Back off to versions before merging in paper branch, so that we have

time to debug a delayed LAN problem.

assign/GNUmakefile.in

 #
-# Insert Copyright Here.
+# EMULAB-COPYRIGHT
+# Copyright (c) 2000-2002 University of Utah and the Flux Group.
+# All rights reserved.
 #
+
 SRCDIR		= @srcdir@
 TESTBED_SRCDIR	= @top_srcdir@
 OBJDIR		= ..
 SUBDIR		= assign
 
+#
+# Support for optional assign binary to avoid LEDA restrictions
+#
+ASSIGNBINARY	= @ASSIGN@
+
 include $(OBJDIR)/Makeconf
 
 all: assign 
 
 include $(TESTBED_SRCDIR)/GNUmakerules
 
-OBJS=parse_top.o parse_ptop.o assign.o pclass.o vclass.o config.o score.o \
-     parser.o
-LIBS+= -lm
-LDFLAGS+= -pipe -O3
-CXXFLAGS = -pipe -I/usr/local/include -ftemplate-depth-30
+LEDA=@LEDA@
 
-# Pick either this
-CXXFLAGS += -O3 
-# or this
+OBJS=score.o parse_top.o parse_ptop.o config.o pclass.o vclass.o
+LIBS+=-L${LEDA} -lD3 -lW -lP -lG -lL -L/usr/X11R6/lib -lX11 -lm -L.
+LDFLAGS+= -O3
+CXXFLAGS = -I${LEDA}/incl
+
+# Pick one of the following:
+CXXFLAGS += -Wall -O3 
 #CXXFLAGS += -O0 -g -Wall -DVERBOSE
-# and then zero or more of these
-#CXXFLAGS += -DSCORE_DEBUG
-#CXXFLAGS += -DSCORE_DEBUG_MORE
-#CXXFLAGS += -DPCLASS_DEBUG
-#CXXFLAGS += -DDUMP_GRAPH
-#CXXFLAGS += -DSCORE_DEBUG_LOTS
-
-# And then, regardless, you can also have this
-#CXXFLAGS += -DSTATS
+#CXXFLAGS += -O0 -g -Wall -DVERBOSE -DSCORE_DEBUG -DPCLASS_DEBUG
+#CXXFLAGS += -O0 -g -Wall -DVERBOSE -DSCORE_DEBUG -DPCLASS_DEBUG -DPCLASS_DEBUG_MORE
+#CXXFLAGS += -O0 -g -Wall -DVERBOSE -DSCORE_DEBUG -DSCORE_DEBUG_MORE -DPCLASS_DEBUG -DPCLASS_DEBUG_MORE
 
-# assign now supports a dizzing array of defines, which are as-yet undocumented
-# Here are the ones used for a typical build:
-# Pick cooling schedule
-CXXFLAGS += -DMELT -DEPSILON_TERMINATE -DCHILL -DNEIGHBOR_LENGTH \
-    -DLOCAL_DERIVATIVE -DALLOW_NEGATIVE_DELTA
-# Bug/scoring fixes
-CXXFLAGS += -DINTERSWITCH_LENGTH -DPNODE_SWITCH_LOAD -DFIX_SHARED_INTERFACES 
-# Various tweaks to the simulated annealing behavior
-CXXFLAGS += -DFIND_PNODE_SEARCH -DNO_REVERT
-# This should be enabled, for better mapping, but has to be disabled
-# for now because it breaks vclasses
-#CXXFLAGS += -DPER_VNODE_TT -DSMART_UNMAP
+#CXXFLAGS += -DSTATS
 
 # If you're looking to turn on or off USE_OPTIMAL, its now a cmdline
 # option. Use OP={0,1} on the command line at run time... :)
 
 DEPLIBS=$(OBJS)
 
-assign: ${DEPLIBS} ${OBJS} 
-	${CXX} -o assign ${LIBS} $(OBJS) ${LDFLAGS}
+ifdef ASSIGNBINARY
+assign:	${ASSIGNBINARY}
+	rm -f assign
+	cp $< assign
+else
+assign: ${DEPLIBS} ${OBJS} assign.o
+	${CXX} assign.o -o assign ${LIBS} $(OBJS) ${LDFLAGS}
+endif
 
 install: $(INSTALL_LIBEXECDIR)/assign 
 

assign/common.h

+/*
+ * EMULAB-COPYRIGHT
+ * Copyright (c) 2000-2002 University of Utah and the Flux Group.
+ * All rights reserved.
+ */
+
 #ifndef __COMON_H
 #define __COMON_H
 
