osgi_and_jruby.txt

osgi_and_jruby.txt

OSGi is supported by JRuby 1.6.0 onwards.

1. OSGiScriptingContainer

Check out that class. Any OSGi app must use this container. In particular, you can add bundles to the jruby classpath easily with this container.

2. LocalScopeContext

By default it is set to SINGLETHREAD. That's the only one that works right now, others will spawn CNFE randomly when used.

There is a trick with the LocalScopeContext. Most of the local scope variables can harm you. So you can override the default local scope context to make it thread local, but that's quite expensive on the CPU (this was written by Federico Feller from my team):

public class MyOSGiScriptingContainer extends OSGiScriptingContainer {
    private final ThreadLocal<LocalContext> contextHolder = new ThreadLocal<LocalContext>() {
        @Override
        public LocalContext initialValue() {
            return getInstance();
        }
    };

    public MyOSGiScriptingContainer(Bundle creator, LocalContextScope scope,
            LocalVariableBehavior behavior, boolean lazy) {
        super(creator, scope, behavior, lazy);
    }

    public MyOSGiScriptingContainer(Bundle creator, LocalContextScope scope,
            LocalVariableBehavior behavior) {
        super(creator, scope, behavior);
    }

    public MyOSGiScriptingContainer(Bundle creator) {
        super(creator);
    }

    @Override
    public BiVariableMap getVarMap() {
        return contextHolder.get().getVarMap(getProvider().getRuntime());
    }

    @Override
    public Object get(String key) {
        return getVarMap().get(getProvider().getRuntime().getTopSelf(), key);
    }

    @Override
    public Object put(String key, Object value) {
        return getVarMap().put(getProvider().getRuntime(), key, value);
    }

    @Override
    public Object put(Object receiver, String key, Object value) {
        return getVarMap().put(receiver, key, value);
    }

    @Override
    public Object get(Object receiver, String key) {
        return getVarMap().get(receiver, key);
    }

    @Override
    public Object remove(Object receiver, String key) {
        return getVarMap().remove(receiver, key);
    }

    @Override
    public void clear() {
        getVarMap().clear();
    }

    @Override
    public Map getAttributeMap() {
        return contextHolder.get().getAttributeMap();
    }

    @Override
    public Object getAttribute(Object key) {
        return getAttributeMap().get(key);
    }

    @Override
    public Object setAttribute(Object key, Object value) {
        return getAttributeMap().put(key, value);
    }

    @Override
    public Object removeAttribute(Object key) {
        return getAttributeMap().remove(key);
    }

    protected LocalContext getInstance() {
        return new LocalContext(getProvider().getRuntime().getInstanceConfig(),
                LocalVariableBehavior.TRANSIENT, true);
    }

}