Diff: mbed-rtos/rtx/rt_Task.c

Revision:

0:1c8f2727e9f5

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-rtos/rtx/rt_Task.c	Thu Apr 03 22:56:32 2014 +0000
@@ -0,0 +1,339 @@
+/*----------------------------------------------------------------------------
+ *      RL-ARM - RTX
+ *----------------------------------------------------------------------------
+ *      Name:    RT_TASK.C
+ *      Purpose: Task functions and system start up.
+ *      Rev.:    V4.60
+ *----------------------------------------------------------------------------
+ *
+ * Copyright (c) 1999-2009 KEIL, 2009-2012 ARM Germany GmbH
+ * All rights reserved.
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *  - Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  - Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *  - Neither the name of ARM  nor the names of its contributors may be used 
+ *    to endorse or promote products derived from this software without 
+ *    specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS AND CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *---------------------------------------------------------------------------*/
+
+#include "rt_TypeDef.h"
+#include "RTX_Config.h"
+#include "rt_System.h"
+#include "rt_Task.h"
+#include "rt_List.h"
+#include "rt_MemBox.h"
+#include "rt_Robin.h"
+#include "rt_HAL_CM.h"
+
+/*----------------------------------------------------------------------------
+ *      Global Variables
+ *---------------------------------------------------------------------------*/
+
+/* Running and next task info. */
+struct OS_TSK os_tsk;
+
+/* Task Control Blocks of idle demon */
+struct OS_TCB os_idle_TCB;
+
+
+/*----------------------------------------------------------------------------
+ *      Local Functions
+ *---------------------------------------------------------------------------*/
+
+OS_TID rt_get_TID (void) {
+  U32 tid;
+
+  for (tid = 1; tid <= os_maxtaskrun; tid++) {
+    if (os_active_TCB[tid-1] == NULL) {
+      return ((OS_TID)tid);
+    }
+  }
+  return (0);
+}
+
+#if defined (__CC_ARM) && !defined (__MICROLIB)
+/*--------------------------- __user_perthread_libspace ---------------------*/
+extern void  *__libspace_start;
+
+void *__user_perthread_libspace (void) {
+  /* Provide a separate libspace for each task. */
+  if (os_tsk.run == NULL) {
+    /* RTX not running yet. */
+    return (&__libspace_start);
+  }
+  return (void *)(os_tsk.run->std_libspace);
+}
+#endif
+
+/*--------------------------- rt_init_context -------------------------------*/
+
+void rt_init_context (P_TCB p_TCB, U8 priority, FUNCP task_body) {
+  /* Initialize general part of the Task Control Block. */
+  p_TCB->cb_type = TCB;
+  p_TCB->state   = READY;
+  p_TCB->prio    = priority;
+  p_TCB->p_lnk   = NULL;
+  p_TCB->p_rlnk  = NULL;
+  p_TCB->p_dlnk  = NULL;
+  p_TCB->p_blnk  = NULL;
+  p_TCB->delta_time    = 0;
+  p_TCB->interval_time = 0;
+  p_TCB->events  = 0;
+  p_TCB->waits   = 0;
+  p_TCB->stack_frame = 0;
+
+  rt_init_stack (p_TCB, task_body);
+}
+
+
+/*--------------------------- rt_switch_req ---------------------------------*/
+
+void rt_switch_req (P_TCB p_new) {
+  /* Switch to next task (identified by "p_new"). */
+  os_tsk.new_tsk   = p_new;
+  p_new->state = RUNNING;
+  DBG_TASK_SWITCH(p_new->task_id);
+}
+
+
+/*--------------------------- rt_dispatch -----------------------------------*/
+
+void rt_dispatch (P_TCB next_TCB) {
+  /* Dispatch next task if any identified or dispatch highest ready task    */
+  /* "next_TCB" identifies a task to run or has value NULL (=no next task)  */
+  if (next_TCB == NULL) {
+    /* Running task was blocked: continue with highest ready task */
+    next_TCB = rt_get_first (&os_rdy);
+    rt_switch_req (next_TCB);
+  }
+  else {
+    /* Check which task continues */
+    if (next_TCB->prio > os_tsk.run->prio) {
+      /* preempt running task */
+      rt_put_rdy_first (os_tsk.run);
+      os_tsk.run->state = READY;
+      rt_switch_req (next_TCB);
+    }
+    else {
+      /* put next task into ready list, no task switch takes place */
+      next_TCB->state = READY;
+      rt_put_prio (&os_rdy, next_TCB);
+    }
+  }
+}
+
+
+/*--------------------------- rt_block --------------------------------------*/
+
+void rt_block (U16 timeout, U8 block_state) {
+  /* Block running task and choose next ready task.                         */
+  /* "timeout" sets a time-out value or is 0xffff (=no time-out).           */
+  /* "block_state" defines the appropriate task state */
+  P_TCB next_TCB;
+
+  if (timeout) {
+    if (timeout < 0xffff) {
+      rt_put_dly (os_tsk.run, timeout);
+    }
+    os_tsk.run->state = block_state;
+    next_TCB = rt_get_first (&os_rdy);
+    rt_switch_req (next_TCB);
+  }
+}
+
+
+/*--------------------------- rt_tsk_pass -----------------------------------*/
+
