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 #include "runtime/thread.hpp"
42
43 DEF_STUB_INTERFACE(ICStub);
44
45 StubQueue* InlineCacheBuffer::_buffer = NULL;
46
47 CompiledICHolder* InlineCacheBuffer::_pending_released = NULL;
48 int InlineCacheBuffer::_pending_count = 0;
49
50 #ifdef ASSERT
51 ICRefillVerifier::ICRefillVerifier()
52 : _refill_requested(false),
53 _refill_remembered(false)
54 {
55 Thread* thread = Thread::current();
56 assert(thread->missed_ic_stub_refill_mark() == NULL, "nesting not supported");
57 thread->set_missed_ic_stub_refill_mark(this);
58 }
59
60 ICRefillVerifier::~ICRefillVerifier() {
61 assert(!_refill_requested || _refill_remembered,
62 "Forgot to refill IC stubs after failed IC transition");
63 Thread::current()->set_missed_ic_stub_refill_mark(NULL);
64 }
65
66 ICRefillVerifierMark::ICRefillVerifierMark(ICRefillVerifier* verifier) {
67 Thread* thread = Thread::current();
68 assert(thread->missed_ic_stub_refill_mark() == NULL, "nesting not supported");
69 thread->set_missed_ic_stub_refill_mark(verifier);
70 }
71
72 ICRefillVerifierMark::~ICRefillVerifierMark() {
73 Thread::current()->set_missed_ic_stub_refill_mark(NULL);
74 }
75
76 static ICRefillVerifier* current_ic_refill_verifier() {
77 Thread* current = Thread::current();
78 ICRefillVerifier* verifier = reinterpret_cast<ICRefillVerifier*>(current->missed_ic_stub_refill_mark());
79 assert(verifier != NULL, "need a verifier for safety");
80 return verifier;
81 }
82 #endif
83
84 void ICStub::finalize() {
85 if (!is_empty()) {
86 ResourceMark rm;
87 CompiledIC *ic = CompiledIC_at(CodeCache::find_compiled(ic_site()), ic_site());
88 assert(CodeCache::find_compiled(ic->instruction_address()) != NULL, "inline cache in non-compiled?");
89
90 assert(this == ICStub_from_destination_address(ic->stub_address()), "wrong owner of ic buffer");
91 ic->set_ic_destination_and_value(destination(), cached_value());
92 }
93 }
94
95
96 address ICStub::destination() const {
97 return InlineCacheBuffer::ic_buffer_entry_point(code_begin());
98 }
99
100 void* ICStub::cached_value() const {
101 return InlineCacheBuffer::ic_buffer_cached_value(code_begin());
102 }
103
104
105 void ICStub::set_stub(CompiledIC *ic, void* cached_val, address dest_addr) {
106 // We cannot store a pointer to the 'ic' object, since it is resource allocated. Instead we
107 // store the location of the inline cache. Then we have enough information recreate the CompiledIC
108 // object when we need to remove the stub.
109 _ic_site = ic->instruction_address();
110
111 // Assemble new stub
112 InlineCacheBuffer::assemble_ic_buffer_code(code_begin(), cached_val, dest_addr);
113 assert(destination() == dest_addr, "can recover destination");
114 assert(cached_value() == cached_val, "can recover destination");
115 }
116
117
118 void ICStub::clear() {
119 if (CompiledIC::is_icholder_entry(destination())) {
120 InlineCacheBuffer::queue_for_release((CompiledICHolder*)cached_value());
121 }
122 _ic_site = NULL;
123 }
124
125
126 #ifndef PRODUCT
127 // anybody calling to this stub will trap
128
129 void ICStub::verify() {
130 }
131
132 void ICStub::print() {
133 tty->print_cr("ICStub: site: " INTPTR_FORMAT, p2i(_ic_site));
134 }
135 #endif
136
137 //-----------------------------------------------------------------------------------------------
138 // Implementation of InlineCacheBuffer
139
140
141 void InlineCacheBuffer::initialize() {
142 if (_buffer != NULL) return; // already initialized
143 _buffer = new StubQueue(new ICStubInterface, 10*K, InlineCacheBuffer_lock, "InlineCacheBuffer");
144 assert (_buffer != NULL, "cannot allocate InlineCacheBuffer");
145 }
146
147
148 ICStub* InlineCacheBuffer::new_ic_stub() {
149 return (ICStub*)buffer()->request_committed(ic_stub_code_size());
150 }
151
152
153 void InlineCacheBuffer::refill_ic_stubs() {
154 #ifdef ASSERT
155 ICRefillVerifier* verifier = current_ic_refill_verifier();
156 verifier->request_remembered();
157 #endif
158 // we ran out of inline cache buffer space; must enter safepoint.
