micropython
diff --git a/‎extmod/uasyncio/lock.py‎
Lines changed: 16 additions & 11 deletions b/‎extmod/uasyncio/lock.py‎
Lines changed: 16 additions & 11 deletions
@@ -6,39 +6,44 @@
 # Lock class for primitive mutex capability
 class Lock:
     def __init__(self):
-        self.state = 0  # 0=unlocked; 1=unlocked but waiting task pending resume; 2=locked
-        self.waiting = core.TaskQueue()  # Queue of Tasks waiting to acquire this Lock
+        # The state can take the following values:
+        # - 0: unlocked
+        # - 1: locked
+        # - <Task>: unlocked but this task has been scheduled to acquire the lock next
+        self.state = 0
+        # Queue of Tasks waiting to acquire this Lock
+        self.waiting = core.TaskQueue()
 
     def locked(self):
-        return self.state == 2
+        return self.state == 1
 
     def release(self):
-        if self.state != 2:
+        if self.state != 1:
             raise RuntimeError
         if self.waiting.peek():
-            # Task(s) waiting on lock, schedule first Task
-            core._task_queue.push_head(self.waiting.pop_head())
-            self.state = 1
+            # Task(s) waiting on lock, schedule next Task
+            self.state = self.waiting.pop_head()
+            core._task_queue.push_head(self.state)
         else:
             # No Task waiting so unlock
             self.state = 0
 
     async def acquire(self):
-        if self.state != 0 or self.waiting.peek():
+        if self.state != 0:
             # Lock unavailable, put the calling Task on the waiting queue
             self.waiting.push_head(core.cur_task)
             # Set calling task's data to the lock's queue so it can be removed if needed
             core.cur_task.data = self.waiting
             try:
                 yield
             except core.CancelledError as er:
-                if self.state == 1:
+                if self.state == core.cur_task:
                     # Cancelled while pending on resume, schedule next waiting Task
-                    self.state = 2
+                    self.state = 1
                     self.release()
                 raise er
         # Lock available, set it as locked
-        self.state = 2
+        self.state = 1
         return True
 
     async def __aenter__(self):