1 /* 2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "incls/_precompiled.incl" 26 #include "incls/_vtableStubs.cpp.incl" 27 28 // ----------------------------------------------------------------------------------------- 29 // Implementation of VtableStub 30 31 address VtableStub::_chunk = NULL; 32 address VtableStub::_chunk_end = NULL; 33 VMReg VtableStub::_receiver_location = VMRegImpl::Bad(); 34 35 static int num_vtable_chunks = 0; 36 37 38 void* VtableStub::operator new(size_t size, int code_size) { 39 assert(size == sizeof(VtableStub), "mismatched size"); 40 num_vtable_chunks++; 41 // compute real VtableStub size (rounded to nearest word) 42 const int real_size = round_to(code_size + sizeof(VtableStub), wordSize); 43 // malloc them in chunks to minimize header overhead 44 const int chunk_factor = 32; 45 if (_chunk == NULL || _chunk + real_size > _chunk_end) { 46 const int bytes = chunk_factor * real_size + pd_code_alignment(); 47 BufferBlob* blob = BufferBlob::create("vtable chunks", bytes); 48 if (blob == NULL) { 49 vm_exit_out_of_memory(bytes, "CodeCache: no room for vtable chunks"); 50 } 51 _chunk = blob->content_begin(); 52 _chunk_end = _chunk + bytes; 53 Forte::register_stub("vtable stub", _chunk, _chunk_end); 54 // Notify JVMTI about this stub. The event will be recorded by the enclosing 55 // JvmtiDynamicCodeEventCollector and posted when this thread has released 56 // all locks. 57 if (JvmtiExport::should_post_dynamic_code_generated()) { 58 JvmtiExport::post_dynamic_code_generated_while_holding_locks("vtable stub", _chunk, _chunk_end); 59 } 60 align_chunk(); 61 } 62 assert(_chunk + real_size <= _chunk_end, "bad allocation"); 63 void* res = _chunk; 64 _chunk += real_size; 65 align_chunk(); 66 return res; 67 } 68 69 70 void VtableStub::print_on(outputStream* st) const { 71 st->print("vtable stub (index = %d, receiver_location = %d, code = [" INTPTR_FORMAT ", " INTPTR_FORMAT "[)", 72 index(), receiver_location(), code_begin(), code_end()); 73 } 74 75 76 // ----------------------------------------------------------------------------------------- 77 // Implementation of VtableStubs 78 // 79 // For each hash value there's a linked list of vtable stubs (with that 80 // hash value). Each list is anchored in a little hash _table, indexed 81 // by that hash value. 82 83 VtableStub* VtableStubs::_table[VtableStubs::N]; 84 int VtableStubs::_number_of_vtable_stubs = 0; 85 86 87 void VtableStubs::initialize() { 88 VtableStub::_receiver_location = SharedRuntime::name_for_receiver(); 89 { 90 MutexLocker ml(VtableStubs_lock); 91 assert(_number_of_vtable_stubs == 0, "potential performance bug: VtableStubs initialized more than once"); 92 assert(is_power_of_2(N), "N must be a power of 2"); 93 for (int i = 0; i < N; i++) { 94 _table[i] = NULL; 95 } 96 } 97 } 98 99 100 address VtableStubs::create_stub(bool is_vtable_stub, int vtable_index, methodOop method) { 101 assert(vtable_index >= 0, "must be positive"); 102 103 VtableStub* s = ShareVtableStubs ? lookup(is_vtable_stub, vtable_index) : NULL; 104 if (s == NULL) { 105 if (is_vtable_stub) { 106 s = create_vtable_stub(vtable_index); 107 } else { 108 s = create_itable_stub(vtable_index); 109 } 110 enter(is_vtable_stub, vtable_index, s); 111 if (PrintAdapterHandlers) { 112 tty->print_cr("Decoding VtableStub %s[%d]@%d", 113 is_vtable_stub? "vtbl": "itbl", vtable_index, VtableStub::receiver_location()); 114 Disassembler::decode(s->code_begin(), s->code_end()); 115 } 116 } 117 return s->entry_point(); 118 } 119 120 121 inline uint VtableStubs::hash(bool is_vtable_stub, int vtable_index){ 122 // Assumption: receiver_location < 4 in most cases. 123 int hash = ((vtable_index << 2) ^ VtableStub::receiver_location()->value()) + vtable_index; 124 return (is_vtable_stub ? ~hash : hash) & mask; 125 } 126 127 128 VtableStub* VtableStubs::lookup(bool is_vtable_stub, int vtable_index) { 129 MutexLocker ml(VtableStubs_lock); 130 unsigned hash = VtableStubs::hash(is_vtable_stub, vtable_index); 131 VtableStub* s = _table[hash]; 132 while( s && !s->matches(is_vtable_stub, vtable_index)) s = s->next(); 133 return s; 134 } 135 136 137 void VtableStubs::enter(bool is_vtable_stub, int vtable_index, VtableStub* s) { 138 MutexLocker ml(VtableStubs_lock); 139 assert(s->matches(is_vtable_stub, vtable_index), "bad vtable stub"); 140 unsigned int h = VtableStubs::hash(is_vtable_stub, vtable_index); 141 // enter s at the beginning of the corresponding list 142 s->set_next(_table[h]); 143 _table[h] = s; 144 _number_of_vtable_stubs++; 145 } 146 147 148 bool VtableStubs::is_entry_point(address pc) { 149 MutexLocker ml(VtableStubs_lock); 150 VtableStub* stub = (VtableStub*)(pc - VtableStub::entry_offset()); 151 uint hash = VtableStubs::hash(stub->is_vtable_stub(), stub->index()); 152 VtableStub* s; 153 for (s = _table[hash]; s != NULL && s != stub; s = s->next()) {} 154 return s == stub; 155 } 156 157 158 bool VtableStubs::contains(address pc) { 159 // simple solution for now - we may want to use 160 // a faster way if this function is called often 161 return stub_containing(pc) != NULL; 162 } 163 164 165 VtableStub* VtableStubs::stub_containing(address pc) { 166 // Note: No locking needed since any change to the data structure 167 // happens with an atomic store into it (we don't care about 168 // consistency with the _number_of_vtable_stubs counter). 169 for (int i = 0; i < N; i++) { 170 for (VtableStub* s = _table[i]; s != NULL; s = s->next()) { 171 if (s->contains(pc)) return s; 172 } 173 } 174 return NULL; 175 } 176 177 void vtableStubs_init() { 178 VtableStubs::initialize(); 179 } 180 181 182 //----------------------------------------------------------------------------------------------------- 183 // Non-product code 184 #ifndef PRODUCT 185 186 extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index) { 187 ResourceMark rm; 188 HandleMark hm; 189 klassOop klass = receiver->klass(); 190 instanceKlass* ik = instanceKlass::cast(klass); 191 klassVtable* vt = ik->vtable(); 192 klass->print(); 193 fatal(err_msg("bad compiled vtable dispatch: receiver " INTPTR_FORMAT ", " 194 "index %d (vtable length %d)", 195 (address)receiver, index, vt->length())); 196 } 197 198 #endif // Product