code: public long hits() {
          Lock readerLock = context.ctxLock.readLock();
          readerLock.lock();
          try {
              return SSLContext.sessionHits(context.ctx);
          } finally {
              readerLock.unlock();
          }
      }
docs: Returns the number of successfully reused sessions. In client mode, a session set with {@code SSL_set_session}
  successfully reused is counted as a hit. In server mode, a session successfully retrieved from internal or
  external cache is counted as a hit.