function QVERIFY(x, debugInfo) {

    if (!(x)) {

        print(debugInfo);

        throw(debugInfo);

    }

}

var consumer = new ScriptSharedMemory;

consumer.setKey("market");

//print("consumer starting");

var tries = 0;;

while(!consumer.attach()) {

    if (tries == 5000) {

        var message = "consumer exiting, waiting too long";

        print(message);

        throw(message);

    }

    ++tries;

    consumer.sleep(1);

}

//print("consumer attached");

var i = 0;

while(true) {

    QVERIFY(consumer.lock(), "lock");

    if (consumer.get(0) == 'Q') {

        consumer.set(0, ++i);

        //print ("consumer sets" + i);

    }

    if (consumer.get(0) == 'E') {

        QVERIFY(consumer.unlock(), "unlock");

        break;

    }

    QVERIFY(consumer.unlock(), "unlock");

    consumer.sleep(10);

}

//print("consumer detaching");

QVERIFY(consumer.detach());