# HG changeset patch
# User Laurent Charignon <lcharignon@fb.com>
# Date 1453408632 28800
# Node ID 4c6053a6b17d682b34fb88bbeb5e94ed9085d900
# Parent  f6d73c8756e2e7db78a7622ce475b49723dd0ca3
run-tests: fix race condition

Before this patch, it was possible for run-tests to crash on a race condition.
The race condition happens in the following case:
- the last test finishes and calls: done.put(None)
- the context switches to the main thread that clears the channels list
- the context switches to the last test mentioned above, it tries to access
channels[channel] and crashes
This happened to me while running run-tests.

This patch fixes the issue by clearing the channel before considering that the
test is done.

diff -r f6d73c8756e2 -r 4c6053a6b17d tests/run-tests.py
--- a/tests/run-tests.py	Thu Jan 21 21:15:52 2016 +0000
+++ b/tests/run-tests.py	Thu Jan 21 12:37:12 2016 -0800
@@ -1526,13 +1526,13 @@
             channels[channel] = "=" + test.name[5:].split(".")[0]
             try:
                 test(result)
+                channels[channel] = ''
                 done.put(None)
             except KeyboardInterrupt:
-                pass
+                channels[channel] = ''
             except: # re-raises
                 done.put(('!', test, 'run-test raised an error, see traceback'))
                 raise
-            channels[channel] = ''
 
         def stat():
             count = 0