@lock

Locks this.

If it is already locked by another thread, the current thread will block until it is unlocked by the other thread.

This function can be used even if g_thread_init has not yet been called, and, in that case, will do nothing.

Note: unlike @lock, this method recursive, which means a thread can lock this several times (and has to unlock it as many times to actually unlock it).

Parameters:

this	a Lockable object.