source: doc/papers/concurrency/examples/PingPong.cc@ 35d1de5

#include <cstdio>

struct Obj {
        Obj() { printf( "Obj constructor\n" ); }
        ~Obj() { printf( "Obj destructor\n" ); }
        int i = 4;
};

struct PingPong {
        const char * name;
        const int N;
        PingPong * partner = nullptr;
        int i = 0;
        void * next = nullptr;

        PingPong( const char * name, int N ) : name(name), N(N) {}

        void operator()() {
                if ( __builtin_expect(next != 0, 1) ) goto *next;
                next = &&cycle;
                for ( ; i < N; i += 1 ) {
                        Obj obj;
                        printf( "X %s %d\n", name, obj.i );
                        obj.i = 7;
#ifdef PRINT
                        printf( "%s %d\n", name, i );
#endif // PRINT
                        asm( "mov  %0,%%rdi" : "=m" (partner) );
                        asm( "mov  %rdi,%rax" );
#ifndef OPT
#ifdef PRINT
                        asm( "add  $40, %rsp" );
#endif // PRINT
                        asm( "popq %rbp" );
#endif // ! OPT

#ifdef OPT
#ifdef PRINT
                        asm( "popq %rbx" );
#endif // PRINT
#endif // OPT
                        asm( "jmp  _ZN8PingPongclEv" );
                  cycle: ;
                        printf( "Y %s %d\n", name, obj.i );
                } // for
        }
};
int main() {
        enum { N =
#ifdef PRINT
                   5
#else
                   1000000000
#endif // PRINT
        };
        PingPong ping = { "ping", N }, pong = { "pong", N };
        ping.partner = &pong; pong.partner = &ping;
        ping();
}

// Local Variables: //
// tab-width: 4 //
// compile-command: "g++-8 -g -DPRINT PingPong.cc" //
// End: //