1 /* 2 * Copyright (c) 1997, 2015, 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_interface/collectedHeap.inline.hpp" 32 #include "interpreter/interpreter.hpp" 33 #include "interpreter/linkResolver.hpp" 34 #include "memory/resourceArea.hpp" 35 #include "memory/universe.inline.hpp" 36 #include "oops/method.hpp" 37 #include "oops/oop.inline.hpp" 38 #include "runtime/mutexLocker.hpp" 39 #include "runtime/stubRoutines.hpp" 40 41 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 42 43 DEF_STUB_INTERFACE(ICStub); 44 45 StubQueue* InlineCacheBuffer::_buffer = NULL; 46 ICStub* InlineCacheBuffer::_next_stub = NULL; 47 48 CompiledICHolder* InlineCacheBuffer::_pending_released = NULL; 49 int InlineCacheBuffer::_pending_count = 0; 50 51 void ICStub::finalize() { 52 if (!is_empty()) { 53 ResourceMark rm; 54 CompiledIC *ic = CompiledIC_at(CodeCache::find_nmethod(ic_site()), ic_site()); 55 assert(CodeCache::find_nmethod(ic->instruction_address()) != NULL, "inline cache in non-nmethod?"); 56 57 assert(this == ICStub_from_destination_address(ic->stub_address()), "wrong owner of ic buffer"); 58 ic->set_ic_destination_and_value(destination(), cached_value()); 59 } 60 } 61 62 63 address ICStub::destination() const { 64 return InlineCacheBuffer::ic_buffer_entry_point(code_begin()); 65 } 66 67 void* ICStub::cached_value() const { 68 return InlineCacheBuffer::ic_buffer_cached_value(code_begin()); 69 } 70 71 72 void ICStub::set_stub(CompiledIC *ic, void* cached_val, address dest_addr) { 73 // We cannot store a pointer to the 'ic' object, since it is resource allocated. Instead we 74 // store the location of the inline cache. Then we have enough information recreate the CompiledIC 75 // object when we need to remove the stub. 76 _ic_site = ic->instruction_address(); 77 78 // Assemble new stub 79 InlineCacheBuffer::assemble_ic_buffer_code(code_begin(), cached_val, dest_addr); 80 assert(destination() == dest_addr, "can recover destination"); 81 assert(cached_value() == cached_val, "can recover destination"); 82 } 83 84 85 void ICStub::clear() { 86 if (CompiledIC::is_icholder_entry(destination())) { 87 InlineCacheBuffer::queue_for_release((CompiledICHolder*)cached_value()); 88 } 89 _ic_site = NULL; 90 } 91 92 93 #ifndef PRODUCT 94 // anybody calling to this stub will trap 95 96 void ICStub::verify() { 97 } 98 99 void ICStub::print() { 100 tty->print_cr("ICStub: site: " INTPTR_FORMAT, _ic_site); 101 } 102 #endif 103 104 //----------------------------------------------------------------------------------------------- 105 // Implementation of InlineCacheBuffer 106 107 void InlineCacheBuffer::init_next_stub() { 108 ICStub* ic_stub = (ICStub*)buffer()->request_committed (ic_stub_code_size()); 109 assert (ic_stub != NULL, "no room for a single stub"); 110 set_next_stub(ic_stub); 111 } 112 113 void InlineCacheBuffer::initialize() { 114 if (_buffer != NULL) return; // already initialized 115 _buffer = new StubQueue(new ICStubInterface, 10*K, InlineCacheBuffer_lock, "InlineCacheBuffer"); 116 assert (_buffer != NULL, "cannot allocate InlineCacheBuffer"); 117 init_next_stub(); 118 } 119 120 121 ICStub* InlineCacheBuffer::new_ic_stub() { 122 while (true) { 123 ICStub* ic_stub = (ICStub*)buffer()->request_committed(ic_stub_code_size()); 124 if (ic_stub != NULL) { 125 return ic_stub; 126 } 127 // we ran out of inline cache buffer space; must enter safepoint. 128 // We do this by forcing a safepoint 129 EXCEPTION_MARK; 130 131 VM_ForceSafepoint vfs; 132 VMThread::execute(&vfs); 133 // We could potential get an async. exception at this point. 