advisory locking example in Mono C#

advisory_locking.cs

using Mono.Unix.Native;
using System.IO;

static bool TryLockProcess(string file_to_lock)
{
	int pid = Syscall.getpid();
	int fd = Syscall.open(file_to_lock, OpenFlags.O_CREAT | OpenFlags.O_RDWR, FilePermissions.DEFFILEMODE);
	if (fd > 0) {
		// a write (exclusive) lock
		Flock wl;
		wl.l_len = 0;
		wl.l_pid = pid;
		wl.l_start = 0;
		wl.l_type = LockType.F_WRLCK;
		wl.l_whence = SeekFlags.SEEK_SET;
		
		// try to set lock
		int res = Syscall.fcntl(fd, FcntlCommand.F_SETLK, ref wl);
		// if can't get lock ...
		if (res != 0 || Syscall.GetLastError() == Errno.EAGAIN) {
			return false;
		} else {
			return true;
		}
	} 
	return false;
}

Note that this implements fcntl() locking, which is different from flock() locking in Linux (despite the name of the structure Flock).

I'm interested to do flock() style locking in Linux, but I don't think Mono provides a way to do it.

doesn`t seems to work anymore (Ubuntu 14.04). is there any updated version?