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From:   Stefano Garzarella <sgarzare@redhat.com>
To:     netdev@vger.kernel.org
Cc:     kvm@vger.kernel.org, Stefan Hajnoczi <stefanha@redhat.com>,
        Dexuan Cui <decui@microsoft.com>,
        virtualization@lists.linux-foundation.org,
        "David S. Miller" <davem@davemloft.net>,
        Jorgen Hansen <jhansen@vmware.com>,
        linux-kernel@vger.kernel.org
Subject: [PATCH v2 05/11] VSOCK: add full barrier between test cases
Date:   Thu,  1 Aug 2019 17:25:35 +0200
Message-Id: <20190801152541.245833-6-sgarzare@redhat.com>
In-Reply-To: <20190801152541.245833-1-sgarzare@redhat.com>
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From: Stefan Hajnoczi <stefanha@redhat.com>

See code comment for details.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 tools/testing/vsock/util.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/tools/testing/vsock/util.c b/tools/testing/vsock/util.c
index f838bcee3589..4280a56ba677 100644
--- a/tools/testing/vsock/util.c
+++ b/tools/testing/vsock/util.c
@@ -161,10 +161,24 @@ void run_tests(const struct test_case *test_cases,
 		printf("%s...", test_cases[i].name);
 		fflush(stdout);
 
-		if (opts->mode == TEST_MODE_CLIENT)
+		if (opts->mode == TEST_MODE_CLIENT) {
+			/* Full barrier before executing the next test.  This
+			 * ensures that client and server are executing the
+			 * same test case.  In particular, it means whoever is
+			 * faster will not see the peer still executing the
+			 * last test.  This is important because port numbers
+			 * can be used by multiple test cases.
+			 */
+			control_expectln("NEXT");
+			control_writeln("NEXT");
+
 			run = test_cases[i].run_client;
-		else
+		} else {
+			control_writeln("NEXT");
+			control_expectln("NEXT");
+
 			run = test_cases[i].run_server;
+		}
 
 		if (run)
 			run(opts);
-- 
2.20.1