1 /*
2 * Copyright (c) 1997, 2006, 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/_icBuffer.cpp.incl"
27
28
29 DEF_STUB_INTERFACE(ICStub);
30
31 StubQueue* InlineCacheBuffer::_buffer = NULL;
32 ICStub* InlineCacheBuffer::_next_stub = NULL;
33
34
35 void ICStub::finalize() {
36 if (!is_empty()) {
37 ResourceMark rm;
38 CompiledIC *ic = CompiledIC_at(ic_site());
39 assert(CodeCache::find_nmethod(ic->instruction_address()) != NULL, "inline cache in non-nmethod?");
40
41 assert(this == ICStub_from_destination_address(ic->stub_address()), "wrong owner of ic buffer");
42 ic->set_cached_oop(cached_oop());
43 ic->set_ic_destination(destination());
44 }
45 }
46
47
48 address ICStub::destination() const {
49 return InlineCacheBuffer::ic_buffer_entry_point(code_begin());
50 }
51
52 oop ICStub::cached_oop() const {
53 return InlineCacheBuffer::ic_buffer_cached_oop(code_begin());
54 }
55
56
57 void ICStub::set_stub(CompiledIC *ic, oop cached_value, address dest_addr) {
58 // We cannot store a pointer to the 'ic' object, since it is resource allocated. Instead we
59 // store the location of the inline cache. Then we have enough information recreate the CompiledIC
60 // object when we need to remove the stub.
61 _ic_site = ic->instruction_address();
62
63 // Assemble new stub
64 InlineCacheBuffer::assemble_ic_buffer_code(code_begin(), cached_value, dest_addr);
65 assert(destination() == dest_addr, "can recover destination");
66 assert(cached_oop() == cached_value, "can recover destination");
67 }
68
69
70 void ICStub::clear() {
71 _ic_site = NULL;
72 }
73
74
75 #ifndef PRODUCT
76 // anybody calling to this stub will trap
77
78 void ICStub::verify() {
79 }
80
81 void ICStub::print() {
82 tty->print_cr("ICStub: site: " INTPTR_FORMAT, _ic_site);
83 }
84 #endif
85
86 //-----------------------------------------------------------------------------------------------
87 // Implementation of InlineCacheBuffer
88
89 void InlineCacheBuffer::init_next_stub() {
90 ICStub* ic_stub = (ICStub*)buffer()->request_committed (ic_stub_code_size());
91 assert (ic_stub != NULL, "no room for a single stub");
92 set_next_stub(ic_stub);
93 }
94
95 void InlineCacheBuffer::initialize() {
96 if (_buffer != NULL) return; // already initialized
97 _buffer = new StubQueue(new ICStubInterface, 10*K, InlineCacheBuffer_lock, "InlineCacheBuffer");
98 assert (_buffer != NULL, "cannot allocate InlineCacheBuffer");
99 init_next_stub();
100 }
101
102
103 ICStub* InlineCacheBuffer::new_ic_stub() {
104 while (true) {
105 ICStub* ic_stub = (ICStub*)buffer()->request_committed(ic_stub_code_size());
106 if (ic_stub != NULL) {
107 return ic_stub;
108 }
109 // we ran out of inline cache buffer space; must enter safepoint.
110 // We do this by forcing a safepoint
111 EXCEPTION_MARK;
112
113 VM_ForceSafepoint vfs;
114 VMThread::execute(&vfs);
115 // We could potential get an async. exception at this point.
116 // In that case we will rethrow it to ourselvs.
117 if (HAS_PENDING_EXCEPTION) {
118 oop exception = PENDING_EXCEPTION;
119 CLEAR_PENDING_EXCEPTION;
120 Thread::send_async_exception(JavaThread::current()->threadObj(), exception);
121 }
122 }
123 ShouldNotReachHere();
124 return NULL;
125 }
126
127
128 void InlineCacheBuffer::update_inline_caches() {
129 if (buffer()->number_of_stubs() > 1) {
130 if (TraceICBuffer) {
131 tty->print_cr("[updating inline caches with %d stubs]", buffer()->number_of_stubs());
132 }
133 buffer()->remove_all();
134 init_next_stub();
135 }
136 }
137
138
139 bool InlineCacheBuffer::contains(address instruction_address) {
140 return buffer()->contains(instruction_address);
141 }
142
143
144 bool InlineCacheBuffer::is_empty() {
145 return buffer()->number_of_stubs() == 1; // always has sentinel
146 }
147
148
149 void InlineCacheBuffer_init() {
150 InlineCacheBuffer::initialize();
151 }
152
153
154 void InlineCacheBuffer::create_transition_stub(CompiledIC *ic, oop cached_oop, address entry) {
155 assert(!SafepointSynchronize::is_at_safepoint(), "should not be called during a safepoint");
156 assert (CompiledIC_lock->is_locked(), "");
157 assert(cached_oop == NULL || cached_oop->is_perm(), "must belong to perm. space");
158 if (TraceICBuffer) { tty->print_cr(" create transition stub for " INTPTR_FORMAT, ic->instruction_address()); }
159
160 // If an transition stub is already associate with the inline cache, then we remove the association.
161 if (ic->is_in_transition_state()) {
162 ICStub* old_stub = ICStub_from_destination_address(ic->stub_address());
163 old_stub->clear();
164 }
165
166 // allocate and initialize new "out-of-line" inline-cache
167 ICStub* ic_stub = get_next_stub();
168 ic_stub->set_stub(ic, cached_oop, entry);
169
170 // Update inline cache in nmethod to point to new "out-of-line" allocated inline cache
171 ic->set_ic_destination(ic_stub->code_begin());
172
173 set_next_stub(new_ic_stub()); // can cause safepoint synchronization
174 }
175
176
177 address InlineCacheBuffer::ic_destination_for(CompiledIC *ic) {
178 ICStub* stub = ICStub_from_destination_address(ic->stub_address());
179 return stub->destination();
180 }
181
182
183 oop InlineCacheBuffer::cached_oop_for(CompiledIC *ic) {
184 ICStub* stub = ICStub_from_destination_address(ic->stub_address());
185 return stub->cached_oop();
186 }