Are Thread.stop and friends ever safe in Java?

Question

The stop(), suspend(), and resume() in java.lang.Thread are deprecated because they are unsafe. The Oracle recommended w

Answer 1

There is no safe way to kill a thread.

Neither there is a subset of situations where it is safe. Even if it is working 100% while testing on Windows, it may corrupt JVM process memory under Solaris or leak thread resources under Linux.

One should always remember that underneath the Java Thread there is a real, native, unsafe thread.

That native thread works with native, low-level, data and control structures. Killing it may leave those native data structures in an invalid state, without a way to recover.

There is no way for Java machine to take all possible consequences into account, as the thread may allocate/use resources not only within JVM process, but within the OS kernel as well.

In other words, if native thread library doesn't provide a safe way to kill() a thread, Java cannot provide any guarantees better than that. And all known to me native implementations state that killing thread is a dangerous business.