JEP 312 – Thread-Local Handshakes
JDK 10 introduced a new option for the JVM – XX:ThreadLocalHandshakes. This option works only for x64 and SPARC based machines.
This option is available to improve VM performance. It allows to perform a callback on application threads without setting a global VM safepoint. This allows the JVM to stop a single thread without stopping all threads.
Since this option is not available for all platforms, other platforms fall back to normal safepoints.