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 46 CompiledICHolder* InlineCacheBuffer::_pending_released = NULL; 47 int InlineCacheBuffer::_pending_count = 0; 48 DEBUG_ONLY(volatile int InlineCacheBuffer::_needs_refill = 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 105 106 107 void InlineCacheBuffer::initialize() { 108 if (_buffer != NULL) return; // already initialized 109 _buffer = new StubQueue(new ICStubInterface, 10*K, InlineCacheBuffer_lock, "InlineCacheBuffer"); 110 assert (_buffer != NULL, "cannot allocate InlineCacheBuffer"); 111 } 112 113 114 ICStub* InlineCacheBuffer::new_ic_stub() { 115 return (ICStub*)buffer()->request_committed(ic_stub_code_size()); 116 } 117 118 119 void InlineCacheBuffer::refill_ic_stubs() { 120 DEBUG_ONLY(Atomic::store(0, &_needs_refill)); 121 // we ran out of inline cache buffer space; must enter safepoint. 122 // We do this by forcing a safepoint 123 EXCEPTION_MARK; 124 125 VM_ICBufferFull ibf; 126 VMThread::execute(&ibf); 127 // We could potential get an async. exception at this point. 128 // In that case we will rethrow it to ourselvs. 129 if (HAS_PENDING_EXCEPTION) { 130 oop exception = PENDING_EXCEPTION; 131 CLEAR_PENDING_EXCEPTION; 132 Thread::send_async_exception(JavaThread::current()->threadObj(), exception); 133 } 134 } 135 136 137 void InlineCacheBuffer::update_inline_caches() { 138 assert(_needs_refill == 0, 139 "Forgot to handle a failed IC transition requiring IC stubs"); 140 if (buffer()->number_of_stubs() > 0) { 141 if (TraceICBuffer) { 142 tty->print_cr("[updating inline caches with %d stubs]", buffer()->number_of_stubs()); 143 } 144 buffer()->remove_all(); 145 } 146 release_pending_icholders(); 147 } 148 149 150 bool InlineCacheBuffer::contains(address instruction_address) { 151 return buffer()->contains(instruction_address); 152 } 153 154 155 bool InlineCacheBuffer::is_empty() { 156 return buffer()->number_of_stubs() == 0; 157 } 158 159 160 void InlineCacheBuffer_init() { 161 InlineCacheBuffer::initialize(); 162 } 163 164 165 bool InlineCacheBuffer::create_transition_stub(CompiledIC *ic, void* cached_value, address entry) { 166 assert(!SafepointSynchronize::is_at_safepoint(), "should not be called during a safepoint"); 167 assert(CompiledICLocker::is_safe(ic->instruction_address()), "mt unsafe call"); 168 if (TraceICBuffer) { 169 tty->print_cr(" create transition stub for " INTPTR_FORMAT " destination " INTPTR_FORMAT " cached value " INTPTR_FORMAT, 170 p2i(ic->instruction_address()), p2i(entry), p2i(cached_value)); 171 } 172 173 // allocate and initialize new "out-of-line" inline-cache 174 ICStub* ic_stub = new_ic_stub(); 175 if (ic_stub == NULL) { 176 DEBUG_ONLY(Atomic::inc(&_needs_refill)); 177 return false; 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 ic_stub->set_stub(ic, cached_value, entry); 187 188 // Update inline cache in nmethod to point to new "out-of-line" allocated inline cache 189 ic->set_ic_destination(ic_stub); 190 return true; 191 } 192 193 194 address InlineCacheBuffer::ic_destination_for(CompiledIC *ic) { 195 ICStub* stub = ICStub_from_destination_address(ic->stub_address()); 196 return stub->destination(); 197 } 198 199 200 void* InlineCacheBuffer::cached_value_for(CompiledIC *ic) { 201 ICStub* stub = ICStub_from_destination_address(ic->stub_address()); 202 return stub->cached_value(); 203 } 204 205 206 // Free CompiledICHolder*s that are no longer in use 207 void InlineCacheBuffer::release_pending_icholders() { 208 assert(SafepointSynchronize::is_at_safepoint(), "should only be called during a safepoint"); 209 CompiledICHolder* holder = _pending_released; 210 _pending_released = NULL; 211 while (holder != NULL) { 212 CompiledICHolder* next = holder->next(); 213 delete holder; 214 holder = next; 215 _pending_count--; 216 } 217 assert(_pending_count == 0, "wrong count"); 218 } 219 220 // Enqueue this icholder for release during the next safepoint. It's 221 // not safe to free them until them since they might be visible to 222 // another thread. 223 void InlineCacheBuffer::queue_for_release(CompiledICHolder* icholder) { 224 MutexLockerEx mex(InlineCacheBuffer_lock, Mutex::_no_safepoint_check_flag); 225 icholder->set_next(_pending_released); 226 _pending_released = icholder; 227 _pending_count++; 228 if (TraceICBuffer) { 229 tty->print_cr("enqueueing icholder " INTPTR_FORMAT " to be freed", p2i(icholder)); 230 } 231 }