Robust/src/Analysis/Locality/LocalityAnalysis.java

   1 package Analysis.Locality;
   2
   3 import java.util.*;
   4 import Analysis.CallGraph.CallGraph;
   5 import IR.SymbolTable;
   6 import IR.State;
   7 import IR.TypeUtil;
   8 import IR.MethodDescriptor;
   9 import IR.Flat.*;
  10 import IR.ClassDescriptor;
  11
  12 public class LocalityAnalysis {
  13     State state;
  14     Stack lbtovisit;
  15     Hashtable<LocalityBinding,LocalityBinding> discovered;
  16     Hashtable<LocalityBinding, Set<LocalityBinding>> dependence;
  17     Hashtable<LocalityBinding, Hashtable<FlatNode,Hashtable<TempDescriptor, Integer>>> temptab;
  18     Hashtable<LocalityBinding, Hashtable<FlatNode, Integer>> atomictab;
  19     Hashtable<LocalityBinding, Hashtable<FlatAtomicEnterNode, Set<TempDescriptor>>> tempstosave;
  20     Hashtable<ClassDescriptor, Set<LocalityBinding>> classtolb;
  21     Hashtable<MethodDescriptor, Set<LocalityBinding>> methodtolb;
  22     private LocalityBinding lbmain;
  23
  24     CallGraph callgraph;
  25     TypeUtil typeutil;
  26     public static final Integer LOCAL=new Integer(0);
  27     public static final Integer GLOBAL=new Integer(1);
  28     public static final Integer EITHER=new Integer(2);
  29     public static final Integer CONFLICT=new Integer(3);
  30
  31     public LocalityAnalysis(State state, CallGraph callgraph, TypeUtil typeutil) {
  32         this.typeutil=typeutil;
  33         this.state=state;
  34         this.discovered=new Hashtable<LocalityBinding,LocalityBinding>();
  35         this.dependence=new Hashtable<LocalityBinding, Set<LocalityBinding>>();
  36         this.temptab=new Hashtable<LocalityBinding, Hashtable<FlatNode,Hashtable<TempDescriptor, Integer>>>();
  37         this.atomictab=new Hashtable<LocalityBinding, Hashtable<FlatNode, Integer>>();
  38         this.lbtovisit=new Stack();
  39         this.callgraph=callgraph;
  40         this.tempstosave=new Hashtable<LocalityBinding, Hashtable<FlatAtomicEnterNode, Set<TempDescriptor>>>();
  41         this.classtolb=new Hashtable<ClassDescriptor, Set<LocalityBinding>>();
  42         this.methodtolb=new Hashtable<MethodDescriptor, Set<LocalityBinding>>();
  43         doAnalysis();
  44     }
  45
  46     public LocalityBinding getMain() {
  47         return lbmain;
  48     }
  49
  50     /** This method returns the set of LocalityBindings that a given
  51      * flatcall could invoke */
  52
  53     public LocalityBinding getBinding(LocalityBinding currlb, FlatCall fc) {
  54         boolean isatomic=getAtomic(currlb).get(fc).intValue()>0;
  55         Hashtable<TempDescriptor, Integer> currtable=getNodeTempInfo(currlb).get(fc);
  56         MethodDescriptor md=fc.getMethod();
  57
  58         boolean isnative=md.getModifiers().isNative();
  59
  60         LocalityBinding lb=new LocalityBinding(md, isatomic);
  61
  62         for(int i=0;i<fc.numArgs();i++) {
  63             TempDescriptor arg=fc.getArg(i);
  64             lb.setGlobal(i,currtable.get(arg));
  65         }
  66         if (fc.getThis()!=null) {
  67             Integer thistype=currtable.get(fc.getThis());
  68             if (thistype==null)
  69                 thistype=EITHER;
  70             lb.setGlobalThis(thistype);
  71         } else
  72             lb.setGlobalThis(EITHER);//default value
  73         if (discovered.containsKey(lb))
  74             lb=discovered.get(lb);
  75         else throw new Error();
  76         return lb;
  77     }
  78
  79
  80     /** This method returns a set of LocalityBindings for the parameter class. */
  81
  82     public Set<LocalityBinding> getClassBindings(ClassDescriptor cd) {
  83         return classtolb.get(cd);
  84     }
  85
  86     /** This method returns a set of LocalityBindings for the parameter method. */
  87
  88     public Set<LocalityBinding> getMethodBindings(MethodDescriptor md) {
  89         return methodtolb.get(md);
  90     }
  91
  92     /** This method returns a set of LocalityBindings.  A
  93      * LocalityBinding specifies a context a method can be invoked in.
