where is queue unblocking scheduled?

["Nelson Liu" <xcliu@cti.com.cn>]

Hi,

Could anyone help me on a question about queue control in NS-2?

When a queue is blocked, it should be unblocked later by calling its
handle function. But where is this handle function scheduled in the 
code? I expected to find it in some target recv functions. But after 
analyzing much of the code, I'm still not sure about it.

Thanks for your help in advance.

Best regards,
Nelson