Fix silent suppression of AssertionError exceptions in _ProfiledLock::_acquire

Author: vlad-scherbich

ddtrace/profiling/collector/_lock.py

@@ -127,8 +127,10 @@ def _acquire(self, inner_func: Callable[..., Any], *args: Any, **kwargs: Any) ->
                 for ddframe in frames:
                     handle.push_frame(ddframe.function_name, ddframe.file_name, 0, ddframe.lineno)
                 handle.flush_sample()
-            except Exception:
-                pass  # nosec
+            except Exception as e:
+                # _maybe_update_self_name throws AssertionError exceptions which need to propagate
+                if type(e) is AssertionError:
+                    raise e
 
     def acquire(self, *args: Any, **kwargs: Any) -> Any:
         return self._acquire(self.__wrapped__.acquire, *args, **kwargs)

releasenotes/notes/fixed-silent-suppression-of-AssertionError-exceptions-in-Lock-profiler-20645079ab43b23d.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    profiling: This fix resolves an issue where AssertionError exceptions were silently suppressed in the `_acquire` method of the Lock profiler (note: this only occurs when assertions are enabled.)

tests/profiling_v2/collector/test_threading.py

@@ -979,6 +979,32 @@ def test_upload_resets_profile(self) -> None:
         with pytest.raises(AssertionError):
             pprof_utils.parse_newest_profile(self.output_filename)
 
+    def test_assertion_error_suppressed_in_acquire(self) -> None:
+        """Ensure that AssertionError exceptions is propagated in the `_acquire` method."""
+
+        with self.collector_class(capture_pct=100):
+            lock = self.lock_class()
+
+            # Patch _maybe_update_self_name to raise AssertionError
+            lock._maybe_update_self_name = mock.Mock(side_effect=AssertionError("test: unexpected frame in stack"))
+
+            with pytest.raises(AssertionError):
+                # acquire() will propagate AssertionError if _maybe_update_self_name raises it
+                lock.acquire()
+
+    def test_other_exceptions_are_suppressed(self) -> None:
+        """Ensure that non - AssertionError exceptions are silently suppressed in the `_acquire` method."""
+
+        with self.collector_class(capture_pct=100):
+            lock = self.lock_class()
+
+            # Patch _maybe_update_self_name to raise RuntimeError
+            lock._maybe_update_self_name = mock.Mock(side_effect=RuntimeError("Some profiling error"))
+
+            # RuntimeError should be caught and suppressed - lock operations should succeed
+            lock.acquire()
+            lock.release()
+
 
 class TestThreadingLockCollector(BaseThreadingLockCollectorTest):
     """Test Lock profiling"""