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=getNodePreTempInfo(currlb,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 a hashtable for a given LocalityBinding
 110      * that tells the current local/global status of temps at the
 111      * beginning of each node in the flat representation. */
 112
 113     public Hashtable<TempDescriptor, Integer> getNodePreTempInfo(LocalityBinding lb, FlatNode fn) {
 114         Hashtable<TempDescriptor, Integer> currtable=new Hashtable<TempDescriptor, Integer>();
 115         Hashtable<FlatNode, Hashtable<TempDescriptor, Integer>> temptable=getNodeTempInfo(lb);
 116
 117         for(int i=0;i<fn.numPrev();i++) {
 118             FlatNode prevnode=fn.getPrev(i);
 119             Hashtable<TempDescriptor, Integer> prevtable=temptable.get(prevnode);
 120             for(Iterator<TempDescriptor> tempit=prevtable.keySet().iterator();tempit.hasNext();) {
 121                 TempDescriptor temp=tempit.next();
 122                 Integer tmpint=prevtable.get(temp);
 123                 Integer oldint=currtable.containsKey(temp)?currtable.get(temp):EITHER;
 124                 Integer newint=merge(tmpint, oldint);
 125                 currtable.put(temp, newint);
 126             }
 127         }
 128         return currtable;
 129     }
 130
 131     /** This method returns an hashtable for a given LocalitBinding
 132      * that tells whether a node in the flat represenation is in a
 133      * transaction or not.  Integer values greater than 0 indicate
 134      * that the node is in a transaction and give the nesting depth.
 135      * The outermost AtomicEnterNode will have a value of 1 and the
 136      * outermost AtomicExitNode will have a value of 0. */
 137
 138     public Hashtable<FlatNode, Integer> getAtomic(LocalityBinding lb) {
 139         return atomictab.get(lb);
 140     }
 141
 142     /** This methods returns a hashtable for a given LocalityBinding
 143      * that tells which temps needs to be saved for each
 144      * AtomicEnterNode.  */
 145
 146     public Hashtable<FlatAtomicEnterNode, Set<TempDescriptor>> getTemps(LocalityBinding lb) {
 147         return tempstosave.get(lb);
 148     }
 149
 150     public Set<TempDescriptor> getTempSet(LocalityBinding lb) {
 151         HashSet<TempDescriptor> set=new HashSet<TempDescriptor>();
 152         Hashtable<FlatAtomicEnterNode, Set<TempDescriptor>> table=getTemps(lb);
 153         if (table!=null)
 154             for(Iterator<FlatAtomicEnterNode> faenit=table.keySet().iterator();faenit.hasNext();) {
 155                 FlatAtomicEnterNode faen=faenit.next();
 156                 set.addAll(table.get(faen));
 157             }
 158         return set;
 159     }
 160
 161     private void doAnalysis() {
 162         computeLocalityBindings();
 163         computeTempstoSave();
 164     }
 165
 166     private void computeLocalityBindings() {
 167         lbmain=new LocalityBinding(typeutil.getMain(), false);
 168         lbmain.setGlobal(0, LOCAL);
 169         lbtovisit.add(lbmain);
 170         discovered.put(lbmain, lbmain);
 171         if (!classtolb.containsKey(lbmain.getMethod().getClassDesc()))
 172             classtolb.put(lbmain.getMethod().getClassDesc(), new HashSet<LocalityBinding>());
 173         classtolb.get(lbmain.getMethod().getClassDesc()).add(lbmain);
 174
 175         if (!methodtolb.containsKey(lbmain.getMethod()))
 176             methodtolb.put(lbmain.getMethod(), new HashSet<LocalityBinding>());
 177         methodtolb.get(lbmain.getMethod()).add(lbmain);
 178
 179         while(!lbtovisit.empty()) {
 180             LocalityBinding lb=(LocalityBinding) lbtovisit.pop();
 181             Integer returnglobal=lb.getGlobalReturn();
 182             MethodDescriptor md=lb.getMethod();
 183             Hashtable<FlatNode,Hashtable<TempDescriptor, Integer>> temptable=new Hashtable<FlatNode,Hashtable<TempDescriptor, Integer>>();
 184             Hashtable<FlatNode, Integer> atomictable=new Hashtable<FlatNode, Integer>();
 185             computeCallsFlags(md, lb, temptable, atomictable);
 186             atomictab.put(lb, atomictable);
 187             temptab.put(lb, temptable);
 188
 189             if (!md.isStatic()&&!returnglobal.equals(lb.getGlobalReturn())) {
 190                 //return type is more precise now
 191                 //rerun everything that call us
 192                 lbtovisit.addAll(dependence.get(lb));
 193             }
 194         }
 195     }
 196
 197     public void computeCallsFlags(MethodDescriptor md, LocalityBinding lb, Hashtable<FlatNode, Hashtable<TempDescriptor, Integer>> temptable, Hashtable<FlatNode, Integer> atomictable) {
