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/codeCache.hpp"
27 #include "code/compiledIC.hpp"
28 #include "code/icBuffer.hpp"
29 #include "code/nmethod.hpp"
30 #include "code/scopeDesc.hpp"
31 #include "gc_interface/collectedHeap.inline.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "interpreter/linkResolver.hpp"
34 #include "memory/resourceArea.hpp"
35 #include "memory/universe.inline.hpp"
36 #include "oops/method.hpp"
37 #include "oops/oop.inline.hpp"
38 #include "oops/oop.inline2.hpp"
39 #include "runtime/mutexLocker.hpp"
40 #include "runtime/stubRoutines.hpp"
41
42 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
43
44 DEF_STUB_INTERFACE(ICStub);
45
46 StubQueue* InlineCacheBuffer::_buffer = NULL;
47 ICStub* InlineCacheBuffer::_next_stub = NULL;
48
49 CompiledICHolder* InlineCacheBuffer::_pending_released = NULL;
50 int InlineCacheBuffer::_pending_count = 0;
51
52 void ICStub::finalize() {
53 if (!is_empty()) {
54 ResourceMark rm;
55 CompiledIC *ic = CompiledIC_at(CodeCache::find_nmethod(ic_site()), ic_site());
56 assert(CodeCache::find_nmethod(ic->instruction_address()) != NULL, "inline cache in non-nmethod?");
57
58 assert(this == ICStub_from_destination_address(ic->stub_address()), "wrong owner of ic buffer");
59 ic->set_ic_destination_and_value(destination(), cached_value());
60 }
61 }
62
63
64 address ICStub::destination() const {
65 return InlineCacheBuffer::ic_buffer_entry_point(code_begin());
66 }
67
68 void* ICStub::cached_value() const {
69 return InlineCacheBuffer::ic_buffer_cached_value(code_begin());
70 }
71
72
73 void ICStub::set_stub(CompiledIC *ic, void* cached_val, address dest_addr) {
74 // We cannot store a pointer to the 'ic' object, since it is resource allocated. Instead we
75 // store the location of the inline cache. Then we have enough information recreate the CompiledIC
76 // object when we need to remove the stub.
77 _ic_site = ic->instruction_address();
78
79 // Assemble new stub
80 InlineCacheBuffer::assemble_ic_buffer_code(code_begin(), cached_val, dest_addr);
81 assert(destination() == dest_addr, "can recover destination");
82 assert(cached_value() == cached_val, "can recover destination");
83 }
84
85
86 void ICStub::clear() {
87 if (CompiledIC::is_icholder_entry(destination())) {
88 InlineCacheBuffer::queue_for_release((CompiledICHolder*)cached_value());
89 }
90 _ic_site = NULL;
91 }
92
93
94 #ifndef PRODUCT
95 // anybody calling to this stub will trap
96
97 void ICStub::verify() {
98 }
99
100 void ICStub::print() {
101 tty->print_cr("ICStub: site: " INTPTR_FORMAT, _ic_site);
102 }
103 #endif
104
105 //-----------------------------------------------------------------------------------------------
106 // Implementation of InlineCacheBuffer
107
108 void InlineCacheBuffer::init_next_stub() {
109 ICStub* ic_stub = (ICStub*)buffer()->request_committed (ic_stub_code_size());
110 assert (ic_stub != NULL, "no room for a single stub");
111 set_next_stub(ic_stub);
112 }
113
114 void InlineCacheBuffer::initialize() {
115 if (_buffer != NULL) return; // already initialized
116 _buffer = new StubQueue(new ICStubInterface, 10*K, InlineCacheBuffer_lock, "InlineCacheBuffer");
117 assert (_buffer != NULL, "cannot allocate InlineCacheBuffer");
118 init_next_stub();
119 }
120
121
122 ICStub* InlineCacheBuffer::new_ic_stub() {
123 while (true) {
124 ICStub* ic_stub = (ICStub*)buffer()->request_committed(ic_stub_code_size());
125 if (ic_stub != NULL) {
126 return ic_stub;
127 }
128 // we ran out of inline cache buffer space; must enter safepoint.
