From f306edb5ecc2edc0f2aa9abf8a97d57099df78e6 Mon Sep 17 00:00:00 2001
From: 8infy <99danilt@gmail.com>
Date: Sun, 1 Sep 2024 19:41:10 +0300
Subject: [PATCH] semaphore: introduce a semaphore_reset helper

This simply clears the internal counter of a semaphore.
---
 kernel-src/include/semaphore.h | 1 +
 kernel-src/lib/semaphore.c     | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/kernel-src/include/semaphore.h b/kernel-src/include/semaphore.h
index 00d1bedd..3d235fcd 100644
--- a/kernel-src/include/semaphore.h
+++ b/kernel-src/include/semaphore.h
@@ -27,6 +27,7 @@ typedef struct semaphore_t{
 int semaphore_wait(semaphore_t *sem, bool interruptible);
 int semaphore_timedwait(semaphore_t *sem, time_t timeoutusec, bool interruptible);
 void semaphore_signal(semaphore_t *sem);
+void semaphore_reset(semaphore_t *sem);
 bool semaphore_test(semaphore_t *sem);
 bool semaphore_haswaiters(semaphore_t *sem);
 
diff --git a/kernel-src/lib/semaphore.c b/kernel-src/lib/semaphore.c
index 872e336b..ac8e39c7 100644
--- a/kernel-src/lib/semaphore.c
+++ b/kernel-src/lib/semaphore.c
@@ -125,6 +125,13 @@ void semaphore_signal(semaphore_t *sem) {
 	interrupt_set(intstate);
 }
 
+void semaphore_reset(semaphore_t *sem) {
+	bool intstate = spinlock_acquireirqclear(&sem->lock);
+	__assert(sem->head == NULL);
+	sem->i = 0;
+	spinlock_releaseirqrestore(&sem->lock, intstate);
+}
+
 bool semaphore_haswaiters(semaphore_t *sem) {
 	bool intstate = interrupt_set(false);
 	spinlock_acquire(&sem->lock);