+void rt_tsk_pass (void) {
+  /* Allow tasks of same priority level to run cooperatively.*/
+  P_TCB p_new;
+
+  p_new = rt_get_same_rdy_prio();
+  if (p_new != NULL) {
+    rt_put_prio ((P_XCB)&os_rdy, os_tsk.run);
+    os_tsk.run->state = READY;
+    rt_switch_req (p_new);
+  }
+}
+
+
+/*--------------------------- rt_tsk_self -----------------------------------*/
+
+OS_TID rt_tsk_self (void) {
+  /* Return own task identifier value. */
+  if (os_tsk.run == NULL) {
+    return (0);
+  }
+  return (os_tsk.run->task_id);
+}
+
+
+/*--------------------------- rt_tsk_prio -----------------------------------*/
+
+OS_RESULT rt_tsk_prio (OS_TID task_id, U8 new_prio) {
+  /* Change execution priority of a task to "new_prio". */
+  P_TCB p_task;
+
+  if (task_id == 0) {
+    /* Change execution priority of calling task. */
+    os_tsk.run->prio = new_prio;
+run:if (rt_rdy_prio() > new_prio) {
+      rt_put_prio (&os_rdy, os_tsk.run);
+      os_tsk.run->state   = READY;
+      rt_dispatch (NULL);
+    }
+    return (OS_R_OK);
+  }
+
+  /* Find the task in the "os_active_TCB" array. */
+  if (task_id > os_maxtaskrun || os_active_TCB[task_id-1] == NULL) {
+    /* Task with "task_id" not found or not started. */
+    return (OS_R_NOK);
+  }
+  p_task = os_active_TCB[task_id-1];
+  p_task->prio = new_prio;
+  if (p_task == os_tsk.run) {
+    goto run;
+  }
+  rt_resort_prio (p_task);
+  if (p_task->state == READY) {
+    /* Task enqueued in a ready list. */
+    p_task = rt_get_first (&os_rdy);
+    rt_dispatch (p_task);
+  }
+  return (OS_R_OK);
+}
+
+/*--------------------------- rt_tsk_delete ---------------------------------*/
+
+OS_RESULT rt_tsk_delete (OS_TID task_id) {
+  /* Terminate the task identified with "task_id". */
+  P_TCB task_context;
+
+  if (task_id == 0 || task_id == os_tsk.run->task_id) {
+    /* Terminate itself. */
+    os_tsk.run->state     = INACTIVE;
+    os_tsk.run->tsk_stack = rt_get_PSP ();
+    rt_stk_check ();
+    os_active_TCB[os_tsk.run->task_id-1] = NULL;
+    
+    os_tsk.run->stack = NULL;
+    DBG_TASK_NOTIFY(os_tsk.run, __FALSE);
+    os_tsk.run = NULL;
+    rt_dispatch (NULL);
+    /* The program should never come to this point. */
+  }
+  else {
+    /* Find the task in the "os_active_TCB" array. */
+    if (task_id > os_maxtaskrun || os_active_TCB[task_id-1] == NULL) {
+      /* Task with "task_id" not found or not started. */
+      return (OS_R_NOK);
+    }
+    task_context = os_active_TCB[task_id-1];
+    rt_rmv_list (task_context);
+    rt_rmv_dly (task_context);
+    os_active_TCB[task_id-1] = NULL;
+    
+    task_context->stack = NULL;
+    DBG_TASK_NOTIFY(task_context, __FALSE);
+  }
+  return (OS_R_OK);
+}
+
+
+/*--------------------------- rt_sys_init -----------------------------------*/
+
+#ifdef __CMSIS_RTOS
+void rt_sys_init (void) {
+#else
+void rt_sys_init (FUNCP first_task, U32 prio_stksz, void *stk) {
+#endif
+  /* Initialize system and start up task declared with "first_task". */
+  U32 i;
+
+  DBG_INIT();
+
+  /* Initialize dynamic memory and task TCB pointers to NULL. */
+  for (i = 0; i < os_maxtaskrun; i++) {
+    os_active_TCB[i] = NULL;
+  }
+  
+  /* Set up TCB of idle demon */
+  os_idle_TCB.task_id = 255;
+  os_idle_TCB.priv_stack = idle_task_stack_size;
+  os_idle_TCB.stack = idle_task_stack;
+  rt_init_context (&os_idle_TCB, 0, os_idle_demon);
+
+  /* Set up ready list: initially empty */
+  os_rdy.cb_type = HCB;
+  os_rdy.p_lnk   = NULL;
+  /* Set up delay list: initially empty */
+  os_dly.cb_type = HCB;
+  os_dly.p_dlnk  = NULL;
+  os_dly.p_blnk  = NULL;
+  os_dly.delta_time = 0;
+
+  /* Fix SP and systemvariables to assume idle task is running  */
+  /* Transform main program into idle task by assuming idle TCB */
+#ifndef __CMSIS_RTOS
+  rt_set_PSP (os_idle_TCB.tsk_stack+32);
+#endif
+  os_tsk.run = &os_idle_TCB;
+  os_tsk.run->state = RUNNING;
+
+  /* Initialize ps queue */
+  os_psq->first = 0;
+  os_psq->last  = 0;
+  os_psq->size  = os_fifo_size;
+
+  rt_init_robin ();
+
+  /* Intitialize SVC and PendSV */
+  rt_svc_init ();
+
+#ifndef __CMSIS_RTOS
+  /* Intitialize and start system clock timer */
+  os_tick_irqn = os_tick_init ();
+  if (os_tick_irqn >= 0) {
+    OS_X_INIT(os_tick_irqn);
+  }
+
+  /* Start up first user task before entering the endless loop */
+  rt_tsk_create (first_task, prio_stksz, stk, NULL);
+#endif
+}
+
+
+/*--------------------------- rt_sys_start ----------------------------------*/
+
+#ifdef __CMSIS_RTOS
+void rt_sys_start (void) {
+  /* Start system */
+
+  /* Intitialize and start system clock timer */
+  os_tick_irqn = os_tick_init ();
+  if (os_tick_irqn >= 0) {
+    OS_X_INIT(os_tick_irqn);
+  }
+}
+#endif
+
+/*----------------------------------------------------------------------------
+ * end of file
+ *---------------------------------------------------------------------------*/