1 /*
2 * Copyright (c) 1997, 2018, 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/shared/collectedHeap.inline.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "interpreter/linkResolver.hpp"
34 #include "memory/resourceArea.hpp"
35 #include "memory/universe.hpp"
36 #include "oops/method.hpp"
37 #include "oops/oop.inline.hpp"
38 #include "runtime/handles.inline.hpp"
39 #include "runtime/mutexLocker.hpp"
40 #include "runtime/stubRoutines.hpp"
41
42 DEF_STUB_INTERFACE(ICStub);
43
44 StubQueue* InlineCacheBuffer::_buffer = NULL;
45 ICStub* InlineCacheBuffer::_next_stub = NULL;
46
47 CompiledICHolder* InlineCacheBuffer::_pending_released = NULL;
48 int InlineCacheBuffer::_pending_count = 0;
49
50 void ICStub::finalize() {
51 if (!is_empty()) {
52 ResourceMark rm;
53 CompiledIC *ic = CompiledIC_at(CodeCache::find_compiled(ic_site()), ic_site());
54 assert(CodeCache::find_compiled(ic->instruction_address()) != NULL, "inline cache in non-compiled?");
55
56 assert(this == ICStub_from_destination_address(ic->stub_address()), "wrong owner of ic buffer");
57 ic->set_ic_destination_and_value(destination(), cached_value());
58 }
59 }
60
61
62 address ICStub::destination() const {
63 return InlineCacheBuffer::ic_buffer_entry_point(code_begin());
64 }
65
66 void* ICStub::cached_value() const {
67 return InlineCacheBuffer::ic_buffer_cached_value(code_begin());
68 }
69
70
71 void ICStub::set_stub(CompiledIC *ic, void* cached_val, address dest_addr) {
72 // We cannot store a pointer to the 'ic' object, since it is resource allocated. Instead we
73 // store the location of the inline cache. Then we have enough information recreate the CompiledIC
74 // object when we need to remove the stub.
75 _ic_site = ic->instruction_address();
76
77 // Assemble new stub
78 InlineCacheBuffer::assemble_ic_buffer_code(code_begin(), cached_val, dest_addr);
79 assert(destination() == dest_addr, "can recover destination");
80 assert(cached_value() == cached_val, "can recover destination");
81 }
82
83
84 void ICStub::clear() {
85 if (CompiledIC::is_icholder_entry(destination())) {
86 InlineCacheBuffer::queue_for_release((CompiledICHolder*)cached_value());
87 }
88 _ic_site = NULL;
89 }
90
91
92 #ifndef PRODUCT
93 // anybody calling to this stub will trap
94
95 void ICStub::verify() {
96 }
97
98 void ICStub::print() {
99 tty->print_cr("ICStub: site: " INTPTR_FORMAT, p2i(_ic_site));
100 }
101 #endif
102
103 //-----------------------------------------------------------------------------------------------
104 // Implementation of InlineCacheBuffer
105
106 void InlineCacheBuffer::init_next_stub() {
107 ICStub* ic_stub = (ICStub*)buffer()->request_committed (ic_stub_code_size());
108 assert (ic_stub != NULL, "no room for a single stub");
109 set_next_stub(ic_stub);
110 }
111
112 void InlineCacheBuffer::initialize() {
113 if (_buffer != NULL) return; // already initialized
114 _buffer = new StubQueue(new ICStubInterface, 10*K, InlineCacheBuffer_lock, "InlineCacheBuffer");
115 assert (_buffer != NULL, "cannot allocate InlineCacheBuffer");
116 init_next_stub();
117 }
118
119
120 ICStub* InlineCacheBuffer::new_ic_stub() {
121 while (true) {
122 ICStub* ic_stub = (ICStub*)buffer()->request_committed(ic_stub_code_size());
123 if (ic_stub != NULL) {
124 return ic_stub;
125 }
126 // we ran out of inline cache buffer space; must enter safepoint.
127 // We do this by forcing a safepoint
128 EXCEPTION_MARK;
129
130 VM_ICBufferFull ibf;
131 VMThread::execute(&ibf);
132 // We could potential get an async. exception at this point.
