From 36169d399c4b1eee359ae51c660b3a6a3b4a8097 Mon Sep 17 00:00:00 2001
From: Joe Thornber <ejt@redhat.com>
Date: Mon, 14 Aug 2017 14:20:59 +0100
Subject: [PATCH] [unit-tests] add failing test.

You currently can get a read lock when a write lock is already held.
---
 unit-tests/block_t.cc | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/unit-tests/block_t.cc b/unit-tests/block_t.cc
index c1a3172..6da67db 100644
--- a/unit-tests/block_t.cc
+++ b/unit-tests/block_t.cc
@@ -233,6 +233,13 @@ TEST(BlockTests, concurrent_read_locks)
 	bm->read_lock(0);
 }
 
+TEST(BlockTests, no_concurrent_read_and_write_locks)
+{
+	bm4096::ptr bm = create_bm<4096>();
+	bm4096::write_ref wr = bm->write_lock(0);
+	ASSERT_THROW(bm->read_lock(0), runtime_error);
+}
+
 TEST(BlockTests, read_then_write)
 {
 	bm4096::ptr bm = create_bm<4096>();