 #include "config.h"
 
-const int MAX_PNODES = 1024;	/* maximum # of physical nodes */
+const int MAX_PNODES = 2048;	/* maximum # of physical nodes */
 
 /*
   To use these on the command line, each entry gets a
@@ -11,78 +17,29 @@ const int MAX_PNODES = 1024;	/* maximum # of physical nodes */
   Here we declare them all and give them defaults.
 */
 
-//static int init_temp = 100;
-static int init_temp = 10;
+static int init_temp = 100;
 static int USE_OPTIMAL = 1;
 static int temp_prob = 130;
-#ifdef LOW_TEMP_STOP
-//static int temp_stop = 1;
-static float temp_stop = .005;
-#else
-static float temp_stop = 2;
-//static int temp_stop = 20;
-#endif
+static int temp_stop = 20;
 static int CYCLES = 20;
 
-// The following are basically arbitrary constants
-// Initial acceptance ratio for melting
-static float X0 = .95;
-//static float epsilon = 0.1;
-#ifdef LOCAL_DERIVATIVE
-static float epsilon = 0.0001;
-#else
-static float epsilon = 0.01;
-#endif
-static float delta = 2;
-//static float delta = 1;
-//static float min_temp_end = 0.01;
-//static float min_temp_end = 10000000.0;
-
-
-// Number of runs to spend melting
-static int melt_trans = 500;
-static int min_neighborhood_size = 500;
-
-
 static float temp_rate = 0.9;
 static float opt_nodes_per_sw = 5.0;
-#ifdef PENALIZE_BANDWIDTH
-static float SCORE_DIRECT_LINK = 0.0;/* Cost of a direct link */
-static float SCORE_INTRASWITCH_LINK = 0.0;/* Cost of an intraswitch link*/
-static float SCORE_INTERSWITCH_LINK = 0.0;/* Cost of an interswitch link*/
-#else
 static float SCORE_DIRECT_LINK = 0.01;/* Cost of a direct link */
-static float SCORE_INTRASWITCH_LINK = 0.02;/* Cost of an intraswitch link*/
-static float SCORE_INTERSWITCH_LINK = 0.2;/* Cost of an interswitch link*/
-#endif
 static float SCORE_DIRECT_LINK_PENALTY = 0.5;/* Cost of overused direct link*/
+static float SCORE_INTRASWITCH_LINK = 0.02;/* Cost of an intraswitch link*/
+static float SCORE_INTERSWITCH_LINK = 0.05;/* Cost of an interswitch link*/
 static float SCORE_NO_CONNECTION = 0.5;/* Cost of not filling a virt. link*/
-static float SCORE_PNODE = 0.2;/* Cost of using a pnode*/
+static float SCORE_PNODE = 0.05;/* Cost of using a pnode*/
 static float SCORE_PNODE_PENALTY = 0.5;/* Cost of overusing a pnode*/
 static float SCORE_SWITCH = 0.5;/* Cost of using a switch.*/
-static float SCORE_UNASSIGNED = 1.0;/* Cost of an unassigned node*/
-static float SCORE_DESIRE = 1.0;/* Multiplier for desire costs*/
-static float SCORE_FEATURE = 1.0;/* Multiplier for feature weights*/
-#ifdef NO_PCLASS_PENALTY
-static float SCORE_PCLASS = 0.0; /* Cost of each pclass */
-#else
+static float SCORE_UNASSIGNED = 1;/* Cost of an unassigned node*/
+static float SCORE_OVER_BANDWIDTH = 0.5;/* Cost of going over bandwidth*/
+static float SCORE_DESIRE = 1;/* Multiplier for desire costs*/
+static float SCORE_FEATURE = 1;/* Multiplier for feature weights*/
 static float SCORE_PCLASS = 0.5; /* Cost of each pclass */
-#endif
-static float SCORE_VCLASS = 1.0; /* vclass score multiplier */
+static float SCORE_VCLASS = 1;	/* vclass score multiplier */
 static float SCORE_EMULATED_LINK = 0.01; /* cost of an emualted link */
-static float SCORE_OUTSIDE_DELAY = 0.5;	/* penalty for going out of delay
-					   requirements */
-static float SCORE_DELAY = 10.0; /* multiplier to distance for delay scoring */
-#ifdef PENALIZE_UNUSED_INTERFACES
-static float SCORE_UNUSED_INTERFACE = 0.04;
-#endif
-
-// The following are used to weight possible link resolutions.  Higher
-// numbers mean a more likely resolution.  Trivial resolutions are always
-// used if possible.
-static float LINK_RESOLVE_DIRECT = 4.0;
-static float LINK_RESOLVE_INTRASWITCH = 2.0;
-static float LINK_RESOLVE_INTERSWITCH = 1.0;
 