  94      * It specifies whether the method is in a transaction and whether
  95      * its parameter objects are locals or globals.  */
  96
  97     public Set<LocalityBinding> getLocalityBindings() {
  98         return discovered.keySet();
  99     }
 100
 101     /** This method returns a hashtable for a given LocalityBinding
 102      * that tells the current local/global status of temps at the each
 103      * node in the flat representation. */
 104
 105     public Hashtable<FlatNode, Hashtable<TempDescriptor, Integer>> getNodeTempInfo(LocalityBinding lb) {
 106         return temptab.get(lb);
 107     }
 108
 109     /** This method returns an hashtable for a given LocalitBinding
 110      * that tells whether a node in the flat represenation is in a
 111      * transaction or not.  Integer values greater than 0 indicate
 112      * that the node is in a transaction and give the nesting depth.
 113      * The outermost AtomicEnterNode will have a value of 1 and the
 114      * outermost AtomicExitNode will have a value of 0. */
 115
 116     public Hashtable<FlatNode, Integer> getAtomic(LocalityBinding lb) {
 117         return atomictab.get(lb);
 118     }
 119
 120     /** This methods returns a hashtable for a given LocalityBinding
 121      * that tells which temps needs to be saved for each
 122      * AtomicEnterNode.  */
 123
 124     public Hashtable<FlatAtomicEnterNode, Set<TempDescriptor>> getTemps(LocalityBinding lb) {
 125         return tempstosave.get(lb);
 126     }
 127
 128     public Set<TempDescriptor> getTempSet(LocalityBinding lb) {
 129         HashSet<TempDescriptor> set=new HashSet<TempDescriptor>();
 130         Hashtable<FlatAtomicEnterNode, Set<TempDescriptor>> table=getTemps(lb);
 131         if (table!=null)
 132             for(Iterator<FlatAtomicEnterNode> faenit=table.keySet().iterator();faenit.hasNext();) {
 133                 FlatAtomicEnterNode faen=faenit.next();
 134                 set.addAll(table.get(faen));
 135             }
 136         return set;
 137     }
 138
 139     private void doAnalysis() {
 140         computeLocalityBindings();
 141         computeTempstoSave();
 142     }
 143
 144     private void computeLocalityBindings() {
 145         lbmain=new LocalityBinding(typeutil.getMain(), false);
 146         lbmain.setGlobal(0, LOCAL);
 147         lbtovisit.add(lbmain);
 148         discovered.put(lbmain, lbmain);
 149         if (!classtolb.containsKey(lbmain.getMethod().getClassDesc()))
 150             classtolb.put(lbmain.getMethod().getClassDesc(), new HashSet<LocalityBinding>());
 151         classtolb.get(lbmain.getMethod().getClassDesc()).add(lbmain);
 152
 153         if (!methodtolb.containsKey(lbmain.getMethod()))
 154             methodtolb.put(lbmain.getMethod(), new HashSet<LocalityBinding>());
 155         methodtolb.get(lbmain.getMethod()).add(lbmain);
 156
 157         while(!lbtovisit.empty()) {
 158             LocalityBinding lb=(LocalityBinding) lbtovisit.pop();
 159             Integer returnglobal=lb.getGlobalReturn();
 160             MethodDescriptor md=lb.getMethod();
 161             Hashtable<FlatNode,Hashtable<TempDescriptor, Integer>> temptable=new Hashtable<FlatNode,Hashtable<TempDescriptor, Integer>>();
 162             Hashtable<FlatNode, Integer> atomictable=new Hashtable<FlatNode, Integer>();
 163             computeCallsFlags(md, lb, temptable, atomictable);
 164             atomictab.put(lb, atomictable);
 165             temptab.put(lb, temptable);
 166
 167             if (!md.isStatic()&&!returnglobal.equals(lb.getGlobalReturn())) {
 168                 //return type is more precise now
 169                 //rerun everything that call us
 170                 lbtovisit.addAll(dependence.get(lb));
 171             }
 172         }
 173     }
 174
 175
 176     public void computeCallsFlags(MethodDescriptor md, LocalityBinding lb, Hashtable<FlatNode, Hashtable<TempDescriptor, Integer>> temptable, Hashtable<FlatNode, Integer> atomictable) {
 177         FlatMethod fm=state.getMethodFlat(md);
 178         HashSet<FlatNode> tovisit=new HashSet<FlatNode>();
 179         tovisit.add(fm.getNext(0));
 180         {
 181             // Build table for initial node
 182             Hashtable<TempDescriptor,Integer> table=new Hashtable<TempDescriptor,Integer>();
 183             temptable.put(fm, table);
 184             atomictable.put(fm, lb.isAtomic()?1:0);
 185             int offset=md.isStatic()?0:1;
 186             if (!md.isStatic()) {
