Fix for #501 and #479 (issues related to pausing a thread with debugg…

…er.set_suspend) (#508)

* Fix issue where pydevd threads could end up being traced.

* Make sure that the stepping command is properly set when a thread is suspended. Fixes #501, #479

ptvsd/_vendored/pydevd/_pydevd_bundle/pydevd_comm.py

@@ -346,7 +346,7 @@ def _stop_trace(self):
                 disable_tracing = False
 
             if disable_tracing:
-                pydevd_tracing.SetTrace(None)  # no debugging on this thread
+                pydevd_tracing.SetTrace(None, apply_to_pydevd_thread=True)  # no debugging on this thread
 
 
 #=======================================================================================================================

ptvsd/_vendored/pydevd/_pydevd_bundle/pydevd_trace_dispatch_regular.py

@@ -26,7 +26,6 @@
 # ELSE
 # ENDIF
 
-
 # Cache where we should keep that we completely skipped entering some context.
 # It needs to be invalidated when:
 # - Breakpoints are changed
@@ -79,6 +78,7 @@ def trace_dispatch(py_db, frame, event, arg):
         thread = threadingCurrentThread()
 
     if getattr(thread, 'pydev_do_not_trace', None):
+        SetTrace(None, apply_to_pydevd_thread=True)
         return None
 
     try:

ptvsd/_vendored/pydevd/pydevd.py

@@ -696,8 +696,14 @@ def add_break_on_exception(
 
 
     def set_suspend(self, thread, stop_reason):
-        thread.additional_info.suspend_type = PYTHON_SUSPEND
-        thread.additional_info.pydev_state = STATE_SUSPEND
+        info = thread.additional_info
+        info.suspend_type = PYTHON_SUSPEND
+        info.pydev_state = STATE_SUSPEND
+        if info.pydev_step_cmd == -1:
+            # If the step command is not specified, set it to step into
+            # to make sure it'll break as soon as possible.
+            info.pydev_step_cmd = CMD_STEP_INTO
+
         thread.stop_reason = stop_reason
 
         # If conditional breakpoint raises any exception during evaluation send details to Java
@@ -1187,7 +1193,8 @@ def write(self, s):
             if IS_PY2:
                 # Need s in bytes
                 if isinstance(s, unicode):
-                    s = s.encode('utf-8', errors='replace')
+                    # Note: python 2.6 does not accept the "errors" keyword.
+                    s = s.encode('utf-8', 'replace')
             else:
                 # Need s in str
                 if isinstance(s, bytes):
@@ -1230,6 +1237,7 @@ def settrace(
     trace_only_current_thread=False,
     overwrite_prev_trace=False,
     patch_multiprocessing=False,
+    stop_at_frame=None,
     ):
     '''Sets the tracing function with the pydev debug function and initializes needed facilities.
 
@@ -1253,6 +1261,9 @@ def settrace(
 
     @param patch_multiprocessing: if True we'll patch the functions which create new processes so that launched
         processes are debugged.
+
+    @param stop_at_frame: if passed it'll stop at the given frame, otherwise it'll stop in the function which 
+        called this method.
     '''
     _set_trace_lock.acquire()
     try:
@@ -1265,6 +1276,7 @@ def settrace(
             trace_only_current_thread,
             overwrite_prev_trace,
             patch_multiprocessing,
+            stop_at_frame,
         )
     finally:
         _set_trace_lock.release()
@@ -1282,6 +1294,7 @@ def _locked_settrace(
     trace_only_current_thread,
     overwrite_prev_trace,
     patch_multiprocessing,
+    stop_at_frame,
     ):
     if patch_multiprocessing:
         try:
@@ -1370,16 +1383,11 @@ def _locked_settrace(
         PyDBCommandThread(debugger).start()
         CheckOutputThread(debugger).start()
 
-        #Suspend as the last thing after all tracing is in place.
-        if suspend:
-            debugger.set_suspend(t, CMD_THREAD_SUSPEND)
-
-
     else:
         # ok, we're already in debug mode, with all set, so, let's just set the break
         debugger = get_global_debugger()
 
-        debugger.set_trace_for_frame_and_parents(get_frame(), False)
+        debugger.set_trace_for_frame_and_parents(get_frame(), also_add_to_passed_frame=False, overwrite_prev_trace=True)
 
         t = threadingCurrentThread()
         try:
@@ -1394,8 +1402,17 @@ def _locked_settrace(
             # Trace future threads?
             debugger.patch_threads()
 
-
-        if suspend:
+    # Suspend as the last thing after all tracing is in place.
+    if suspend:
+        if stop_at_frame is not None:
+            # If the step was set we have to go to run state and
+            # set the proper frame for it to stop.
+            additional_info.pydev_state = STATE_RUN
+            additional_info.pydev_step_cmd = CMD_STEP_OVER
+            additional_info.pydev_step_stop = stop_at_frame
+            additional_info.suspend_type = PYTHON_SUSPEND
+        else:
+            # Ask to break as soon as possible.
             debugger.set_suspend(t, CMD_THREAD_SUSPEND)
 
