PY-28911: Prevent pydevd_tracing.SetTrace from being reentered

As it causes a deadlock on a non-recursive lock

python/helpers/pydev/_pydevd_bundle/pydevd_tracing.py

@@ -1,3 +1,5 @@
+from contextlib import contextmanager
+
 from _pydevd_bundle.pydevd_constants import get_frame
 from _pydev_imps._pydev_saved_modules import thread, threading
 
@@ -67,6 +69,20 @@ def _internal_set_trace(tracing_func):
         TracingFunctionHolder._original_tracing(tracing_func)
 
 
+@contextmanager
+def _do_not_trace_ctx():
+    current_thread = threading.currentThread()
+    do_not_trace_before = getattr(current_thread, 'pydev_do_not_trace', None)
+    if do_not_trace_before:
+        yield
+        return
+    current_thread.pydev_do_not_trace = True
+    try:
+        yield
+    finally:
+        current_thread.pydev_do_not_trace = do_not_trace_before
+
+
 def SetTrace(tracing_func, frame_eval_func=None, dummy_tracing_func=None):
     if tracing_func is not None and frame_eval_func is not None:
         # There is no need to set tracing function if frame evaluation is available
@@ -78,13 +94,14 @@ def SetTrace(tracing_func, frame_eval_func=None, dummy_tracing_func=None):
         sys.settrace(tracing_func)
         return
 
-    TracingFunctionHolder._lock.acquire()
-    try:
-        TracingFunctionHolder._warn = False
-        _internal_set_trace(tracing_func)
-        TracingFunctionHolder._warn = True
-    finally:
-        TracingFunctionHolder._lock.release()
+    with _do_not_trace_ctx():
+        TracingFunctionHolder._lock.acquire()
+        try:
+            TracingFunctionHolder._warn = False
+            _internal_set_trace(tracing_func)
+            TracingFunctionHolder._warn = True
+        finally:
+            TracingFunctionHolder._lock.release()
 
 
 def replace_sys_set_trace_func():