 187                 table.put(fm.getParameter(0), lb.getGlobalThis());
 188             }
 189             for(int i=offset;i<fm.numParameters();i++) {
 190                 TempDescriptor temp=fm.getParameter(i);
 191                 Integer b=lb.isGlobal(i-offset);
 192                 table.put(temp,b);
 193             }
 194         }
 195
 196         while(!tovisit.isEmpty()) {
 197             FlatNode fn=tovisit.iterator().next();
 198             tovisit.remove(fn);
 199             Hashtable<TempDescriptor, Integer> currtable=new Hashtable<TempDescriptor, Integer>();
 200             int atomicstate=0;
 201             for(int i=0;i<fn.numPrev();i++) {
 202                 FlatNode prevnode=fn.getPrev(i);
 203                 if (atomictable.containsKey(prevnode)) {
 204                     atomicstate=atomictable.get(prevnode).intValue();
 205                 }
 206                 if (!temptable.containsKey(prevnode))
 207                     continue;
 208                 Hashtable<TempDescriptor, Integer> prevtable=temptable.get(prevnode);
 209                 for(Iterator<TempDescriptor> tempit=prevtable.keySet().iterator();tempit.hasNext();) {
 210                     TempDescriptor temp=tempit.next();
 211                     Integer tmpint=prevtable.get(temp);
 212                     Integer oldint=currtable.containsKey(temp)?currtable.get(temp):EITHER;
 213                     Integer newint=merge(tmpint, oldint);
 214                     currtable.put(temp, newint);
 215                 }
 216             }
 217             atomictable.put(fn, atomicstate);
 218             // Process this node
 219             switch(fn.kind()) {
 220             case FKind.FlatAtomicEnterNode:
 221                 processAtomicEnterNode((FlatAtomicEnterNode)fn, atomictable);
 222                 if (!lb.isAtomic())
 223                     lb.setHasAtomic();
 224                 break;
 225             case FKind.FlatAtomicExitNode:
 226                 processAtomicExitNode((FlatAtomicExitNode)fn, atomictable);
 227                 break;
 228             case FKind.FlatCall:
 229                 processCallNode(lb, (FlatCall)fn, currtable, isAtomic(atomictable, fn));
 230                 break;
 231             case FKind.FlatFieldNode:
 232                 processFieldNode(lb, (FlatFieldNode)fn, isAtomic(atomictable, fn), currtable);
 233                 break;
 234             case FKind.FlatSetFieldNode:
 235                 processSetFieldNode(lb, (FlatSetFieldNode)fn, isAtomic(atomictable,fn), currtable);
 236                 break;
 237             case FKind.FlatNew:
 238                 processNew(lb, (FlatNew)fn, isAtomic(atomictable, fn), currtable);
 239                 break;
 240             case FKind.FlatOpNode:
 241                 processOpNode((FlatOpNode)fn, currtable);
 242                 break;
 243             case FKind.FlatCastNode:
 244                 processCastNode((FlatCastNode)fn, currtable);
 245                 break;
 246             case FKind.FlatLiteralNode:
 247                 processLiteralNode((FlatLiteralNode)fn, currtable);
 248                 break;
 249             case FKind.FlatReturnNode:
 250                 processReturnNode(lb, (FlatReturnNode)fn, currtable);
 251                 break;
 252             case FKind.FlatSetElementNode:
 253                 processSetElementNode(lb, (FlatSetElementNode)fn, currtable, isAtomic(atomictable, fn));
 254                 break;
 255             case FKind.FlatElementNode:
 256                 processElementNode(lb, (FlatElementNode)fn, currtable, isAtomic(atomictable, fn));
 257                 break;
 258             case FKind.FlatCondBranch:
 259             case FKind.FlatBackEdge:
 260             case FKind.FlatNop:
 261                 //No action needed for these
 262                 break;
 263             case FKind.FlatFlagActionNode:
 264             case FKind.FlatCheckNode:
 265             case FKind.FlatTagDeclaration:
 266                 throw new Error("Incompatible with tasks!");
 267             case FKind.FlatMethod:
 268             default:
 269                 throw new Error();
 270             }
 271             Hashtable<TempDescriptor,Integer> oldtable=temptable.get(fn);
 272             if (oldtable==null||!oldtable.equals(currtable)) {
 273                 // Update table for this node
 274                 temptable.put(fn, currtable);
 275                 for(int i=0;i<fn.numNext();i++) {
