From: Vratko Polak <vrpolak@cisco.com>
Date: Tue, 28 Jul 2020 14:38:55 +0000 (+0200)
Subject: Soak: Avoid a possible deadlock.
X-Git-Url: https://gerrit.fd.io/r/gitweb?p=csit.git;a=commitdiff_plain;h=3f0822a35efc2fd61bcc4040bea13519f389b655

Soak: Avoid a possible deadlock.

Change-Id: I31c2d7744b5cd3021132fb188480b8edec74986c
Signed-off-by: Vratko Polak <vrpolak@cisco.com>
---

diff --git a/resources/libraries/python/PLRsearch/PLRsearch.py b/resources/libraries/python/PLRsearch/PLRsearch.py
index fb4ee1a4d0..ec58fbd10f 100644
--- a/resources/libraries/python/PLRsearch/PLRsearch.py
+++ b/resources/libraries/python/PLRsearch/PLRsearch.py
@@ -601,15 +601,17 @@ class PLRsearch:
 
             dilled_function = dill.dumps(value_logweight_func)
             boss_pipe_end, worker_pipe_end = multiprocessing.Pipe()
-            boss_pipe_end.send(
-                (dimension, dilled_function, focus_tracker, max_samples)
-            )
+            # Do not send yet, run the worker first to avoid a deadlock.
+            # See https://stackoverflow.com/a/15716500
             worker = multiprocessing.Process(
                 target=Integrator.try_estimate_nd,
                 args=(worker_pipe_end, 10.0, self.trace_enabled)
             )
             worker.daemon = True
             worker.start()
+            boss_pipe_end.send(
+                (dimension, dilled_function, focus_tracker, max_samples)
+            )
             return boss_pipe_end
 
         erf_pipe = start_computing(self.lfit_erf, erf_focus_tracker)