Chronicle Queue memory mapping file to reduce avoid garbage collection? - memory-mapped-files

Question

I have a question about how the Chronicle queue avoids garbage collection:
I understand that the Chronicle queue uses a memory mapping file so that it can save an object into main memory or dist rather than into JVM. However, when a processor deserializes the object from the main memory, it still needs to create a new instance. So where exactly Chronicle queue avoid garbage collection?
See the below case that comes from a Chronicle github example. When performs write to/read operation, it still needs to create a new instance using MyObject me = new MyObject() and "me" will be garbaged collected.
public class Example {
static class MyObject implements Marshallable {
String name;
int age;
#Override
public String toString() {
return Marshallable.$toString(this);
}
}
public static void main(String[] args) throws IOException {
// will write the .cq4 file to working directory
SingleChronicleQueue queue = SingleChronicleQueueBuilder.builder().path(Files
.createTempDirectory("queue").toFile()).build();
ExcerptAppender appender = queue.acquireAppender();
ExcerptTailer tailer = queue.createTailer();
MyObject me = new MyObject();
me.name = "rob";
me.age = 40;
// write 'MyObject' to the queue
appender.writeDocument(me);
// read 'MyObject' from the queue
MyObject result = new MyObject();
tailer.readDocument(result);
System.out.println(result);
}
}

Answer 1

You can reuse the object you deserialise into.
// created once
MyObject result = new MyObject();
// this can be called multiple times with the same object
tailer.readDocument(result);
The String is also pooled reducing garbage.
This way you can write and read millions of messages but only create one or two objects.