--- /dev/null
+// Copyright 2018, 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt)
+
+#include <boost/shared_ptr.hpp>
+#include <boost/weak_ptr.hpp>
+#include <boost/smart_ptr/detail/lightweight_thread.hpp>
+#include <boost/bind/bind.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+static boost::shared_ptr<int> sp( new int );
+static boost::weak_ptr<int> wp( sp );
+
+void f1( int n )
+{
+ for( int i = 0; i < n; ++i )
+ {
+ boost::weak_ptr<int> p1( wp );
+
+ BOOST_TEST( !wp.expired() );
+ BOOST_TEST( wp.lock() != 0 );
+ }
+}
+
+void f2( int n )
+{
+ for( int i = 0; i < n; ++i )
+ {
+ boost::weak_ptr<int> p1( wp );
+
+ BOOST_TEST( wp.expired() );
+ BOOST_TEST( wp.lock() == 0 );
+ }
+}
+
+int main()
+{
+ int const N = 100000; // iterations
+ int const M = 8; // threads
+
+ boost::detail::lw_thread_t th[ M ] = {};
+
+ for( int i = 0; i < M; ++i )
+ {
+ boost::detail::lw_thread_create( th[ i ], boost::bind( f1, N ) );
+ }
+
+ for( int i = 0; i < M; ++i )
+ {
+ boost::detail::lw_thread_join( th[ i ] );
+ }
+
+ BOOST_TEST_EQ( sp.use_count(), 1 );
+ BOOST_TEST_EQ( wp.use_count(), 1 );
+
+ sp.reset();
+
+ BOOST_TEST_EQ( sp.use_count(), 0 );
+ BOOST_TEST_EQ( wp.use_count(), 0 );
+
+ for( int i = 0; i < M; ++i )
+ {
+ boost::detail::lw_thread_create( th[ i ], boost::bind( f2, N ) );
+ }
+
+ for( int i = 0; i < M; ++i )
+ {
+ boost::detail::lw_thread_join( th[ i ] );
+ }
+
+ wp.reset();
+
+ return boost::report_errors();
+}