 276                     tovisit.add(fn.getNext(i));
 277                 }
 278             }
 279         }
 280     }
 281
 282     private static boolean isAtomic(Hashtable<FlatNode, Integer> atomictable, FlatNode fn) {
 283         return atomictable.get(fn).intValue()>0;
 284     }
 285
 286     private static Integer merge(Integer a, Integer b) {
 287         if (a==null||a.equals(EITHER))
 288             return b;
 289         if (b==null||b.equals(EITHER))
 290             return a;
 291         if (a.equals(b))
 292             return a;
 293         return CONFLICT;
 294     }
 295
 296     void processCallNode(LocalityBinding currlb, FlatCall fc, Hashtable<TempDescriptor, Integer> currtable, boolean isatomic) {
 297         MethodDescriptor nodemd=fc.getMethod();
 298         Set methodset=null;
 299         if (nodemd.isStatic()||nodemd.getReturnType()==null) {
 300             methodset=new HashSet();
 301             methodset.add(nodemd);
 302         } else {
 303             methodset=callgraph.getMethods(nodemd, fc.getThis().getType());
 304         }
 305         Integer currreturnval=EITHER; //Start off with the either value
 306         for(Iterator methodit=methodset.iterator();methodit.hasNext();) {
 307             MethodDescriptor md=(MethodDescriptor) methodit.next();
 308             boolean isnative=md.getModifiers().isNative();
 309
 310             LocalityBinding lb=new LocalityBinding(md, isatomic);
 311             if (isnative&&isatomic) {
 312                 System.out.println("Don't call native methods in atomic blocks!");
 313             }
 314             for(int i=0;i<fc.numArgs();i++) {
 315                 TempDescriptor arg=fc.getArg(i);
 316                 if(isnative&&(currtable.get(arg).equals(GLOBAL)||
 317                               currtable.get(arg).equals(CONFLICT)))
 318                    throw new Error("Potential call to native method "+md+" with global parameter:\n"+currlb.getExplanation());
 319                 lb.setGlobal(i,currtable.get(arg));
 320             }
 321             if (fc.getThis()!=null) {
 322                 Integer thistype=currtable.get(fc.getThis());
 323                 if (thistype==null)
 324                     thistype=EITHER;
 325                 if(thistype.equals(CONFLICT))
 326                     throw new Error("Using type that can be either local or global in context:\n"+currlb.getExplanation());
 327                 if(thistype.equals(GLOBAL)&&!isatomic)
 328                     throw new Error("Using global object outside of transaction in context:\n"+currlb.getExplanation());
 329                 if (isnative&&thistype.equals(GLOBAL))
 330                     throw new Error("Potential call to native method "+md+" on global objects:\n"+currlb.getExplanation());
 331                 lb.setGlobalThis(thistype);
 332             } else
 333                 lb.setGlobalThis(EITHER);//default value
 334
 335             //lb is built
 336             if (!discovered.containsKey(lb)) {
 337                 if (isnative)
 338                     lb.setGlobalReturn(LOCAL);
 339                 else
 340                     lb.setGlobalReturn(EITHER);
 341                 lb.setParent(currlb);
 342                 lbtovisit.add(lb);
 343                 discovered.put(lb, lb);
 344                 if (!classtolb.containsKey(lb.getMethod().getClassDesc()))
 345                     classtolb.put(lb.getMethod().getClassDesc(), new HashSet<LocalityBinding>());
 346                 classtolb.get(lb.getMethod().getClassDesc()).add(lb);
 347                 if (!methodtolb.containsKey(lb.getMethod()))
 348                     methodtolb.put(lb.getMethod(), new HashSet<LocalityBinding>());
 349                 methodtolb.get(lb.getMethod()).add(lb);
 350             } else
 351                 lb=discovered.get(lb);
 352             Integer returnval=lb.getGlobalReturn();
 353             currreturnval=merge(returnval, currreturnval);
 354             if (!dependence.containsKey(lb))
 355                 dependence.put(lb, new HashSet<LocalityBinding>());
 356             dependence.get(lb).add(currlb);
 357         }
 358         if (fc.getReturnTemp()!=null) {
 359             currtable.put(fc.getReturnTemp(), currreturnval);
 360         }
 361     }
 362
 363     void processFieldNode(LocalityBinding lb, FlatFieldNode ffn, boolean transaction, Hashtable<TempDescriptor, Integer> currtable) {
 364         Integer type=currtable.get(ffn.getSrc());
 365         TempDescriptor dst=ffn.getDst();
