public int readPid(Path workingDir) {
    return ProcessUtils.readPid(workingDir.resolve(getPidFileName()));
  }
Enumeration of GemFire {@link ControllableProcess} types and the file names associated with
controlling its lifecycle.

@since GemFire 8.0
geode-core/src/main/java/org/apache/geode/internal/process/ProcessType.java