BufferUnderflowException in Getting Started

[pjulien]

I am trying to determine if the following wiki page is out of date or is exposing a bug in the system:

https://github.com/OpenHFT/Chronicle-Queue/blob/master/docs/HowItWorks.md#getting-started

Using Windows 8.1, Java 8u25 and Chronicle Queue 3.3.3 with no modifications other than adding a package declaration, I get the following:

Exception in thread "main" java.lang.IllegalStateException: java.nio.BufferUnderflowException
    at net.openhft.lang.io.AbstractBytes.readObject(AbstractBytes.java:1990)
    at com.test.ExampleCacheMain.main(ExampleCacheMain.java:26)
Caused by: java.nio.BufferUnderflowException
    at net.openhft.lang.io.AbstractBytes.returnOrThrowEndOfBuffer(AbstractBytes.java:195)
    at net.openhft.lang.io.AbstractBytes.readByteOrThrow(AbstractBytes.java:439)
    at net.openhft.lang.io.AbstractBytes.readUnsignedByteOrThrow(AbstractBytes.java:433)
    at net.openhft.lang.io.serialization.BytesMarshallableSerializer.readSerializable(BytesMarshallableSerializer.java:123)
    at net.openhft.lang.io.AbstractBytes.readObject(AbstractBytes.java:1988)
    ... 1 more

Modifying to use readUTF and writeUTF, I get:

Exception in thread "main" java.nio.BufferUnderflowException
    at net.openhft.lang.io.AbstractBytes.returnOrThrowEndOfBuffer(AbstractBytes.java:195)
    at net.openhft.lang.io.AbstractBytes.readByteOrThrow(AbstractBytes.java:439)
    at net.openhft.lang.io.AbstractBytes.readUnsignedByteOrThrow(AbstractBytes.java:433)
    at net.openhft.lang.io.AbstractBytes.readUTF0(AbstractBytes.java:202)
    at net.openhft.lang.io.AbstractBytes.readUTF(AbstractBytes.java:698)
    at com.test.ExampleCacheMain.main(ExampleCacheMain.java:26)

[lburgazzoli]

There is an error in the GettingStarted: you should always check if there is an Excerpt to read before reading it so you should do:

while(!reader.nextIndex());
Object obj = reader.readObject();
reader.finish();

If you want to read all the Excerpts :

while(true) {
    if(reader.nextIndex()) {
        Object obj = reader.readObject();
        reader.finish();
   } else {
       // sleep, do nothing, yeld, etc
   }
}

I've updated the getting-started guide

[pjulien]

Thanks works for me now.