Bug 198345 Memory Leak problem in BIRT.
Memory Leak problem is detected in BIRT 2.2, most of which is supposed caused by unreleased rhino script objects. There are two indentified sources of problem at current stage, both of which are located in class birt.core.script.JavascriptEvalUtil 1.The class keeps a static scriptable object "sharedScope". Because it is a static variable it will not be destroyed until the jvm terminate. We should not use this static scriptable object any more, rather, we should ask client of this class to pass in a scope. 2.The class also keeps a static list "cachedCompiledScript". It is for speeding up the script evaluation process. We should keep this cache to per Data Engine rather than JVM-wise.
core/org.eclipse.birt.core/src/org/eclipse/birt/core/script/JavascriptEvalUtil.java
new Object[]{ timeVal } );
    		}
    		finally
    		{
    			Context.exit();
    		}
    	}
    	else
    		return value;
    }
    
	/**
	 * If caller does not have a scope for evaluation, the caller can use this
	 * method to evaluate expression. But if caller has its own scope which can
	 * be used, the better way is call the method of convertToJavascriptValue(
	 * Object value, Scriptable scope ).
	 * 
	 * @param value
	 * @return
	 */
	public static Object convertToJavascriptValue( Object value )
	{
		if ( sharedScope == null )
		{
			Context cx = Context.enter( );
			sharedScope = new ImporterTopLevel( cx );
			Context.exit( );
		}
		return convertToJavascriptValue( value, sharedScope );
	}