From: Xiao-Feng Li <[EMAIL PROTECTED]> > Thread suspension happens in many situations in JVM, such as for GC, > for java.lang.Thread.suspend(), etc. There are various techniques to > suspend a thread. Basically we can classify them into two categories: > preemptive and voluntary.
> The preemptive approach requires the suspender, say a GC thread, > suspend the execution of a target thread asynchronously with IPC > mechanism or OS APIs. If the suspended thread happened to be in a > region of code (Java or native) that could be enumerated, the live > references were collected. This kind of region is called safe-region, > and the suspended point is a safe-point. If the suspended point is not > in safe-region, the thread would be resumed and stopped again until it > ended up in a safe-region randomly or on purpose. Sun's HotSpot VMs patch compiled native code to stop thread at the safe points, on which a stack map is provided. It's smart but prone to causes subtle problems, an engineer working on the VM said. Kazuyuki Shudo [EMAIL PROTECTED] http://www.shudo.net/
