@Override
    public int getProcessId() {
      return getpid();
    }
holds a reference of {@link SignalHandler} installed in {@link #daemonize} for SIGHUP to
avoid it being GCed. Assumes that the NativeCalls instance itself is a singleton and never
GCed.
geode-core/src/main/java/org/apache/geode/internal/shared/NativeCallsJNAImpl.java