134 // In that case we will rethrow it to ourselvs. 135 if (HAS_PENDING_EXCEPTION) { 136 oop exception = PENDING_EXCEPTION; 137 CLEAR_PENDING_EXCEPTION; 138 Thread::send_async_exception(JavaThread::current()->threadObj(), exception); 139 } 140 } 141 ShouldNotReachHere(); 142 return NULL; 143 } 144 145 146 void InlineCacheBuffer::update_inline_caches() { 147 if (buffer()->number_of_stubs() > 1) { 148 if (TraceICBuffer) { 149 tty->print_cr("[updating inline caches with %d stubs]", buffer()->number_of_stubs()); 150 } 151 buffer()->remove_all(); 152 init_next_stub(); 153 } 154 release_pending_icholders(); 155 } 156 157 158 bool InlineCacheBuffer::contains(address instruction_address) { 159 return buffer()->contains(instruction_address); 160 } 161 162 163 bool InlineCacheBuffer::is_empty() { 164 return buffer()->number_of_stubs() == 1; // always has sentinel 165 } 166 167 168 void InlineCacheBuffer_init() { 169 InlineCacheBuffer::initialize(); 170 } 171 172 173 void InlineCacheBuffer::create_transition_stub(CompiledIC *ic, void* cached_value, address entry) { 174 assert(!SafepointSynchronize::is_at_safepoint(), "should not be called during a safepoint"); 175 assert (CompiledIC_lock->is_locked(), ""); 176 if (TraceICBuffer) { 177 tty->print_cr(" create transition stub for " INTPTR_FORMAT " destination " INTPTR_FORMAT " cached value " INTPTR_FORMAT, 178 ic->instruction_address(), entry, cached_value); 179 } 180 181 // If an transition stub is already associate with the inline cache, then we remove the association. 182 if (ic->is_in_transition_state()) { 183 ICStub* old_stub = ICStub_from_destination_address(ic->stub_address()); 184 old_stub->clear(); 185 } 186 187 // allocate and initialize new "out-of-line" inline-cache 188 ICStub* ic_stub = get_next_stub(); 189 ic_stub->set_stub(ic, cached_value, entry); 190 191 // Update inline cache in nmethod to point to new "out-of-line" allocated inline cache 192 ic->set_ic_destination(ic_stub); 193 194 set_next_stub(new_ic_stub()); // can cause safepoint synchronization 195 } 196 197 198 address InlineCacheBuffer::ic_destination_for(CompiledIC *ic) { 199 ICStub* stub = ICStub_from_destination_address(ic->stub_address()); 200 return stub->destination(); 201 } 202 203 204 void* InlineCacheBuffer::cached_value_for(CompiledIC *ic) { 205 ICStub* stub = ICStub_from_destination_address(ic->stub_address()); 206 return stub->cached_value(); 207 } 208 209 210 // Free CompiledICHolder*s that are no longer in use 211 void InlineCacheBuffer::release_pending_icholders() { 212 assert(SafepointSynchronize::is_at_safepoint(), "should only be called during a safepoint"); 213 CompiledICHolder* holder = _pending_released; 214 _pending_released = NULL; 215 while (holder != NULL) { 216 CompiledICHolder* next = holder->next(); 217 delete holder; 218 holder = next; 219 _pending_count--; 220 } 221 assert(_pending_count == 0, "wrong count"); 222 } 223 224 // Enqueue this icholder for release during the next safepoint. It's 225 // not safe to free them until them since they might be visible to 226 // another thread. 227 void InlineCacheBuffer::queue_for_release(CompiledICHolder* icholder) { 228 MutexLockerEx mex(InlineCacheBuffer_lock); 229 icholder->set_next(_pending_released); 230 _pending_released = icholder; 231 _pending_count++; 232 if (TraceICBuffer) { 233 tty->print_cr("enqueueing icholder " INTPTR_FORMAT " to be freed", icholder); 234 } 235 }