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