tool/mbed/mbed-sdk/libraries/rtos/rtx/TARGET_CORTEX_M/rt_Task.c

   1 /*----------------------------------------------------------------------------
   2  *      RL-ARM - RTX
   3  *----------------------------------------------------------------------------
   4  *      Name:    RT_TASK.C
   5  *      Purpose: Task functions and system start up.
   6  *      Rev.:    V4.60
   7  *----------------------------------------------------------------------------
   8  *
   9  * Copyright (c) 1999-2009 KEIL, 2009-2012 ARM Germany GmbH
  10  * All rights reserved.
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions are met:
  13  *  - Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *  - Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *  - Neither the name of ARM  nor the names of its contributors may be used
  19  *    to endorse or promote products derived from this software without
  20  *    specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  23  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS AND CONTRIBUTORS BE
  26  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  32  * POSSIBILITY OF SUCH DAMAGE.
  33  *---------------------------------------------------------------------------*/
  34
  35 #include "rt_TypeDef.h"
  36 #include "RTX_Conf.h"
  37 #include "rt_System.h"
  38 #include "rt_Task.h"
  39 #include "rt_List.h"
  40 #include "rt_MemBox.h"
  41 #include "rt_Robin.h"
  42 #include "rt_HAL_CM.h"
  43
  44 /*----------------------------------------------------------------------------
  45  *      Global Variables
  46  *---------------------------------------------------------------------------*/
  47
  48 /* Running and next task info. */
  49 struct OS_TSK os_tsk;
  50
  51 /* Task Control Blocks of idle demon */
  52 struct OS_TCB os_idle_TCB;
  53
  54
  55 /*----------------------------------------------------------------------------
  56  *      Local Functions
  57  *---------------------------------------------------------------------------*/
  58
  59 OS_TID rt_get_TID (void) {
  60   U32 tid;
  61
  62   for (tid = 1; tid <= os_maxtaskrun; tid++) {
  63     if (os_active_TCB[tid-1] == NULL) {
  64       return ((OS_TID)tid);
  65     }
  66   }
  67   return (0);
  68 }
  69
  70 #if defined (__CC_ARM) && !defined (__MICROLIB)
  71 /*--------------------------- __user_perthread_libspace ---------------------*/
  72 extern void  *__libspace_start;
  73
  74 void *__user_perthread_libspace (void) {
  75   /* Provide a separate libspace for each task. */
  76   if (os_tsk.run == NULL) {
  77     /* RTX not running yet. */
  78     return (&__libspace_start);
  79   }
  80   return (void *)(os_tsk.run->std_libspace);
  81 }
  82 #endif
  83
  84 /*--------------------------- rt_init_context -------------------------------*/
  85
  86 void rt_init_context (P_TCB p_TCB, U8 priority, FUNCP task_body) {
  87   /* Initialize general part of the Task Control Block. */
  88   p_TCB->cb_type = TCB;
  89   p_TCB->state   = READY;
  90   p_TCB->prio    = priority;
  91   p_TCB->p_lnk   = NULL;
  92   p_TCB->p_rlnk  = NULL;
  93   p_TCB->p_dlnk  = NULL;
  94   p_TCB->p_blnk  = NULL;
  95   p_TCB->delta_time    = 0;
  96   p_TCB->interval_time = 0;
  97   p_TCB->events  = 0;
  98   p_TCB->waits   = 0;
  99   p_TCB->stack_frame = 0;
 100
 101   rt_init_stack (p_TCB, task_body);
 102 }
 103
 104
 105 /*--------------------------- rt_switch_req ---------------------------------*/
 106
 107 void rt_switch_req (P_TCB p_new) {
 108   /* Switch to next task (identified by "p_new"). */
 109   os_tsk.new_tsk   = p_new;
 110   p_new->state = RUNNING;
