process after realtime seconds elapsed |
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5 | * @ingroup POSIXAPI |
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6 | */ |
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7 | |
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8 | /* |
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9 | * 3.4.1 Schedule Alarm, P1003.1b-1993, p. 79 |
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10 | */ |
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11 | |
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12 | /* COPYRIGHT (c) 1989-2013. |
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13 | * On-Line Applications Research Corporation (OAR). |
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14 | * |
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15 | * The license and distribution terms for this file may be |
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16 | * found in the file LICENSE in this distribution or at |
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17 | * http://www.rtems.com/license/LICENSE. |
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18 | */ |
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19 | |
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20 | #if HAVE_CONFIG_H |
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21 | #include "config.h" |
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22 | #endif |
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23 | |
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24 | #include <unistd.h> |
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25 | |
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26 | #include <rtems/posix/pthreadimpl.h> |
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27 | #include <rtems/posix/psignalimpl.h> |
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28 | #include <rtems/score/threaddispatch.h> |
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29 | #include <rtems/score/todimpl.h> |
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30 | #include <rtems/score/watchdogimpl.h> |
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31 | |
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32 | /* |
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33 | * _POSIX_signals_Alarm_TSR |
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34 | */ |
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35 | static void _POSIX_signals_Alarm_TSR( |
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36 | Objects_Id id __attribute__((unused)), |
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37 | void *argument __attribute__((unused)) |
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38 | ) |
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39 | { |
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40 | #if defined(RTEMS_DEBUG) |
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41 | int status; |
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42 | #define KILL_STATUS status = |
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43 | #else |
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44 | #define KILL_STATUS (void) |
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45 | #endif |
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46 | |
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47 | KILL_STATUS kill( getpid(), SIGALRM ); |
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48 | |
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49 | #if defined(RTEMS_DEBUG) |
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50 | /* |
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51 | * There is no reason to think this might fail but we should be |
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52 | * cautious. |
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53 | */ |
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54 | _Assert(status == 0); |
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55 | #endif |
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56 | } |
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57 | |
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58 | static Watchdog_Control _POSIX_signals_Alarm_timer = WATCHDOG_INITIALIZER( |
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59 | _POSIX_signals_Alarm_TSR, |
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60 | 0, |
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61 | NULL |
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62 | ); |
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63 | |
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64 | unsigned int alarm( |
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65 | unsigned int seconds |
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66 | ) |
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67 | { |
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68 | unsigned int remaining = 0; |
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69 | Watchdog_Control *the_timer; |
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70 | Watchdog_States state; |
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71 | |
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72 | the_timer = &_POSIX_signals_Alarm_timer; |
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73 | |
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74 | _Thread_Disable_dispatch(); |
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75 | |
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76 | state = _Watchdog_Remove( the_timer ); |
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77 | if ( (state == WATCHDOG_ACTIVE) || (state == WATCHDOG_REMOVE_IT) ) { |
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78 | /* |
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79 | * The stop_time and start_time fields are snapshots of ticks since |
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80 | * boot. Since alarm() is dealing in seconds, we must account for |
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81 | * this. |
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82 | */ |
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83 | |
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84 | remaining = the_timer->initial - |
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85 | ((the_timer->stop_time - the_timer->start_time) / TOD_TICKS_PER_SECOND); |
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86 | } |
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87 | |
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88 | if ( seconds ) |
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89 | _Watchdog_Insert_seconds( the_timer, seconds ); |
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90 | |
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91 | _Thread_Enable_dispatch(); |
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92 | |
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93 | return remaining; |
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94 | } |
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