From 7c630ece5442978ed5947379576ef271bfd094d8 Mon Sep 17 00:00:00 2001
From: Max Wash <mbswash@gmail.com>
Date: Sat, 14 Mar 2026 22:20:10 +0000
Subject: [PATCH] sched: add wait begin/end functions that don't change thread
 state

these functions can be used when waiting on multiple queues at once, to prevent
the thread state from being changed unexpectedly while initialising a set of wait items.
---
 include/kernel/wait.h |  6 ++++++
 sched/wait.c          | 20 ++++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/include/kernel/wait.h b/include/kernel/wait.h
index 07af1d5..2903702 100644
--- a/include/kernel/wait.h
+++ b/include/kernel/wait.h
@@ -32,6 +32,12 @@ struct waitqueue {
 extern void wait_item_init(struct wait_item *item, struct thread *thr);
 extern void thread_wait_begin(struct wait_item *waiter, struct waitqueue *q);
 extern void thread_wait_end(struct wait_item *waiter, struct waitqueue *q);
+extern void thread_wait_begin_nosleep(
+	struct wait_item *waiter,
+	struct waitqueue *q);
+extern void thread_wait_end_nosleep(
+	struct wait_item *waiter,
+	struct waitqueue *q);
 extern void wait_on_queue(struct waitqueue *q);
 extern void wakeup_queue(struct waitqueue *q);
 extern void wakeup_one(struct waitqueue *q);
diff --git a/sched/wait.c b/sched/wait.c
index 06f7ea9..0005bac 100644
--- a/sched/wait.c
+++ b/sched/wait.c
@@ -32,6 +32,26 @@ void thread_wait_end(struct wait_item *waiter, struct waitqueue *q)
 	spin_unlock_irqrestore(&q->wq_lock, flags);
 }
 
+void thread_wait_begin_nosleep(struct wait_item *waiter, struct waitqueue *q)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&q->wq_lock, &flags);
+
+	queue_push_back(&q->wq_waiters, &waiter->w_entry);
+
+	spin_unlock_irqrestore(&q->wq_lock, flags);
+}
+
+void thread_wait_end_nosleep(struct wait_item *waiter, struct waitqueue *q)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&q->wq_lock, &flags);
+
+	queue_delete(&q->wq_waiters, &waiter->w_entry);
+
+	spin_unlock_irqrestore(&q->wq_lock, flags);
+}
+
 void wakeup_queue(struct waitqueue *q)
 {
 	unsigned long flags;