 static struct config_param options[] = {
   { "IT",	CONFIG_INT,	&init_temp,			0 },
@@ -96,6 +53,7 @@ static struct config_param options[] = {
   { "1S",	CONFIG_FLOAT,	&SCORE_INTERSWITCH_LINK,	0 },
   { "2S",	CONFIG_FLOAT,	&SCORE_INTRASWITCH_LINK,	0 },
   { "NC",	CONFIG_FLOAT,	&SCORE_NO_CONNECTION,		0 },
+  { "OB",	CONFIG_FLOAT,	&SCORE_OVER_BANDWIDTH,		0 },
   { "DL",	CONFIG_FLOAT,	&SCORE_DIRECT_LINK,		0 },
   { "DP",	CONFIG_FLOAT,	&SCORE_DIRECT_LINK_PENALTY,	0 },
   { "PN",	CONFIG_FLOAT,	&SCORE_PNODE,			0 },
@@ -105,41 +63,12 @@ static struct config_param options[] = {
   { "SW",	CONFIG_FLOAT,	&SCORE_SWITCH,			0 },
   { "EL",	CONFIG_FLOAT,	&SCORE_EMULATED_LINK,		0 },
   { "ON",	CONFIG_FLOAT,	&opt_nodes_per_sw,		0 },
-  { "TR",	CONFIG_FLOAT,	&temp_rate,			0 },
-  { "LD",       CONFIG_FLOAT,   &LINK_RESOLVE_DIRECT,           0 },
-  { "LI",       CONFIG_FLOAT,   &LINK_RESOLVE_INTRASWITCH,      0 },
-  { "LT",       CONFIG_FLOAT,   &LINK_RESOLVE_INTERSWITCH,      0 },
-  { "OD",       CONFIG_FLOAT,   &SCORE_OUTSIDE_DELAY,           0 },
-  { "DM",       CONFIG_FLOAT,   &SCORE_DELAY,                   0 }
+  { "TR",	CONFIG_FLOAT,	&temp_rate,			0 }
 };
 
 static int noptions = sizeof(options) / sizeof(options[0]);
 
-void parse_options(char **argv, struct config_param options[], int nopt);
-
-struct eqstr
-{
-  bool operator()(const char* A, const char* B) const
-  {
-    return (! strcmp(A, B));
-  }
-};
-
-enum edge_data_t {edge_data};
-enum vertex_data_t {vertex_data};
+#endif
 
-namespace boost {
-  BOOST_INSTALL_PROPERTY(edge,data);
-  BOOST_INSTALL_PROPERTY(vertex,data);
-}
 
-typedef hash_map<crope,crope> name_name_map;
-typedef slist<crope> name_slist;
 
-template <class T> struct hashptr {
-  size_t operator()(T const &A) const {
-    return (size_t) A;
-  }
-};
-
-#endif

assign/config.h

 /*
- * Copyright (c) 1999-2001 The University of Utah and the Flux Group.
+ * EMULAB-COPYRIGHT
+ * Copyright (c) 2000-2002 University of Utah and the Flux Group.
  * All rights reserved.
  */
 
@@ -24,7 +25,7 @@ struct config_param {
 /* types */
 #define CONFIG_INT	0
 #define CONFIG_FLOAT	1
-  
+
 void parse_options(char **argv, struct config_param options[], int nopt);
 int config_parse(char **args, struct config_param cparams[], int nparams);
 void dump_options(const char *str, struct config_param cparams[], int nparams);

assign/parse_ptop.cc

-#include "port.h"
-
-#include <hash_map>
-#include <slist>
-#include <rope>
-#include <hash_set>
-
-#include <boost/config.hpp>
-#include <boost/utility.hpp>
-#include <boost/property_map.hpp>
-#include <boost/graph/graph_traits.hpp>
-#include <boost/graph/adjacency_list.hpp>
-
+/*
+ * EMULAB-COPYRIGHT
+ * Copyright (c) 2000-2002 University of Utah and the Flux Group.
+ * All rights reserved.
+ */
+
+/*
+ * parse ptop files.  These are basic topologies
+ * that are used to represent the physical topology.
+ *
+ * format:
+ * node <name> <type> [<type2> ...]
+ *   <type> = <t>[:<max>]
+ *   <t>    = pc | switch | dnard
+ *   <max>  = how many virtual entities of that type per physical entity.
+ * link <name> <src>[:<mac>] <dst>[:<mac>] <size> <number>
+ */
+
+#include <LEDA/graph_alg.h>
+#include <LEDA/graphwin.h>
+#include <LEDA/ugraph.h>
+#include <LEDA/dictionary.h>
+#include <LEDA/map.h>
+#include <LEDA/graph_iterator.h>
+#include <LEDA/sortseq.h>
 #include <iostream.h>
-
-using namespace boost;
-
-using namespace boost;
+#include <string.h>
+#include <stdio.h>
 
