rtems-omk-template/appfoo/scheduler_edf.c

   1 #include "scheduler_edf.h"
   2 #include "rbtree.h"
   3 #include <stdio.h>
   4 #include <rtems/system.h>
   5 #include <rtems/score/isr.h>
   6 #include <rtems/score/watchdog.h>
   7 #include <rtems/score/wkspace.h>
   8
   9 /* let the scheduler talk */
  10 #define SCHED_VERBOSE
  11
  12
  13 void _Scheduler_edf_Initialize(void) {
  14         #ifdef SCHED_VERBOSE
  15         printf("Sched: Initialize");
  16         #endif
  17         // initialize the RB tree
  18         _Thread_Ready_EDF_chain.root = NULL;
  19         _Thread_Ready_EDF_chain.first = NULL;
  20         _Thread_Heir = NULL;
  21         _Thread_Executing = NULL;
  22 }
  23
  24 void _Scheduler_edf_Block(  Thread_Control    *the_thread ) {
  25         #ifdef SCHED_VERBOSE
  26         printf("Sched: Block");
  27         #endif
  28         _Scheduler_edf_Extract(the_thread);
  29 }
  30
  31 void _Scheduler_edf_Schedule(void) {
  32         #ifdef SCHED_VERBOSE
  33         printf("Sched: Schedule");
  34         #endif
  35         // set the heir
  36         _Thread_Heir = (Thread_Control *) _Thread_Ready_EDF_chain.first;
  37 }
  38
  39 void * _Scheduler_edf_Allocate(  Thread_Control      *the_thread) {
  40         #ifdef SCHED_VERBOSE
  41         printf("Sched: Allocate");
  42         #endif
  43         void * sched;
  44         RBT_Node *schinfo;
  45         sched = _Workspace_Allocate (sizeof(RBT_Node));
  46         the_thread->scheduler_info = (RBT_Node *) sched;
  47         the_thread->real_priority = ABS_DEADLINE_MAXIMUM - _Watchdog_Ticks_since_boot-2;
  48         the_thread->is_preemptible = TRUE;
  49         the_thread->budget_algorithm = THREAD_CPU_BUDGET_ALGORITHM_NONE;
  50         the_thread->budget_callout = NULL;
  51
  52         schinfo = (RBT_Node *)(the_thread->scheduler_info);
  53         schinfo->rel_deadline = the_thread->real_priority;
  54         schinfo->abs_deadline = 0;
  55         schinfo->left = NULL;
  56         schinfo->right = NULL;
  57         schinfo->parent = NULL;
  58         schinfo->ready_chain = &_Thread_Ready_EDF_chain;
  59
  60         return sched;
  61 }
  62
  63 void _Scheduler_edf_Free(  Thread_Control      *the_thread) {
  64         #ifdef SCHED_VERBOSE
  65         printf("Sched: Free");
  66         #endif
  67         _Workspace_Free (the_thread->scheduler_info);
  68 }
  69
  70 void _Scheduler_edf_Update(  Thread_Control      *the_thread) {
  71         #ifdef SCHED_VERBOSE
  72         printf("Sched: Update");
  73         #endif
  74         // after a priority changes, just extract and insert again
  75         //in case it is in the tree
  76         EDF_Chain_Control* chain = ((RBT_Node*)the_thread->scheduler_info)->ready_chain;
  77         _RBT_Extract(chain, the_thread);
  78         _RBT_Insert(chain, the_thread); // preserve the abs_deadline
  79 }
  80
  81 void _Scheduler_edf_Unblock(  Thread_Control    *the_thread ) {
  82         #ifdef SCHED_VERBOSE
  83         printf("Sched: Unblock");
  84         #endif
  85         _Scheduler_edf_Enqueue(the_thread);
  86 }
  87
  88 void _Scheduler_edf_Yield( void ) {
  89         #ifdef SCHED_VERBOSE
  90         printf("Sched: Yield");
  91         #endif
  92
  93         RBT_Node *sched_info;
  94         ISR_Level                      level;
  95         Thread_Control                *executing;
  96         EDF_Chain_Control                 *ready;
  97
  98         executing  = _Thread_Executing;
  99         sched_info = (RBT_Node *) executing->scheduler_info;
 100         ready      = sched_info->ready_chain;
 101         _ISR_Disable( level );
 102         if ( !_RBT_Has_only_one_node( ready ) ) {
 103                 _RBT_Extract(ready,executing);
 104                 _RBT_Insert(ready,executing); // preserve the abs_deadline
 105
 106                 _ISR_Flash( level );
 107
 108                 if ( _Thread_Is_heir( executing ) )
 109                         _Thread_Heir = (Thread_Control *) ready->first;
 110                 _Thread_Dispatch_necessary = TRUE;
 111         }
 112         else if ( !_Thread_Is_heir( executing ) )
 113                 _Thread_Dispatch_necessary = TRUE;
 114
 115         _ISR_Enable( level );
 116         // --------------------------------
 117
 118 }
 119
 120 void _Scheduler_edf_Enqueue(  Thread_Control    *the_thread) {
 121         #ifdef SCHED_VERBOSE
 122         printf("Sched: Enqueue");
 123         #endif
 124         RBT_Node *node = (RBT_Node*)the_thread->scheduler_info;
 125         EDF_Chain_Control *chain = node->ready_chain;
 126         node->abs_deadline = _Watchdog_Ticks_since_boot + node->rel_deadline;
 127         _RBT_Insert(chain,the_thread);
 128 }
 129
 130 void _Scheduler_edf_Enqueue_first(  Thread_Control    *the_thread) {
 131         #ifdef SCHED_VERBOSE
 132         printf("Sched: Enqueue_first");
 133         #endif
 134         // FIXME: force first position
 135         EDF_Chain_Control* chain = ((RBT_Node*)the_thread->scheduler_info)->ready_chain;
 136         _RBT_Insert(chain,the_thread);
 137 }
 138
 139 void _Scheduler_edf_Extract(  Thread_Control     *the_thread) {
 140         #ifdef SCHED_VERBOSE
 141         printf("Sched: Extract");
 142         #endif
 143         EDF_Chain_Control* chain = ((RBT_Node*)the_thread->scheduler_info)->ready_chain;
 144         _RBT_Extract(chain,the_thread);
 145 }
 146