Add new api to support more aggressive cleanup when suprocesses are being terminated. Ref #139.

Author: ionelmc

src/pytest_cov/embed.py

@@ -14,18 +14,15 @@
 info passed via env vars.
 """
 import os
+import signal
+
+active_cov = None
 
 
 def multiprocessing_start(_):
     cov = init()
     if cov:
-        multiprocessing.util.Finalize(None, multiprocessing_finish, args=(cov,), exitpriority=1000)
-
-
-def multiprocessing_finish(cov):
-    cov.stop()
-    cov.save()
-
+        multiprocessing.util.Finalize(None, cleanup, args=(cov,), exitpriority=1000)
 
 try:
     import multiprocessing.util
@@ -38,6 +35,7 @@ def multiprocessing_finish(cov):
 def init():
     # Only continue if ancestor process has set everything needed in
     # the env.
+    global active_cov
 
     cov_source = os.environ.get('COV_CORE_SOURCE')
     cov_config = os.environ.get('COV_CORE_CONFIG')
@@ -55,7 +53,7 @@ def init():
             cov_config = True
 
         # Activate coverage for this process.
-        cov = coverage.coverage(
+        cov = active_cov = coverage.coverage(
             source=cov_source,
             data_suffix=True,
             config_file=cov_config,
@@ -67,3 +65,25 @@ def init():
         cov._warn_no_data = False
         cov._warn_unimported_source = False
         return cov
+
+def _cleanup(cov):
+    cov.stop()
+    cov.save()
+
+def cleanup(cov=None):
+    global active_cov
+
+    if cov:
+        _cleanup(cov)
+    if active_cov is not cov:
+        _cleanup(active_cov)
+    active_cov = None
+multiprocessing_finish = cleanup  # in case someone dared to use this internal
+
+
+def _sigterm_handler(*_):
+    cleanup()
+
+
+def cleanup_on_sigterm():
+    signal.signal(signal.SIGTERM, _sigterm_handler)

src/pytest_cov/plugin.py

@@ -283,7 +283,7 @@ def pytest_runtest_setup(self, item):
 
     def pytest_runtest_teardown(self, item):
         if self.cov is not None:
-            embed.multiprocessing_finish(self.cov)
+            embed.cleanup(self.cov)
             self.cov = None
 
 

tests/test_pytest_cov.py

@@ -135,19 +135,6 @@ def test_foo(cov):
     assert cov is None
 '''
 
-MULTIPROCESSING_SCRIPT = '''
-import multiprocessing
-
-def target_fn():
-    a = True
-    return a
-
-def test_run_target():
-    p = multiprocessing.Process(target=target_fn)
-    p.start()
-    p.join()
-'''
-
 SCRIPT_FAIL = '''
 def test_fail():
     assert False
@@ -761,7 +748,18 @@ def test_funcarg_not_active(testdir):
 def test_multiprocessing_subprocess(testdir):
     py.test.importorskip('multiprocessing.util')
 
-    script = testdir.makepyfile(MULTIPROCESSING_SCRIPT)
+    script = testdir.makepyfile('''
+import multiprocessing
+
+def target_fn():
+    a = True
+    return a
+
+def test_run_target():
+    p = multiprocessing.Process(target=target_fn)
+    p.start()
+    p.join()
+''')
 
     result = testdir.runpytest('-v',
                                '--cov=%s' % script.dirpath(),
@@ -776,6 +774,41 @@ def test_multiprocessing_subprocess(testdir):
     assert result.ret == 0
 
 
+def test_multiprocessing_subprocess_with_terminate(testdir):
+    py.test.importorskip('multiprocessing.util')
+
+    script = testdir.makepyfile('''
+import multiprocessing
+import time
+from pytest_cov.embed import cleanup_on_sigterm
+cleanup_on_sigterm()
+
+event = multiprocessing.Event()
+
+def target_fn():
+    a = True
+    event.set()
+    time.sleep(5)
+
+def test_run_target():
+    p = multiprocessing.Process(target=target_fn)
+    p.start()
+    event.wait(1)
+    p.terminate()
+''')
+
+    result = testdir.runpytest('-v',
+                               '--cov=%s' % script.dirpath(),
+                               '--cov-report=term-missing',
+                               script)
+
+    result.stdout.fnmatch_lines([
+        '*- coverage: platform *, python * -*',
+        'test_multiprocessing_subprocess* 14 * 100%*',
+        '*1 passed*'
+    ])
+    assert result.ret == 0
+
 MODULE = '''
 def func():
     return 1