vm/code/codeTable.hpp

   1 /* Copyright 1994, LongView Technologies L.L.C. $Revision: 1.13 $ */
   2 /* Copyright (c) 2006, Sun Microsystems, Inc.
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  22 */
  23
  24 #ifdef DELTA_COMPILER
  25
  26 // The code table is used to find nmethods in the zone.
  27 // It is a hash table, where each bucket contains a list of nmethods.
  28
  29 //%note
  30 // Should implement free list like symbolTable (Lars 2/10-95)
  31
  32 const int codeTableSize  = 2048;
  33 const int debugTableSize = 256;
  34
  35 struct codeTableEntry;
  36
  37 struct codeTableLink : public CHeapObj {
  38   // instance variable
  39   nmethod*       nm;
  40   codeTableLink* next;
  41
  42   // memory operations
  43   bool verify(int i);
  44 };
  45
  46 struct codeTableEntry : ValueObj {
  47   // methods are tagged, links are not.
  48   void* nmethod_or_link;
  49   bool  is_empty()   { return nmethod_or_link == NULL; }
  50   bool  is_nmethod() { return (int) nmethod_or_link & 1; }
  51   void  clear()      { nmethod_or_link = NULL; }
  52
  53   nmethod* get_nmethod() {
  54     return (nmethod*) ((int) nmethod_or_link - 1);
  55   }
  56   void set_nmethod(nmethod* nm) {
  57     assert_oop_aligned(nm);
  58     nmethod_or_link = (void*) ((int) nm + 1); }
  59
  60   codeTableLink* get_link() { return (codeTableLink*) nmethod_or_link; }
  61   void set_link(codeTableLink* l) {
  62     assert_oop_aligned(l);
  63     nmethod_or_link = (void*) l;
  64   }
  65
  66   // memory operations
  67   void deallocate();
  68
  69   int length();   // returns the number of nmethod in this bucket.
  70
  71   bool verify(int i);
  72 };
  73
  74 class codeTable : public PrintableCHeapObj{
  75  protected:
  76   int             tableSize;
  77   codeTableEntry* buckets;
  78
  79   codeTableEntry* at(int index)       { return &buckets[index]; }
  80   codeTableEntry* bucketFor(int hash) { return at(hash & (tableSize - 1)); }
  81   codeTableLink*  new_link(nmethod* nm, codeTableLink* n = NULL);
  82
  83  public:
  84   codeTable(int size);
  85   void clear();
  86   nmethod* lookup(LookupKey* L);
  87   bool verify();
  88
  89   void print();
  90
  91   void print_stats();
  92
  93   // Tells whether a nmethod is present
  94   bool is_present(nmethod* nm);
  95
  96   // Removes a nmethod from the table
  97   void remove(nmethod* nm);
  98
  99  protected:
 100   // should always add through zone->addToCodeTable()
 101   void add(nmethod* nm);
 102   void addIfAbsent(nmethod* nm); // add only if not there yet
 103
 104   friend class zone;
 105 };
 106
 107 #endif