129 // We do this by forcing a safepoint
130 EXCEPTION_MARK;
131
132 VM_ForceSafepoint vfs;
133 VMThread::execute(&vfs);
134 // We could potential get an async. exception at this point.
135 // In that case we will rethrow it to ourselvs.
136 if (HAS_PENDING_EXCEPTION) {
137 oop exception = PENDING_EXCEPTION;
138 CLEAR_PENDING_EXCEPTION;
139 Thread::send_async_exception(JavaThread::current()->threadObj(), exception);
140 }
141 }
142 ShouldNotReachHere();
143 return NULL;
144 }
145
146
147 void InlineCacheBuffer::update_inline_caches() {
148 if (buffer()->number_of_stubs() > 1) {
149 if (TraceICBuffer) {
150 tty->print_cr("[updating inline caches with %d stubs]", buffer()->number_of_stubs());
151 }
152 buffer()->remove_all();
153 init_next_stub();
154 }
155 release_pending_icholders();
156 }
157
158
159 bool InlineCacheBuffer::contains(address instruction_address) {
160 return buffer()->contains(instruction_address);
161 }
162
163
164 bool InlineCacheBuffer::is_empty() {
165 return buffer()->number_of_stubs() == 1; // always has sentinel
166 }
167
168
169 void InlineCacheBuffer_init() {
170 InlineCacheBuffer::initialize();
171 }
172
173
174 void InlineCacheBuffer::create_transition_stub(CompiledIC *ic, void* cached_value, address entry) {
175 assert(!SafepointSynchronize::is_at_safepoint(), "should not be called during a safepoint");
176 assert (CompiledIC_lock->is_locked(), "");
177 if (TraceICBuffer) {
178 tty->print_cr(" create transition stub for " INTPTR_FORMAT " destination " INTPTR_FORMAT " cached value " INTPTR_FORMAT,
179 ic->instruction_address(), entry, cached_value);
180 }
181
182 // If an transition stub is already associate with the inline cache, then we remove the association.
183 if (ic->is_in_transition_state()) {
184 ICStub* old_stub = ICStub_from_destination_address(ic->stub_address());
185 old_stub->clear();
186 }
187
188 // allocate and initialize new "out-of-line" inline-cache
189 ICStub* ic_stub = get_next_stub();
190 ic_stub->set_stub(ic, cached_value, entry);
191
192 // Update inline cache in nmethod to point to new "out-of-line" allocated inline cache
193 ic->set_ic_destination(ic_stub);
194
195 set_next_stub(new_ic_stub()); // can cause safepoint synchronization
196 }
197
198
199 address InlineCacheBuffer::ic_destination_for(CompiledIC *ic) {
200 ICStub* stub = ICStub_from_destination_address(ic->stub_address());
201 return stub->destination();
202 }
203
204
205 void* InlineCacheBuffer::cached_value_for(CompiledIC *ic) {
206 ICStub* stub = ICStub_from_destination_address(ic->stub_address());
207 return stub->cached_value();
208 }
209
210
211 // Free CompiledICHolder*s that are no longer in use
212 void InlineCacheBuffer::release_pending_icholders() {
213 assert(SafepointSynchronize::is_at_safepoint(), "should only be called during a safepoint");
214 CompiledICHolder* holder = _pending_released;
215 _pending_released = NULL;
216 while (holder != NULL) {
217 CompiledICHolder* next = holder->next();
218 delete holder;
219 holder = next;
220 _pending_count--;
221 }
222 assert(_pending_count == 0, "wrong count");
223 }
224
225 // Enqueue this icholder for release during the next safepoint. It's
226 // not safe to free them until them since they might be visible to
227 // another thread.
228 void InlineCacheBuffer::queue_for_release(CompiledICHolder* icholder) {
229 MutexLockerEx mex(InlineCacheBuffer_lock);
230 icholder->set_next(_pending_released);
231 _pending_released = icholder;
232 _pending_count++;
233 if (TraceICBuffer) {
234 tty->print_cr("enqueueing icholder " INTPTR_FORMAT " to be freed", icholder);
235 }
236 }