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Dependencies:   mbed

mbed-rtos/rtx/rt_Mutex.c@0:52468b19aa21, 2020-07-29 (annotated)

Committer:
alanffrench
Date:
Wed Jul 29 18:51:38 2020 +0000
Revision:
0:52468b19aa21
Threads

Who changed what in which revision?

UserRevisionLine numberNew contents of line
alanffrench 0:52468b19aa21 1 /*----------------------------------------------------------------------------
alanffrench 0:52468b19aa21 2 * RL-ARM - RTX
alanffrench 0:52468b19aa21 3 *----------------------------------------------------------------------------
alanffrench 0:52468b19aa21 4 * Name: RT_MUTEX.C
alanffrench 0:52468b19aa21 5 * Purpose: Implements mutex synchronization objects
alanffrench 0:52468b19aa21 6 * Rev.: V4.60
alanffrench 0:52468b19aa21 7 *----------------------------------------------------------------------------
alanffrench 0:52468b19aa21 8 *
alanffrench 0:52468b19aa21 9 * Copyright (c) 1999-2009 KEIL, 2009-2012 ARM Germany GmbH
alanffrench 0:52468b19aa21 10 * All rights reserved.
alanffrench 0:52468b19aa21 11 * Redistribution and use in source and binary forms, with or without
alanffrench 0:52468b19aa21 12 * modification, are permitted provided that the following conditions are met:
alanffrench 0:52468b19aa21 13 * - Redistributions of source code must retain the above copyright
alanffrench 0:52468b19aa21 14 * notice, this list of conditions and the following disclaimer.
alanffrench 0:52468b19aa21 15 * - Redistributions in binary form must reproduce the above copyright
alanffrench 0:52468b19aa21 16 * notice, this list of conditions and the following disclaimer in the
alanffrench 0:52468b19aa21 17 * documentation and/or other materials provided with the distribution.
alanffrench 0:52468b19aa21 18 * - Neither the name of ARM nor the names of its contributors may be used
alanffrench 0:52468b19aa21 19 * to endorse or promote products derived from this software without
alanffrench 0:52468b19aa21 20 * specific prior written permission.
alanffrench 0:52468b19aa21 21 *
alanffrench 0:52468b19aa21 22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
alanffrench 0:52468b19aa21 23 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
alanffrench 0:52468b19aa21 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
alanffrench 0:52468b19aa21 25 * ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS AND CONTRIBUTORS BE
alanffrench 0:52468b19aa21 26 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
alanffrench 0:52468b19aa21 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
alanffrench 0:52468b19aa21 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
alanffrench 0:52468b19aa21 29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
alanffrench 0:52468b19aa21 30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
alanffrench 0:52468b19aa21 31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
alanffrench 0:52468b19aa21 32 * POSSIBILITY OF SUCH DAMAGE.