 #include "common.h"
-#include "delay.h"
 #include "physical.h"
-#include "parser.h"
 
-extern name_pvertex_map pname2vertex;
-extern name_slist ptypes;
-
-#define ptop_error(s) errors++;cerr << "PTOP:" << line << ": " << s << endl
+extern dictionary<string,node> pname2node;
+extern node pnodes[MAX_PNODES];	// int -> node map
+node_array<int> switch_index;
+extern list<string> ptypes;
 
 int parse_ptop(tb_pgraph &PG, tb_sgraph &SG, istream& i)
 {
-  int num_nodes = 0;
-  int line=0,errors=0;
-  char inbuf[1024];
-  string_vector parsed_line;
-
+  int switchi=0;
+  node no1;
+  edge ed1;
+  string s1, s2;
+  char inbuf[255];
+  char n1[32], n2[32];
+  int size, num;
+  int n=1;
+  char *snext;
+  char *snode;
+  char *scur;
+  char lname[32];
+  int isswitch;
+
+  switch_index.init(PG,MAX_PNODES,0);
+  pnodes[0] = NULL;
   while (!i.eof()) {
-    line++;
-    i.getline(inbuf,1024);
-    parsed_line = split_line(inbuf,' ');
-    if (parsed_line.size() == 0) {continue;}
-
-    crope command = parsed_line[0];
-
-    if (command.compare("node") == 0) {
-      if (parsed_line.size() < 3) {
-	ptop_error("Bad node line, too few arguments.");
+    char *ret;
+    i.getline(inbuf, 254);
+    ret = strchr(inbuf, '\n');
+    if (ret) *ret = 0;
+    if (strlen(inbuf) == 0) { continue; }
+    
+    if (!strncmp(inbuf, "node", 4)) {
+      isswitch = 0;
+      snext = inbuf;
+      scur = strsep(&snext," ");
+      if (strcmp("node",scur) != 0) {
+	fprintf(stderr, "bad node line: %s\n", inbuf);
       } else {
-	num_nodes++;
-	crope name = parsed_line[1];
-	bool isswitch = false;
-	pvertex pv = add_vertex(PG);
-	tb_pnode *p = new tb_pnode();
-	put(pvertex_pmap,pv,p);
-	p->name = name;
-	p->typed = false;
-	p->max_load = 0;
-	p->current_load = 0;
-	p->pnodes_used = 0;
-//#ifdef PENALIZE_UNUSED_INTERFACES
-	p->total_interfaces = 0;
-//#endif
-	
-	unsigned int i;
-	for (i = 2;
-	     (i < parsed_line.size()) &&
-	       (parsed_line[i].compare("-") != 0);++i) {
-	  crope type,load;
-	  if (split_two(parsed_line[i],':',type,load,"1") != 0) {
-	    ptop_error("Bad node line, no load for type: " << type << ".");
-	  }
+	scur = strsep(&snext," ");
+	snode = scur;
+	string s(snode);
+#ifdef GRAPH_DEBUG
+	cout << "Found phys. node '"<<snode<<"'\n";
+#endif
+	no1 = PG.new_node();
+	PG[no1].name=string(snode);
+	PG[no1].typed = false;
+	PG[no1].max_load = 0;
+	PG[no1].current_load = 0;
+	PG[no1].pnodes_used=0;
+	while ((scur = strsep(&snext," ")) != NULL &&
+	       (strcmp(scur,"-"))) {
+	  char *t,*load=scur;
 	  int iload;
-	  if (sscanf(load.c_str(),"%d",&iload) != 1) {
-	    ptop_error("Bad node line, bad load: " << load << ".");
-	    iload = 1;
+	  t = strsep(&load,":");
+	  string stype(t);
+	  if (load) {
+	    if (sscanf(load,"%d",&iload) != 1) {
+	      fprintf(stderr,"Bad load specifier: %s\n",load);
+	      iload=1;
+	    }
+	  } else {
+	    iload=1;
 	  }
-	  ptypes.push_front(type);
-	  if (type.compare("switch") == 0) {
-	    isswitch = true;
-	    p->types["switch"] = 1;
-	    svertex sv = add_vertex(SG);