 

ptvsd/_vendored/pydevd/pydevd_tracing.py

@@ -69,7 +69,7 @@ def _internal_set_trace(tracing_func):
         TracingFunctionHolder._original_tracing(tracing_func)
 
 
-def SetTrace(tracing_func, frame_eval_func=None, dummy_tracing_func=None):
+def SetTrace(tracing_func, frame_eval_func=None, dummy_tracing_func=None, apply_to_pydevd_thread=False):
     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
         frame_eval_func()
@@ -82,8 +82,9 @@ def SetTrace(tracing_func, frame_eval_func=None, dummy_tracing_func=None):
 
     current_thread = threading.currentThread()
     do_not_trace_before = getattr(current_thread, 'pydev_do_not_trace', None)
-    if do_not_trace_before:
-        return
+    if not apply_to_pydevd_thread:
+        if do_not_trace_before:
+            return
     try:
         TracingFunctionHolder._lock.acquire()
         current_thread.pydev_do_not_trace = True  # avoid settrace reentering

ptvsd/_vendored/pydevd/tests_python/_debugger_case_settrace.py

@@ -0,0 +1,26 @@
+def ask_for_stop(use_back):
+    import pydevd
+    if use_back:
+        pydevd.settrace(stop_at_frame=sys._getframe().f_back)
+    else:
+        pydevd.settrace()
+    print('Will stop here if use_back==False.')
+
+
+def outer_method():
+    ask_for_stop(True)
+    print('will stop here.')
+    ask_for_stop(False)
+
+
+if __name__ == '__main__':
+    import os
+    import sys
+    root_dirname = os.path.dirname(os.path.dirname(__file__))
+
+    if root_dirname not in sys.path:
+        sys.path.append(root_dirname)
+
+    outer_method()        
+    print('TEST SUCEEDED!')
+

ptvsd/_vendored/pydevd/tests_python/test_debugger.py

@@ -1490,6 +1490,28 @@ def run(self):
 
         self.finished_ok = True
 
+#=======================================================================================================================
+# WriterCaseSetTrace
+#======================================================================================================================
+class WriterCaseSetTrace(debugger_unittest.AbstractWriterThread):
+
+    TEST_FILE = debugger_unittest._get_debugger_test_file('_debugger_case_settrace.py')
+
+    def run(self):
+        self.start_socket()
+
+        self.write_make_initial_run()
+
+        thread_id, frame_id, line = self.wait_for_breakpoint_hit('108', True)
+        assert line == 12, 'Expected return to be in line 12, was: %s' % line
+        self.write_run_thread(thread_id)
+
+        thread_id, frame_id, line = self.wait_for_breakpoint_hit('105', True)
+        assert line == 7, 'Expected return to be in line 7, was: %s' % line
+        self.write_run_thread(thread_id)
+
+        self.finished_ok = True
+
 #=======================================================================================================================
 # WriterThreadCaseRedirectOutput
 #======================================================================================================================
@@ -1817,6 +1839,9 @@ def test_case_handled_exceptions2(self):
     def test_case_handled_exceptions3(self):
         self.check_case(WriterThreadCaseHandledExceptions3)
 
+    def test_case_settrace(self):
+        self.check_case(WriterCaseSetTrace)
+
     def test_redirect_output(self):
         self.check_case(WriterThreadCaseRedirectOutput)
 

ptvsd/attach_server.py

@@ -5,22 +5,14 @@
 import threading
 
 import pydevd
-# TODO: Why import these?
-from _pydevd_bundle.pydevd_custom_frames import (  # noqa
-    CustomFramesContainer, custom_frames_container_init,
-)
-from _pydevd_bundle.pydevd_additional_thread_info import (
-    PyDBAdditionalThreadInfo,
-)
 from _pydevd_bundle.pydevd_comm import (
-    get_global_debugger, CMD_THREAD_SUSPEND,
+    get_global_debugger,
 )
 
 # TODO: Why import run_module & run_file?
 from ptvsd._local import run_module, run_file  # noqa
 from ptvsd._remote import enable_attach as ptvsd_enable_attach
 
-
 DEFAULT_HOST = '0.0.0.0'
 DEFAULT_PORT = 5678
 
@@ -73,7 +65,6 @@ def enable_attach(address=(DEFAULT_HOST, DEFAULT_PORT), redirect_output=True):
     _attached.clear()
     ptvsd_enable_attach(address, redirect_output, on_attach=_attached.set)
 
-
 # TODO: Add disable_attach()?
 
 
@@ -90,11 +81,9 @@ def break_into_debugger():
     if not _attached.isSet() or debugger is None:
         return
 
-    thread = pydevd.threadingCurrentThread()
-    try:
-        additional_info = thread.additional_info
-    except AttributeError:
-        additional_info = PyDBAdditionalThreadInfo()
-        thread.additional_info = additional_info
-
-    debugger.set_suspend(thread, CMD_THREAD_SUSPEND)
+    import sys
+    pydevd.settrace(
+        suspend=True,
+        trace_only_current_thread=True,
+        patch_multiprocessing=False,
+        stop_at_frame=sys._getframe().f_back)