alanffrench 0:52468b19aa21 33 *---------------------------------------------------------------------------*/
alanffrench 0:52468b19aa21 34
alanffrench 0:52468b19aa21 35 #include "rt_TypeDef.h"
alanffrench 0:52468b19aa21 36 #include "RTX_Config.h"
alanffrench 0:52468b19aa21 37 #include "rt_List.h"
alanffrench 0:52468b19aa21 38 #include "rt_Task.h"
alanffrench 0:52468b19aa21 39 #include "rt_Mutex.h"
alanffrench 0:52468b19aa21 40 #include "rt_HAL_CM.h"
alanffrench 0:52468b19aa21 41
alanffrench 0:52468b19aa21 42
alanffrench 0:52468b19aa21 43 /*----------------------------------------------------------------------------
alanffrench 0:52468b19aa21 44 * Functions
alanffrench 0:52468b19aa21 45 *---------------------------------------------------------------------------*/
alanffrench 0:52468b19aa21 46
alanffrench 0:52468b19aa21 47
alanffrench 0:52468b19aa21 48 /*--------------------------- rt_mut_init -----------------------------------*/
alanffrench 0:52468b19aa21 49
alanffrench 0:52468b19aa21 50 void rt_mut_init (OS_ID mutex) {
alanffrench 0:52468b19aa21 51 /* Initialize a mutex object */
alanffrench 0:52468b19aa21 52 P_MUCB p_MCB = mutex;
alanffrench 0:52468b19aa21 53
alanffrench 0:52468b19aa21 54 p_MCB->cb_type = MUCB;
alanffrench 0:52468b19aa21 55 p_MCB->prio = 0;
alanffrench 0:52468b19aa21 56 p_MCB->level = 0;
alanffrench 0:52468b19aa21 57 p_MCB->p_lnk = NULL;
alanffrench 0:52468b19aa21 58 p_MCB->owner = NULL;
alanffrench 0:52468b19aa21 59 }
alanffrench 0:52468b19aa21 60
alanffrench 0:52468b19aa21 61
alanffrench 0:52468b19aa21 62 /*--------------------------- rt_mut_delete ---------------------------------*/
alanffrench 0:52468b19aa21 63
alanffrench 0:52468b19aa21 64 #ifdef __CMSIS_RTOS
alanffrench 0:52468b19aa21 65 OS_RESULT rt_mut_delete (OS_ID mutex) {
alanffrench 0:52468b19aa21 66 /* Delete a mutex object */
alanffrench 0:52468b19aa21 67 P_MUCB p_MCB = mutex;
alanffrench 0:52468b19aa21 68 P_TCB p_TCB;
alanffrench 0:52468b19aa21 69
alanffrench 0:52468b19aa21 70 /* Restore owner task's priority. */
alanffrench 0:52468b19aa21 71 if (p_MCB->level != 0) {
alanffrench 0:52468b19aa21 72 p_MCB->owner->prio = p_MCB->prio;
alanffrench 0:52468b19aa21 73 if (p_MCB->owner != os_tsk.run) {
alanffrench 0:52468b19aa21 74 rt_resort_prio (p_MCB->owner);
alanffrench 0:52468b19aa21 75 }
alanffrench 0:52468b19aa21 76 }
alanffrench 0:52468b19aa21 77
alanffrench 0:52468b19aa21 78 while (p_MCB->p_lnk != NULL) {
alanffrench 0:52468b19aa21 79 /* A task is waiting for mutex. */
alanffrench 0:52468b19aa21 80 p_TCB = rt_get_first ((P_XCB)p_MCB);
alanffrench 0:52468b19aa21 81 rt_ret_val(p_TCB, 0/*osOK*/);
alanffrench 0:52468b19aa21 82 rt_rmv_dly(p_TCB);
alanffrench 0:52468b19aa21 83 p_TCB->state = READY;
alanffrench 0:52468b19aa21 84 rt_put_prio (&os_rdy, p_TCB);
alanffrench 0:52468b19aa21 85 }
alanffrench 0:52468b19aa21 86
alanffrench 0:52468b19aa21 87 if (os_rdy.p_lnk && (os_rdy.p_lnk->prio > os_tsk.run->prio)) {
alanffrench 0:52468b19aa21 88 /* preempt running task */