-	    tb_switch *s = new tb_switch();
-	    put(svertex_pmap,sv,s);
-	    s->mate = pv;
-	    p->sgraph_switch = sv;
+	  ptypes.push(stype);
+	  if (strcmp(t,"switch") == 0) {
+	    isswitch = 1;
+	    PG[no1].types.insert(stype,1);
+	    PG[no1].the_switch = no1;
+	    node sw = SG.new_node();
+	    SG[sw].mate = no1;
+	    PG[no1].sgraph_switch = sw;
+	    switch_index[no1] = switchi++;
 	  } else {
-	    p->types[type] = iload;
+	    PG[no1].types.insert(stype,iload);
 	  }
 	}
-	for (i=i+1;i<parsed_line.size();++i) {
-	  crope feature,cost;
-	  if (split_two(parsed_line[i],':',feature,cost,"0") != 0) {
-	    ptop_error("Bad node line, no cost for feature: " <<
-		       feature << ".");
-	  }
-	  double gcost;
-	  if (sscanf(cost.c_str(),"%lg",&gcost) != 1) {
-	    ptop_error("Bad node line, bad cost: " << gcost << ".");
-	    gcost = 0;
+	/* Either end of line or - .  Read in features */
+	while ((scur = strsep(&snext," ")) != NULL) {
+	  char *feature=scur;
+	  double icost;
+	  char *t;
+	  t = strsep(&feature,":");
+	  string sfeat(t);
+	  if ((! feature) || sscanf(feature,"%lg",&icost) != 1) {
+	    fprintf(stderr,"Bad cost specifier for %s\n",t);
+	    icost = 0.01;
 	  }
-	  p->features[feature] = gcost;
+	  PG[no1].features.insert(sfeat,icost);
 	}
-	pname2vertex[name] = pv;
+	/* Done */
+	if (! isswitch)
+	  pnodes[n++]=no1;
+	pname2node.insert(s, no1);
       }
-    } else if (command.compare("link") == 0) {
-      if (parsed_line.size() < 7) {
-	ptop_error("Bad link line, too few arguments.");
-      }
-      int num = 1;
-#ifdef PENALIZE_BANDWIDTH
-      float penalty;
-      if (parsed_line.size() == 8) {
-	if (sscanf(parsed_line[7].c_str(),"%f",&penalty) != 1) {
-	  ptop_error("Bad number argument: " << parsed_line[7] << ".");
-	  penalty=1.0;
+    }
+    else if (!strncmp(inbuf, "link", 4)) {
+      if (sscanf(inbuf, "link %s %s %s %d %d", lname, n1, n2, &size, &num)
+	  != 5) {
+	fprintf(stderr, "bad link line: %s\n", inbuf);
+      } else {
+	string linkname(lname);
+	char *snode,*smac;
+	char *dnode,*dmac;
+	smac = n1;
+	dmac = n2;
+	snode = strsep(&smac,":");
+	dnode = strsep(&dmac,":");
+	if (pname2node.lookup(snode) == nil) {
+	  fprintf(stderr,"PTOP error: Unknown source node %s\n",snode);
+	  exit(1);
 	}
-      }
-#else
-      if (parsed_line.size() == 8) {
-	if (sscanf(parsed_line[7].c_str(),"%d",&num) != 1) {
-	  ptop_error("Bad number argument: " << parsed_line[7] << ".");
-	  num=1;
+	if (pname2node.lookup(dnode) == nil) {
+	  fprintf(stderr,"PTOP error: Unknown destination node %s\n",dnode);
+	  exit(1);
 	}
-      }
-#endif
-
-#ifdef FIX_PLINK_ENDPOINTS
-      bool fixends = false;
-      if (parsed_line.size() == 9) {
-	  if (parsed_line[8].compare("fixends") == 0) {
-	      fixends = true;
-	  }
-      }
-#else
-      if (parsed_line.size() > 8) {
-	ptop_error("Bad link line, too many arguments.");
-      }
-#endif
-      crope name = parsed_line[1];
-      crope src,srcmac;
-      split_two(parsed_line[2],':',src,srcmac,"(null)");
-      crope dst,dstmac;
-      split_two(parsed_line[3],':',dst,dstmac,"(null)");
