Fix race condition in TLSProxy

mattcaswell · mattcaswell · commit 018632ae986a · 2017-11-07T10:51:17.000Z
Normally TLSProxy waits for the s_server process to finish before continuing. However in cases where serverconnects > 1 we need to keep the s_server process around for a later test so we continue immediately. This means that TAP test output can end up being printed to stdout at the same time as s_server is printing stuff. This confuses the test runner and can cause spurious test failures. This commit introduces a small delay in cases where serverconnects > 1 in order to give s_server enough time to finish what it was doing before we continue to the next test. Fixes openssl#4129 Reviewed-by: Rich Salz <rsalz@openssl.org> (Merged from openssl#4660)
diff --git a/util/perl/TLSProxy/Proxy.pm b/util/perl/TLSProxy/Proxy.pm
@@ -23,6 +23,7 @@ use TLSProxy::Certificate;
 use TLSProxy::CertificateVerify;
 use TLSProxy::ServerKeyExchange;
 use TLSProxy::NewSessionTicket;
+use Time::HiRes qw/usleep/;
 
 my $have_IPv6 = 0;
 my $IP_factory;
@@ -343,6 +344,9 @@ sub clientstart
               .$self->serverpid."\n";
         waitpid( $self->serverpid, 0);
         die "exit code $? from server process\n" if $? != 0;
+    } else {
+        # Give s_server sufficient time to finish what it was doing
+        usleep(250000);
     }
     die "clientpid is zero\n" if $self->clientpid == 0;
     print "Waiting for client process to close: ".$self->clientpid."\n";
