Question: I get an error ''Green threads not supported'' when tried to use -gree

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Question: I get an error "Green threads not supported" when tried to use -green option on Windows.
But my application runs just fine...
Does this mean that by default JVM is using native option?

Answer: Just Solaris and Linux support the option -green threads. Green threads are independent of native threads and less efficient. The downside is that using green threads means system threads on Linux are not taken advantage of and so the Java virtual machine is not scalable when additional CPUs are added.
On Windows JVM uses native threading.

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Is it something new in J2SE 1.4.1?

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Question: Is it something new in J2SE 1.4.1?

Answer:
I would like to say about next things that I was glad to read about:

1. Over 2000 bug fixes!!!
2. Two new garbage collectors have been added to improve application performance: 
   Concurrent Mark and Sweep Collector. This collector executes mostly concurrently with the application. It trades the utilization of processing power that would otherwise be available to the application for shorter garbage collection pause times.
   Parallel Garbage Collector. This collector enables garbage collection to occur on multiple threads for better performance on multiprocessor machines.
   P.S. A few flags were added to command line to manage those GSs...
3. The Sun SecureRandom implementation now also makes use of an operating system-provided entropy source on Windows platforms,  which can improve the startup time of cryptographic applications considerably.
4. A deadlock detection utility has been added to the Java HotSpot VM. The utility is invoked by a ctrl+ (on Linux or the Solaris Operating Environment) or a ctrl-break (on Microsoft Windows) on the command line while an application is running.
   The utility detects Java-platform-level deadlocks, including locking done from the Java Native Interface (JNI), the Java Virtual Machine Profiler Interface (JVMPI), and Java Virtual Machine Debug Interface (JVMDI). When invoked, the utility displays a thread dump to standard out and indicates any Java-platform-level deadlocks it detects. Refer to this sample output.
   If the application is deadlocked because two or more threads are involved in a cycle to acquire monitors, then the list of such threads and monitors involved in the deadlocks are displayed. Note, however, that this will not find deadlocks involving threads waiting on monitors on which no signal will be forthcoming.

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