 366         if (type.equals(LOCAL)) {
 367             if (ffn.getField().isGlobal())
 368                 currtable.put(dst,GLOBAL);
 369             else
 370                 currtable.put(dst,LOCAL);
 371         } else if (type.equals(GLOBAL)) {
 372             if (!transaction)
 373                 throw new Error("Global access outside of a transaction in context:\n"+lb.getExplanation());
 374             if (ffn.getField().getType().isPrimitive())
 375                 currtable.put(dst, LOCAL); // primitives are local
 376             else
 377                 currtable.put(dst, GLOBAL);
 378         } else if (type.equals(EITHER)) {
 379             if (ffn.getField().getType().isPrimitive())
 380                 currtable.put(dst, LOCAL); // primitives are local
 381             else if (ffn.getField().isGlobal())
 382                 currtable.put(dst, GLOBAL);
 383             else
 384                 currtable.put(dst, EITHER);
 385         } else if (type.equals(CONFLICT)) {
 386             throw new Error("Access to object that could be either global or local in context:\n"+lb.getExplanation());
 387         }
 388     }
 389
 390     //need to handle primitives
 391     void processSetFieldNode(LocalityBinding lb, FlatSetFieldNode fsfn, boolean transaction, Hashtable<TempDescriptor, Integer> currtable) {
 392         Integer srctype=currtable.get(fsfn.getSrc());
 393         Integer dsttype=currtable.get(fsfn.getDst());
 394
 395         if (dsttype.equals(LOCAL)) {
 396             if (fsfn.getField().isGlobal()) {
 397                 if (!(srctype.equals(GLOBAL)||srctype.equals(EITHER)))
 398                     throw new Error("Writing possible local reference to global field in context: \n"+lb.getExplanation());
 399             } else {
 400                 if (!(srctype.equals(LOCAL)||srctype.equals(EITHER)))
 401                     throw new Error("Writing possible global reference to local object in context: \n"+lb.getExplanation());
 402             }
 403         } else if (dsttype.equals(GLOBAL)) {
 404             if (!transaction)
 405                 throw new Error("Global access outside of a transaction in context:\n"+lb.getExplanation());
 406             //okay to store primitives in global object
 407             if (srctype.equals(LOCAL) && fsfn.getField().getType().isPrimitive())
 408                 return;
 409             if (!(srctype.equals(GLOBAL)||srctype.equals(EITHER)))
 410                 throw new Error("Writing possible local reference to global object in context:\n"+lb.getExplanation());
 411         } else if (dsttype.equals(EITHER)) {
 412             if (srctype.equals(CONFLICT))
 413                 throw new Error("Using reference that could be local or global in context:\n"+lb.getExplanation());
 414         } else if (dsttype.equals(CONFLICT)) {
 415             throw new Error("Access to object that could be either global or local in context:\n"+lb.getExplanation());
 416         }
 417     }
 418
 419     void processNew(LocalityBinding lb, FlatNew fn, boolean transaction, Hashtable<TempDescriptor, Integer> currtable) {
 420         if (fn.isGlobal()&&!transaction) {
 421             throw new Error("Allocating global object outside of transaction in context:"+lb.getExplanation());
 422         }
 423         if (fn.isGlobal())
 424             currtable.put(fn.getDst(), GLOBAL);
 425         else
 426             currtable.put(fn.getDst(), LOCAL);
 427     }
 428
 429     void processOpNode(FlatOpNode fon, Hashtable<TempDescriptor, Integer> currtable) {
 430         /* Just propagate value */
 431         currtable.put(fon.getDest(), currtable.get(fon.getLeft()));
 432     }
 433
 434     void processCastNode(FlatCastNode fcn, Hashtable<TempDescriptor, Integer> currtable) {
 435         currtable.put(fcn.getDst(), currtable.get(fcn.getSrc()));
 436     }
 437
 438     void processLiteralNode(FlatLiteralNode fln, Hashtable<TempDescriptor, Integer> currtable) {
 439         //null is either
 440         if (fln.getValue()==null)
 441             currtable.put(fln.getDst(), EITHER);
 442         else
 443             currtable.put(fln.getDst(), LOCAL);
 444     }
 445
 446     void processReturnNode(LocalityBinding lb, FlatReturnNode frn, Hashtable<TempDescriptor, Integer> currtable) {
 447         if(frn.getReturnTemp()!=null) {
 448             Integer returntype=currtable.get(frn.getReturnTemp());
 449             lb.setGlobalReturn(merge(returntype, lb.getGlobalReturn()));
