droptailを定義するプログラムを参考にして、バッファの前からパケットが落ちるLIFOの「dropfront」を定義するプログラムを作成したいです。droptailのプログラムを載せるので、dropfrontのファイルを教えてください。
/* * Copyright (c) 1994 Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the Computer Systems * Engineering Group at Lawrence Berkeley Laboratory. * 4. Neither the name of the University nor of the Laboratory may be used * to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef lint static const char rcsid[] = "@(#) $Header: /cvsroot/nsnam/ns-2/queue/drop-tail.cc,v 1.17 2004/10/28 23:35:37 haldar Exp $ (LBL)"; #endif #include "drop-tail.h" static class DropTailClass : public TclClass { public: DropTailClass() : TclClass("Queue/DropTail") {} TclObject* create(int, const char*const*) { return (new DropTail); } } class_drop_tail; void DropTail::reset() { Queue::reset(); } int DropTail::command(int argc, const char*const* argv) { if (argc==2) { if (strcmp(argv[1], "printstats") == 0) { print_summarystats(); return (TCL_OK); } if (strcmp(argv[1], "shrink-queue") == 0) { shrink_queue(); return (TCL_OK); } } if (argc == 3) { if (!strcmp(argv[1], "packetqueue-attach")) { delete q_; if (!(q_ = (PacketQueue*) TclObject::lookup(argv[2]))) return (TCL_ERROR); else { pq_ = q_; return (TCL_OK); } } } return Queue::command(argc, argv); } /* * drop-tail */ void DropTail::enque(Packet* p) { if (summarystats) { Queue::updateStats(qib_?q_->byteLength():q_->length()); } int qlimBytes = qlim_ * mean_pktsize_; if ((!qib_ && (q_->length() + 1) >= qlim_) || (qib_ && (q_->byteLength() + hdr_cmn::access(p)->size()) >= qlimBytes)){ // if the queue would overflow if we added this packet... if (drop_front_) { /* remove from head of queue */ q_->enque(p); Packet *pp = q_->deque(); drop(pp); } else { drop(p); } } else { q_->enque(p); } } //AG if queue size changes, we drop excessive packets... void DropTail::shrink_queue() { int qlimBytes = qlim_ * mean_pktsize_; if (debug_) printf("shrink-queue: time %5.2f qlen %d, qlim %d\n", Scheduler::instance().clock(), q_->length(), qlim_); while ((!qib_ && q_->length() > qlim_) || (qib_ && q_->byteLength() > qlimBytes)) { if (drop_front_) { /* remove from head of queue */ Packet *pp = q_->deque(); drop(pp); } else { Packet *pp = q_->tail(); q_->remove(pp); drop(pp); } } } Packet* DropTail::deque() { if (summarystats && &Scheduler::instance() != NULL) { Queue::updateStats(qib_?q_->byteLength():q_->length()); } return q_->deque(); } void DropTail::print_summarystats() { //double now = Scheduler::instance().clock(); printf("True average queue: %5.3f", true_ave_); if (qib_) printf(" (in bytes)"); printf(" time: %5.3f\n", total_time_); }
あなたの回答
tips
プレビュー