source: tests/concurrency/waituntil/channels.cfa

#include <select.hfa>
#include <thread.hfa>
#include <channel.hfa>

channel(long long int) A, B, C;

volatile bool done = false;
long long int globalTotal = 0;

thread Server1 {};
void main( Server1 & this ) {
    long long int a, b, c, i = 0, myTotal = 0;
    for( ;;i++ ) {
        when( i % 2 == 0 ) waituntil( a << A ) { myTotal += a; }
        or when( i % 4 < 2 ) waituntil( b << B ) { myTotal += b; }
        or waituntil( c << C ) { if ( c == -1 ) break; myTotal += c; }
        or when( i % 8 < 4 ) else {}
    }
    __atomic_fetch_add( &globalTotal, myTotal, __ATOMIC_SEQ_CST );
}

thread Drainer {}; // ensures that the changing when states of Server1 don't result in a deadlock
void main( Drainer & this ) {
    long long int a, b, c, myTotal = 0;
    for( ;; ) {
        waituntil( a << A ) { myTotal += a; }
        or waituntil( b << B ) { myTotal += b; }
        or waituntil( c << C ) { if ( c == -1 ) break; myTotal += c; }
        or else {}
    }
    __atomic_fetch_add( &globalTotal, myTotal, __ATOMIC_SEQ_CST );
}

thread Churner {}; // performs non-waituntil try insert/remove operations to add churn/interference
void main( Churner & this ) {
    long long int out, myTotal = 0;
    bool success;
    while( !done ) {
        try_insert( A, 0 );
        try_insert( B, 0 );
        try_insert( C, 0 );
        [out, success] = try_remove( A );
        if ( success ) myTotal += out;
        [out, success] = try_remove( B );
        if ( success ) myTotal += out;
        [out, success] = try_remove( C );
        if ( success ) myTotal += out;
    }
    __atomic_fetch_add( &globalTotal, myTotal, __ATOMIC_SEQ_CST );
}

size_t numtimes = 100000;
size_t numServers = 3;
int main( int argc, char * argv[] ) {
    if ( argc == 2 )
        numtimes = atoi( argv[1] );

    processor p[numServers + 2];
    A{5};
    B{5};
    C{5};

    long long int total = 0;
    printf("start\n");
    {
        Server1 s[numServers];
        Drainer d;
        {
            Churner c;
            for( long long int j = 0; j < numtimes; j++ ) {
                when( j % 2 == 0 ) waituntil( A << j ) { total += j; }
                or when( j % 4 < 2 ) waituntil( B << j ) { total += j; }
                and when( j % 8 < 4 ) waituntil( C << j ) { total += j; }
            }
            done = true;
            printf("terminating churner\n");
        }
        printf("waiting for empty channels\n");
        while( get_count( A ) > 0 || get_count( B ) > 0 || get_count( C ) > 0 ) { }
        printf("sending sentinels\n");
        for ( i; numServers + 1 ) insert( C, -1 );
        printf("joining servers\n");
    }
    if ( total != globalTotal ) 
        printf("CHECKSUM MISMATCH!! Main thread got %lld, server sum is %lld\n", total, globalTotal);
    printf("done\n");
}