From: Peter Rabbitson <ribasushi@cpan.org>
Date: Thu, 10 Mar 2016 18:02:00 +0000 (+0100)
Subject: Really work around RT#108390 (630e2ea8a)
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=820a29360e4920d9edff9e9cefe721b8a265e40d;p=dbsrgits%2FDBIx-Class-Historic.git

Really work around RT#108390 (630e2ea8a)

A certain chain of events can still deadlock things without an explicit flush
---

diff --git a/t/lib/DBICTest/Util.pm b/t/lib/DBICTest/Util.pm
index 68b6e2c..b084560 100644
--- a/t/lib/DBICTest/Util.pm
+++ b/t/lib/DBICTest/Util.pm
@@ -88,7 +88,21 @@ sub await_flock ($$) {
 
     # "say something" every 10 cycles to work around RT#108390
     # jesus christ our tooling is such a crock of shit :(
-    print "#\n" if not $tries % 10;
+    unless ( $tries % 10 ) {
+
+      # Turning on autoflush is crucial: if stars align just right buffering
+      # will ensure we never actually call write() underneath until the grand
+      # timeout is reached (and that's too long). Reproducible via
+      #
+      # DBICTEST_VERSION_WARNS_INDISCRIMINATELY=1 \
+      # DBICTEST_RUN_ALL_TESTS=1 \
+      # strace -f \
+      # prove -lj10 xt/extra/internals/
+      #
+      select( ( select(\*STDOUT), $|=1 )[0] );
+
+      print "#\n";
+    }
   }
 
   return $res;