Frazer Legge / mbed-rtos

Official mbed Real Time Operating System based on the RTX implementation of the CMSIS-RTOS API open standard.

Dependents:   Assignment_3__Embedded_Software

Fork of mbed-rtos by mbed official

rtx/TARGET_ARM7/rt_Mutex.c@124:b63b65f13991, 2018-03-16 (annotated)

Committer:
f_legge
Date:
Fri Mar 16 13:44:31 2018 +0000
Revision:
124:b63b65f13991
Parent:
80:2dab120a94c2 
WattBob_Compat;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 80:2dab120a94c2 1 /*----------------------------------------------------------------------------
mbed_official 80:2dab120a94c2 2 * RL-ARM - RTX
mbed_official 80:2dab120a94c2 3 *----------------------------------------------------------------------------
mbed_official 80:2dab120a94c2 4 * Name: RT_MUTEX.C
mbed_official 80:2dab120a94c2 5 * Purpose: Implements mutex synchronization objects
mbed_official 80:2dab120a94c2 6 * Rev.: V4.60
mbed_official 80:2dab120a94c2 7 *----------------------------------------------------------------------------
mbed_official 80:2dab120a94c2 8 *
mbed_official 80:2dab120a94c2 9 * Copyright (c) 1999-2009 KEIL, 2009-2015 ARM Germany GmbH
mbed_official 80:2dab120a94c2 10 * All rights reserved.
mbed_official 80:2dab120a94c2 11 * Redistribution and use in source and binary forms, with or without
mbed_official 80:2dab120a94c2 12 * modification, are permitted provided that the following conditions are met:
mbed_official 80:2dab120a94c2 13 * - Redistributions of source code must retain the above copyright
mbed_official 80:2dab120a94c2 14 * notice, this list of conditions and the following disclaimer.
mbed_official 80:2dab120a94c2 15 * - Redistributions in binary form must reproduce the above copyright
mbed_official 80:2dab120a94c2 16 * notice, this list of conditions and the following disclaimer in the
mbed_official 80:2dab120a94c2 17 * documentation and/or other materials provided with the distribution.
mbed_official 80:2dab120a94c2 18 * - Neither the name of ARM nor the names of its contributors may be used
mbed_official 80:2dab120a94c2 19 * to endorse or promote products derived from this software without
mbed_official 80:2dab120a94c2 20 * specific prior written permission.
mbed_official 80:2dab120a94c2 21 *
mbed_official 80:2dab120a94c2 22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
mbed_official 80:2dab120a94c2 23 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
mbed_official 80:2dab120a94c2 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
mbed_official 80:2dab120a94c2 25 * ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS AND CONTRIBUTORS BE
mbed_official 80:2dab120a94c2 26 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
mbed_official 80:2dab120a94c2 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
mbed_official 80:2dab120a94c2 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
mbed_official 80:2dab120a94c2 29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
mbed_official 80:2dab120a94c2 30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
mbed_official 80:2dab120a94c2 31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
mbed_official 80:2dab120a94c2 32 * POSSIBILITY OF SUCH DAMAGE.
