1 /*
2 * Copyright (c) 1997, 2019, 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 "oops/method.hpp"
36 #include "oops/oop.inline.hpp"
37 #include "runtime/handles.inline.hpp"
38 #include "runtime/mutexLocker.inline.hpp"
39 #include "runtime/stubRoutines.hpp"
40 #include "runtime/thread.hpp"
41
42 DEF_STUB_INTERFACE(ICStub);
43
44 StubQueue* InlineCacheBuffer::_buffer = NULL;
45
46 CompiledICHolder* InlineCacheBuffer::_pending_released = NULL;
47 int InlineCacheBuffer::_pending_count = 0;
48
49 #ifdef ASSERT
50 ICRefillVerifier::ICRefillVerifier()
51 : _refill_requested(false),
52 _refill_remembered(false)
53 {
54 Thread* thread = Thread::current();
55 assert(thread->missed_ic_stub_refill_verifier() == NULL, "nesting not supported");
56 thread->set_missed_ic_stub_refill_verifier(this);
57 }
58
59 ICRefillVerifier::~ICRefillVerifier() {
60 assert(!_refill_requested || _refill_remembered,
61 "Forgot to refill IC stubs after failed IC transition");
62 Thread::current()->set_missed_ic_stub_refill_verifier(NULL);
63 }
64
65 ICRefillVerifierMark::ICRefillVerifierMark(ICRefillVerifier* verifier) {
66 Thread* thread = Thread::current();
67 assert(thread->missed_ic_stub_refill_verifier() == NULL, "nesting not supported");
68 thread->set_missed_ic_stub_refill_verifier(verifier);
69 }
70
71 ICRefillVerifierMark::~ICRefillVerifierMark() {
72 Thread::current()->set_missed_ic_stub_refill_verifier(NULL);
73 }
74
75 static ICRefillVerifier* current_ic_refill_verifier() {
76 Thread* current = Thread::current();
77 ICRefillVerifier* verifier = current->missed_ic_stub_refill_verifier();
78 assert(verifier != NULL, "need a verifier for safety");
79 return verifier;
80 }
81 #endif
82
83 void ICStub::finalize() {
84 if (!is_empty()) {
85 ResourceMark rm;
86 CompiledIC *ic = CompiledIC_at(CodeCache::find_compiled(ic_site()), ic_site());
87 assert(CodeCache::find_compiled(ic->instruction_address()) != NULL, "inline cache in non-compiled?");
88
89 assert(this == ICStub_from_destination_address(ic->stub_address()), "wrong owner of ic buffer");
90 ic->set_ic_destination_and_value(destination(), cached_value());
91 }
92 }
93
94
95 address ICStub::destination() const {
96 return InlineCacheBuffer::ic_buffer_entry_point(code_begin());
97 }
98
99 void* ICStub::cached_value() const {
100 return InlineCacheBuffer::ic_buffer_cached_value(code_begin());
101 }
102
103
104 void ICStub::set_stub(CompiledIC *ic, void* cached_val, address dest_addr) {
105 // We cannot store a pointer to the 'ic' object, since it is resource allocated. Instead we
106 // store the location of the inline cache. Then we have enough information recreate the CompiledIC
107 // object when we need to remove the stub.
108 _ic_site = ic->instruction_address();
109
110 // Assemble new stub
111 InlineCacheBuffer::assemble_ic_buffer_code(code_begin(), cached_val, dest_addr);
112 assert(destination() == dest_addr, "can recover destination");
113 assert(cached_value() == cached_val, "can recover destination");
114 }
115
116
117 void ICStub::clear() {
118 if (CompiledIC::is_icholder_entry(destination())) {
119 InlineCacheBuffer::queue_for_release((CompiledICHolder*)cached_value());
120 }
121 _ic_site = NULL;
122 }
123
124
125 #ifndef PRODUCT
126 // anybody calling to this stub will trap
127
128 void ICStub::verify() {
129 }
130
131 void ICStub::print() {
132 tty->print_cr("ICStub: site: " INTPTR_FORMAT, p2i(_ic_site));
133 }
134 #endif
135
136 //-----------------------------------------------------------------------------------------------
137 // Implementation of InlineCacheBuffer
138
139
140 void InlineCacheBuffer::initialize() {
141 if (_buffer != NULL) return; // already initialized
142 _buffer = new StubQueue(new ICStubInterface, 10*K, InlineCacheBuffer_lock, "InlineCacheBuffer");
143 assert (_buffer != NULL, "cannot allocate InlineCacheBuffer");
144 }
145
146
147 ICStub* InlineCacheBuffer::new_ic_stub() {
148 return (ICStub*)buffer()->request_committed(ic_stub_code_size());
149 }
150
151
152 void InlineCacheBuffer::refill_ic_stubs() {
153 #ifdef ASSERT
154 ICRefillVerifier* verifier = current_ic_refill_verifier();
155 verifier->request_remembered();
156 #endif
157 // we ran out of inline cache buffer space; must enter safepoint.
