/**
* @brief Reset the specified task state bits
*
* This routine resets the specified task state bits. When a task's state bits
* are zero, the task may be scheduled to run. The tasks's state bits are a
* bitmask of the TF_xxx bits. Each TF_xxx bit indicates a reason why the task
* must not be scheduled to run.
*
* @param X Pointer to task
* @param bits Bitmask of TF_xxx bits to reset
* @return N/A
*
* @internal
* When operating on microkernel objects, this routine is invoked in the
* context of the microkernel server fiber. However, since microkernel tasks
* may pend/unpend on nanokernel objects, interrupts must be locked to
* prevent data corruption.
* @endinternal
*/
void _k_state_bit_reset(struct k_task *X, uint32_t bits)
{
unsigned int key = irq_lock();
uint32_t f_old = X->state; /* old state bits */
uint32_t f_new = f_old & ~bits; /* new state bits */
X->state = f_new; /* Update task's state bits */
if ((f_old != 0) && (f_new == 0)) {
/*
* The task may now be scheduled to run (but could not
* previously) as all the TF_xxx bits are clear. It must
* be added to the list of schedulable tasks.
*/
struct k_tqhd *H = _k_task_priority_list + X->priority;
X->next = NULL;
H->tail->next = X;
H->tail = X;
_k_task_priority_bitmap[X->priority >> 5] |=
(1 << (X->priority & 0x1F));
}
irq_unlock(key);
#ifdef CONFIG_TASK_MONITOR
f_new ^= f_old;
if ((_k_monitor_mask & MON_STATE) && (f_new)) {
/*
* Task monitoring is enabled and the new state bits are
* different than the old state bits.
*
* <f_new> now contains the bits that are different.
*/
_k_task_monitor(X, f_new | MO_STBIT0);
}
#endif
}
/**
*
* @brief The microkernel thread entry point
*
* This function implements the microkernel fiber. It waits for command
* packets to arrive on its command stack. It executes all commands on the
* stack and then sets up the next task that is ready to run. Next it
* goes to wait on further inputs on the command stack.
*
* @return Does not return.
*/
FUNC_NORETURN void _k_server(int unused1, int unused2)
{
struct k_args *pArgs;
struct k_task *pNextTask;
ARG_UNUSED(unused1);
ARG_UNUSED(unused2);
/* indicate that failure of this fiber may be fatal to the entire system
*/
_nanokernel.current->flags |= ESSENTIAL;
while (1) { /* forever */
(void) nano_fiber_stack_pop(&_k_command_stack, (uint32_t *)&pArgs,
TICKS_UNLIMITED); /* will schedule */
do {
int cmd_type = (int)pArgs & KERNEL_CMD_TYPE_MASK;
if (cmd_type == KERNEL_CMD_PACKET_TYPE) {
/* process command packet */
#ifdef CONFIG_TASK_MONITOR
if (_k_monitor_mask & MON_KSERV) {
_k_task_monitor_args(pArgs);
}
#endif
(*pArgs->Comm)(pArgs);
} else if (cmd_type == KERNEL_CMD_EVENT_TYPE) {
/* give event */
#ifdef CONFIG_TASK_MONITOR
if (_k_monitor_mask & MON_EVENT) {
_k_task_monitor_args(pArgs);
}
#endif
kevent_t event = (int)pArgs & ~KERNEL_CMD_TYPE_MASK;
_k_do_event_signal(event);
} else { /* cmd_type == KERNEL_CMD_SEMAPHORE_TYPE */
/* give semaphore */
#ifdef CONFIG_TASK_MONITOR
/* task monitoring for giving semaphore not implemented */
#endif
ksem_t sem = (int)pArgs & ~KERNEL_CMD_TYPE_MASK;
_k_sem_struct_value_update(1, (struct _k_sem_struct *)sem);
}
/*
* check if another fiber (of equal or greater priority)
* needs to run
*/
if (_nanokernel.fiber) {
fiber_yield();
}
} while (nano_fiber_stack_pop(&_k_command_stack, (uint32_t *)&pArgs,
TICKS_NONE));
pNextTask = next_task_select();
if (_k_current_task != pNextTask) {
/*
* switch from currently selected task to a different
* one
*/
#ifdef CONFIG_WORKLOAD_MONITOR
if (pNextTask->id == 0x00000000) {
_k_workload_monitor_idle_start();
} else if (_k_current_task->id == 0x00000000) {
_k_workload_monitor_idle_end();
}
#endif
_k_current_task = pNextTask;
_nanokernel.task = (struct tcs *)pNextTask->workspace;
#ifdef CONFIG_TASK_MONITOR
if (_k_monitor_mask & MON_TSWAP) {
_k_task_monitor(_k_current_task, 0);
}
#endif
}
}
/*
* Code analyzers may complain that _k_server() uses an infinite loop
* unless we indicate that this is intentional
*/
CODE_UNREACHABLE;
}