//----------------------------------------------------------------------------------------------------//
// @func - sys_pthread_setschedparam
//! @desc
//! Change the scheduling parameters of the thread identified by 'thread'
//! @param
//! - thread is the identifier of the target thread
//! - policy is the target's new required scheduling policy
//! - param is the target's new required scheduling parameters
//! @return
//! - Return 0 on success
//! - Return ESRCH if target thread not found
//! - Return EINVAL if scheduling parameters are invalid
//! - Return -1 on unhandled errors
//! @note
//! - policy is ignored
//----------------------------------------------------------------------------------------------------//
int sys_pthread_setschedparam (pthread_t thread, int policy, struct sched_param *param)
{
pthread_info_t *thread_info;
thread_info = pthread_get_info (thread);
if (thread_info == NULL)
return ESRCH;
if ((param->sched_priority > PRIO_LOWEST) // Check requested priority change
|| (param->sched_priority < PRIO_HIGHEST))
return EINVAL;
if (thread_info->parent->pid == current_pid ||
thread_info->parent->state == PROC_DELAY) { // Just need to change the priority
thread_info->parent->priority = param->sched_priority;
} else if (thread_info->parent->state == PROC_READY) { // cannot handle processes which are blocked
if (pdelq (&ready_q[thread_info->parent->priority],
thread_info->parent->pid) < 0) // Remove from corresponding priority queue
return -1;
thread_info->parent->priority = param->sched_priority; // Change priority and enqueue in new queue
penq (&ready_q[thread_info->parent->priority], thread_info->parent->pid, 0);
} else if (thread_info->parent->state == PROC_WAIT ||
thread_info->parent->state == PROC_TIMED_WAIT) { // Thread currently blocked
if (prio_pdelq (thread_info->parent->blockq, // Remove from corresponding wait queue
thread_info->parent->pid) < 0)
return -1;
thread_info->parent->priority = param->sched_priority; // Change priority and enqueue in new queue
prio_penq (thread_info->parent->blockq, thread_info->parent->pid, 0);
}
resched = 1;
return 0;
}
static void handle_timeout (signed char pid)
{
if (ptable[pid].blockq) {
#if SCHED_TYPE == SCHED_RR
pdelq (ptable[pid].blockq, pid);
#elif SCHED_TYPE == SCHED_PRIO
prio_pdelq (ptable[pid].blockq, pid);
#endif
ptable[pid].timeout = 1;
ptable[pid].blockq = NULL;
}
ptable[pid].state = PROC_READY;
#if SCHED_TYPE == SCHED_RR
penq (&ready_q[0], pid, 0);
#else /* SCHED_TYPE == SCHED_PRIO */
penq (&ready_q[ptable[pid].priority], pid, 0);
#endif
resched = 1;
}
