#include <pthread.h>
#include <thread>
#include <mutex>
#include <dios.h>
#include <rst/termsec.h> // for user-defined resource sections

struct SpinLock {
    void lock() {
        termsec::CheckFunction check;
        while ( _flag.test_and_set() ) { }
    }

    void unlock() {
        _flag.clear();
    }

  private:
    std::atomic_flag _flag = ATOMIC_FLAG_INIT;
};

int main() {
    pthread_rwlock_t rwl = PTHREAD_RWLOCK_INITIALIZER;
    std::mutex mtx;
    SpinLock spin;

    std::thread
        t0( [&] {
            while ( true ) {
                std::unique_lock lmtx( mtx );
                // wait for:
                pthread_rwlock_wrlock( &rwl );
                pthread_rwlock_unlock( &rwl );
            }
        } ),
        t1( [&] {
            while ( true ) {
                pthread_rwlock_rdlock( &rwl );
                // wait for:
                { std::unique_lock lsp( spin ); }
                pthread_rwlock_unlock( &rwl );
            }
        } ),
        t2( [&] {
            while ( true ) {
                std::unique_lock lsp( spin );
                // wait for:
                std::unique_lock lmtx( mtx );
            }
        } );
    int x = 0;
    while ( true ) {
        x = (x + 1) % 2;
    }
}