sched: Improve mutex

Qwinci · Nov 28, 2023 · 38c017c · 38c017c
1 parent 1ea6678
commit 38c017c
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Showing 2 changed files with 12 additions and 10 deletions.
diff --git a/kernel/src/sched/mutex.c b/kernel/src/sched/mutex.c
@@ -7,16 +7,14 @@ bool mutex_try_lock(Mutex* self) {
 }
 
 void mutex_lock(Mutex* self) {
-	bool result = atomic_exchange_explicit(&self->inner, true, memory_order_acquire);
-	if (result) {
-		Task* task = arch_get_cur_task();
-		Ipl old = arch_ipl_set(IPL_CRITICAL);
+	Ipl old = arch_ipl_set(IPL_CRITICAL);
+	spinlock_lock(&self->task_protector);
 
+	if (self->inner) {
+		Task* task = arch_get_cur_task();
 		task->status = TASK_STATUS_WAITING;
 		task->next = NULL;
 
-		spinlock_lock(&self->task_protector);
-
 		if (self->waiting_tasks) {
 			self->waiting_tasks_end->next = task;
 			self->waiting_tasks_end = task;
@@ -27,24 +25,28 @@ void mutex_lock(Mutex* self) {
 		}
 
 		spinlock_unlock(&self->task_protector);
-
 		arch_ipl_set(old);
 		sched();
 	}
+	else {
+		self->inner = true;
+		spinlock_unlock(&self->task_protector);
+		arch_ipl_set(old);
+	}
 }
 
 void mutex_unlock(Mutex* self) {
-	atomic_store_explicit(&self->inner, false, memory_order_release);
 	Ipl old = arch_ipl_set(IPL_CRITICAL);
 	spinlock_lock(&self->task_protector);
 	if (self->waiting_tasks) {
 		Task* task = self->waiting_tasks;
 		self->waiting_tasks = task->next;
 		spinlock_unlock(&self->task_protector);
-		arch_ipl_set(old);
 		sched_unblock(task);
+		arch_ipl_set(old);
 	}
 	else {
+		self->inner = false;
 		spinlock_unlock(&self->task_protector);
 		arch_ipl_set(old);
 	}

diff --git a/kernel/src/sched/mutex.h b/kernel/src/sched/mutex.h
@@ -7,8 +7,8 @@ typedef struct Task Task;
 typedef struct {
 	Task* waiting_tasks;
 	Task* waiting_tasks_end;
-	atomic_bool inner;
 	Spinlock task_protector;
+	bool inner;
 } Mutex;
 
 bool mutex_try_lock(Mutex* self);