1 /*
2 * Copyright (c) 1997, 2017, 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 // -----------------------------------------------------------------------------------------
44 // Implementation of VtableStub
45
46 address VtableStub::_chunk = NULL;
47 address VtableStub::_chunk_end = NULL;
48 VMReg VtableStub::_receiver_location = VMRegImpl::Bad();
49
50
51 void* VtableStub::operator new(size_t size, int code_size) throw() {
52 assert(size == sizeof(VtableStub), "mismatched size");
53 // compute real VtableStub size (rounded to nearest word)
54 const int real_size = align_up(code_size + (int)sizeof(VtableStub), wordSize);
55 // malloc them in chunks to minimize header overhead
56 const int chunk_factor = 32;
57 if (_chunk == NULL || _chunk + real_size > _chunk_end) {
58 const int bytes = chunk_factor * real_size + pd_code_alignment();
59
60 // There is a dependency on the name of the blob in src/share/vm/prims/jvmtiCodeBlobEvents.cpp
61 // If changing the name, update the other file accordingly.
62 BufferBlob* blob = BufferBlob::create("vtable chunks", bytes);
63 if (blob == NULL) {
64 return NULL;
65 }
66 _chunk = blob->content_begin();
67 _chunk_end = _chunk + bytes;
68 Forte::register_stub("vtable stub", _chunk, _chunk_end);
69 align_chunk();
70 }
71 assert(_chunk + real_size <= _chunk_end, "bad allocation");
72 void* res = _chunk;
73 _chunk += real_size;
74 align_chunk();
75 return res;
76 }
77
78
79 void VtableStub::print_on(outputStream* st) const {
80 st->print("vtable stub (index = %d, receiver_location = " INTX_FORMAT ", code = [" INTPTR_FORMAT ", " INTPTR_FORMAT "[)",
81 index(), p2i(receiver_location()), p2i(code_begin()), p2i(code_end()));
82 }
83
84
85 // -----------------------------------------------------------------------------------------
86 // Implementation of VtableStubs
87 //
88 // For each hash value there's a linked list of vtable stubs (with that
89 // hash value). Each list is anchored in a little hash _table, indexed
90 // by that hash value.
91
92 VtableStub* VtableStubs::_table[VtableStubs::N];
93 int VtableStubs::_number_of_vtable_stubs = 0;
94
95
96 void VtableStubs::initialize() {
97 VtableStub::_receiver_location = SharedRuntime::name_for_receiver();
98 {
99 MutexLocker ml(VtableStubs_lock);
100 assert(_number_of_vtable_stubs == 0, "potential performance bug: VtableStubs initialized more than once");
101 assert(is_power_of_2(N), "N must be a power of 2");
102 for (int i = 0; i < N; i++) {
103 _table[i] = NULL;
104 }
105 }
106 }
107
108
109 address VtableStubs::find_stub(bool is_vtable_stub, int vtable_index) {
110 assert(vtable_index >= 0, "must be positive");
111
112 VtableStub* s = ShareVtableStubs ? lookup(is_vtable_stub, vtable_index) : NULL;
113 if (s == NULL) {
114 if (is_vtable_stub) {
115 s = create_vtable_stub(vtable_index);
116 } else {
117 s = create_itable_stub(vtable_index);
118 }
119
120 // Creation of vtable or itable can fail if there is not enough free space in the code cache.
121 if (s == NULL) {
122 return NULL;
123 }
124
125 enter(is_vtable_stub, vtable_index, s);
126 if (PrintAdapterHandlers) {
127 tty->print_cr("Decoding VtableStub %s[%d]@" INTX_FORMAT,
128 is_vtable_stub? "vtbl": "itbl", vtable_index, p2i(VtableStub::receiver_location()));
129 Disassembler::decode(s->code_begin(), s->code_end());
130 }
131 // Notify JVMTI about this stub. The event will be recorded by the enclosing
132 // JvmtiDynamicCodeEventCollector and posted when this thread has released
133 // all locks.
134 if (JvmtiExport::should_post_dynamic_code_generated()) {
135 JvmtiExport::post_dynamic_code_generated_while_holding_locks(is_vtable_stub? "vtable stub": "itable stub",
136 s->code_begin(), s->code_end());
137 }
138 }
139 return s->entry_point();
140 }
141
142
143 inline uint VtableStubs::hash(bool is_vtable_stub, int vtable_index){
144 // Assumption: receiver_location < 4 in most cases.
145 int hash = ((vtable_index << 2) ^ VtableStub::receiver_location()->value()) + vtable_index;
146 return (is_vtable_stub ? ~hash : hash) & mask;
147 }
148
149
150 VtableStub* VtableStubs::lookup(bool is_vtable_stub, int vtable_index) {
151 MutexLocker ml(VtableStubs_lock);
152 unsigned hash = VtableStubs::hash(is_vtable_stub, vtable_index);
153 VtableStub* s = _table[hash];
154 while( s && !s->matches(is_vtable_stub, vtable_index)) s = s->next();
155 return s;
156 }
157
158
159 void VtableStubs::enter(bool is_vtable_stub, int vtable_index, VtableStub* s) {
160 MutexLocker ml(VtableStubs_lock);
161 assert(s->matches(is_vtable_stub, vtable_index), "bad vtable stub");
162 unsigned int h = VtableStubs::hash(is_vtable_stub, vtable_index);
163 // enter s at the beginning of the corresponding list
164 s->set_next(_table[h]);
165 _table[h] = s;
166 _number_of_vtable_stubs++;
167 }
168
169
170 bool VtableStubs::is_entry_point(address pc) {
171 MutexLocker ml(VtableStubs_lock);
172 VtableStub* stub = (VtableStub*)(pc - VtableStub::entry_offset());
173 uint hash = VtableStubs::hash(stub->is_vtable_stub(), stub->index());
174 VtableStub* s;
175 for (s = _table[hash]; s != NULL && s != stub; s = s->next()) {}
176 return s == stub;
177 }
178
179
180 bool VtableStubs::contains(address pc) {
181 // simple solution for now - we may want to use
182 // a faster way if this function is called often
183 return stub_containing(pc) != NULL;
184 }
185
186
187 VtableStub* VtableStubs::stub_containing(address pc) {
188 // Note: No locking needed since any change to the data structure
189 // happens with an atomic store into it (we don't care about
190 // consistency with the _number_of_vtable_stubs counter).
191 for (int i = 0; i < N; i++) {
192 for (VtableStub* s = _table[i]; s != NULL; s = s->next()) {
193 if (s->contains(pc)) return s;
194 }
195 }
196 return NULL;
197 }
198
199 void vtableStubs_init() {
200 VtableStubs::initialize();
201 }
202
203 void VtableStubs::vtable_stub_do(void f(VtableStub*)) {
204 for (int i = 0; i < N; i++) {
205 for (VtableStub* s = _table[i]; s != NULL; s = s->next()) {
206 f(s);
207 }
208 }
209 }
210
211
212 //-----------------------------------------------------------------------------------------------------
213 // Non-product code
214 #ifndef PRODUCT
215
216 extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index) {
217 ResourceMark rm;
218 HandleMark hm;
219 Klass* klass = receiver->klass();
220 InstanceKlass* ik = InstanceKlass::cast(klass);
221 klassVtable vt = ik->vtable();
222 ik->print();
223 fatal("bad compiled vtable dispatch: receiver " INTPTR_FORMAT ", "
224 "index %d (vtable length %d)",
225 p2i(receiver), index, vt.length());
226 }
227
228 #endif // PRODUCT