| /* |
| * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "code/vtableStubs.hpp" |
| #include "compiler/compileBroker.hpp" |
| #include "compiler/disassembler.hpp" |
| #include "logging/log.hpp" |
| #include "memory/allocation.inline.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "oops/instanceKlass.hpp" |
| #include "oops/klass.inline.hpp" |
| #include "oops/klassVtable.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "prims/forte.hpp" |
| #include "prims/jvmtiExport.hpp" |
| #include "runtime/handles.inline.hpp" |
| #include "runtime/mutexLocker.hpp" |
| #include "runtime/sharedRuntime.hpp" |
| #include "utilities/align.hpp" |
| #include "utilities/powerOfTwo.hpp" |
| #ifdef COMPILER2 |
| #include "opto/matcher.hpp" |
| #endif |
| |
| // ----------------------------------------------------------------------------------------- |
| // Implementation of VtableStub |
| |
| address VtableStub::_chunk = nullptr; |
| address VtableStub::_chunk_end = nullptr; |
| VMReg VtableStub::_receiver_location = VMRegImpl::Bad(); |
| |
| |
| void* VtableStub::operator new(size_t size, int code_size) throw() { |
| assert_lock_strong(VtableStubs_lock); |
| assert(size == sizeof(VtableStub), "mismatched size"); |
| // compute real VtableStub size (rounded to nearest word) |
| const int real_size = align_up(code_size + (int)sizeof(VtableStub), wordSize); |
| // malloc them in chunks to minimize header overhead |
| const int chunk_factor = 32; |
| if (_chunk == nullptr || _chunk + real_size > _chunk_end) { |
| const int bytes = chunk_factor * real_size + pd_code_alignment(); |
| |
| // There is a dependency on the name of the blob in src/share/vm/prims/jvmtiCodeBlobEvents.cpp |
| // If changing the name, update the other file accordingly. |
| VtableBlob* blob = VtableBlob::create("vtable chunks", bytes); |
| if (blob == nullptr) { |
| return nullptr; |
| } |
| _chunk = blob->content_begin(); |
| _chunk_end = _chunk + bytes; |
| Forte::register_stub("vtable stub", _chunk, _chunk_end); |
| align_chunk(); |
| } |
| assert(_chunk + real_size <= _chunk_end, "bad allocation"); |
| void* res = _chunk; |
| _chunk += real_size; |
| align_chunk(); |
| return res; |
| } |
| |
| |
| void VtableStub::print_on(outputStream* st) const { |
| st->print("vtable stub (index = %d, receiver_location = " INTX_FORMAT ", code = [" INTPTR_FORMAT ", " INTPTR_FORMAT "])", |
| index(), p2i(receiver_location()), p2i(code_begin()), p2i(code_end())); |
| } |
| |
| void VtableStub::print() const { print_on(tty); } |
| |
| // ----------------------------------------------------------------------------------------- |
| // Implementation of VtableStubs |
| // |
| // For each hash value there's a linked list of vtable stubs (with that |
| // hash value). Each list is anchored in a little hash _table, indexed |
| // by that hash value. |
| |
| VtableStub* volatile VtableStubs::_table[VtableStubs::N]; |
| int VtableStubs::_vtab_stub_size = 0; |
| int VtableStubs::_itab_stub_size = 0; |
| |
| #if defined(PRODUCT) |
| // These values are good for the PRODUCT case (no tracing). |
| static const int first_vtableStub_size = 64; |
| static const int first_itableStub_size = 256; |
| #else |
| // These values are good for the non-PRODUCT case (when tracing can be switched on). |
| // To find out, run test workload with |
| // -Xlog:vtablestubs=Trace -XX:+CountCompiledCalls -XX:+DebugVtables |
| // and use the reported "estimate" value. |
| // Here is a list of observed worst-case values: |
| // vtable itable |
| // aarch64: 460 324 |
| // arm: ? ? |
| // ppc (linux, BE): 404 288 |
| // ppc (linux, LE): 356 276 |
| // ppc (AIX): 416 296 |
| // s390x: 408 256 |
| // Solaris-sparc: 792 348 |
| // x86 (Linux): 670 309 |
| // x86 (MacOS): 682 321 |
| static const int first_vtableStub_size = 1024; |
| static const int first_itableStub_size = 512; |
| #endif |
| |
| |
| void VtableStubs::initialize() { |
| assert(VtableStub::_receiver_location == VMRegImpl::Bad(), "initialized multiple times?"); |
| |
| VtableStub::_receiver_location = SharedRuntime::name_for_receiver(); |
| { |
| MutexLocker ml(VtableStubs_lock, Mutex::_no_safepoint_check_flag); |
| for (int i = 0; i < N; i++) { |
| Atomic::store(&_table[i], (VtableStub*)nullptr); |
| } |
| } |
| } |
| |
| |
| int VtableStubs::code_size_limit(bool is_vtable_stub) { |
| if (is_vtable_stub) { |
| return _vtab_stub_size > 0 ? _vtab_stub_size : first_vtableStub_size; |
| } else { // itable stub |
| return _itab_stub_size > 0 ? _itab_stub_size : first_itableStub_size; |
| } |
| } // code_size_limit |
| |
| |
| void VtableStubs::check_and_set_size_limit(bool is_vtable_stub, |
| int code_size, |
| int padding) { |
| const char* name = is_vtable_stub ? "vtable" : "itable"; |
| |
| guarantee(code_size <= code_size_limit(is_vtable_stub), |
| "buffer overflow in %s stub, code_size is %d, limit is %d", name, code_size, code_size_limit(is_vtable_stub)); |