mbed_official 80:2dab120a94c2 33 *---------------------------------------------------------------------------*/
mbed_official 80:2dab120a94c2 34
mbed_official 80:2dab120a94c2 35 #include "rt_TypeDef.h"
mbed_official 80:2dab120a94c2 36 #include "RTX_Conf.h"
mbed_official 80:2dab120a94c2 37 #include "rt_List.h"
mbed_official 80:2dab120a94c2 38 #include "rt_Task.h"
mbed_official 80:2dab120a94c2 39 #include "rt_Mutex.h"
mbed_official 80:2dab120a94c2 40 #include "rt_HAL_CM.h"
mbed_official 80:2dab120a94c2 41
mbed_official 80:2dab120a94c2 42
mbed_official 80:2dab120a94c2 43 /*----------------------------------------------------------------------------
mbed_official 80:2dab120a94c2 44 * Functions
mbed_official 80:2dab120a94c2 45 *---------------------------------------------------------------------------*/
mbed_official 80:2dab120a94c2 46
mbed_official 80:2dab120a94c2 47
mbed_official 80:2dab120a94c2 48 /*--------------------------- rt_mut_init -----------------------------------*/
mbed_official 80:2dab120a94c2 49
mbed_official 80:2dab120a94c2 50 void rt_mut_init (OS_ID mutex) {
mbed_official 80:2dab120a94c2 51 /* Initialize a mutex object */
mbed_official 80:2dab120a94c2 52 P_MUCB p_MCB = mutex;
mbed_official 80:2dab120a94c2 53
mbed_official 80:2dab120a94c2 54 p_MCB->cb_type = MUCB;
mbed_official 80:2dab120a94c2 55 p_MCB->prio = 0;
mbed_official 80:2dab120a94c2 56 p_MCB->level = 0;
mbed_official 80:2dab120a94c2 57 p_MCB->p_lnk = NULL;
mbed_official 80:2dab120a94c2 58 p_MCB->owner = NULL;
mbed_official 80:2dab120a94c2 59 }
mbed_official 80:2dab120a94c2 60
mbed_official 80:2dab120a94c2 61
mbed_official 80:2dab120a94c2 62 /*--------------------------- rt_mut_delete ---------------------------------*/
mbed_official 80:2dab120a94c2 63
mbed_official 80:2dab120a94c2 64 #ifdef __CMSIS_RTOS
mbed_official 80:2dab120a94c2 65 OS_RESULT rt_mut_delete (OS_ID mutex) {
mbed_official 80:2dab120a94c2 66 /* Delete a mutex object */
mbed_official 80:2dab120a94c2 67 P_MUCB p_MCB = mutex;
mbed_official 80:2dab120a94c2 68 P_TCB p_TCB;
mbed_official 80:2dab120a94c2 69
mbed_official 80:2dab120a94c2 70 /* Restore owner task's priority. */
mbed_official 80:2dab120a94c2 71 if (p_MCB->level != 0) {
mbed_official 80:2dab120a94c2 72 p_MCB->owner->prio = p_MCB->prio;
mbed_official 80:2dab120a94c2 73 if (p_MCB->owner != os_tsk.run) {
mbed_official 80:2dab120a94c2 74 rt_resort_prio (p_MCB->owner);
mbed_official 80:2dab120a94c2 75 }
mbed_official 80:2dab120a94c2 76 }
mbed_official 80:2dab120a94c2 77
mbed_official 80:2dab120a94c2 78 while (p_MCB->p_lnk != NULL) {
mbed_official 80:2dab120a94c2 79 /* A task is waiting for mutex. */
mbed_official 80:2dab120a94c2 80 p_TCB = rt_get_first ((P_XCB)p_MCB);
mbed_official 80:2dab120a94c2 81 rt_ret_val(p_TCB, 0/*osOK*/);
mbed_official 80:2dab120a94c2 82 rt_rmv_dly(p_TCB);
mbed_official 80:2dab120a94c2 83 p_TCB->state = READY;
mbed_official 80:2dab120a94c2 84 rt_put_prio (&os_rdy, p_TCB);
mbed_official 80:2dab120a94c2 85 }
mbed_official 80:2dab120a94c2 86
mbed_official 80:2dab120a94c2 87 if (os_rdy.p_lnk && (os_rdy.p_lnk->prio > os_tsk.run->prio)) {
mbed_official 80:2dab120a94c2 88 /* preempt running task */
