tmk_core/tool/mbed/mbed-sdk/libraries/rtos/rtx/TARGET_CORTEX_M/rt_Robin.c

   1 /*----------------------------------------------------------------------------
   2  *      RL-ARM - RTX
   3  *----------------------------------------------------------------------------
   4  *      Name:    RT_ROBIN.C
   5  *      Purpose: Round Robin Task switching
   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_List.h"
  38 #include "rt_Task.h"
  39 #include "rt_Time.h"
  40 #include "rt_Robin.h"
  41 #include "rt_HAL_CM.h"
  42
  43 /*----------------------------------------------------------------------------
  44  *      Global Variables
  45  *---------------------------------------------------------------------------*/
  46
  47 struct OS_ROBIN os_robin;
  48
  49
  50 /*----------------------------------------------------------------------------
  51  *      Global Functions
  52  *---------------------------------------------------------------------------*/
  53
  54 /*--------------------------- rt_init_robin ---------------------------------*/
  55
  56 __weak void rt_init_robin (void) {
  57   /* Initialize Round Robin variables. */
  58   os_robin.task = NULL;
  59   os_robin.tout = (U16)os_rrobin;
  60 }
  61
  62 /*--------------------------- rt_chk_robin ----------------------------------*/
  63
  64 __weak void rt_chk_robin (void) {
  65   /* Check if Round Robin timeout expired and switch to the next ready task.*/
  66   P_TCB p_new;
  67
  68   if (os_robin.task != os_rdy.p_lnk) {
  69     /* New task was suspended, reset Round Robin timeout. */
  70     os_robin.task = os_rdy.p_lnk;
  71     os_robin.time = (U16)os_time + os_robin.tout - 1;
  72   }
  73   if (os_robin.time == (U16)os_time) {
  74     /* Round Robin timeout has expired, swap Robin tasks. */
  75     os_robin.task = NULL;
  76     p_new = rt_get_first (&os_rdy);
  77     rt_put_prio ((P_XCB)&os_rdy, p_new);
  78   }
  79 }
  80
  81 /*----------------------------------------------------------------------------
  82  * end of file
  83  *---------------------------------------------------------------------------*/
  84