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 CompileBroker::handle_full_code_cache(CodeBlobType::NonMethod);
67 return NULL;
68 }
69 _chunk = blob->content_begin();
70 _chunk_end = _chunk + bytes;
71 Forte::register_stub("vtable stub", _chunk, _chunk_end);
72 align_chunk();
73 }
74 assert(_chunk + real_size <= _chunk_end, "bad allocation");
75 void* res = _chunk;
76 _chunk += real_size;
77 align_chunk();
78 return res;
79 }
80
81
82 void VtableStub::print_on(outputStream* st) const {
83 st->print("vtable stub (index = %d, receiver_location = %d, code = [" INTPTR_FORMAT ", " INTPTR_FORMAT "[)",
84 index(), receiver_location(), code_begin(), code_end());
85 }
86
87
88 // -----------------------------------------------------------------------------------------
89 // Implementation of VtableStubs
90 //
91 // For each hash value there's a linked list of vtable stubs (with that
92 // hash value). Each list is anchored in a little hash _table, indexed
93 // by that hash value.
94
95 VtableStub* VtableStubs::_table[VtableStubs::N];
96 int VtableStubs::_number_of_vtable_stubs = 0;
97
98
99 void VtableStubs::initialize() {
100 VtableStub::_receiver_location = SharedRuntime::name_for_receiver();
101 {
102 MutexLocker ml(VtableStubs_lock);
103 assert(_number_of_vtable_stubs == 0, "potential performance bug: VtableStubs initialized more than once");
104 assert(is_power_of_2(N), "N must be a power of 2");
105 for (int i = 0; i < N; i++) {
106 _table[i] = NULL;
107 }
108 }
109 }
110
111
112 address VtableStubs::find_stub(bool is_vtable_stub, int vtable_index) {
113 assert(vtable_index >= 0, "must be positive");
114
115 VtableStub* s = ShareVtableStubs ? lookup(is_vtable_stub, vtable_index) : NULL;
116 if (s == NULL) {
117 if (is_vtable_stub) {
118 s = create_vtable_stub(vtable_index);
119 } else {
120 s = create_itable_stub(vtable_index);
121 }
122
123 // Creation of vtable or itable can fail if there is not enough free space in the code cache.
124 if (s == NULL) {
125 return NULL;
126 }
127
128 enter(is_vtable_stub, vtable_index, s);
129 if (PrintAdapterHandlers) {
130 tty->print_cr("Decoding VtableStub %s[%d]@%d",
131 is_vtable_stub? "vtbl": "itbl", vtable_index, VtableStub::receiver_location());
132 Disassembler::decode(s->code_begin(), s->code_end());
133 }
134 // Notify JVMTI about this stub. The event will be recorded by the enclosing
135 // JvmtiDynamicCodeEventCollector and posted when this thread has released
136 // all locks.
137 if (JvmtiExport::should_post_dynamic_code_generated()) {
138 JvmtiExport::post_dynamic_code_generated_while_holding_locks(is_vtable_stub? "vtable stub": "itable stub",
139 s->code_begin(), s->code_end());
140 }
141 }
142 return s->entry_point();
143 }
144
145
146 inline uint VtableStubs::hash(bool is_vtable_stub, int vtable_index){
147 // Assumption: receiver_location < 4 in most cases.
148 int hash = ((vtable_index << 2) ^ VtableStub::receiver_location()->value()) + vtable_index;
149 return (is_vtable_stub ? ~hash : hash) & mask;
150 }
151
152
153 VtableStub* VtableStubs::lookup(bool is_vtable_stub, int vtable_index) {
154 MutexLocker ml(VtableStubs_lock);
155 unsigned hash = VtableStubs::hash(is_vtable_stub, vtable_index);
156 VtableStub* s = _table[hash];
157 while( s && !s->matches(is_vtable_stub, vtable_index)) s = s->next();
158 return s;
159 }
160
161
162 void VtableStubs::enter(bool is_vtable_stub, int vtable_index, VtableStub* s) {
163 MutexLocker ml(VtableStubs_lock);
164 assert(s->matches(is_vtable_stub, vtable_index), "bad vtable stub");
165 unsigned int h = VtableStubs::hash(is_vtable_stub, vtable_index);
166 // enter s at the beginning of the corresponding list
167 s->set_next(_table[h]);
168 _table[h] = s;
169 _number_of_vtable_stubs++;
170 }
171
172
173 bool VtableStubs::is_entry_point(address pc) {
174 MutexLocker ml(VtableStubs_lock);
175 VtableStub* stub = (VtableStub*)(pc - VtableStub::entry_offset());
176 uint hash = VtableStubs::hash(stub->is_vtable_stub(), stub->index());
177 VtableStub* s;
178 for (s = _table[hash]; s != NULL && s != stub; s = s->next()) {}
179 return s == stub;
180 }
181
182
183 bool VtableStubs::contains(address pc) {
184 // simple solution for now - we may want to use
185 // a faster way if this function is called often
186 return stub_containing(pc) != NULL;
187 }
188
189
190 VtableStub* VtableStubs::stub_containing(address pc) {
191 // Note: No locking needed since any change to the data structure
192 // happens with an atomic store into it (we don't care about
193 // consistency with the _number_of_vtable_stubs counter).
194 for (int i = 0; i < N; i++) {
195 for (VtableStub* s = _table[i]; s != NULL; s = s->next()) {
196 if (s->contains(pc)) return s;
197 }
198 }
199 return NULL;
200 }
201
202 void vtableStubs_init() {
203 VtableStubs::initialize();
204 }
205
206 void VtableStubs::vtable_stub_do(void f(VtableStub*)) {
207 for (int i = 0; i < N; i++) {
208 for (VtableStub* s = _table[i]; s != NULL; s = s->next()) {
209 f(s);
210 }
211 }
212 }
213
214
215 //-----------------------------------------------------------------------------------------------------
216 // Non-product code
217 #ifndef PRODUCT
218
219 extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index) {
220 ResourceMark rm;
221 HandleMark hm;
222 Klass* klass = receiver->klass();
223 InstanceKlass* ik = InstanceKlass::cast(klass);
224 klassVtable* vt = ik->vtable();
225 ik->print();
226 fatal(err_msg("bad compiled vtable dispatch: receiver " INTPTR_FORMAT ", "
227 "index %d (vtable length %d)",
228 (address)receiver, index, vt->length()));
229 }
230
231 #endif // Product