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