Merge pull request #3321 from boegel/fix_test_toy_lock_cleanup_signals

fix broken test_toy_lock_cleanup_signals & properly clean up after using SIGALRM signal in tests

Author: akesandgren

test/framework/run.py

@@ -206,22 +206,27 @@ def test_run_cmd_negative_exit_code(self):
         def handler(signum, _):
             raise RuntimeError("Signal handler called with signal %s" % signum)
 
-        # set the signal handler and a 3-second alarm
-        signal.signal(signal.SIGALRM, handler)
-        signal.alarm(3)
+        orig_sigalrm_handler = signal.getsignal(signal.SIGALRM)
 
-        (_, ec) = run_cmd("kill -9 $$", log_ok=False)
-        self.assertEqual(ec, -9)
+        try:
+            # set the signal handler and a 3-second alarm
+            signal.signal(signal.SIGALRM, handler)
+            signal.alarm(3)
 
-        # reset the alarm
-        signal.alarm(0)
-        signal.alarm(3)
+            (_, ec) = run_cmd("kill -9 $$", log_ok=False)
+            self.assertEqual(ec, -9)
 
-        (_, ec) = run_cmd_qa("kill -9 $$", {}, log_ok=False)
-        self.assertEqual(ec, -9)
+            # reset the alarm
+            signal.alarm(0)
+            signal.alarm(3)
 
-        # disable the alarm
-        signal.alarm(0)
+            (_, ec) = run_cmd_qa("kill -9 $$", {}, log_ok=False)
+            self.assertEqual(ec, -9)
+
+        finally:
+            # cleanup: disable the alarm + reset signal handler for SIGALRM
+            signal.signal(signal.SIGALRM, orig_sigalrm_handler)
+            signal.alarm(0)
 
     def test_run_cmd_bis(self):
         """More 'complex' test for run_cmd function."""

test/framework/toy_build.py

@@ -51,7 +51,8 @@
 from easybuild.tools.build_log import EasyBuildError
 from easybuild.tools.config import get_module_syntax, get_repositorypath
 from easybuild.tools.environment import modify_env
-from easybuild.tools.filetools import adjust_permissions, mkdir, read_file, remove_dir, remove_file, which, write_file
+from easybuild.tools.filetools import adjust_permissions, change_dir, mkdir, read_file, remove_dir, remove_file
+from easybuild.tools.filetools import which, write_file
 from easybuild.tools.module_generator import ModuleGeneratorTcl
 from easybuild.tools.modules import Lmod
 from easybuild.tools.py2vs3 import reload, string_type
@@ -2743,8 +2744,10 @@ def test_toy_build_lock(self):
         # also test use of --ignore-locks
         self.test_toy_build(extra_args=extra_args + ['--ignore-locks'], verify=True, raise_error=True)
 
+        orig_sigalrm_handler = signal.getsignal(signal.SIGALRM)
+
         # define a context manager that remove a lock after a while, so we can check the use of --wait-for-lock
-        class remove_lock_after:
+        class remove_lock_after(object):
             def __init__(self, seconds, lock_fp):
                 self.seconds = seconds
                 self.lock_fp = lock_fp
@@ -2757,7 +2760,9 @@ def __enter__(self):
                 signal.alarm(self.seconds)
 
             def __exit__(self, type, value, traceback):
-                pass
+                # clean up SIGALRM signal handler, and cancel scheduled alarm
+                signal.signal(signal.SIGALRM, orig_sigalrm_handler)
+                signal.alarm(0)
 
         # wait for lock to be removed, with 1 second interval of checking;
         # check with both --wait-on-lock-interval and deprecated --wait-on-lock options
@@ -2850,11 +2855,15 @@ def __exit__(self, type, value, traceback):
     def test_toy_lock_cleanup_signals(self):
         """Test cleanup of locks after EasyBuild session gets a cancellation signal."""
 
+        orig_wd = os.getcwd()
+
         locks_dir = os.path.join(self.test_installpath, 'software', '.locks')
         self.assertFalse(os.path.exists(locks_dir))
 
+        orig_sigalrm_handler = signal.getsignal(signal.SIGALRM)
+
         # context manager which stops the function being called with the specified signal
-        class wait_and_signal:
+        class wait_and_signal(object):
             def __init__(self, seconds, signum):
                 self.seconds = seconds
                 self.signum = signum
@@ -2867,7 +2876,9 @@ def __enter__(self):
                 signal.alarm(self.seconds)
 
             def __exit__(self, type, value, traceback):
-                pass
+                # clean up SIGALRM signal handler, and cancel scheduled alarm
+                signal.signal(signal.SIGALRM, orig_sigalrm_handler)
+                signal.alarm(0)
 
         # add extra sleep command to ensure session takes long enough
         test_ecs_dir = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'easyconfigs', 'test_ecs')
@@ -2883,7 +2894,15 @@ def __exit__(self, type, value, traceback):
             (signal.SIGQUIT, SystemExit),
         ]
         for (signum, exc) in signums:
+
+            # avoid recycling stderr of previous test
+            stderr = ''
+
             with wait_and_signal(1, signum):
+
+                # change back to original working directory before each test
+                change_dir(orig_wd)
+
                 self.mock_stderr(True)
                 self.mock_stdout(True)
                 self.assertErrorRegex(exc, '.*', self.test_toy_build, ec_file=test_ec, verify=False,