block monitor

v6d2ctx/pain.py

@@ -1,3 +1,4 @@
+import asyncio
 import os
 import time
 
@@ -48,3 +49,28 @@ class FrameTrace(Instrumentation):
             print(frame.f_code.co_filename, frame.f_lineno)
             frame = frame.f_back
         return await method(*args, **kwargs)
+
+
+class ABlockMonitor:
+    __task: asyncio.Future
+    __max: float
+
+    def __init__(self, threshold=0.0) -> None:
+        self.__max = threshold
+
+    async def _monitor(self):
+        while True:
+            delta = 10
+            t = time.time()
+            await asyncio.sleep(delta)
+            spent = time.time() - t
+            delay = spent - delta
+            if delay > self.__max:
+                self.__max = delay
+                print(f'block monitor reached new peak delay {delay:.3f}')
+
+    async def __aenter__(self):
+        self.__task = asyncio.get_running_loop().create_task(self._monitor())
+
+    async def __aexit__(self, exc_type, exc_val, exc_tb):
+        self.__task.cancel()