 450         }
 451     }
 452
 453     void processSetElementNode(LocalityBinding lb, FlatSetElementNode fsen, Hashtable<TempDescriptor, Integer> currtable, boolean isatomic) {
 454         Integer srctype=currtable.get(fsen.getSrc());
 455         Integer dsttype=currtable.get(fsen.getDst());
 456
 457         if (dsttype.equals(LOCAL)) {
 458             if (!(srctype.equals(LOCAL)||srctype.equals(EITHER)))
 459                 throw new Error("Writing possible global reference to local object in context:\n"+lb.getExplanation());
 460         } else if (dsttype.equals(GLOBAL)) {
 461             if (!(srctype.equals(GLOBAL)||srctype.equals(EITHER)))
 462                 throw new Error("Writing possible local reference to global object in context:\n"+lb.getExplanation());
 463             if (!isatomic)
 464                 throw new Error("Global access outside of a transaction in context:\n"+lb.getExplanation());
 465         } else if (dsttype.equals(EITHER)) {
 466             if (srctype.equals(CONFLICT))
 467                 throw new Error("Using reference that could be local or global in context:\n"+lb.getExplanation());
 468         } else if (dsttype.equals(CONFLICT)) {
 469             throw new Error("Access to object that could be either global or local in context:\n"+lb.getExplanation());
 470         }
 471     }
 472
 473     void processElementNode(LocalityBinding lb, FlatElementNode fen, Hashtable<TempDescriptor, Integer> currtable, boolean isatomic) {
 474         Integer type=currtable.get(fen.getSrc());
 475         TempDescriptor dst=fen.getDst();
 476         if (type.equals(LOCAL)) {
 477             currtable.put(dst,LOCAL);
 478         } else if (type.equals(GLOBAL)) {
 479             if (!isatomic)
 480                 throw new Error("Global access outside of a transaction in context:\n"+lb.getExplanation());
 481             currtable.put(dst, GLOBAL);
 482         } else if (type.equals(EITHER)) {
 483             currtable.put(dst, EITHER);
 484         } else if (type.equals(CONFLICT)) {
 485             throw new Error("Access to object that could be either global or local in context:\n"+lb.getExplanation());
 486         }
 487     }
 488
 489     void processAtomicEnterNode(FlatAtomicEnterNode fen, Hashtable<FlatNode, Integer> atomictable) {
 490         int atomic=atomictable.get(fen).intValue();
 491         atomictable.put(fen, new Integer(atomic+1));
 492     }
 493
 494     void processAtomicExitNode(FlatAtomicExitNode fen, Hashtable<FlatNode, Integer> atomictable) {
 495         int atomic=atomictable.get(fen).intValue();
 496         atomictable.put(fen, new Integer(atomic-1));
 497     }
 498
 499     private Hashtable<FlatNode, Set<TempDescriptor>> computeLiveTemps(FlatMethod fm) {
 500         Hashtable<FlatNode, Set<TempDescriptor>> nodetotemps=new Hashtable<FlatNode, Set<TempDescriptor>>();
 501
 502         Set<FlatNode> toprocess=fm.getNodeSet();
 503
 504         while(!toprocess.isEmpty()) {
 505             FlatNode fn=toprocess.iterator().next();
 506             toprocess.remove(fn);
 507
 508             List<TempDescriptor> reads=Arrays.asList(fn.readsTemps());
 509             List<TempDescriptor> writes=Arrays.asList(fn.readsTemps());
 510
 511             HashSet<TempDescriptor> tempset=new HashSet<TempDescriptor>();
 512             for(int i=0;i<fn.numNext();i++) {
 513                 FlatNode fnnext=fn.getNext(i);
 514                 if (nodetotemps.containsKey(fnnext))
 515                     tempset.addAll(nodetotemps.get(fnnext));
 516             }
 517             tempset.removeAll(writes);
 518             tempset.addAll(reads);
 519             if (!nodetotemps.containsKey(fn)||
 520                 nodetotemps.get(fn).equals(tempset)) {
 521                 nodetotemps.put(fn, tempset);
 522                 for(int i=0;i<fn.numPrev();i++)
 523                     toprocess.add(fn.getPrev(i));
 524             }
 525         }
 526         return nodetotemps;
 527     }
 528
 529     private void computeTempstoSave() {
 530         for(Iterator<LocalityBinding> lbit=getLocalityBindings().iterator();lbit.hasNext();) {
 531             LocalityBinding lb=lbit.next();
 532             computeTempstoSave(lb);
 533         }
 534     }
 535
 536     /* Need to checkpoint all temps that could be read from along any
 537      * path that are either:
 538        1) Written to by any assignment inside the transaction
 539        2) Read from a global temp.
