42 lines
1.3 KiB
C
42 lines
1.3 KiB
C
#include "kernel/system.h"
|
|
#include <signal.h>
|
|
#include <sys/sigcontext.h>
|
|
#include <minix/endpoint.h>
|
|
|
|
/*===========================================================================*
|
|
* do_schedule *
|
|
*===========================================================================*/
|
|
PUBLIC int do_schedule(struct proc * caller, message * m_ptr)
|
|
{
|
|
struct proc *p;
|
|
|
|
p = proc_addr(_ENDPOINT_P(m_ptr->SCHEDULING_ENDPOINT));
|
|
|
|
/* Make sure the priority number given is within the allowed range.*/
|
|
if (m_ptr->SCHEDULING_PRIORITY < TASK_Q ||
|
|
m_ptr->SCHEDULING_PRIORITY > NR_SCHED_QUEUES)
|
|
return(EINVAL);
|
|
|
|
/* Only system processes can schedule processes */
|
|
if (! (priv(caller)->s_flags & SYS_PROC))
|
|
return(EPERM);
|
|
|
|
/* Only this process' scheduler can schedule it */
|
|
if (caller != p->p_scheduler)
|
|
return(EPERM);
|
|
|
|
/* In some cases, we might be rescheduling a runnable process. In such
|
|
* a case (i.e. if we are updating the priority) we set the NO_QUANTUM
|
|
* flag before the generic unset to dequeue/enqueue the process
|
|
*/
|
|
if (proc_is_runnable(p))
|
|
RTS_SET(p, RTS_NO_QUANTUM);
|
|
|
|
/* Clear the scheduling bit and enqueue the process */
|
|
p->p_priority = m_ptr->SCHEDULING_PRIORITY;
|
|
p->p_ticks_left = m_ptr->SCHEDULING_QUANTUM;
|
|
|
|
RTS_UNSET(p, RTS_NO_QUANTUM);
|
|
|
|
return(OK);
|
|
}
|