Notify user about gevent before halting debugger. Fixes https://github.com/microsoft/ptvsd/issues/2057

src/debugpy/_vendored/pydevd/.travis/install_python_deps.sh

@@ -37,7 +37,7 @@ if [ "$PYDEVD_PYTHON_VERSION" = "3.6" ]; then
 fi
 
 if [ "$PYDEVD_PYTHON_VERSION" = "3.7" ]; then
-    conda install --yes pyqt=5 matplotlib
+    conda install --yes pyqt=5 matplotlib gevent
     # Note: track the latest web framework versions.
     pip install "django"
     pip install "cherrypy"
@@ -50,7 +50,8 @@ if [ "$PYDEVD_PYTHON_VERSION" = "3.8" ]; then
     pip install "psutil"
     pip install "numpy"
     pip install trio
-    
+    pip install gevent
+
     # Note: track the latest web framework versions.
     pip install "django"
     pip install "cherrypy"

src/debugpy/_vendored/pydevd/_pydev_bundle/pydev_log.py

@@ -1,12 +1,9 @@
 from _pydevd_bundle.pydevd_constants import DebugInfoHolder, SHOW_COMPILE_CYTHON_COMMAND_LINE, NULL
-from _pydev_imps._pydev_saved_modules import threading
 from contextlib import contextmanager
 import traceback
 import os
 import sys
 
-currentThread = threading.currentThread
-
 
 class _LoggingGlobals(object):
 
@@ -182,6 +179,20 @@ def error_once(msg, *args):
         critical(message)
 
 
+def exception_once(msg, *args):
+    try:
+        if args:
+            message = msg % args
+        else:
+            message = str(msg)
+    except:
+        message = '%s - %s' % (msg, args)
+
+    if message not in _LoggingGlobals._warn_once_map:
+        _LoggingGlobals._warn_once_map[message] = True
+        exception(message)
+
+
 def debug_once(msg, *args):
     if DebugInfoHolder.DEBUG_TRACE_LEVEL >= 3:
         error_once(msg, *args)

src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_comm.py

@@ -95,7 +95,8 @@ from _pydevd_bundle import pydevd_xml
 from _pydevd_bundle import pydevd_vm_type
 import sys
 import traceback
-from _pydevd_bundle.pydevd_utils import quote_smart as quote, compare_object_attrs_key
+from _pydevd_bundle.pydevd_utils import quote_smart as quote, compare_object_attrs_key, \
+    notify_about_gevent_if_needed
 from _pydev_bundle import pydev_log
 from _pydev_bundle.pydev_log import exception as pydev_log_exception
 from _pydev_bundle import _pydev_completer
@@ -141,6 +142,7 @@ class PyDBDaemonThread(threading.Thread):
             -- Note: use through run_as_pydevd_daemon_thread().
         '''
         threading.Thread.__init__(self)
+        notify_about_gevent_if_needed()
         self._py_db = weakref.ref(py_db)
         self._kill_received = False
         mark_as_pydevd_daemon_thread(self)
@@ -294,6 +296,7 @@ class ReaderThread(PyDBDaemonThread):
                 # client itself closes the connection (although on kill received we stop actually
                 # processing anything read).
                 try:
+                    notify_about_gevent_if_needed()
                     line = self._read_line()
 
                     if len(line) == 0:
@@ -436,6 +439,7 @@ class WriterThread(PyDBDaemonThread):
                     for listener in self.py_db.dap_messages_listeners:
                         listener.before_send(cmd.as_dict)
 
+                notify_about_gevent_if_needed()
                 cmd.send(self.sock)
 
                 if cmd.id == CMD_EXIT:

src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_constants.py

@@ -151,7 +151,15 @@ try:
 except AttributeError:
     PY_IMPL_NAME = ''
 
-SUPPORT_GEVENT = os.getenv('GEVENT_SUPPORT', 'False') == 'True'
+SUPPORT_GEVENT = os.getenv('GEVENT_SUPPORT', 'False') in ('True', 'true', '1')
+
+GEVENT_SUPPORT_NOT_SET_MSG = os.getenv(
+    'GEVENT_SUPPORT_NOT_SET_MSG',
+    'It seems that the gevent monkey-patching is being used.\n'
+    'Please set an environment variable with:\n'
+    'GEVENT_SUPPORT=True\n'
+    'to enable gevent support in the debugger.'
+)
 