 111   DBG_TASK_SWITCH(p_new->task_id);
 112 }
 113
 114
 115 /*--------------------------- rt_dispatch -----------------------------------*/
 116
 117 void rt_dispatch (P_TCB next_TCB) {
 118   /* Dispatch next task if any identified or dispatch highest ready task    */
 119   /* "next_TCB" identifies a task to run or has value NULL (=no next task)  */
 120   if (next_TCB == NULL) {
 121     /* Running task was blocked: continue with highest ready task */
 122     next_TCB = rt_get_first (&os_rdy);
 123     rt_switch_req (next_TCB);
 124   }
 125   else {
 126     /* Check which task continues */
 127     if (next_TCB->prio > os_tsk.run->prio) {
 128       /* preempt running task */
 129       rt_put_rdy_first (os_tsk.run);
 130       os_tsk.run->state = READY;
 131       rt_switch_req (next_TCB);
 132     }
 133     else {
 134       /* put next task into ready list, no task switch takes place */
 135       next_TCB->state = READY;
 136       rt_put_prio (&os_rdy, next_TCB);
 137     }
 138   }
 139 }
 140
 141
 142 /*--------------------------- rt_block --------------------------------------*/
 143
 144 void rt_block (U16 timeout, U8 block_state) {
 145   /* Block running task and choose next ready task.                         */
 146   /* "timeout" sets a time-out value or is 0xffff (=no time-out).           */
 147   /* "block_state" defines the appropriate task state */
 148   P_TCB next_TCB;
 149
 150   if (timeout) {
 151     if (timeout < 0xffff) {
 152       rt_put_dly (os_tsk.run, timeout);
 153     }
 154     os_tsk.run->state = block_state;
 155     next_TCB = rt_get_first (&os_rdy);
 156     rt_switch_req (next_TCB);
 157   }
 158 }
 159
 160
 161 /*--------------------------- rt_tsk_pass -----------------------------------*/
 162
 163 void rt_tsk_pass (void) {
 164   /* Allow tasks of same priority level to run cooperatively.*/
 165   P_TCB p_new;
 166
 167   p_new = rt_get_same_rdy_prio();
 168   if (p_new != NULL) {
 169     rt_put_prio ((P_XCB)&os_rdy, os_tsk.run);
 170     os_tsk.run->state = READY;
 171     rt_switch_req (p_new);
 172   }
 173 }
 174
 175
 176 /*--------------------------- rt_tsk_self -----------------------------------*/
 177
 178 OS_TID rt_tsk_self (void) {
 179   /* Return own task identifier value. */
 180   if (os_tsk.run == NULL) {
 181     return (0);
 182   }
 183   return (os_tsk.run->task_id);
 184 }
 185
 186
 187 /*--------------------------- rt_tsk_prio -----------------------------------*/
 188
 189 OS_RESULT rt_tsk_prio (OS_TID task_id, U8 new_prio) {
 190   /* Change execution priority of a task to "new_prio". */
 191   P_TCB p_task;
 192
 193   if (task_id == 0) {
 194     /* Change execution priority of calling task. */
 195     os_tsk.run->prio = new_prio;
 196 run:if (rt_rdy_prio() > new_prio) {
 197       rt_put_prio (&os_rdy, os_tsk.run);
 198       os_tsk.run->state   = READY;
 199       rt_dispatch (NULL);
 200     }
 201     return (OS_R_OK);
 202   }
 203
 204   /* Find the task in the "os_active_TCB" array. */
 205   if (task_id > os_maxtaskrun || os_active_TCB[task_id-1] == NULL) {
 206     /* Task with "task_id" not found or not started. */
 207     return (OS_R_NOK);
 208   }
 209   p_task = os_active_TCB[task_id-1];
 210   p_task->prio = new_prio;
 211   if (p_task == os_tsk.run) {
 212     goto run;
 213   }
 214   rt_resort_prio (p_task);
 215   if (p_task->state == READY) {
 216     /* Task enqueued in a ready list. */
 217     p_task = rt_get_first (&os_rdy);
 218     rt_dispatch (p_task);
 219   }
 220   return (OS_R_OK);
 221 }
 222
 223 /*--------------------------- rt_tsk_delete ---------------------------------*/
 224