 198         FlatMethod fm=state.getMethodFlat(md);
 199         HashSet<FlatNode> tovisit=new HashSet<FlatNode>();
 200         tovisit.add(fm.getNext(0));
 201         {
 202             // Build table for initial node
 203             Hashtable<TempDescriptor,Integer> table=new Hashtable<TempDescriptor,Integer>();
 204             temptable.put(fm, table);
 205             atomictable.put(fm, lb.isAtomic()?1:0);
 206             int offset=md.isStatic()?0:1;
 207             if (!md.isStatic()) {
 208                 table.put(fm.getParameter(0), lb.getGlobalThis());
 209             }
 210             for(int i=offset;i<fm.numParameters();i++) {
 211                 TempDescriptor temp=fm.getParameter(i);
 212                 Integer b=lb.isGlobal(i-offset);
 213                 table.put(temp,b);
 214             }
 215         }
 216
 217         while(!tovisit.isEmpty()) {
 218             FlatNode fn=tovisit.iterator().next();
 219             tovisit.remove(fn);
 220             Hashtable<TempDescriptor, Integer> currtable=new Hashtable<TempDescriptor, Integer>();
 221             int atomicstate=0;
 222             for(int i=0;i<fn.numPrev();i++) {
 223                 FlatNode prevnode=fn.getPrev(i);
 224                 if (atomictable.containsKey(prevnode)) {
 225                     atomicstate=atomictable.get(prevnode).intValue();
 226                 }
 227                 if (!temptable.containsKey(prevnode))
 228                     continue;
 229                 Hashtable<TempDescriptor, Integer> prevtable=temptable.get(prevnode);
 230                 for(Iterator<TempDescriptor> tempit=prevtable.keySet().iterator();tempit.hasNext();) {
 231                     TempDescriptor temp=tempit.next();
 232                     Integer tmpint=prevtable.get(temp);
 233                     Integer oldint=currtable.containsKey(temp)?currtable.get(temp):EITHER;
 234                     Integer newint=merge(tmpint, oldint);
 235                     currtable.put(temp, newint);
 236                 }
 237             }
 238             atomictable.put(fn, atomicstate);
 239             // Process this node
 240             switch(fn.kind()) {
 241             case FKind.FlatAtomicEnterNode:
 242                 processAtomicEnterNode((FlatAtomicEnterNode)fn, atomictable);
 243                 if (!lb.isAtomic())
 244                     lb.setHasAtomic();
 245                 break;
 246             case FKind.FlatAtomicExitNode:
 247                 processAtomicExitNode((FlatAtomicExitNode)fn, atomictable);
 248                 break;
 249             case FKind.FlatCall:
 250                 processCallNode(lb, (FlatCall)fn, currtable, isAtomic(atomictable, fn));
 251                 break;
 252             case FKind.FlatFieldNode:
 253                 processFieldNode(lb, (FlatFieldNode)fn, isAtomic(atomictable, fn), currtable);
 254                 break;
 255             case FKind.FlatSetFieldNode:
 256                 processSetFieldNode(lb, (FlatSetFieldNode)fn, isAtomic(atomictable,fn), currtable);
 257                 break;
 258             case FKind.FlatNew:
 259                 processNew(lb, (FlatNew)fn, isAtomic(atomictable, fn), currtable);
 260                 break;
 261             case FKind.FlatOpNode:
 262                 processOpNode((FlatOpNode)fn, currtable);
 263                 break;
 264             case FKind.FlatCastNode:
 265                 processCastNode((FlatCastNode)fn, currtable);
 266                 break;
 267             case FKind.FlatLiteralNode:
 268                 processLiteralNode((FlatLiteralNode)fn, currtable);
 269                 break;
 270             case FKind.FlatReturnNode:
 271                 processReturnNode(lb, (FlatReturnNode)fn, currtable);
 272                 break;
 273             case FKind.FlatSetElementNode:
 274                 processSetElementNode(lb, (FlatSetElementNode)fn, currtable, isAtomic(atomictable, fn));
 275                 break;
 276             case FKind.FlatElementNode:
 277                 processElementNode(lb, (FlatElementNode)fn, currtable, isAtomic(atomictable, fn));
 278                 break;
 279             case FKind.FlatCondBranch:
 280             case FKind.FlatBackEdge:
 281             case FKind.FlatNop:
 282                 //No action needed for these
 283                 break;
 284             case FKind.FlatFlagActionNode:
 285             case FKind.FlatCheckNode:
 286             case FKind.FlatTagDeclaration:
 287                 throw new Error("Incompatible with tasks!");
 288             case FKind.FlatMethod:
 289             default:
 290                 throw new Error();
 291             }
 292             Hashtable<TempDescriptor,Integer> oldtable=temptable.get(fn);
 293             if (oldtable==null||!oldtable.equals(currtable)) {
 294                 // Update table for this node
 295                 temptable.put(fn, currtable);
 296                 for(int i=0;i<fn.numNext();i++) {
 297                     tovisit.add(fn.getNext(i));
 298                 }
 299             }
 300         }
 301     }
 302
 303     private static boolean isAtomic(Hashtable<FlatNode, Integer> atomictable, FlatNode fn) {
 304         return atomictable.get(fn).intValue()>0;
 305     }
 306
 307     private static Integer merge(Integer a, Integer b) {
 308         if (a==null||a.equals(EITHER))
 309             return b;
 310         if (b==null||b.equals(EITHER))
 311             return a;
 312         if (a.equals(b))
 313             return a;
 314         return CONFLICT;
 315     }
 316
 317     void processCallNode(LocalityBinding currlb, FlatCall fc, Hashtable<TempDescriptor, Integer> currtable, boolean isatomic) {
 318         MethodDescriptor nodemd=fc.getMethod();
 319         Set methodset=null;
 320         if (nodemd.isStatic()||nodemd.getReturnType()==null) {
 321             methodset=new HashSet();
 322             methodset.add(nodemd);
 323         } else {
 324             methodset=callgraph.getMethods(nodemd, fc.getThis().getType());
 325         }
 326         Integer currreturnval=EITHER; //Start off with the either value
 327         for(Iterator methodit=methodset.iterator();methodit.hasNext();) {
 328             MethodDescriptor md=(MethodDescriptor) methodit.next();
 329             boolean isnative=md.getModifiers().isNative();
 330
 331             LocalityBinding lb=new LocalityBinding(md, isatomic);
 332             if (isnative&&isatomic) {
 333                 System.out.println("Don't call native methods in atomic blocks!");
 334             }
 335             for(int i=0;i<fc.numArgs();i++) {
 336                 TempDescriptor arg=fc.getArg(i);
 337                 if(isnative&&(currtable.get(arg).equals(GLOBAL)||
 338                               currtable.get(arg).equals(CONFLICT)))
 339                    throw new Error("Potential call to native method "+md+" with global parameter:\n"+currlb.getExplanation());
 340                 lb.setGlobal(i,currtable.get(arg));
 341             }
 342             if (fc.getThis()!=null) {
 343                 Integer thistype=currtable.get(fc.getThis());
 344                 if (thistype==null)
 345                     thistype=EITHER;
 346                 if(thistype.equals(CONFLICT))
 347                     throw new Error("Using type that can be either local or global in context:\n"+currlb.getExplanation());
 348                 if(thistype.equals(GLOBAL)&&!isatomic)
 349                     throw new Error("Using global object outside of transaction in context:\n"+currlb.getExplanation());
 350                 if (isnative&&thistype.equals(GLOBAL))
 351                     throw new Error("Potential call to native method "+md+" on global objects:\n"+currlb.getExplanation());
 352                 lb.setGlobalThis(thistype);
 353             } //else
 354             //lb.setGlobalThis(EITHER);//default value
 355
 356             //lb is built
 357             if (!discovered.containsKey(lb)) {
 358                 if (isnative)
 359                     lb.setGlobalReturn(LOCAL);
 360                 else
 361                     lb.setGlobalReturn(EITHER);
 362                 lb.setParent(currlb);
 363                 lbtovisit.add(lb);
 364                 discovered.put(lb, lb);
 365                 if (!classtolb.containsKey(lb.getMethod().getClassDesc()))
 366                     classtolb.put(lb.getMethod().getClassDesc(), new HashSet<LocalityBinding>());
 367                 classtolb.get(lb.getMethod().getClassDesc()).add(lb);
 368                 if (!methodtolb.containsKey(lb.getMethod()))
 369                     methodtolb.put(lb.getMethod(), new HashSet<LocalityBinding>());
 370                 methodtolb.get(lb.getMethod()).add(lb);
 371             } else
 372                 lb=discovered.get(lb);
 373             Integer returnval=lb.getGlobalReturn();
 374             currreturnval=merge(returnval, currreturnval);
 375             if (!dependence.containsKey(lb))
 376                 dependence.put(lb, new HashSet<LocalityBinding>());
 377             dependence.get(lb).add(currlb);
 378         }
 379         if (fc.getReturnTemp()!=null) {
 380             currtable.put(fc.getReturnTemp(), currreturnval);