alanffrench 0:52468b19aa21 89 rt_put_prio (&os_rdy, os_tsk.run);
alanffrench 0:52468b19aa21 90 os_tsk.run->state = READY;
alanffrench 0:52468b19aa21 91 rt_dispatch (NULL);
alanffrench 0:52468b19aa21 92 }
alanffrench 0:52468b19aa21 93
alanffrench 0:52468b19aa21 94 p_MCB->cb_type = 0;
alanffrench 0:52468b19aa21 95
alanffrench 0:52468b19aa21 96 return (OS_R_OK);
alanffrench 0:52468b19aa21 97 }
alanffrench 0:52468b19aa21 98 #endif
alanffrench 0:52468b19aa21 99
alanffrench 0:52468b19aa21 100
alanffrench 0:52468b19aa21 101 /*--------------------------- rt_mut_release --------------------------------*/
alanffrench 0:52468b19aa21 102
alanffrench 0:52468b19aa21 103 OS_RESULT rt_mut_release (OS_ID mutex) {
alanffrench 0:52468b19aa21 104 /* Release a mutex object */
alanffrench 0:52468b19aa21 105 P_MUCB p_MCB = mutex;
alanffrench 0:52468b19aa21 106 P_TCB p_TCB;
alanffrench 0:52468b19aa21 107
alanffrench 0:52468b19aa21 108 if (p_MCB->level == 0 || p_MCB->owner != os_tsk.run) {
alanffrench 0:52468b19aa21 109 /* Unbalanced mutex release or task is not the owner */
alanffrench 0:52468b19aa21 110 return (OS_R_NOK);
alanffrench 0:52468b19aa21 111 }
alanffrench 0:52468b19aa21 112 if (--p_MCB->level != 0) {
alanffrench 0:52468b19aa21 113 return (OS_R_OK);
alanffrench 0:52468b19aa21 114 }
alanffrench 0:52468b19aa21 115 /* Restore owner task's priority. */
alanffrench 0:52468b19aa21 116 os_tsk.run->prio = p_MCB->prio;
alanffrench 0:52468b19aa21 117 if (p_MCB->p_lnk != NULL) {
alanffrench 0:52468b19aa21 118 /* A task is waiting for mutex. */
alanffrench 0:52468b19aa21 119 p_TCB = rt_get_first ((P_XCB)p_MCB);
alanffrench 0:52468b19aa21 120 #ifdef __CMSIS_RTOS
alanffrench 0:52468b19aa21 121 rt_ret_val(p_TCB, 0/*osOK*/);
alanffrench 0:52468b19aa21 122 #else
alanffrench 0:52468b19aa21 123 rt_ret_val(p_TCB, OS_R_MUT);
alanffrench 0:52468b19aa21 124 #endif
alanffrench 0:52468b19aa21 125 rt_rmv_dly (p_TCB);
alanffrench 0:52468b19aa21 126 /* A waiting task becomes the owner of this mutex. */
alanffrench 0:52468b19aa21 127 p_MCB->level = 1;
alanffrench 0:52468b19aa21 128 p_MCB->owner = p_TCB;
alanffrench 0:52468b19aa21 129 p_MCB->prio = p_TCB->prio;
alanffrench 0:52468b19aa21 130 /* Priority inversion, check which task continues. */
alanffrench 0:52468b19aa21 131 if (os_tsk.run->prio >= rt_rdy_prio()) {
alanffrench 0:52468b19aa21 132 rt_dispatch (p_TCB);
alanffrench 0:52468b19aa21 133 }
alanffrench 0:52468b19aa21 134 else {
alanffrench 0:52468b19aa21 135 /* Ready task has higher priority than running task. */
alanffrench 0:52468b19aa21 136 rt_put_prio (&os_rdy, os_tsk.run);
alanffrench 0:52468b19aa21 137 rt_put_prio (&os_rdy, p_TCB);
alanffrench 0:52468b19aa21 138 os_tsk.run->state = READY;
alanffrench 0:52468b19aa21 139 p_TCB->state = READY;
alanffrench 0:52468b19aa21 140 rt_dispatch (NULL);
alanffrench 0:52468b19aa21 141 }
alanffrench 0:52468b19aa21 142 }
alanffrench 0:52468b19aa21 143 else {
alanffrench 0:52468b19aa21 144 /* Check if own priority raised by priority inversion. */