-      crope bw = parsed_line[4];
-      crope delay = parsed_line[5];
-      crope loss = parsed_line[6];
-      int ibw,idelay;
-      double gloss;
-
-      
-      if ((sscanf(bw.c_str(),"%d",&ibw) != 1) ||
-	  (sscanf(delay.c_str(),"%d",&idelay) != 1) ||
-	  (sscanf(loss.c_str(),"%lg",&gloss) != 1)) {
-	ptop_error("Bad link line, bad delay characteristics.");
-      }
-
-#define ISSWITCH(n) (n->types.find("switch") != n->types.end())
-      pvertex srcv = pname2vertex[src];
-      pvertex dstv = pname2vertex[dst];
-      tb_pnode *srcnode = get(pvertex_pmap,srcv);
-      tb_pnode *dstnode = get(pvertex_pmap,dstv);
-      
-      for (int cur = 0;cur<num;++cur) {
-	pedge pe = (add_edge(srcv,dstv,PG)).first;
-	tb_plink *pl = new tb_plink();
-	put(pedge_pmap,pe,pl);
-	pl->delay_info.bandwidth = ibw;
-	pl->delay_info.delay = idelay;
-	pl->delay_info.loss = gloss;
-	pl->bw_used = 0;
-	pl->name = name;
-	pl->emulated = 0;
-	pl->nonemulated = 0;
-#ifdef FIX_PLINK_ENDPOINTS
-	pl->fixends = fixends;
-#endif
-#ifdef PENALIZE_BANDWIDTH
-	pl->penalty = penalty;
-#endif
-	pl->type = tb_plink::PLINK_NORMAL;
-	pl->srcmac = srcmac;
-	pl->dstmac = dstmac;
-	if (ISSWITCH(srcnode) && ISSWITCH(dstnode)) {
-	  if (cur != 0) {
-	    cout <<
-	      "Warning: Extra links between switches will be ignored. (" <<
-	      name << ")" << endl;
-	  } else {
-	    svertex src_switch = get(pvertex_pmap,srcv)->sgraph_switch;
-	    svertex dst_switch = get(pvertex_pmap,dstv)->sgraph_switch;
-	    sedge swedge = add_edge(src_switch,dst_switch,SG).first;
-	    tb_slink *sl = new tb_slink();
-	    put(sedge_pmap,swedge,sl);
-	    sl->mate = pe;
-	    pl->type = tb_plink::PLINK_INTERSWITCH;
+	node node1 = pname2node.access(snode);
+	node node2 = pname2node.access(dnode);
+#define ISSWITCH(n) (PG[n].types.lookup("switch") != nil)
+	for (int i = 0; i < num; ++i) {
+	  ed1=PG.new_edge(node1, node2);
+	  PG[ed1].bandwidth=size;
+	  PG[ed1].bw_used=0;
+	  PG[ed1].name=linkname;
+	  PG[ed1].emulated=0;
+	  PG[ed1].nonemulated=0;
+	  if (smac)
+	    PG[ed1].srcmac = string(smac);
+	  else
+	    PG[ed1].srcmac = string("(null)");
+	  if (dmac)
+	    PG[ed1].dstmac = string(dmac);
+	  else
+	    PG[ed1].dstmac = string("(null)");
+	  if (ISSWITCH(node1) && ISSWITCH(node2)) {
+	    if (i != 0) {
+	      cout <<
+		"Warning: Extra links between switches will be ignored." <<
+		endl;
+	    }
+	    edge swedge = SG.new_edge(PG[node1].sgraph_switch,
+				      PG[node2].sgraph_switch);
+	    SG[swedge].mate = ed1;
 	  }
 	}
-	if (ISSWITCH(srcnode) &&
-	    ! ISSWITCH(dstnode)) {
-	  dstnode->switches.insert(srcv);
-//#ifdef PENALIZE_UNUSED_INTERFACES
-	  dstnode->total_interfaces++;
-//#endif
-	}
-	else if (ISSWITCH(dstnode) &&
-		 ! ISSWITCH(srcnode)) {
-	  srcnode->switches.insert(dstv);
-//#ifdef PENALIZE_UNUSED_INTERFACES
-	  srcnode->total_interfaces++;
-//#endif
-	}
+	if (ISSWITCH(node1) &&
+	    ! ISSWITCH(node2))
+	  PG[node2].the_switch = node1;
+	else if (ISSWITCH(node2) &&
+		 ! ISSWITCH(node1))
+	  PG[node1].the_switch = node2;