JNA(Java Native Access) and Linux 2.6 (x86_64) system call example #1 using Groovy.

t_jna_linux64_syscall_1.groovy

/*
 * JNA and Linux 2.6 (x86_64) system call example #1.
 * (no copyright, license-free, AS-IS, for any commercial or oss or free source code)
 */
@Grapes(
@Grab(group='net.java.dev.jna', module='jna', version='4.0.0')
)
import com.sun.jna.*

/** @see /usr/include/asm/unistd_64.h */
interface SYSCALL64 {
    final int getpid = 39;
    final int getppid = 110;
    final int gettid = 186;
}

interface GLIBC extends Library {
    void printf(String format, Object... args);
    int getpid();
    int getppid();
    int syscall(int number, Object... args);
}

class Syscall {
    final GLIBC glibc
    Syscall(GLIBC glibc) {
        this.glibc = glibc
    }
    int getpid() {
        return this.glibc.syscall(SYSCALL64.getpid)
    }
    int getppid() {
        return this.glibc.syscall(SYSCALL64.getppid)
    }
    int gettid() {
        return this.glibc.syscall(SYSCALL64.gettid)
    }
}


GLIBC glibc = (GLIBC)Native.loadLibrary('c', GLIBC.class)

println glibc.dump();
println glibc.inspect();
glibc.printf("Hello, %s World!\n", "JNA")

Syscall sc = new Syscall(glibc)

int current_ntid = sc.gettid()
println 'gettid() = ' + current_ntid

println 'now, try : strace -e trace=getpid,getppid -p ' + current_ntid

def c = System.console()
c.readLine('continue?')

println 'getpid() = ' + sc.getpid()
println 'getppid() = ' + sc.getppid()