133 // In that case we will rethrow it to ourselvs.
134 if (HAS_PENDING_EXCEPTION) {
135 oop exception = PENDING_EXCEPTION;
136 CLEAR_PENDING_EXCEPTION;
137 Thread::send_async_exception(JavaThread::current()->threadObj(), exception);
138 }
139 }
140 ShouldNotReachHere();
141 return NULL;
142 }
143
144
145 void InlineCacheBuffer::update_inline_caches() {
146 if (buffer()->number_of_stubs() > 1) {
147 if (TraceICBuffer) {
148 tty->print_cr("[updating inline caches with %d stubs]", buffer()->number_of_stubs());
149 }
150 buffer()->remove_all();
151 init_next_stub();
152 }
153 release_pending_icholders();
154 }
155
156
157 bool InlineCacheBuffer::contains(address instruction_address) {
158 return buffer()->contains(instruction_address);
159 }
160
161
162 bool InlineCacheBuffer::is_empty() {
163 return buffer()->number_of_stubs() == 1; // always has sentinel
164 }
165
166
167 void InlineCacheBuffer_init() {
168 InlineCacheBuffer::initialize();
169 }
170
171
172 void InlineCacheBuffer::create_transition_stub(CompiledIC *ic, void* cached_value, address entry) {
173 assert(!SafepointSynchronize::is_at_safepoint(), "should not be called during a safepoint");
174 assert (CompiledIC_lock->is_locked(), "");
175 if (TraceICBuffer) {
176 tty->print_cr(" create transition stub for " INTPTR_FORMAT " destination " INTPTR_FORMAT " cached value " INTPTR_FORMAT,
177 p2i(ic->instruction_address()), p2i(entry), p2i(cached_value));
178 }
179
180 // If an transition stub is already associate with the inline cache, then we remove the association.
181 if (ic->is_in_transition_state()) {
182 ICStub* old_stub = ICStub_from_destination_address(ic->stub_address());
183 old_stub->clear();
184 }
185
186 // allocate and initialize new "out-of-line" inline-cache
187 ICStub* ic_stub = get_next_stub();
188 ic_stub->set_stub(ic, cached_value, entry);
189
190 // Update inline cache in nmethod to point to new "out-of-line" allocated inline cache
191 ic->set_ic_destination(ic_stub);
192
193 set_next_stub(new_ic_stub()); // can cause safepoint synchronization
194 }
195
196
197 address InlineCacheBuffer::ic_destination_for(CompiledIC *ic) {
198 ICStub* stub = ICStub_from_destination_address(ic->stub_address());
199 return stub->destination();
200 }
201
202
203 void* InlineCacheBuffer::cached_value_for(CompiledIC *ic) {
204 ICStub* stub = ICStub_from_destination_address(ic->stub_address());
205 return stub->cached_value();
206 }
207
208
209 // Free CompiledICHolder*s that are no longer in use
210 void InlineCacheBuffer::release_pending_icholders() {
211 assert(SafepointSynchronize::is_at_safepoint(), "should only be called during a safepoint");
212 CompiledICHolder* holder = _pending_released;
213 _pending_released = NULL;
214 while (holder != NULL) {
215 CompiledICHolder* next = holder->next();
216 delete holder;
217 holder = next;
218 _pending_count--;
219 }
220 assert(_pending_count == 0, "wrong count");
221 }
222
223 // Enqueue this icholder for release during the next safepoint. It's
224 // not safe to free them until them since they might be visible to
225 // another thread.
226 void InlineCacheBuffer::queue_for_release(CompiledICHolder* icholder) {
227 MutexLockerEx mex(InlineCacheBuffer_lock, Mutex::_no_safepoint_check_flag);
228 if (icholder->is_enqueued()) {
229 return;
230 }
231 icholder->set_next(_pending_released);
232 icholder->set_enqueued();
233 _pending_released = icholder;
234 _pending_count++;
235 if (TraceICBuffer) {
236 tty->print_cr("enqueueing icholder " INTPTR_FORMAT " to be freed", p2i(icholder));
237 }
238 }