1 /* 2 * Copyright (c) 1997, 2014, 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 "precompiled.hpp" 26 #include "code/vtableStubs.hpp" 27 #include "compiler/compileBroker.hpp" 28 #include "compiler/disassembler.hpp" 29 #include "memory/allocation.inline.hpp" 30 #include "memory/resourceArea.hpp" 31 #include "oops/instanceKlass.hpp" 32 #include "oops/klassVtable.hpp" 33 #include "oops/oop.inline.hpp" 34 #include "prims/forte.hpp" 35 #include "prims/jvmtiExport.hpp" 36 #include "runtime/handles.inline.hpp" 37 #include "runtime/mutexLocker.hpp" 38 #include "runtime/sharedRuntime.hpp" 39 #ifdef COMPILER2 40 #include "opto/matcher.hpp" 41 #endif 42 43 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 44 45 // ----------------------------------------------------------------------------------------- 46 // Implementation of VtableStub 47 48 address VtableStub::_chunk = NULL; 49 address VtableStub::_chunk_end = NULL; 50 VMReg VtableStub::_receiver_location = VMRegImpl::Bad(); 51 52 53 void* VtableStub::operator new(size_t size, int code_size) throw() { 54 assert(size == sizeof(VtableStub), "mismatched size"); 55 // compute real VtableStub size (rounded to nearest word) 56 const int real_size = round_to(code_size + sizeof(VtableStub), wordSize); 57 // malloc them in chunks to minimize header overhead 58 const int chunk_factor = 32; 59 if (_chunk == NULL || _chunk + real_size > _chunk_end) { 60 const int bytes = chunk_factor * real_size + pd_code_alignment(); 61 62 // There is a dependency on the name of the blob in src/share/vm/prims/jvmtiCodeBlobEvents.cpp 63 // If changing the name, update the other file accordingly. 64 BufferBlob* blob = BufferBlob::create("vtable chunks", bytes); 65 if (blob == NULL) { 66 return NULL; 67 } 68 _chunk = blob->content_begin(); 69 _chunk_end = _chunk + bytes; 70 Forte::register_stub("vtable stub", _chunk, _chunk_end); 71 align_chunk(); 72 } 73 assert(_chunk + real_size <= _chunk_end, "bad allocation"); 74 void* res = _chunk; 75 _chunk += real_size; 76 align_chunk(); 77 return res; 78 } 79 80 81 void VtableStub::print_on(outputStream* st) const { 82 st->print("vtable stub (index = %d, receiver_location = %d, code = [" INTPTR_FORMAT ", " INTPTR_FORMAT "[)", 83 index(), receiver_location(), code_begin(), code_end()); 84 } 85 86 87 // ----------------------------------------------------------------------------------------- 88 // Implementation of VtableStubs 89 // 90 // For each hash value there's a linked list of vtable stubs (with that 91 // hash value). Each list is anchored in a little hash _table, indexed 92 // by that hash value. 93 94 VtableStub* VtableStubs::_table[VtableStubs::N]; 95 int VtableStubs::_number_of_vtable_stubs = 0; 96 97 98 void VtableStubs::initialize() { 99 VtableStub::_receiver_location = SharedRuntime::name_for_receiver(); 100 { 101 MutexLocker ml(VtableStubs_lock); 102 assert(_number_of_vtable_stubs == 0, "potential performance bug: VtableStubs initialized more than once"); 103 assert(is_power_of_2(N), "N must be a power of 2"); 104 for (int i = 0; i < N; i++) { 105 _table[i] = NULL; 106 } 107 } 108 } 109 110 111 address VtableStubs::find_stub(bool is_vtable_stub, int vtable_index) { 112 assert(vtable_index >= 0, "must be positive"); 113 114 VtableStub* s = ShareVtableStubs ? lookup(is_vtable_stub, vtable_index) : NULL; 115 if (s == NULL) { 116 if (is_vtable_stub) { 117 s = create_vtable_stub(vtable_index); 118 } else { 119 s = create_itable_stub(vtable_index); 120 } 121 122 // Creation of vtable or itable can fail if there is not enough free space in the code cache. 