lbf.cc

NS2网络仿真软件是目前最为流行的网络仿真模拟软件

is now. 
*/

#include "bt-core.h"

static class LBFClass : public TclClass {
public:
	LBFClass() : TclClass ("LBF") {}
	TclObject* create(int,const char*const*) {
		return (new LBF());
	}
}class_lbf;

LBF::LBF() :tokens_(0),th_(this),sh_(this), firsttime_(1)
{
	inputQ_=new PacketQueue();
	blockedQ_ = new PacketQueue();
	bind("conn_handle_",&conn_handle_);
}
	
void LBF::setParameters (flowSpec* qos)
{
	if (qos->token_rate <= 0) {
		tokenRate_ = -1.0;
		peak_bw_ = 1e+8;
	}
	else {
		tokenRate_ = 1000*(qos->token_rate);
		bucket_ = qos->token_bucket;
		tokens_ = (double)bucket_;
		qlength_ = qos->input_qlen;
		peak_bw_ = 1000*(qos->peak_bw);
	}
}

void LBF::recv(Packet *p, Handler *)
{
	hdr_cmn* ch = HDR_CMN(p);
	int size = ch->size()<<3;
	Scheduler& s = Scheduler::instance();
	if (tokenRate_ < 0.0) {
		// by-pass token bucket
		blockedQ_->enque(p);
		if (blockedQ_->length() == 1) 
			s.schedule(&sh_, &send_ev_, size/peak_bw_);
		return;
	}

	int len = inputQ_->length();

	if (len && len < qlength_) {
		inputQ_->enque(p);
		return;
	}
	else if (len >= qlength_) {
		drop(p);
		return;
	}


	if (firsttime_) {
		lastupdate_ = s.clock();
		firsttime_ = 0;
	}
	else 
		updatetokens();

	if (tokens_ >= size) {
		blockedQ_->enque(p);
		tokens_ -= size;
		//printf("DEBUG: Tokens decremented %e, clock %e, CH %d\n", tokens_, s.clock(), conn_handle_);

		if (blockedQ_->length() == 1) 
			s.schedule(&sh_, &send_ev_, size/peak_bw_);
	}
	else {
		
		if (qlength_) {
			inputQ_->enque(p);
			s.schedule(&th_, p, (size - tokens_)/tokenRate_);
		}
		else {
			drop(p);
		}
	}
}

void LBF::release()
{
	Scheduler& s = Scheduler::instance();
	
	Packet *p=inputQ_->deque();
	updatetokens();
	hdr_cmn* ch = HDR_CMN(p);
	int size = ch->size()<<3;

	blockedQ_->enque(p);
	if (blockedQ_->length() == 1) 
		s.schedule(&sh_, &send_ev_, size/peak_bw_);
	//tokens_ -= size;
	tokens_ = 0.0;
	//printf("DEBUG: Tokens decremented %e, clock %e, CH %d\n", tokens_, s.clock(), conn_handle_);

	if (inputQ_->length()) {
		p=inputQ_->head();
		hdr_cmn* ch = HDR_CMN(p);
		size = ch->size()<<3;
		s.schedule(&th_, p, (size-tokens_)/tokenRate_);
	}
}


void LBF::updatetokens(void)
{
	Scheduler& s = Scheduler::instance();
	tokens_ += (s.clock()-lastupdate_)*tokenRate_;
	tokens_ = (tokens_ > bucket_) ? bucket_ : tokens_;
	lastupdate_ = s.clock();
	//printf("DEBUG: Updated tokens %e, clock %e CH %d\n", tokens_, s.clock(), conn_handle_);
}

void
TokenHandler::handle (Event* e)
{
	lbf_->release();
}

void SendHandler::handle (Event* e)
{
	Scheduler& s = Scheduler::instance();
	Packet* p = lbf_->blockedQ_->deque();
	hdr_cmn* hdr = HDR_CMN(p);
	lbf_->downtarget_->recv(p,lbf_);
	//printf("DEBUG:SIZE: %d LBF released packet, clock %e, CH %d\n", hdr->size(), s.clock(), lbf_->conn_handle_);
	if (p = lbf_->blockedQ_->head()) {
		hdr_cmn* ch = HDR_CMN(p);
		int pktsize = ch->size()<<3;
		s.schedule(this, e, pktsize/lbf_->peak_bw_);
	}	
	else if (lbf_->inputQ_->length() == 0) {
		L2CAP* up = (L2CAP*)(lbf_->uptarget_);
		up->callback(lbf_->conn_handle_);	
	}
}