mbed_official 80:2dab120a94c2 89 rt_put_prio (&os_rdy, os_tsk.run);
mbed_official 80:2dab120a94c2 90 os_tsk.run->state = READY;
mbed_official 80:2dab120a94c2 91 rt_dispatch (NULL);
mbed_official 80:2dab120a94c2 92 }
mbed_official 80:2dab120a94c2 93
mbed_official 80:2dab120a94c2 94 p_MCB->cb_type = 0;
mbed_official 80:2dab120a94c2 95
mbed_official 80:2dab120a94c2 96 return (OS_R_OK);
mbed_official 80:2dab120a94c2 97 }
mbed_official 80:2dab120a94c2 98 #endif
mbed_official 80:2dab120a94c2 99
mbed_official 80:2dab120a94c2 100
mbed_official 80:2dab120a94c2 101 /*--------------------------- rt_mut_release --------------------------------*/
mbed_official 80:2dab120a94c2 102
mbed_official 80:2dab120a94c2 103 OS_RESULT rt_mut_release (OS_ID mutex) {
mbed_official 80:2dab120a94c2 104 /* Release a mutex object */
mbed_official 80:2dab120a94c2 105 P_MUCB p_MCB = mutex;
mbed_official 80:2dab120a94c2 106 P_TCB p_TCB;
mbed_official 80:2dab120a94c2 107
mbed_official 80:2dab120a94c2 108 if (p_MCB->level == 0 || p_MCB->owner != os_tsk.run) {
mbed_official 80:2dab120a94c2 109 /* Unbalanced mutex release or task is not the owner */
mbed_official 80:2dab120a94c2 110 return (OS_R_NOK);
mbed_official 80:2dab120a94c2 111 }
mbed_official 80:2dab120a94c2 112 if (--p_MCB->level != 0) {
mbed_official 80:2dab120a94c2 113 return (OS_R_OK);
mbed_official 80:2dab120a94c2 114 }
mbed_official 80:2dab120a94c2 115 /* Restore owner task's priority. */
mbed_official 80:2dab120a94c2 116 os_tsk.run->prio = p_MCB->prio;
mbed_official 80:2dab120a94c2 117 if (p_MCB->p_lnk != NULL) {
mbed_official 80:2dab120a94c2 118 /* A task is waiting for mutex. */
mbed_official 80:2dab120a94c2 119 p_TCB = rt_get_first ((P_XCB)p_MCB);
mbed_official 80:2dab120a94c2 120 #ifdef __CMSIS_RTOS
mbed_official 80:2dab120a94c2 121 rt_ret_val(p_TCB, 0/*osOK*/);
mbed_official 80:2dab120a94c2 122 #else
mbed_official 80:2dab120a94c2 123 rt_ret_val(p_TCB, OS_R_MUT);
mbed_official 80:2dab120a94c2 124 #endif
mbed_official 80:2dab120a94c2 125 rt_rmv_dly (p_TCB);
mbed_official 80:2dab120a94c2 126 /* A waiting task becomes the owner of this mutex. */
mbed_official 80:2dab120a94c2 127 p_MCB->level = 1;
mbed_official 80:2dab120a94c2 128 p_MCB->owner = p_TCB;
mbed_official 80:2dab120a94c2 129 p_MCB->prio = p_TCB->prio;
mbed_official 80:2dab120a94c2 130 /* Priority inversion, check which task continues. */
mbed_official 80:2dab120a94c2 131 if (os_tsk.run->prio >= rt_rdy_prio()) {
mbed_official 80:2dab120a94c2 132 rt_dispatch (p_TCB);
mbed_official 80:2dab120a94c2 133 }
mbed_official 80:2dab120a94c2 134 else {
mbed_official 80:2dab120a94c2 135 /* Ready task has higher priority than running task. */
mbed_official 80:2dab120a94c2 136 rt_put_prio (&os_rdy, os_tsk.run);
mbed_official 80:2dab120a94c2 137 rt_put_prio (&os_rdy, p_TCB);
mbed_official 80:2dab120a94c2 138 os_tsk.run->state = READY;
mbed_official 80:2dab120a94c2 139 p_TCB->state = READY;
mbed_official 80:2dab120a94c2 140 rt_dispatch (NULL);
mbed_official 80:2dab120a94c2 141 }
mbed_official 80:2dab120a94c2 142 }
mbed_official 80:2dab120a94c2 143 else {
mbed_official 80:2dab120a94c2 144 /* Check if own priority raised by priority inversion. */