158 // We do this by forcing a safepoint
159 EXCEPTION_MARK;
160
161 VM_ICBufferFull ibf;
162 VMThread::execute(&ibf);
163 // We could potential get an async. exception at this point.
164 // In that case we will rethrow it to ourselvs.
165 if (HAS_PENDING_EXCEPTION) {
166 oop exception = PENDING_EXCEPTION;
167 CLEAR_PENDING_EXCEPTION;
168 Thread::send_async_exception(JavaThread::current()->threadObj(), exception);
169 }
170 }
171
172
173 void InlineCacheBuffer::update_inline_caches() {
174 if (buffer()->number_of_stubs() > 0) {
175 if (TraceICBuffer) {
176 tty->print_cr("[updating inline caches with %d stubs]", buffer()->number_of_stubs());
177 }
178 buffer()->remove_all();
179 }
180 release_pending_icholders();
181 }
182
183
184 bool InlineCacheBuffer::contains(address instruction_address) {
185 return buffer()->contains(instruction_address);
186 }
187
188
189 bool InlineCacheBuffer::is_empty() {
190 return buffer()->number_of_stubs() == 0;
191 }
192
193
194 void InlineCacheBuffer_init() {
195 InlineCacheBuffer::initialize();
196 }
197
198 bool InlineCacheBuffer::create_transition_stub(CompiledIC *ic, void* cached_value, address entry) {
199 assert(!SafepointSynchronize::is_at_safepoint(), "should not be called during a safepoint");
200 assert(CompiledICLocker::is_safe(ic->instruction_address()), "mt unsafe call");
201 if (TraceICBuffer) {
202 tty->print_cr(" create transition stub for " INTPTR_FORMAT " destination " INTPTR_FORMAT " cached value " INTPTR_FORMAT,
203 p2i(ic->instruction_address()), p2i(entry), p2i(cached_value));
204 }
205
206 // allocate and initialize new "out-of-line" inline-cache
207 ICStub* ic_stub = new_ic_stub();
208 if (ic_stub == NULL) {
209 #ifdef ASSERT
210 ICRefillVerifier* verifier = current_ic_refill_verifier();
211 verifier->request_refill();
212 #endif
213 return false;
214 }
215
216 // If an transition stub is already associate with the inline cache, then we remove the association.
217 if (ic->is_in_transition_state()) {
218 ICStub* old_stub = ICStub_from_destination_address(ic->stub_address());
219 old_stub->clear();
220 }
221
222 ic_stub->set_stub(ic, cached_value, entry);
223
224 // Update inline cache in nmethod to point to new "out-of-line" allocated inline cache
225 ic->set_ic_destination(ic_stub);
226 return true;
227 }
228
229
230 address InlineCacheBuffer::ic_destination_for(CompiledIC *ic) {
231 ICStub* stub = ICStub_from_destination_address(ic->stub_address());
232 return stub->destination();
233 }
234
235
236 void* InlineCacheBuffer::cached_value_for(CompiledIC *ic) {
237 ICStub* stub = ICStub_from_destination_address(ic->stub_address());
238 return stub->cached_value();
239 }
240
241
242 // Free CompiledICHolder*s that are no longer in use
243 void InlineCacheBuffer::release_pending_icholders() {
244 assert(SafepointSynchronize::is_at_safepoint(), "should only be called during a safepoint");
245 CompiledICHolder* holder = _pending_released;
246 _pending_released = NULL;
247 while (holder != NULL) {
248 CompiledICHolder* next = holder->next();
249 delete holder;
250 holder = next;
251 _pending_count--;
252 }
253 assert(_pending_count == 0, "wrong count");
254 }
255
256 // Enqueue this icholder for release during the next safepoint. It's
257 // not safe to free them until them since they might be visible to
258 // another thread.
259 void InlineCacheBuffer::queue_for_release(CompiledICHolder* icholder) {
260 MutexLocker mex(InlineCacheBuffer_lock, Mutex::_no_safepoint_check_flag);
261 icholder->set_next(_pending_released);
262 _pending_released = icholder;
263 _pending_count++;
264 if (TraceICBuffer) {
265 tty->print_cr("enqueueing icholder " INTPTR_FORMAT " to be freed", p2i(icholder));
266 }
267 }