 USE_LIB_COPY = SUPPORT_GEVENT
 

src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_utils.py

@@ -1,6 +1,7 @@
 from __future__ import nested_scopes
 import traceback
 import warnings
+from _pydev_bundle import pydev_log
 
 try:
     from urllib import quote
@@ -9,7 +10,8 @@ except:
 
 import inspect
 import sys
-from _pydevd_bundle.pydevd_constants import IS_PY3K, USE_CUSTOM_SYS_CURRENT_FRAMES, IS_PYPY
+from _pydevd_bundle.pydevd_constants import IS_PY3K, USE_CUSTOM_SYS_CURRENT_FRAMES, IS_PYPY, SUPPORT_GEVENT, \
+    GEVENT_SUPPORT_NOT_SET_MSG
 from _pydev_imps._pydev_saved_modules import threading
 
 
@@ -243,3 +245,29 @@ def convert_dap_log_message_to_expression(log_message):
         return repr(expression)
     # Note: use '%' to be compatible with Python 2.6.
     return repr(expression) + ' % (' + ', '.join(str(x) for x in expression_vars) + ',)'
+
+
+def notify_about_gevent_if_needed(stream=None):
+    '''
+    When debugging with gevent check that the gevent flag is used if the user uses the gevent
+    monkey-patching.
+
+    :return bool:
+        Returns True if a message had to be shown to the user and False otherwise.
+    '''
+    stream = stream if stream is not None else sys.stderr
+    if not SUPPORT_GEVENT:
+        gevent_monkey = sys.modules.get('gevent.monkey')
+        if gevent_monkey is not None:
+            try:
+                saved = gevent_monkey.saved
+            except AttributeError:
+                pydev_log.exception_once('Error checking for gevent monkey-patching.')
+                return False
+
+            if saved:
+                # Note: print to stderr as it may deadlock the debugger.
+                sys.stderr.write('%s\n' % (GEVENT_SUPPORT_NOT_SET_MSG,))
+                return True
+
+    return False

src/debugpy/_vendored/pydevd/conftest.py

@@ -279,6 +279,85 @@ Memory after: %s
 
 from tests_python.regression_check import data_regression, datadir, original_datadir
 
+
+@pytest.fixture
+def pyfile(request, tmpdir):
+    """
+    Based on debugpy pyfile fixture (adapter for older versions of Python)
+
+    A fixture providing a factory function that generates .py files.
+
+    The returned factory takes a single function with an empty argument list,
+    generates a temporary file that contains the code corresponding to the
+    function body, and returns the full path to the generated file. Idiomatic
+    use is as a decorator, e.g.:
+
+        @pyfile
+        def script_file():
+            print('fizz')
+            print('buzz')
+
+    will produce a temporary file named script_file.py containing:
+
+        print('fizz')
+        print('buzz')
+
+    and the variable script_file will contain the path to that file.
+
+    In order for the factory to be able to extract the function body properly,
+    function header ("def") must all be on a single line, with nothing after
+    the colon but whitespace.
+
+    Note that because the code is physically in a separate file when it runs,
+    it cannot reuse top-level module imports - it must import all the modules
+    that it uses locally. When linter complains, use #noqa.
+
+    Returns a py.path.local instance that has the additional attribute "lines".
+    After the source is writen to disk, tests.code.get_marked_line_numbers() is
+    invoked on the resulting file to compute the value of that attribute.
+    """
+    import types
+    import inspect
+
+    def factory(source):
+        assert isinstance(source, types.FunctionType)
+        name = source.__name__
+        source, _ = inspect.getsourcelines(source)
+
+        # First, find the "def" line.
+        def_lineno = 0
+        for line in source:
+            line = line.strip()
+            if line.startswith("def") and line.endswith(":"):
+                break
+            def_lineno += 1
+        else:
+            raise ValueError("Failed to locate function header.")
+
+        # Remove everything up to and including "def".
+        source = source[def_lineno + 1 :]
+        assert source
+
+        # Now we need to adjust indentation. Compute how much the first line of
+        # the body is indented by, then dedent all lines by that amount. Blank
+        # lines don't matter indentation-wise, and might not be indented to begin
+        # with, so just replace them with a simple newline.
+        line = source[0]
+        indent = len(line) - len(line.lstrip())
+        source = [l[indent:] if l.strip() else "\n" for l in source]
+        source = "".join(source)
+
+        # Write it to file.
+        tmpfile = os.path.join(str(tmpdir), name + ".py")
+        assert not os.path.exists(tmpfile), '%s already exists.' % (tmpfile,)
+        with open(tmpfile, 'w') as stream:
+            stream.write(source)
+
+        return tmpfile
+
+    return factory
+
+
 if IS_JYTHON or IS_IRONPYTHON:
 
