From 44bbb86a75043b38bdfb9ed6ff4be0764e3fc905 Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Mon, 13 Oct 2025 14:53:04 -0400 Subject: kern: proc: Implement process sleeping and waking Signed-off-by: Ian Moffett --- src/sys/os/os_sched.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) (limited to 'src/sys/os/os_sched.c') diff --git a/src/sys/os/os_sched.c b/src/sys/os/os_sched.c index d5824aa..e636f0a 100644 --- a/src/sys/os/os_sched.c +++ b/src/sys/os/os_sched.c @@ -111,9 +111,28 @@ sched_deq(struct sched_queue *q, struct proc **procp) } spinlock_acquire(&q->lock); - proc = TAILQ_FIRST(&q->q); - TAILQ_REMOVE(&q->q, proc, link); + if ((proc = TAILQ_FIRST(&q->q)) == NULL) { + spinlock_release(&q->lock); + return -EAGAIN; + } + + /* Find a process that is not sleeping */ + while (proc != NULL) { + if (ISSET(proc->flags, PROC_SLEEPING)) { + proc = TAILQ_NEXT(proc, link); + continue; + } + + break; + } + + /* Is there anything? */ + if (proc == NULL) { + spinlock_release(&q->lock); + return -EAGAIN; + } + TAILQ_REMOVE(&q->q, proc, link); *procp = proc; --q->nproc; spinlock_release(&q->lock); -- cgit v1.2.3