159 // We do this by forcing a safepoint
160 EXCEPTION_MARK;
161
162 VM_ICBufferFull ibf;
163 VMThread::execute(&ibf);
164 // We could potential get an async. exception at this point.
165 // In that case we will rethrow it to ourselvs.
166 if (HAS_PENDING_EXCEPTION) {
167 oop exception = PENDING_EXCEPTION;
168 CLEAR_PENDING_EXCEPTION;
169 Thread::send_async_exception(JavaThread::current()->threadObj(), exception);
170 }
171 }
172
173
174 void InlineCacheBuffer::update_inline_caches() {
175 if (buffer()->number_of_stubs() > 0) {
176 if (TraceICBuffer) {
177 tty->print_cr("[updating inline caches with %d stubs]", buffer()->number_of_stubs());
178 }
179 buffer()->remove_all();
180 }
181 release_pending_icholders();
182 }
183
184
185 bool InlineCacheBuffer::contains(address instruction_address) {
186 return buffer()->contains(instruction_address);
187 }
188
189
190 bool InlineCacheBuffer::is_empty() {
191 return buffer()->number_of_stubs() == 0;
192 }
193
194
195 void InlineCacheBuffer_init() {
196 InlineCacheBuffer::initialize();
197 }
198
199 bool InlineCacheBuffer::create_transition_stub(CompiledIC *ic, void* cached_value, address entry) {
200 assert(!SafepointSynchronize::is_at_safepoint(), "should not be called during a safepoint");
201 assert(CompiledICLocker::is_safe(ic->instruction_address()), "mt unsafe call");
202 if (TraceICBuffer) {
203 tty->print_cr(" create transition stub for " INTPTR_FORMAT " destination " INTPTR_FORMAT " cached value " INTPTR_FORMAT,
204 p2i(ic->instruction_address()), p2i(entry), p2i(cached_value));
205 }
206
207 // allocate and initialize new "out-of-line" inline-cache
208 ICStub* ic_stub = new_ic_stub();
209 if (ic_stub == NULL) {
210 #ifdef ASSERT
211 ICRefillVerifier* verifier = current_ic_refill_verifier();
212 verifier->request_refill();
213 #endif
214 return false;
215 }
216
217 // If an transition stub is already associate with the inline cache, then we remove the association.
218 if (ic->is_in_transition_state()) {
219 ICStub* old_stub = ICStub_from_destination_address(ic->stub_address());
220 old_stub->clear();
221 }
222
223 ic_stub->set_stub(ic, cached_value, entry);
224
225 // Update inline cache in nmethod to point to new "out-of-line" allocated inline cache
226 ic->set_ic_destination(ic_stub);
227 return true;
228 }
229
230
231 address InlineCacheBuffer::ic_destination_for(CompiledIC *ic) {
232 ICStub* stub = ICStub_from_destination_address(ic->stub_address());
233 return stub->destination();
234 }
235
236
237 void* InlineCacheBuffer::cached_value_for(CompiledIC *ic) {
238 ICStub* stub = ICStub_from_destination_address(ic->stub_address());
239 return stub->cached_value();
240 }
241
242
243 // Free CompiledICHolder*s that are no longer in use
244 void InlineCacheBuffer::release_pending_icholders() {
245 assert(SafepointSynchronize::is_at_safepoint(), "should only be called during a safepoint");
246 CompiledICHolder* holder = _pending_released;
247 _pending_released = NULL;
248 while (holder != NULL) {
249 CompiledICHolder* next = holder->next();
250 delete holder;
251 holder = next;
252 _pending_count--;
253 }
254 assert(_pending_count == 0, "wrong count");
255 }
256
257 // Enqueue this icholder for release during the next safepoint. It's
258 // not safe to free them until them since they might be visible to
259 // another thread.
260 void InlineCacheBuffer::queue_for_release(CompiledICHolder* icholder) {
261 MutexLockerEx mex(InlineCacheBuffer_lock, Mutex::_no_safepoint_check_flag);
262 icholder->set_next(_pending_released);
263 _pending_released = icholder;
264 _pending_count++;
265 if (TraceICBuffer) {
266 tty->print_cr("enqueueing icholder " INTPTR_FORMAT " to be freed", p2i(icholder));
267 }
268 }