1 | /** |
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2 | * @file |
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3 | * |
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4 | * @brief RTEMS Set Task Priority |
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5 | * @ingroup ClassicTasks |
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6 | */ |
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7 | |
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8 | /* |
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9 | * COPYRIGHT (c) 1989-2014. |
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10 | * On-Line Applications Research Corporation (OAR). |
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11 | * |
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12 | * The license and distribution terms for this file may be |
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13 | * found in the file LICENSE in this distribution or at |
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14 | * http://www.rtems.org/license/LICENSE. |
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15 | */ |
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16 | |
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17 | #if HAVE_CONFIG_H |
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18 | #include "config.h" |
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19 | #endif |
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20 | |
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21 | #include <rtems/rtems/tasksimpl.h> |
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22 | #include <rtems/score/schedulerimpl.h> |
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23 | #include <rtems/score/threadimpl.h> |
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24 | |
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25 | static rtems_status_code _RTEMS_tasks_Set_priority( |
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26 | Thread_Control *the_thread, |
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27 | const Scheduler_Control *scheduler, |
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28 | Priority_Control new_priority, |
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29 | Thread_queue_Context *queue_context |
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30 | ) |
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31 | { |
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32 | Priority_Control core_new_priority; |
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33 | bool valid; |
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34 | Per_CPU_Control *cpu_self; |
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35 | |
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36 | core_new_priority = _RTEMS_Priority_To_core( |
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37 | scheduler, |
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38 | new_priority, |
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39 | &valid |
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40 | ); |
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41 | |
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42 | if ( !valid ) { |
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43 | _Thread_Wait_release( the_thread, queue_context ); |
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44 | return RTEMS_INVALID_PRIORITY; |
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45 | } |
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46 | |
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47 | _Thread_Priority_change( |
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48 | the_thread, |
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49 | &the_thread->Real_priority, |
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50 | core_new_priority, |
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51 | false, |
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52 | queue_context |
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53 | ); |
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54 | cpu_self = _Thread_queue_Dispatch_disable( queue_context ); |
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55 | _Thread_Wait_release( the_thread, queue_context ); |
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56 | _Thread_Priority_update( queue_context ); |
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57 | _Thread_Dispatch_enable( cpu_self ); |
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58 | return RTEMS_SUCCESSFUL; |
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59 | } |
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60 | |
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61 | rtems_status_code rtems_task_set_priority( |
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62 | rtems_id id, |
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63 | rtems_task_priority new_priority, |
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64 | rtems_task_priority *old_priority_p |
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65 | ) |
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66 | { |
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67 | Thread_Control *the_thread; |
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68 | Thread_queue_Context queue_context; |
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69 | const Scheduler_Control *scheduler; |
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70 | Priority_Control old_priority; |
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71 | rtems_status_code status; |
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72 | |
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73 | if ( old_priority_p == NULL ) { |
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74 | return RTEMS_INVALID_ADDRESS; |
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75 | } |
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76 | |
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77 | _Thread_queue_Context_initialize( &queue_context ); |
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78 | _Thread_queue_Context_clear_priority_updates( &queue_context ); |
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79 | the_thread = _Thread_Get( id, &queue_context.Lock_context.Lock_context ); |
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80 | |
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81 | if ( the_thread == NULL ) { |
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82 | #if defined(RTEMS_MULTIPROCESSING) |
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83 | return _RTEMS_tasks_MP_Set_priority( id, new_priority, old_priority_p ); |
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84 | #else |
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85 | return RTEMS_INVALID_ID; |
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86 | #endif |
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87 | } |
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88 | |
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89 | _Thread_Wait_acquire_critical( the_thread, &queue_context ); |
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90 | |
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91 | scheduler = _Thread_Scheduler_get_home( the_thread ); |
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92 | old_priority = _Thread_Get_priority( the_thread ); |
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93 | |
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94 | if ( new_priority != RTEMS_CURRENT_PRIORITY ) { |
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95 | status = _RTEMS_tasks_Set_priority( |
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96 | the_thread, |
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97 | scheduler, |
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98 | new_priority, |
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99 | &queue_context |
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100 | ); |
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101 | } else { |
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102 | _Thread_Wait_release( the_thread, &queue_context ); |
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103 | status = RTEMS_SUCCESSFUL; |
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104 | } |
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105 | |
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106 | *old_priority_p = _RTEMS_Priority_From_core( scheduler, old_priority ); |
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107 | return status; |
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108 | } |
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