* @flist: pointer to list of the free slots associated with queue
* @entry: pointer to the memory allocated for the list slots.
* @fifo_lock: the lock to ensure atomicity of slot manipulation operations.
* @flist: pointer to list of the free slots associated with queue
* @entry: pointer to the memory allocated for the list slots.
* @fifo_lock: the lock to ensure atomicity of slot manipulation operations.