source: doc/theses/colby_parsons_MMAth/benchmarks/channels/cfa/hot_potato.cfa @ d24b1985

#include <locks.hfa>
#include <fstream.hfa>
#include <stdio.h>
#include <channel.hfa>
#include <thread.hfa>
#include <time.hfa>
#include <string.h>

size_t total_operations = 0;
size_t Processors = 1, Tasks = 1;

owner_lock o;

// typedef channel_base( int, exp_backoff_then_block_lock ) Channel;
typedef channel( int ) Channel;

Channel * chain;

bool done = false;
int id_counter = 0;
thread Task { int id; int right; };
static inline void ?{}( Task & this ) with(this) {
    id = __atomic_fetch_add( &id_counter, 1, __ATOMIC_SEQ_CST );
    right = (id + 1) % Tasks;
}
void main(Task & this) with(this) {
    size_t runs = 0;
    int my_id = id;
    int my_right = right;
    for ( ;; ) {
        if ( done ) break;
        remove( chain[my_id] );
        insert( chain[my_right], 0 );
        runs++;
    }
    lock( o );
    total_operations += runs;
    unlock( o );
}


int main( int argc, char * argv[] ) {
    switch ( argc ) {
          case 3:
                if ( strcmp( argv[2], "d" ) != 0 ) {                    // default ?
                        Tasks = atoi( argv[2] );
            if ( Tasks < 1 ) goto Usage;
                } // if
          case 2:
                if ( strcmp( argv[1], "d" ) != 0 ) {                    // default ?
                        Processors = atoi( argv[1] );
                        if ( Processors < 1 ) goto Usage;
                } // if
          case 1:                                                                                       // use defaults
                break;
          default:
          Usage:
                sout | "Usage: " | argv[0]
             | " [ processors (> 0) | 'd' (default " | Processors
                         | ") ] [ channel size (>= 0) | 'd' (default " | Tasks
                         | ") ]" ;
                exit( EXIT_FAILURE );
        } // switch
    Tasks = Processors;
    processor proc[Processors - 1];

    chain = aalloc( Tasks );
    for ( i; Tasks ) {
        chain[i]{ 3 };
    }

    insert( chain[0], 0 );
    {
        Task t[Tasks];
        sleep(10`s);
        done = true;
        for ( j; Tasks )
            insert( chain[j], 0 );
    }
    
    sout | total_operations;

    adelete(chain);

    return 0;
}