mbed_official 80:2dab120a94c2 145 if (rt_rdy_prio() > os_tsk.run->prio) {
mbed_official 80:2dab120a94c2 146 rt_put_prio (&os_rdy, os_tsk.run);
mbed_official 80:2dab120a94c2 147 os_tsk.run->state = READY;
mbed_official 80:2dab120a94c2 148 rt_dispatch (NULL);
mbed_official 80:2dab120a94c2 149 }
mbed_official 80:2dab120a94c2 150 }
mbed_official 80:2dab120a94c2 151 return (OS_R_OK);
mbed_official 80:2dab120a94c2 152 }
mbed_official 80:2dab120a94c2 153
mbed_official 80:2dab120a94c2 154
mbed_official 80:2dab120a94c2 155 /*--------------------------- rt_mut_wait -----------------------------------*/
mbed_official 80:2dab120a94c2 156
mbed_official 80:2dab120a94c2 157 OS_RESULT rt_mut_wait (OS_ID mutex, U16 timeout) {
mbed_official 80:2dab120a94c2 158 /* Wait for a mutex, continue when mutex is free. */
mbed_official 80:2dab120a94c2 159 P_MUCB p_MCB = mutex;
mbed_official 80:2dab120a94c2 160
mbed_official 80:2dab120a94c2 161 if (p_MCB->level == 0) {
mbed_official 80:2dab120a94c2 162 p_MCB->owner = os_tsk.run;
mbed_official 80:2dab120a94c2 163 p_MCB->prio = os_tsk.run->prio;
mbed_official 80:2dab120a94c2 164 goto inc;
mbed_official 80:2dab120a94c2 165 }
mbed_official 80:2dab120a94c2 166 if (p_MCB->owner == os_tsk.run) {
mbed_official 80:2dab120a94c2 167 /* OK, running task is the owner of this mutex. */
mbed_official 80:2dab120a94c2 168 inc:p_MCB->level++;
mbed_official 80:2dab120a94c2 169 return (OS_R_OK);
mbed_official 80:2dab120a94c2 170 }
mbed_official 80:2dab120a94c2 171 /* Mutex owned by another task, wait until released. */
mbed_official 80:2dab120a94c2 172 if (timeout == 0) {
mbed_official 80:2dab120a94c2 173 return (OS_R_TMO);
mbed_official 80:2dab120a94c2 174 }
mbed_official 80:2dab120a94c2 175 /* Raise the owner task priority if lower than current priority. */
mbed_official 80:2dab120a94c2 176 /* This priority inversion is called priority inheritance. */
mbed_official 80:2dab120a94c2 177 if (p_MCB->prio < os_tsk.run->prio) {
mbed_official 80:2dab120a94c2 178 p_MCB->owner->prio = os_tsk.run->prio;
mbed_official 80:2dab120a94c2 179 rt_resort_prio (p_MCB->owner);
mbed_official 80:2dab120a94c2 180 }
mbed_official 80:2dab120a94c2 181 if (p_MCB->p_lnk != NULL) {
mbed_official 80:2dab120a94c2 182 rt_put_prio ((P_XCB)p_MCB, os_tsk.run);
mbed_official 80:2dab120a94c2 183 }
mbed_official 80:2dab120a94c2 184 else {
mbed_official 80:2dab120a94c2 185 p_MCB->p_lnk = os_tsk.run;
mbed_official 80:2dab120a94c2 186 os_tsk.run->p_lnk = NULL;
mbed_official 80:2dab120a94c2 187 os_tsk.run->p_rlnk = (P_TCB)p_MCB;
mbed_official 80:2dab120a94c2 188 }
mbed_official 80:2dab120a94c2 189 rt_block(timeout, WAIT_MUT);
mbed_official 80:2dab120a94c2 190 return (OS_R_TMO);
mbed_official 80:2dab120a94c2 191 }
mbed_official 80:2dab120a94c2 192
mbed_official 80:2dab120a94c2 193
mbed_official 80:2dab120a94c2 194 /*----------------------------------------------------------------------------
mbed_official 80:2dab120a94c2 195 * end of file
mbed_official 80:2dab120a94c2 196 *---------------------------------------------------------------------------*/
mbed_official 80:2dab120a94c2 197