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(this); 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 }