OS_RESULT rt_mut_release (OS_ID mutex) {
/* Release a mutex object */
P_MUCB p_MCB = mutex;
P_TCB p_TCB;
if (p_MCB->level == 0 || p_MCB->owner != os_tsk.run) {
/* Unbalanced mutex release or task is not the owner */
return (OS_R_NOK);
}
__DMB();
if (--p_MCB->level != 0) {
return (OS_R_OK);
}
/* Restore owner task's priority. */
os_tsk.run->prio = p_MCB->prio;
if (p_MCB->p_lnk != NULL) {
/* A task is waiting for mutex. */
p_TCB = rt_get_first ((P_XCB)p_MCB);
#ifdef __CMSIS_RTOS
rt_ret_val(p_TCB, 0/*osOK*/);
#else
rt_ret_val(p_TCB, OS_R_MUT);
#endif
rt_rmv_dly (p_TCB);
/* A waiting task becomes the owner of this mutex. */
p_MCB->level = 1;
p_MCB->owner = p_TCB;
p_MCB->prio = p_TCB->prio;
/* Priority inversion, check which task continues. */
if (os_tsk.run->prio >= rt_rdy_prio()) {
rt_dispatch (p_TCB);
}
else {
/* Ready task has higher priority than running task. */
rt_put_prio (&os_rdy, os_tsk.run);
rt_put_prio (&os_rdy, p_TCB);
os_tsk.run->state = READY;
p_TCB->state = READY;
rt_dispatch (NULL);
}
}
else {
/* Check if own priority raised by priority inversion. */
if (rt_rdy_prio() > os_tsk.run->prio) {
rt_put_prio (&os_rdy, os_tsk.run);
os_tsk.run->state = READY;
rt_dispatch (NULL);
}
}
return (OS_R_OK);
}
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);
}
OS_RESULT rt_mut_release (OS_ID mutex) {
/* Release a mutex object */
P_MUCB p_MCB = mutex;
P_TCB p_TCB;
P_MUCB p_mlnk;
U8 prio;
if ((p_MCB->level == 0U) || (p_MCB->owner != os_tsk.run)) {
/* Unbalanced mutex release or task is not the owner */
return (OS_R_NOK);
}
if (--p_MCB->level != 0U) {
return (OS_R_OK);
}
/* Remove mutex from task mutex owner list. */
p_mlnk = os_tsk.run->p_mlnk;
if (p_mlnk == p_MCB) {
os_tsk.run->p_mlnk = p_MCB->p_mlnk;
}
else {
while (p_mlnk) {
if (p_mlnk->p_mlnk == p_MCB) {
p_mlnk->p_mlnk = p_MCB->p_mlnk;
break;
}
p_mlnk = p_mlnk->p_mlnk;
}
}
/* Restore owner task's priority. */
prio = os_tsk.run->prio_base;
p_mlnk = os_tsk.run->p_mlnk;
while (p_mlnk) {
if ((p_mlnk->p_lnk != NULL) && (p_mlnk->p_lnk->prio > prio)) {
/* A task with higher priority is waiting for mutex. */
prio = p_mlnk->p_lnk->prio;
}
p_mlnk = p_mlnk->p_mlnk;
}
os_tsk.run->prio = prio;
if (p_MCB->p_lnk != NULL) {
/* A task is waiting for mutex. */
p_TCB = rt_get_first ((P_XCB)p_MCB);
#ifdef __CMSIS_RTOS
rt_ret_val(p_TCB, 0U/*osOK*/);
#else
rt_ret_val(p_TCB, OS_R_MUT);
#endif
rt_rmv_dly (p_TCB);
/* A waiting task becomes the owner of this mutex. */
p_MCB->level = 1U;
p_MCB->owner = p_TCB;
p_MCB->p_mlnk = p_TCB->p_mlnk;
p_TCB->p_mlnk = p_MCB;
/* Priority inversion, check which task continues. */
if (os_tsk.run->prio >= rt_rdy_prio()) {
rt_dispatch (p_TCB);
}
else {
/* Ready task has higher priority than running task. */