 381         }
 382     }
 383
 384     void processFieldNode(LocalityBinding lb, FlatFieldNode ffn, boolean transaction, Hashtable<TempDescriptor, Integer> currtable) {
 385         Integer type=currtable.get(ffn.getSrc());
 386         TempDescriptor dst=ffn.getDst();
 387         if (type.equals(LOCAL)) {
 388             if (ffn.getField().isGlobal())
 389                 currtable.put(dst,GLOBAL);
 390             else
 391                 currtable.put(dst,LOCAL);
 392         } else if (type.equals(GLOBAL)) {
 393             if (!transaction)
 394                 throw new Error("Global access outside of a transaction in context:\n"+lb.getExplanation());
 395             if (ffn.getField().getType().isPrimitive())
 396                 currtable.put(dst, LOCAL); // primitives are local
 397             else
 398                 currtable.put(dst, GLOBAL);
 399         } else if (type.equals(EITHER)) {
 400             if (ffn.getField().getType().isPrimitive())
 401                 currtable.put(dst, LOCAL); // primitives are local
 402             else if (ffn.getField().isGlobal())
 403                 currtable.put(dst, GLOBAL);
 404             else
 405                 currtable.put(dst, EITHER);
 406         } else if (type.equals(CONFLICT)) {
 407             throw new Error("Access to object that could be either global or local in context:\n"+lb.getExplanation());
 408         }
 409     }
 410
 411     //need to handle primitives
 412     void processSetFieldNode(LocalityBinding lb, FlatSetFieldNode fsfn, boolean transaction, Hashtable<TempDescriptor, Integer> currtable) {
 413         Integer srctype=currtable.get(fsfn.getSrc());
 414         Integer dsttype=currtable.get(fsfn.getDst());
 415
 416         if (dsttype.equals(LOCAL)) {
 417             if (fsfn.getField().isGlobal()) {
 418                 if (!(srctype.equals(GLOBAL)||srctype.equals(EITHER)))
 419                     throw new Error("Writing possible local reference to global field in context: \n"+lb.getExplanation());
 420             } else {
 421                 if (!(srctype.equals(LOCAL)||srctype.equals(EITHER)))
 422                     throw new Error("Writing possible global reference to local object in context: \n"+lb.getExplanation());
 423             }
 424         } else if (dsttype.equals(GLOBAL)) {
 425             if (!transaction)
 426                 throw new Error("Global access outside of a transaction in context:\n"+lb.getExplanation());
 427             //okay to store primitives in global object
 428             if (srctype.equals(LOCAL) && fsfn.getField().getType().isPrimitive())
 429                 return;
 430             if (!(srctype.equals(GLOBAL)||srctype.equals(EITHER)))
 431                 throw new Error("Writing possible local reference to global object in context:\n"+lb.getExplanation());
 432         } else if (dsttype.equals(EITHER)) {
 433             if (srctype.equals(CONFLICT))
 434                 throw new Error("Using reference that could be local or global in context:\n"+lb.getExplanation());
 435         } else if (dsttype.equals(CONFLICT)) {
 436             throw new Error("Access to object that could be either global or local in context:\n"+lb.getExplanation());
 437         }
 438     }
 439
 440     void processNew(LocalityBinding lb, FlatNew fn, boolean transaction, Hashtable<TempDescriptor, Integer> currtable) {
 441         if (fn.isGlobal()&&!transaction) {
 442             throw new Error("Allocating global object outside of transaction in context:"+lb.getExplanation());
 443         }
 444         if (fn.isGlobal())
 445             currtable.put(fn.getDst(), GLOBAL);
 446         else
 447             currtable.put(fn.getDst(), LOCAL);
 448     }
 449
 450     void processOpNode(FlatOpNode fon, Hashtable<TempDescriptor, Integer> currtable) {
 451         /* Just propagate value */
 452         currtable.put(fon.getDest(), currtable.get(fon.getLeft()));
 453     }
 454
 455     void processCastNode(FlatCastNode fcn, Hashtable<TempDescriptor, Integer> currtable) {
 456         currtable.put(fcn.getDst(), currtable.get(fcn.getSrc()));
 457     }
 458
 459     void processLiteralNode(FlatLiteralNode fln, Hashtable<TempDescriptor, Integer> currtable) {
 460         //null is either
 461         if (fln.getValue()==null)
 462             currtable.put(fln.getDst(), EITHER);
 463         else
 464             currtable.put(fln.getDst(), LOCAL);
 465     }
 466
 467     void processReturnNode(LocalityBinding lb, FlatReturnNode frn, Hashtable<TempDescriptor, Integer> currtable) {
 468         if(frn.getReturnTemp()!=null) {
