From 469316fae0404d3631de87611bbe117e6eab957c Mon Sep 17 00:00:00 2001
From: Pau Espin Pedrol <pespin@sysmocom.de>
Date: Wed, 17 May 2017 14:51:31 +0200
Subject: [PATCH] Handle termination signals to exit gracefully and prevent
 resource leak

Make sure we free the reserved resources and kill launched subprocesses
before stopping. Before this patch it was not the case for instance if we
received a SIGTREM signal from kill.

Change-Id: I039e4d1908a04bf606b101ddc6a186ba67e6178e
---
 src/osmo-gsm-tester.py       | 15 ++++++++++++++-
 src/osmo_gsm_tester/suite.py | 35 ++++++++++++++++++++---------------
 2 files changed, 34 insertions(+), 16 deletions(-)

diff --git a/src/osmo-gsm-tester.py b/src/osmo-gsm-tester.py
index 504c6a90..766f3566 100755
--- a/src/osmo-gsm-tester.py
+++ b/src/osmo-gsm-tester.py
@@ -68,11 +68,23 @@ created, which will collect logs and reports.
 
 import sys
 import argparse
+from signal import *
 from osmo_gsm_tester import __version__
 from osmo_gsm_tester import trial, suite, log, config
 
+def sig_handler_cleanup(signum, frame):
+    print("killed by signal %d" % signum)
+    # This sys.exit() will raise a SystemExit base exception at the current
+    # point of execution. Code must be prepared to clean system-wide resources
+    # by using the "finally" section. This allows at the end 'atexit' hooks to
+    # be called before exiting.
+    sys.exit(1)
+
 def main():
 
+    for sig in (SIGINT, SIGTERM, SIGQUIT, SIGPIPE, SIGHUP):
+        signal(sig, sig_handler_cleanup)
+
     parser = argparse.ArgumentParser(epilog=__doc__, formatter_class=argparse.RawTextHelpFormatter)
     # Note: since we're using RawTextHelpFormatter to keep nicely separate
     # paragraphs in the long help text, we unfortunately also need to take care
@@ -184,7 +196,8 @@ optional.''')
                 if status == trial.Trial.FAIL:
                     any_failed = True
                 trials_run.append(current_trial)
-        except:
+        except Exception:
+            # Do not catch here subclasses of BaseException such as SystemExit, let them finish the program
             current_trial.log_exn()
 
     sys.stderr.flush()
diff --git a/src/osmo_gsm_tester/suite.py b/src/osmo_gsm_tester/suite.py
index e05f0d7f..64de2dbb 100644
--- a/src/osmo_gsm_tester/suite.py
+++ b/src/osmo_gsm_tester/suite.py
@@ -223,21 +223,26 @@ class SuiteRun(log.Origin):
 
     def run_tests(self, names=None):
         self.log('Suite run start')
-        self.mark_start()
-        if not self.reserved_resources:
-            self.reserve_resources()
-        for test in self.definition.tests:
-            if names and not test.name() in names:
-                test.set_skip()
-                self.test_skipped_ctr += 1
-                self.tests.append(test)
-                continue
-            with self:
-                st = test.run(self)
-                if st == Test.FAIL:
-                    self.test_failed_ctr += 1
-                self.tests.append(test)
-        self.stop_processes()
+        try:
+            self.mark_start()
+            if not self.reserved_resources:
+                self.reserve_resources()
+            for test in self.definition.tests:
+                if names and not test.name() in names:
+                    test.set_skip()
+                    self.test_skipped_ctr += 1
+                    self.tests.append(test)
+                    continue
+                with self:
+                    st = test.run(self)
+                    if st == Test.FAIL:
+                        self.test_failed_ctr += 1
+                    self.tests.append(test)
+        finally:
+            # if sys.exit() called from signal handler (e.g. SIGINT), SystemExit
+            # base exception is raised. Make sure to stop processes in this
+            # finally section. Resources are automatically freed with 'atexit'.
+            self.stop_processes()
         self.duration = time.time() - self.start_timestamp
         if self.test_failed_ctr:
             self.status = SuiteRun.FAIL