123 if (s == NULL) { 124 return NULL; 125 } 126 127 enter(is_vtable_stub, vtable_index, s); 128 if (PrintAdapterHandlers) { 129 tty->print_cr("Decoding VtableStub %s[%d]@%d", 130 is_vtable_stub? "vtbl": "itbl", vtable_index, VtableStub::receiver_location()); 131 Disassembler::decode(s->code_begin(), s->code_end()); 132 } 133 // Notify JVMTI about this stub. The event will be recorded by the enclosing 134 // JvmtiDynamicCodeEventCollector and posted when this thread has released 135 // all locks. 136 if (JvmtiExport::should_post_dynamic_code_generated()) { 137 JvmtiExport::post_dynamic_code_generated_while_holding_locks(is_vtable_stub? "vtable stub": "itable stub", 138 s->code_begin(), s->code_end()); 139 } 140 } 141 return s->entry_point(); 142 } 143 144 145 inline uint VtableStubs::hash(bool is_vtable_stub, int vtable_index){ 146 // Assumption: receiver_location < 4 in most cases. 147 int hash = ((vtable_index << 2) ^ VtableStub::receiver_location()->value()) + vtable_index; 148 return (is_vtable_stub ? ~hash : hash) & mask; 149 } 150 151 152 VtableStub* VtableStubs::lookup(bool is_vtable_stub, int vtable_index) { 153 MutexLocker ml(VtableStubs_lock); 154 unsigned hash = VtableStubs::hash(is_vtable_stub, vtable_index); 155 VtableStub* s = _table[hash]; 156 while( s && !s->matches(is_vtable_stub, vtable_index)) s = s->next(); 157 return s; 158 } 159 160 161 void VtableStubs::enter(bool is_vtable_stub, int vtable_index, VtableStub* s) { 162 MutexLocker ml(VtableStubs_lock); 163 assert(s->matches(is_vtable_stub, vtable_index), "bad vtable stub"); 164 unsigned int h = VtableStubs::hash(is_vtable_stub, vtable_index); 165 // enter s at the beginning of the corresponding list 166 s->set_next(_table[h]); 167 _table[h] = s; 168 _number_of_vtable_stubs++; 169 } 170 171 172 bool VtableStubs::is_entry_point(address pc) { 173 MutexLocker ml(VtableStubs_lock); 174 VtableStub* stub = (VtableStub*)(pc - VtableStub::entry_offset()); 175 uint hash = VtableStubs::hash(stub->is_vtable_stub(), stub->index()); 176 VtableStub* s; 177 for (s = _table[hash]; s != NULL && s != stub; s = s->next()) {} 178 return s == stub; 179 } 180 181 182 bool VtableStubs::contains(address pc) { 183 // simple solution for now - we may want to use 184 // a faster way if this function is called often 185 return stub_containing(pc) != NULL; 186 } 187 188 189 VtableStub* VtableStubs::stub_containing(address pc) { 190 // Note: No locking needed since any change to the data structure 191 // happens with an atomic store into it (we don't care about 192 // consistency with the _number_of_vtable_stubs counter). 193 for (int i = 0; i < N; i++) { 194 for (VtableStub* s = _table[i]; s != NULL; s = s->next()) { 195 if (s->contains(pc)) return s; 196 } 197 } 198 return NULL; 199 } 200 201 void vtableStubs_init() { 202 VtableStubs::initialize(); 203 } 204 205 void VtableStubs::vtable_stub_do(void f(VtableStub*)) { 206 for (int i = 0; i < N; i++) { 207 for (VtableStub* s = _table[i]; s != NULL; s = s->next()) { 208 f(s); 209 } 210 } 211 } 212 213 214 //----------------------------------------------------------------------------------------------------- 215 // Non-product code 216 #ifndef PRODUCT 217 218 extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index) { 219 ResourceMark rm; 220 HandleMark hm; 221 Klass* klass = receiver->klass(); 222 InstanceKlass* ik = InstanceKlass::cast(klass); 223 klassVtable* vt = ik->vtable(); 224 ik->print(); 225 fatal(err_msg("bad compiled vtable dispatch: receiver " INTPTR_FORMAT ", " 226 "index %d (vtable length %d)", 227 (address)receiver, index, vt->length())); 228 } 229 230 #endif // Product