1// Copyright 2023 Peter Dimov
2// Distributed under the Boost Software License, Version 1.0.
3// https://www.boost.org/LICENSE_1_0.txt
4
5#include <boost/unordered/detail/foa/rw_spinlock.hpp>
6#include <boost/compat/shared_lock.hpp>
7#include <boost/core/lightweight_test.hpp>
8#include <mutex>
9#include <thread>
10#include <cstdio>
11
12using boost::unordered::detail::foa::rw_spinlock;
13
14static int count = 0;
15static rw_spinlock sp;
16
17void f( int k, int m, int n )
18{
19 std::printf( format: "Thread %d of %d started.\n", k, m );
20
21 for( int i = 0; i < n; ++i )
22 {
23 int oldc;
24
25 for( ;; )
26 {
27 {
28 boost::compat::shared_lock<rw_spinlock> lock( sp );
29 oldc = count;
30 }
31
32 if( oldc % m == k ) break;
33 }
34
35 {
36 std::lock_guard<rw_spinlock> lock( sp );
37 if( count == oldc ) ++count;
38 }
39 }
40
41 std::printf( format: "Thread %d of %d finished.\n", k, m );
42}
43
44int main()
45{
46 int const N = 100; // total iterations
47 int const M = 4; // threads
48
49 std::thread th[ M ];
50
51 for( int i = 0; i < M; ++i )
52 {
53 th[ i ] = std::thread( f, i, M, N );
54 }
55
56 for( int i = 0; i < M; ++i )
57 {
58 th[ i ].join();
59 }
60
61 BOOST_TEST_EQ( count, N * M );
62
63 return boost::report_errors();
64}
65

source code of boost/libs/unordered/test/cfoa/rw_spinlock_test8.cpp