     # On Jython and IronPython, it's a no-op.

src/debugpy/_vendored/pydevd/tests_python/test_debugger_json.py

@@ -2781,6 +2781,41 @@ def test_wait_for_attach_gevent(case_setup_remote_attach_to):
         writer.finished_ok = True
 
 
+@pytest.mark.skipif(not TEST_GEVENT, reason='Gevent not installed.')
+def test_notify_gevent(case_setup, pyfile):
+
+    def get_environ(writer):
+        # I.e.: Make sure that gevent support is disabled
+        env = os.environ.copy()
+        env['GEVENT_SUPPORT'] = ''
+        return env
+
+    @pyfile
+    def case_gevent():
+        from gevent import monkey
+        monkey.patch_all()
+        print('TEST SUCEEDED')
+
+    def additional_output_checks(writer, stdout, stderr):
+        assert 'environment variable' in stderr
+        assert 'GEVENT_SUPPORT=True' in stderr
+
+    with case_setup.test_file(
+            case_gevent,
+            get_environ=get_environ,
+            additional_output_checks=additional_output_checks,
+            EXPECTED_RETURNCODE='any',
+            FORCE_KILL_PROCESS_WHEN_FINISHED_OK=True
+        ) as writer:
+        json_facade = JsonFacade(writer)
+        json_facade.write_launch()
+        json_facade.write_make_initial_run()
+
+        wait_for_condition(lambda: 'GEVENT_SUPPORT=True' in writer.get_stderr())
+
+        writer.finished_ok = True
+
+
 @pytest.mark.skipif(IS_JYTHON, reason='Flaky on Jython.')
 def test_path_translation_and_source_reference(case_setup):
 

src/debugpy/_vendored/pydevd/tests_python/test_utilities.py

@@ -2,7 +2,7 @@ import threading
 
 from _pydevd_bundle.pydevd_comm import pydevd_find_thread_by_id
 from _pydevd_bundle.pydevd_utils import convert_dap_log_message_to_expression
-from tests_python.debug_constants import IS_PY26, IS_PY3K
+from tests_python.debug_constants import IS_PY26, IS_PY3K, TEST_GEVENT
 import sys
 from _pydevd_bundle.pydevd_constants import IS_CPYTHON, IS_WINDOWS
 import pytest
@@ -277,9 +277,10 @@ def _build_launch_env():
     return cwd, environ
 
 
-def _check_in_separate_process(method_name, module_name='test_utilities'):
+def _check_in_separate_process(method_name, module_name='test_utilities', update_env={}):
     import subprocess
     cwd, environ = _build_launch_env()
+    environ.update(update_env)
 
     subprocess.check_call(
         [sys.executable, '-c', 'import %(module_name)s;%(module_name)s.%(method_name)s()' % dict(
@@ -336,3 +337,27 @@ def test_get_ppid():
     else:
         assert api._get_windows_ppid() is not None
 
+
+def _check_gevent(expect_msg):
+    from _pydevd_bundle.pydevd_utils import notify_about_gevent_if_needed
+    assert not notify_about_gevent_if_needed()
+    import gevent
+    assert not notify_about_gevent_if_needed()
+    import gevent.monkey
+    assert not notify_about_gevent_if_needed()
+    gevent.monkey.patch_all()
+    assert notify_about_gevent_if_needed() == expect_msg
+
+
+def check_notify_on_gevent_loaded():
+    _check_gevent(True)
+
+
+def check_dont_notify_on_gevent_loaded():
+    _check_gevent(False)
+
+
+@pytest.mark.skipif(not TEST_GEVENT, reason='Gevent not installed.')
+def test_gevent_notify():
+    _check_in_separate_process('check_notify_on_gevent_loaded', update_env={'GEVENT_SUPPORT': ''})
+    _check_in_separate_process('check_dont_notify_on_gevent_loaded', update_env={'GEVENT_SUPPORT': 'True'})