alanffrench 0:52468b19aa21 145 if (rt_rdy_prio() > os_tsk.run->prio) {
alanffrench 0:52468b19aa21 146 rt_put_prio (&os_rdy, os_tsk.run);
alanffrench 0:52468b19aa21 147 os_tsk.run->state = READY;
alanffrench 0:52468b19aa21 148 rt_dispatch (NULL);
alanffrench 0:52468b19aa21 149 }
alanffrench 0:52468b19aa21 150 }
alanffrench 0:52468b19aa21 151 return (OS_R_OK);
alanffrench 0:52468b19aa21 152 }
alanffrench 0:52468b19aa21 153
alanffrench 0:52468b19aa21 154
alanffrench 0:52468b19aa21 155 /*--------------------------- rt_mut_wait -----------------------------------*/
alanffrench 0:52468b19aa21 156
alanffrench 0:52468b19aa21 157 OS_RESULT rt_mut_wait (OS_ID mutex, U16 timeout) {
alanffrench 0:52468b19aa21 158 /* Wait for a mutex, continue when mutex is free. */
alanffrench 0:52468b19aa21 159 P_MUCB p_MCB = mutex;
alanffrench 0:52468b19aa21 160
alanffrench 0:52468b19aa21 161 if (p_MCB->level == 0) {
alanffrench 0:52468b19aa21 162 p_MCB->owner = os_tsk.run;
alanffrench 0:52468b19aa21 163 p_MCB->prio = os_tsk.run->prio;
alanffrench 0:52468b19aa21 164 goto inc;
alanffrench 0:52468b19aa21 165 }
alanffrench 0:52468b19aa21 166 if (p_MCB->owner == os_tsk.run) {
alanffrench 0:52468b19aa21 167 /* OK, running task is the owner of this mutex. */
alanffrench 0:52468b19aa21 168 inc:p_MCB->level++;
alanffrench 0:52468b19aa21 169 return (OS_R_OK);
alanffrench 0:52468b19aa21 170 }
alanffrench 0:52468b19aa21 171 /* Mutex owned by another task, wait until released. */
alanffrench 0:52468b19aa21 172 if (timeout == 0) {
alanffrench 0:52468b19aa21 173 return (OS_R_TMO);
alanffrench 0:52468b19aa21 174 }
alanffrench 0:52468b19aa21 175 /* Raise the owner task priority if lower than current priority. */
alanffrench 0:52468b19aa21 176 /* This priority inversion is called priority inheritance. */
alanffrench 0:52468b19aa21 177 if (p_MCB->prio < os_tsk.run->prio) {
alanffrench 0:52468b19aa21 178 p_MCB->owner->prio = os_tsk.run->prio;
alanffrench 0:52468b19aa21 179 rt_resort_prio (p_MCB->owner);
alanffrench 0:52468b19aa21 180 }
alanffrench 0:52468b19aa21 181 if (p_MCB->p_lnk != NULL) {
alanffrench 0:52468b19aa21 182 rt_put_prio ((P_XCB)p_MCB, os_tsk.run);
alanffrench 0:52468b19aa21 183 }
alanffrench 0:52468b19aa21 184 else {
alanffrench 0:52468b19aa21 185 p_MCB->p_lnk = os_tsk.run;
alanffrench 0:52468b19aa21 186 os_tsk.run->p_lnk = NULL;
alanffrench 0:52468b19aa21 187 os_tsk.run->p_rlnk = (P_TCB)p_MCB;
alanffrench 0:52468b19aa21 188 }
alanffrench 0:52468b19aa21 189 rt_block(timeout, WAIT_MUT);
alanffrench 0:52468b19aa21 190 return (OS_R_TMO);
alanffrench 0:52468b19aa21 191 }
alanffrench 0:52468b19aa21 192
alanffrench 0:52468b19aa21 193
alanffrench 0:52468b19aa21 194 /*----------------------------------------------------------------------------
alanffrench 0:52468b19aa21 195 * end of file
alanffrench 0:52468b19aa21 196 *---------------------------------------------------------------------------*/
alanffrench 0:52468b19aa21 197