 225 OS_RESULT rt_tsk_delete (OS_TID task_id) {
 226   /* Terminate the task identified with "task_id". */
 227   P_TCB task_context;
 228
 229   if (task_id == 0 || task_id == os_tsk.run->task_id) {
 230     /* Terminate itself. */
 231     os_tsk.run->state     = INACTIVE;
 232     os_tsk.run->tsk_stack = rt_get_PSP ();
 233     rt_stk_check ();
 234     os_active_TCB[os_tsk.run->task_id-1] = NULL;
 235
 236     os_tsk.run->stack = NULL;
 237     DBG_TASK_NOTIFY(os_tsk.run, __FALSE);
 238     os_tsk.run = NULL;
 239     rt_dispatch (NULL);
 240     /* The program should never come to this point. */
 241   }
 242   else {
 243     /* Find the task in the "os_active_TCB" array. */
 244     if (task_id > os_maxtaskrun || os_active_TCB[task_id-1] == NULL) {
 245       /* Task with "task_id" not found or not started. */
 246       return (OS_R_NOK);
 247     }
 248     task_context = os_active_TCB[task_id-1];
 249     rt_rmv_list (task_context);
 250     rt_rmv_dly (task_context);
 251     os_active_TCB[task_id-1] = NULL;
 252
 253     task_context->stack = NULL;
 254     DBG_TASK_NOTIFY(task_context, __FALSE);
 255   }
 256   return (OS_R_OK);
 257 }
 258
 259
 260 /*--------------------------- rt_sys_init -----------------------------------*/
 261
 262 #ifdef __CMSIS_RTOS
 263 void rt_sys_init (void) {
 264 #else
 265 void rt_sys_init (FUNCP first_task, U32 prio_stksz, void *stk) {
 266 #endif
 267   /* Initialize system and start up task declared with "first_task". */
 268   U32 i;
 269
 270   DBG_INIT();
 271
 272   /* Initialize dynamic memory and task TCB pointers to NULL. */
 273   for (i = 0; i < os_maxtaskrun; i++) {
 274     os_active_TCB[i] = NULL;
 275   }
 276
 277   /* Set up TCB of idle demon */
 278   os_idle_TCB.task_id = 255;
 279   os_idle_TCB.priv_stack = idle_task_stack_size;
 280   os_idle_TCB.stack = idle_task_stack;
 281   rt_init_context (&os_idle_TCB, 0, os_idle_demon);
 282
 283   /* Set up ready list: initially empty */
 284   os_rdy.cb_type = HCB;
 285   os_rdy.p_lnk   = NULL;
 286   /* Set up delay list: initially empty */
 287   os_dly.cb_type = HCB;
 288   os_dly.p_dlnk  = NULL;
 289   os_dly.p_blnk  = NULL;
 290   os_dly.delta_time = 0;
 291
 292   /* Fix SP and systemvariables to assume idle task is running  */
 293   /* Transform main program into idle task by assuming idle TCB */
 294 #ifndef __CMSIS_RTOS
 295   rt_set_PSP (os_idle_TCB.tsk_stack+32);
 296 #endif
 297   os_tsk.run = &os_idle_TCB;
 298   os_tsk.run->state = RUNNING;
 299
 300   /* Initialize ps queue */
 301   os_psq->first = 0;
 302   os_psq->last  = 0;
 303   os_psq->size  = os_fifo_size;
 304
 305   rt_init_robin ();
 306
 307   /* Intitialize SVC and PendSV */
 308   rt_svc_init ();
 309
 310 #ifndef __CMSIS_RTOS
 311   /* Intitialize and start system clock timer */
 312   os_tick_irqn = os_tick_init ();
 313   if (os_tick_irqn >= 0) {
 314     OS_X_INIT(os_tick_irqn);
 315   }
 316
 317   /* Start up first user task before entering the endless loop */
 318   rt_tsk_create (first_task, prio_stksz, stk, NULL);
 319 #endif
 320 }
 321
 322
 323 /*--------------------------- rt_sys_start ----------------------------------*/
 324
 325 #ifdef __CMSIS_RTOS
 326 void rt_sys_start (void) {
 327   /* Start system */
 328
 329   /* Intitialize and start system clock timer */
 330   os_tick_irqn = os_tick_init ();
 331   if (os_tick_irqn >= 0) {
 332     OS_X_INIT(os_tick_irqn);
 333   }
 334 }
 335 #endif
 336
 337 /*----------------------------------------------------------------------------
 338  * end of file
 339  *---------------------------------------------------------------------------*/