 469             Integer returntype=currtable.get(frn.getReturnTemp());
 470             lb.setGlobalReturn(merge(returntype, lb.getGlobalReturn()));
 471         }
 472     }
 473
 474     void processSetElementNode(LocalityBinding lb, FlatSetElementNode fsen, Hashtable<TempDescriptor, Integer> currtable, boolean isatomic) {
 475         Integer srctype=currtable.get(fsen.getSrc());
 476         Integer dsttype=currtable.get(fsen.getDst());
 477
 478         if (dsttype.equals(LOCAL)) {
 479             if (!(srctype.equals(LOCAL)||srctype.equals(EITHER)))
 480                 throw new Error("Writing possible global reference to local object in context:\n"+lb.getExplanation());
 481         } else if (dsttype.equals(GLOBAL)) {
 482             if (!(srctype.equals(GLOBAL)||srctype.equals(EITHER)))
 483                 throw new Error("Writing possible local reference to global object in context:\n"+lb.getExplanation());
 484             if (!isatomic)
 485                 throw new Error("Global access outside of a transaction in context:\n"+lb.getExplanation());
 486         } else if (dsttype.equals(EITHER)) {
 487             if (srctype.equals(CONFLICT))
 488                 throw new Error("Using reference that could be local or global in context:\n"+lb.getExplanation());
 489         } else if (dsttype.equals(CONFLICT)) {
 490             throw new Error("Access to object that could be either global or local in context:\n"+lb.getExplanation());
 491         }
 492     }
 493
 494     void processElementNode(LocalityBinding lb, FlatElementNode fen, Hashtable<TempDescriptor, Integer> currtable, boolean isatomic) {
 495         Integer type=currtable.get(fen.getSrc());
 496         TempDescriptor dst=fen.getDst();
 497         if (type.equals(LOCAL)) {
 498             currtable.put(dst,LOCAL);
 499         } else if (type.equals(GLOBAL)) {
 500             if (!isatomic)
 501                 throw new Error("Global access outside of a transaction in context:\n"+lb.getExplanation());
 502             currtable.put(dst, GLOBAL);
 503         } else if (type.equals(EITHER)) {
 504             currtable.put(dst, EITHER);
 505         } else if (type.equals(CONFLICT)) {
 506             throw new Error("Access to object that could be either global or local in context:\n"+lb.getExplanation());
 507         }
 508     }
 509
 510     void processAtomicEnterNode(FlatAtomicEnterNode fen, Hashtable<FlatNode, Integer> atomictable) {
 511         int atomic=atomictable.get(fen).intValue();
 512         atomictable.put(fen, new Integer(atomic+1));
 513     }
 514
 515     void processAtomicExitNode(FlatAtomicExitNode fen, Hashtable<FlatNode, Integer> atomictable) {
 516         int atomic=atomictable.get(fen).intValue();
 517         atomictable.put(fen, new Integer(atomic-1));
 518     }
 519
 520     private Hashtable<FlatNode, Set<TempDescriptor>> computeLiveTemps(FlatMethod fm) {
 521         Hashtable<FlatNode, Set<TempDescriptor>> nodetotemps=new Hashtable<FlatNode, Set<TempDescriptor>>();
 522
 523         Set<FlatNode> toprocess=fm.getNodeSet();
 524
 525         while(!toprocess.isEmpty()) {
 526             FlatNode fn=toprocess.iterator().next();
 527             toprocess.remove(fn);
 528
 529             List<TempDescriptor> reads=Arrays.asList(fn.readsTemps());
 530             List<TempDescriptor> writes=Arrays.asList(fn.readsTemps());
 531
 532             HashSet<TempDescriptor> tempset=new HashSet<TempDescriptor>();
 533             for(int i=0;i<fn.numNext();i++) {
 534                 FlatNode fnnext=fn.getNext(i);
 535                 if (nodetotemps.containsKey(fnnext))
 536                     tempset.addAll(nodetotemps.get(fnnext));
 537             }
 538             tempset.removeAll(writes);
 539             tempset.addAll(reads);
 540             if (!nodetotemps.containsKey(fn)||
 541                 nodetotemps.get(fn).equals(tempset)) {
 542                 nodetotemps.put(fn, tempset);
 543                 for(int i=0;i<fn.numPrev();i++)
 544                     toprocess.add(fn.getPrev(i));
 545             }
 546         }
 547         return nodetotemps;
 548     }
 549
 550     private void computeTempstoSave() {
 551         for(Iterator<LocalityBinding> lbit=getLocalityBindings().iterator();lbit.hasNext();) {
 552             LocalityBinding lb=lbit.next();
 553             computeTempstoSave(lb);
 554         }
 555     }
 556
 557     /* Need to checkpoint all temps that could be read from along any
 558      * path that are either:
 559        1) Written to by any assignment inside the transaction
 560        2) Read from a global temp.
