Why does the matlab exported java package(.jar) run faster than matlab exported c library (.so)?

Hello!

We just export our MatLab algorithm files(*.m) to Java package(*.jar) and C library(*.so) by using MatLab R2014b's "deploytool" on Ubuntu 16.04 desktop. But when We deploy them to our CentOS 7 server, our Java program calling the exported java package runs faster than our C program calling the exported C library. Their time cost comparison is about 2.48s vs 3.54s. We just count the time cost by getting the system time stamp before and after calling the key exported interface(e.g: mlfParMyInterface()) and computing their diff. We use the parfor in our exported interface. Actually, it has same comparision result to call the serial computing interface(e.g: mlfMyInterface()) of one-by-one.

So how could this happen between the exported Java and C library?

Thanks a lot!