 540
 541        Generate tempstosave map from
 542        localitybinding->flatatomicenternode->Set<TempDescriptors>
 543     */
 544
 545     private void computeTempstoSave(LocalityBinding lb) {
 546         if (lb.isAtomic())
 547             return;
 548         Hashtable<FlatNode, Integer> atomictab=getAtomic(lb);
 549         Hashtable<FlatNode, Hashtable<TempDescriptor, Integer>> temptab=getNodeTempInfo(lb);
 550         MethodDescriptor md=lb.getMethod();
 551         FlatMethod fm=state.getMethodFlat(md);
 552
 553         Hashtable<FlatNode, Set<TempDescriptor>> nodetotemps=computeLiveTemps(fm);
 554         Hashtable<FlatAtomicEnterNode, Set<TempDescriptor>> nodetosavetemps=new Hashtable<FlatAtomicEnterNode, Set<TempDescriptor>>();
 555         tempstosave.put(lb, nodetosavetemps);
 556
 557         Hashtable<FlatNode, FlatAtomicEnterNode> nodemap=new Hashtable<FlatNode, FlatAtomicEnterNode>();
 558
 559         HashSet<FlatNode> toprocess=new HashSet<FlatNode>();
 560         HashSet<FlatNode> discovered=new HashSet<FlatNode>();
 561         toprocess.add(fm);
 562         discovered.add(fm);
 563         while(!toprocess.isEmpty()) {
 564             FlatNode fn=toprocess.iterator().next();
 565             toprocess.remove(fn);
 566             boolean isatomic=atomictab.get(fn).intValue()>0;
 567             if (isatomic&&
 568                 atomictab.get(fn.getPrev(0)).intValue()==0) {
 569                 assert(fn.getPrev(0).kind()==FKind.FlatAtomicEnterNode);
 570                 nodemap.put(fn, (FlatAtomicEnterNode)fn);
 571                 nodetosavetemps.put((FlatAtomicEnterNode)fn, new HashSet<TempDescriptor>());
 572             } else if (isatomic) {
 573                 FlatAtomicEnterNode atomicnode=nodemap.get(fn);
 574                 Set<TempDescriptor> livetemps=nodetotemps.get(fn);
 575                 List<TempDescriptor> reads=Arrays.asList(fn.readsTemps());
 576                 List<TempDescriptor> writes=Arrays.asList(fn.readsTemps());
 577
 578                 for(Iterator<TempDescriptor> tempit=livetemps.iterator();tempit.hasNext();) {
 579                     TempDescriptor tmp=tempit.next();
 580                     if (writes.contains(tmp)) {
 581                         nodetosavetemps.get(atomicnode).add(tmp);
 582                     } else if (reads.contains(tmp)&&temptab.get(fn).get(tmp)==GLOBAL) {
 583                         nodetosavetemps.get(atomicnode).add(tmp);
 584                     }
 585                 }
 586             }
 587             for(int i=0;i<fn.numNext();i++) {
 588                 FlatNode fnnext=fn.getNext(i);
 589                 if (!discovered.contains(fnnext)) {
 590                     discovered.add(fnnext);
 591                     toprocess.add(fnnext);
 592                     if(isatomic) {
 593                         nodemap.put(fnnext, nodemap.get(fn));
 594                     }
 595                 }
 596             }
 597         }
 598     }
 599 }