1 /*
2 * Copyright (c) 1997, 2013, 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/disassembler.hpp"
28 #include "memory/allocation.inline.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "oops/instanceKlass.hpp"
31 #include "oops/klassVtable.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "prims/forte.hpp"
34 #include "prims/jvmtiExport.hpp"
35 #include "runtime/handles.inline.hpp"
36 #include "runtime/mutexLocker.hpp"
37 #include "runtime/sharedRuntime.hpp"
38 #ifdef COMPILER2
39 #include "opto/matcher.hpp"
40 #endif
41
42 // -----------------------------------------------------------------------------------------
43 // Implementation of VtableStub
44
45 address VtableStub::_chunk = NULL;
46 address VtableStub::_chunk_end = NULL;
47 VMReg VtableStub::_receiver_location = VMRegImpl::Bad();
48
49
50 void* VtableStub::operator new(size_t size, int code_size) throw() {
51 assert(size == sizeof(VtableStub), "mismatched size");
52 // compute real VtableStub size (rounded to nearest word)
53 const int real_size = round_to(code_size + sizeof(VtableStub), wordSize);
54 // malloc them in chunks to minimize header overhead
55 const int chunk_factor = 32;
56 if (_chunk == NULL || _chunk + real_size > _chunk_end) {
57 const int bytes = chunk_factor * real_size + pd_code_alignment();
58 BufferBlob* blob = BufferBlob::create("vtable chunks", bytes);
59 if (blob == NULL) {
60 return NULL;
61 }
62 _chunk = blob->content_begin();
63 _chunk_end = _chunk + bytes;
64 Forte::register_stub("vtable stub", _chunk, _chunk_end);
65 align_chunk();
66 }
67 assert(_chunk + real_size <= _chunk_end, "bad allocation");
68 void* res = _chunk;
69 _chunk += real_size;
70 align_chunk();
71 return res;
72 }
73
74
75 void VtableStub::print_on(outputStream* st) const {
76 st->print("vtable stub (index = %d, receiver_location = %d, code = [" INTPTR_FORMAT ", " INTPTR_FORMAT "[)",
77 index(), receiver_location(), code_begin(), code_end());
78 }
79
80
81 // -----------------------------------------------------------------------------------------
82 // Implementation of VtableStubs
83 //
84 // For each hash value there's a linked list of vtable stubs (with that
85 // hash value). Each list is anchored in a little hash _table, indexed
86 // by that hash value.
87
88 VtableStub* VtableStubs::_table[VtableStubs::N];
89 int VtableStubs::_number_of_vtable_stubs = 0;
90
91
92 void VtableStubs::initialize() {
93 VtableStub::_receiver_location = SharedRuntime::name_for_receiver();
94 {
95 MutexLocker ml(VtableStubs_lock);
96 assert(_number_of_vtable_stubs == 0, "potential performance bug: VtableStubs initialized more than once");
97 assert(is_power_of_2(N), "N must be a power of 2");
98 for (int i = 0; i < N; i++) {
99 _table[i] = NULL;
100 }
101 }
102 }
103
104
105 address VtableStubs::find_stub(bool is_vtable_stub, int vtable_index) {
106 assert(vtable_index >= 0, "must be positive");
107
108 VtableStub* s = ShareVtableStubs ? lookup(is_vtable_stub, vtable_index) : NULL;
109 if (s == NULL) {
110 if (is_vtable_stub) {
111 s = create_vtable_stub(vtable_index);
112 } else {
113 s = create_itable_stub(vtable_index);
114 }
115
116 // Creation of vtable or itable can fail if there is not enough free space in the code cache.
117 if (s == NULL) {
118 return NULL;
119 }
120
121 enter(is_vtable_stub, vtable_index, s);
122 if (PrintAdapterHandlers) {
123 tty->print_cr("Decoding VtableStub %s[%d]@%d",
124 is_vtable_stub? "vtbl": "itbl", vtable_index, VtableStub::receiver_location());
125 Disassembler::decode(s->code_begin(), s->code_end());
126 }
127 // Notify JVMTI about this stub. The event will be recorded by the enclosing
128 // JvmtiDynamicCodeEventCollector and posted when this thread has released
129 // all locks.