rt_put_prio (&os_rdy, os_tsk.run);
rt_put_prio (&os_rdy, p_TCB);
os_tsk.run->state = READY;
p_TCB->state = READY;
rt_dispatch (NULL);
}
}
else {
/* Check if own priority lowered by priority inversion. */
if (rt_rdy_prio() > os_tsk.run->prio) {
rt_put_prio (&os_rdy, os_tsk.run);
os_tsk.run->state = READY;
rt_dispatch (NULL);
}
}
return (OS_R_OK);
}
OS_RESULT rt_tsk_delete (OS_TID task_id) {
/* Terminate the task identified with "task_id". */
P_TCB task_context;
P_TCB p_TCB;
P_MUCB p_MCB, p_MCB0;
if ((task_id == 0U) || (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 ();
p_MCB = os_tsk.run->p_mlnk;
while (p_MCB) {
/* Release mutexes owned by this task */
if (p_MCB->p_lnk) {
/* A task is waiting for mutex. */
p_TCB = rt_get_first ((P_XCB)p_MCB);
#ifdef __CMSIS_RTOS
rt_ret_val (p_TCB, 0U/*osOK*/);
#else
rt_ret_val (p_TCB, OS_R_MUT);
#endif
rt_rmv_dly (p_TCB);
p_TCB->state = READY;
rt_put_prio (&os_rdy, p_TCB);
/* A waiting task becomes the owner of this mutex. */
p_MCB0 = p_MCB->p_mlnk;
p_MCB->level = 1U;
p_MCB->owner = p_TCB;
p_MCB->p_mlnk = p_TCB->p_mlnk;
p_TCB->p_mlnk = p_MCB;
p_MCB = p_MCB0;
}
else {
p_MCB0 = p_MCB->p_mlnk;
p_MCB->level = 0U;
p_MCB->owner = NULL;
p_MCB->p_mlnk = NULL;
p_MCB = p_MCB0;
}
}
os_active_TCB[os_tsk.run->task_id-1U] = NULL;
rt_free_box (mp_stk, os_tsk.run->stack);
os_tsk.run->stack = NULL;
DBG_TASK_NOTIFY(os_tsk.run, __FALSE);
rt_free_box (mp_tcb, os_tsk.run);
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-1U] == NULL)) {
/* Task with "task_id" not found or not started. */
return (OS_R_NOK);
}
task_context = os_active_TCB[task_id-1U];
rt_rmv_list (task_context);
rt_rmv_dly (task_context);
p_MCB = task_context->p_mlnk;
while (p_MCB) {
/* Release mutexes owned by this task */
if (p_MCB->p_lnk) {
/* A task is waiting for mutex. */
p_TCB = rt_get_first ((P_XCB)p_MCB);
#ifdef __CMSIS_RTOS
rt_ret_val (p_TCB, 0U/*osOK*/);
#else
rt_ret_val (p_TCB, OS_R_MUT);
#endif
rt_rmv_dly (p_TCB);
p_TCB->state = READY;
rt_put_prio (&os_rdy, p_TCB);
/* A waiting task becomes the owner of this mutex. */
p_MCB0 = p_MCB->p_mlnk;
p_MCB->level = 1U;
p_MCB->owner = p_TCB;
p_MCB->p_mlnk = p_TCB->p_mlnk;
p_TCB->p_mlnk = p_MCB;
p_MCB = p_MCB0;
}
else {
p_MCB0 = p_MCB->p_mlnk;
p_MCB->level = 0U;
p_MCB->owner = NULL;
p_MCB->p_mlnk = NULL;
p_MCB = p_MCB0;
}
}
os_active_TCB[task_id-1U] = NULL;
rt_free_box (mp_stk, task_context->stack);
task_context->stack = NULL;
DBG_TASK_NOTIFY(task_context, __FALSE);
rt_free_box (mp_tcb, task_context);
if (rt_rdy_prio() > os_tsk.run->prio) {
/* Ready task has higher priority than running task. */
os_tsk.run->state = READY;
rt_put_prio (&os_rdy, os_tsk.run);
rt_dispatch (NULL);
}
}
return (OS_R_OK);
}