 561
 562        Generate tempstosave map from
 563        localitybinding->flatatomicenternode->Set<TempDescriptors>
 564     */
 565
 566     private void computeTempstoSave(LocalityBinding lb) {
 567         if (lb.isAtomic())
 568             return;
 569         Hashtable<FlatNode, Integer> atomictab=getAtomic(lb);
 570         Hashtable<FlatNode, Hashtable<TempDescriptor, Integer>> temptab=getNodeTempInfo(lb);
 571         MethodDescriptor md=lb.getMethod();
 572         FlatMethod fm=state.getMethodFlat(md);
 573
 574         Hashtable<FlatNode, Set<TempDescriptor>> nodetotemps=computeLiveTemps(fm);
 575         Hashtable<FlatAtomicEnterNode, Set<TempDescriptor>> nodetosavetemps=new Hashtable<FlatAtomicEnterNode, Set<TempDescriptor>>();
 576         tempstosave.put(lb, nodetosavetemps);
 577
 578         Hashtable<FlatNode, FlatAtomicEnterNode> nodemap=new Hashtable<FlatNode, FlatAtomicEnterNode>();
 579
 580         HashSet<FlatNode> toprocess=new HashSet<FlatNode>();
 581         HashSet<FlatNode> discovered=new HashSet<FlatNode>();
 582         toprocess.add(fm);
 583         discovered.add(fm);
 584         while(!toprocess.isEmpty()) {
 585             FlatNode fn=toprocess.iterator().next();
 586             toprocess.remove(fn);
 587             boolean isatomic=atomictab.get(fn).intValue()>0;
 588             if (isatomic&&
 589                 atomictab.get(fn.getPrev(0)).intValue()==0) {
 590                 assert(fn.getPrev(0).kind()==FKind.FlatAtomicEnterNode);
 591                 nodemap.put(fn, (FlatAtomicEnterNode)fn);
 592                 nodetosavetemps.put((FlatAtomicEnterNode)fn, new HashSet<TempDescriptor>());
 593             } else if (isatomic) {
 594                 FlatAtomicEnterNode atomicnode=nodemap.get(fn);
 595                 Set<TempDescriptor> livetemps=nodetotemps.get(fn);
 596                 List<TempDescriptor> reads=Arrays.asList(fn.readsTemps());
 597                 List<TempDescriptor> writes=Arrays.asList(fn.readsTemps());
 598
 599                 for(Iterator<TempDescriptor> tempit=livetemps.iterator();tempit.hasNext();) {
 600                     TempDescriptor tmp=tempit.next();
 601                     if (writes.contains(tmp)) {
 602                         nodetosavetemps.get(atomicnode).add(tmp);
 603                     } else if (reads.contains(tmp)&&temptab.get(fn).get(tmp)==GLOBAL) {
 604                         nodetosavetemps.get(atomicnode).add(tmp);
 605                     }
 606                 }
 607             }
 608             for(int i=0;i<fn.numNext();i++) {
 609                 FlatNode fnnext=fn.getNext(i);
 610                 if (!discovered.contains(fnnext)) {
 611                     discovered.add(fnnext);
 612                     toprocess.add(fnnext);
 613                     if(isatomic) {
 614                         nodemap.put(fnnext, nodemap.get(fn));
 615                     }
 616                 }
 617             }
 618         }
 619     }
 620 }