130 if (JvmtiExport::should_post_dynamic_code_generated()) {
131 JvmtiExport::post_dynamic_code_generated_while_holding_locks(is_vtable_stub? "vtable stub": "itable stub",
132 s->code_begin(), s->code_end());
133 }
134 }
135 return s->entry_point();
136 }
137
138
139 inline uint VtableStubs::hash(bool is_vtable_stub, int vtable_index){
140 // Assumption: receiver_location < 4 in most cases.
141 int hash = ((vtable_index << 2) ^ VtableStub::receiver_location()->value()) + vtable_index;
142 return (is_vtable_stub ? ~hash : hash) & mask;
143 }
144
145
146 VtableStub* VtableStubs::lookup(bool is_vtable_stub, int vtable_index) {
147 MutexLocker ml(VtableStubs_lock);
148 unsigned hash = VtableStubs::hash(is_vtable_stub, vtable_index);
149 VtableStub* s = _table[hash];
150 while( s && !s->matches(is_vtable_stub, vtable_index)) s = s->next();
151 return s;
152 }
153
154
155 void VtableStubs::enter(bool is_vtable_stub, int vtable_index, VtableStub* s) {
156 MutexLocker ml(VtableStubs_lock);
157 assert(s->matches(is_vtable_stub, vtable_index), "bad vtable stub");
158 unsigned int h = VtableStubs::hash(is_vtable_stub, vtable_index);
159 // enter s at the beginning of the corresponding list
160 s->set_next(_table[h]);
161 _table[h] = s;
162 _number_of_vtable_stubs++;
163 }
164
165
166 bool VtableStubs::is_entry_point(address pc) {
167 MutexLocker ml(VtableStubs_lock);
168 VtableStub* stub = (VtableStub*)(pc - VtableStub::entry_offset());
169 uint hash = VtableStubs::hash(stub->is_vtable_stub(), stub->index());
170 VtableStub* s;
171 for (s = _table[hash]; s != NULL && s != stub; s = s->next()) {}
172 return s == stub;
173 }
174
175
176 bool VtableStubs::contains(address pc) {
177 // simple solution for now - we may want to use
178 // a faster way if this function is called often
179 return stub_containing(pc) != NULL;
180 }
181
182
183 VtableStub* VtableStubs::stub_containing(address pc) {
184 // Note: No locking needed since any change to the data structure
185 // happens with an atomic store into it (we don't care about
186 // consistency with the _number_of_vtable_stubs counter).
187 for (int i = 0; i < N; i++) {
188 for (VtableStub* s = _table[i]; s != NULL; s = s->next()) {
189 if (s->contains(pc)) return s;
190 }
191 }
192 return NULL;
193 }
194
195 void vtableStubs_init() {
196 VtableStubs::initialize();
197 }
198
199 void VtableStubs::vtable_stub_do(void f(VtableStub*)) {
200 for (int i = 0; i < N; i++) {
201 for (VtableStub* s = _table[i]; s != NULL; s = s->next()) {
202 f(s);
203 }
204 }
205 }
206
207
208 //-----------------------------------------------------------------------------------------------------
209 // Non-product code
210 #ifndef PRODUCT
211
212 extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index) {
213 ResourceMark rm;
214 HandleMark hm;
215 Klass* klass = receiver->klass();
216 InstanceKlass* ik = InstanceKlass::cast(klass);
217 klassVtable* vt = ik->vtable();
218 ik->print();
219 fatal(err_msg("bad compiled vtable dispatch: receiver " INTPTR_FORMAT ", "
220 "index %d (vtable length %d)",
221 (address)receiver, index, vt->length()));
222 }
223
224 #endif // Product