Add rw_spinlock tests

test/cfoa/rw_spinlock_test3.cpp

@@ -0,0 +1,49 @@
+// Copyright 2023 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/unordered/detail/foa/rw_spinlock.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <mutex>
+#include <thread>
+#include <cstdio>
+
+using boost::unordered::detail::foa::rw_spinlock;
+
+static int count = 0;
+static rw_spinlock sp;
+
+void f( int k, int n )
+{
+    std::printf( "Thread %d started.\n", k );
+
+    for( int i = 0; i < n; ++i )
+    {
+        std::lock_guard<rw_spinlock> lock( sp );
+        ++count;
+    }
+
+    std::printf( "Thread %d finished.\n", k );
+}
+
+int main()
+{
+    int const N = 1000000; // iterations
+    int const M = 8;       // threads
+
+    std::thread th[ M ];
+
+    for( int i = 0; i < M; ++i )
+    {
+        th[ i ] = std::thread( f, i, N );
+    }
+
+    for( int i = 0; i < M; ++i )
+    {
+        th[ i ].join();
+    }
+
+    BOOST_TEST_EQ( count, N * M );
+
+    return boost::report_errors();
+}