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1 /* |
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2 * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. |
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8 * |
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9 * This code is distributed in the hope that it will be useful, but WITHOUT |
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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12 * version 2 for more details (a copy is included in the LICENSE file that |
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13 * accompanied this code). |
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14 * |
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15 * You should have received a copy of the GNU General Public License version |
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16 * 2 along with this work; if not, write to the Free Software Foundation, |
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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18 * |
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19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
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20 * CA 95054 USA or visit www.sun.com if you need additional information or |
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21 * have any questions. |
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22 * |
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23 */ |
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24 |
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25 // A VtableStub holds an individual code stub for a pair (vtable index, #args) for either itables or vtables |
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26 // There's a one-to-one relationship between a VtableStub and such a pair. |
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27 |
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28 class VtableStub { |
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29 private: |
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30 friend class VtableStubs; |
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31 |
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32 static address _chunk; // For allocation |
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33 static address _chunk_end; // For allocation |
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34 static VMReg _receiver_location; // Where to find receiver |
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35 |
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36 VtableStub* _next; // Pointer to next entry in hash table |
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37 const short _index; // vtable index |
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38 short _ame_offset; // Where an AbstractMethodError might occur |
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39 short _npe_offset; // Where a NullPointerException might occur |
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40 bool _is_vtable_stub; // True if vtable stub, false, is itable stub |
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41 /* code follows here */ // The vtableStub code |
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42 |
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43 void* operator new(size_t size, int code_size); |
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44 |
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45 VtableStub(bool is_vtable_stub, int index) |
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46 : _next(NULL), _is_vtable_stub(is_vtable_stub), |
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47 _index(index), _ame_offset(-1), _npe_offset(-1) {} |
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48 VtableStub* next() const { return _next; } |
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49 int index() const { return _index; } |
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50 static VMReg receiver_location() { return _receiver_location; } |
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51 void set_next(VtableStub* n) { _next = n; } |
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52 address code_begin() const { return (address)(this + 1); } |
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53 address code_end() const { return code_begin() + pd_code_size_limit(_is_vtable_stub); } |
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54 address entry_point() const { return code_begin(); } |
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55 static int entry_offset() { return sizeof(class VtableStub); } |
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56 |
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57 bool matches(bool is_vtable_stub, int index) const { |
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58 return _index == index && _is_vtable_stub == is_vtable_stub; |
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59 } |
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60 bool contains(address pc) const { return code_begin() <= pc && pc < code_end(); } |
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61 |
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62 void set_exception_points(address npe_addr, address ame_addr) { |
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63 _npe_offset = npe_addr - code_begin(); |
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64 _ame_offset = ame_addr - code_begin(); |
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65 assert(is_abstract_method_error(ame_addr), "offset must be correct"); |
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66 assert(is_null_pointer_exception(npe_addr), "offset must be correct"); |
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67 assert(!is_abstract_method_error(npe_addr), "offset must be correct"); |
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68 assert(!is_null_pointer_exception(ame_addr), "offset must be correct"); |
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69 } |
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70 |
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71 // platform-dependent routines |
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72 static int pd_code_size_limit(bool is_vtable_stub); |
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73 static int pd_code_alignment(); |
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74 // CNC: Removed because vtable stubs are now made with an ideal graph |
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75 // static bool pd_disregard_arg_size(); |
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76 |
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77 static void align_chunk() { |
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78 uintptr_t off = (uintptr_t)( _chunk + sizeof(VtableStub) ) % pd_code_alignment(); |
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79 if (off != 0) _chunk += pd_code_alignment() - off; |
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80 } |
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81 |
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82 public: |
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83 // Query |
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84 bool is_itable_stub() { return !_is_vtable_stub; } |
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85 bool is_vtable_stub() { return _is_vtable_stub; } |
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86 bool is_abstract_method_error(address epc) { return epc == code_begin()+_ame_offset; } |
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87 bool is_null_pointer_exception(address epc) { return epc == code_begin()+_npe_offset; } |
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88 |
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89 void print(); |
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90 }; |
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91 |
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92 |
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93 // VtableStubs creates the code stubs for compiled calls through vtables. |
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94 // There is one stub per (vtable index, args_size) pair, and the stubs are |
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95 // never deallocated. They don't need to be GCed because they contain no oops. |
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96 |
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97 class VtableStubs : AllStatic { |
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98 public: // N must be public (some compilers need this for _table) |
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99 enum { |
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100 N = 256, // size of stub table; must be power of two |
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101 mask = N - 1 |
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102 }; |
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103 |
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104 private: |
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105 static VtableStub* _table[N]; // table of existing stubs |
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106 static int _number_of_vtable_stubs; // number of stubs created so far (for statistics) |
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107 |
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108 static VtableStub* create_vtable_stub(int vtable_index); |
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109 static VtableStub* create_itable_stub(int vtable_index); |
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110 static VtableStub* lookup (bool is_vtable_stub, int vtable_index); |
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111 static void enter (bool is_vtable_stub, int vtable_index, VtableStub* s); |
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112 static inline uint hash (bool is_vtable_stub, int vtable_index); |
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113 |
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114 public: |
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115 static address create_stub(bool is_vtable_stub, int vtable_index, methodOop method); // return the entry point of a stub for this call |
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116 static bool is_entry_point(address pc); // is pc a vtable stub entry point? |
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117 static bool contains(address pc); // is pc within any stub? |
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118 static VtableStub* stub_containing(address pc); // stub containing pc or NULL |
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119 static int number_of_vtable_stubs() { return _number_of_vtable_stubs; } |
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120 static void initialize(); |
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121 }; |