Merge branch '1.x' into chore/gevent-on-fork

ddtrace/internal/nogevent.py

@@ -37,6 +37,7 @@ def is_module_patched(module):
 thread_get_ident = get_original(six.moves._thread.__name__, "get_ident")
 Thread = get_original("threading", "Thread")
 Lock = get_original("threading", "Lock")
+RLock = get_original("threading", "RLock")
 
 is_threading_patched = is_module_patched("threading")
 

ddtrace/profiling/_threading.pyx

@@ -69,7 +69,9 @@ class _ThreadLink(_thread_link_base):
     # Key is a thread_id
     # Value is a weakref to an object
     _thread_id_to_object = attr.ib(factory=dict, repr=False, init=False, type=typing.Dict[int, _weakref_type])
-    _lock = attr.ib(factory=nogevent.Lock, repr=False, init=False, type=nogevent.Lock)
+    # Note that this lock has to be reentrant as spans can be activated unexpectedly in the same thread
+    # ex. during a gc weakref finalize callback
+    _lock = attr.ib(factory=nogevent.RLock, repr=False, init=False, type=nogevent.RLock)
 
     def link_object(
             self,

ddtrace/sampler.py

@@ -214,7 +214,7 @@ class DatadogSampler(RateByServiceSampler):
     provided. It is not used when the agent supplied sample rates are used.
     """
 
-    __slots__ = ("limiter", "rules", "_default_sampler")
+    __slots__ = ("limiter", "rules")
 
     NO_RATE_LIMIT = -1
     DEFAULT_RATE_LIMIT = 100

releasenotes/notes/profiling-threadlink-lock-27df798c36ed64e6.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    profiling: fix a possible deadlock due to spans being activated unexpectedly.

tests/internal/test_module.py

@@ -18,10 +18,11 @@ def ensure_no_module_watchdog():
     if was_installed:
         ModuleWatchdog.uninstall()
 
-    yield
-
-    if was_installed:
-        ModuleWatchdog.install()
+    try:
+        yield
+    finally:
+        if was_installed:
+            ModuleWatchdog.install()
 
 
 @pytest.fixture
@@ -80,11 +81,6 @@ def test_import_origin_hook_for_module_not_yet_imported():
     path = os.getenv("MODULE_ORIGIN")
     hook = mock.Mock()
 
-    try:
-        ModuleWatchdog.install()
-    except RuntimeError:
-        pass
-
     ModuleWatchdog.register_origin_hook(path, hook)
 
     hook.assert_not_called()
@@ -118,11 +114,6 @@ def test_import_module_hook_for_module_not_yet_imported():
     name = "tests.test_module"
     hook = mock.Mock()
 
-    try:
-        ModuleWatchdog.install()
-    except RuntimeError:
-        pass
-
     ModuleWatchdog.register_module_hook(name, hook)
 
     hook.assert_not_called()
@@ -157,11 +148,6 @@ def test_module_deleted():
     path = os.getenv("MODULE_ORIGIN")
     hook = mock.Mock()
 
-    try:
-        ModuleWatchdog.install()
-    except RuntimeError:
-        pass
-
     ModuleWatchdog.register_origin_hook(path, hook)
     ModuleWatchdog.register_module_hook(name, hook)
 
@@ -351,3 +337,5 @@ def test_module_watchdog_dict_shallow_copy():
 
     # Ensure that they match
     assert original_modules == new_modules
+
+    ModuleWatchdog.uninstall()