| |
| if (is_vtable_stub) { |
| if (log_is_enabled(Trace, vtablestubs)) { |
| if ( (_vtab_stub_size > 0) && ((code_size + padding) > _vtab_stub_size) ) { |
| log_trace(vtablestubs)("%s size estimate needed adjustment from %d to %d bytes", |
| name, _vtab_stub_size, code_size + padding); |
| } |
| } |
| if ( (code_size + padding) > _vtab_stub_size ) { |
| _vtab_stub_size = code_size + padding; |
| } |
| } else { // itable stub |
| if (log_is_enabled(Trace, vtablestubs)) { |
| if ( (_itab_stub_size > 0) && ((code_size + padding) > _itab_stub_size) ) { |
| log_trace(vtablestubs)("%s size estimate needed adjustment from %d to %d bytes", |
| name, _itab_stub_size, code_size + padding); |
| } |
| } |
| if ( (code_size + padding) > _itab_stub_size ) { |
| _itab_stub_size = code_size + padding; |
| } |
| } |
| return; |
| } // check_and_set_size_limit |
| |
| |
| void VtableStubs::bookkeeping(MacroAssembler* masm, outputStream* out, VtableStub* s, |
| address npe_addr, address ame_addr, bool is_vtable_stub, |
| int index, int slop_bytes, int index_dependent_slop) { |
| const char* name = is_vtable_stub ? "vtable" : "itable"; |
| const int stub_length = code_size_limit(is_vtable_stub); |
| |
| if (log_is_enabled(Trace, vtablestubs)) { |
| log_trace(vtablestubs)("%s #%d at " PTR_FORMAT ": size: %d, estimate: %d, slop area: %d", |
| name, index, p2i(s->code_begin()), |
| (int)(masm->pc() - s->code_begin()), |
| stub_length, |
| (int)(s->code_end() - masm->pc())); |
| } |
| guarantee(masm->pc() <= s->code_end(), "%s #%d: overflowed buffer, estimated len: %d, actual len: %d, overrun: %d", |
| name, index, stub_length, |
| (int)(masm->pc() - s->code_begin()), |
| (int)(masm->pc() - s->code_end())); |
| assert((masm->pc() + index_dependent_slop) <= s->code_end(), "%s #%d: spare space for 32-bit offset: required = %d, available = %d", |
| name, index, index_dependent_slop, |
| (int)(s->code_end() - masm->pc())); |
| |
| // After the first vtable/itable stub is generated, we have a much |
| // better estimate for the stub size. Remember/update this |
| // estimate after some sanity checks. |
| check_and_set_size_limit(is_vtable_stub, masm->offset(), slop_bytes); |
| s->set_exception_points(npe_addr, ame_addr); |
| } |
| |
| |
| address VtableStubs::find_stub(bool is_vtable_stub, int vtable_index) { |
| assert(vtable_index >= 0, "must be positive"); |
| |
| VtableStub* s; |
| { |
| MutexLocker ml(VtableStubs_lock, Mutex::_no_safepoint_check_flag); |
| s = lookup(is_vtable_stub, vtable_index); |
| if (s == nullptr) { |
| if (is_vtable_stub) { |
| s = create_vtable_stub(vtable_index); |
| } else { |
| s = create_itable_stub(vtable_index); |
| } |
| |
| // Creation of vtable or itable can fail if there is not enough free space in the code cache. |
| if (s == nullptr) { |
| return nullptr; |
| } |
| |
| enter(is_vtable_stub, vtable_index, s); |
| if (PrintAdapterHandlers) { |
| tty->print_cr("Decoding VtableStub %s[%d]@" PTR_FORMAT " [" PTR_FORMAT ", " PTR_FORMAT "] (" SIZE_FORMAT " bytes)", |
| is_vtable_stub? "vtbl": "itbl", vtable_index, p2i(VtableStub::receiver_location()), |
| p2i(s->code_begin()), p2i(s->code_end()), pointer_delta(s->code_end(), s->code_begin(), 1)); |
| Disassembler::decode(s->code_begin(), s->code_end()); |
| } |
| // Notify JVMTI about this stub. The event will be recorded by the enclosing |
| // JvmtiDynamicCodeEventCollector and posted when this thread has released |
| // all locks. Only post this event if a new state is not required. Creating a new state would |
| // cause a safepoint and the caller of this code has a NoSafepointVerifier. |
| if (JvmtiExport::should_post_dynamic_code_generated()) { |
| JvmtiExport::post_dynamic_code_generated_while_holding_locks(is_vtable_stub? "vtable stub": "itable stub", |
| s->code_begin(), s->code_end()); |
| } |
| } |
| } |
| return s->entry_point(); |
| } |
| |
| |
| inline uint VtableStubs::hash(bool is_vtable_stub, int vtable_index){ |
| // Assumption: receiver_location < 4 in most cases. |
| int hash = ((vtable_index << 2) ^ VtableStub::receiver_location()->value()) + vtable_index; |
| return (is_vtable_stub ? ~hash : hash) & mask; |
| } |
| |
| |
| VtableStub* VtableStubs::lookup(bool is_vtable_stub, int vtable_index) { |
| assert_lock_strong(VtableStubs_lock); |
| unsigned hash = VtableStubs::hash(is_vtable_stub, vtable_index); |
| VtableStub* s = Atomic::load(&_table[hash]); |
| while( s && !s->matches(is_vtable_stub, vtable_index)) s = s->next(); |
| return s; |
| } |
| |
| |
| void VtableStubs::enter(bool is_vtable_stub, int vtable_index, VtableStub* s) { |
| assert_lock_strong(VtableStubs_lock); |
| assert(s->matches(is_vtable_stub, vtable_index), "bad vtable stub"); |
| unsigned int h = VtableStubs::hash(is_vtable_stub, vtable_index); |
| // Insert s at the beginning of the corresponding list. |
| s->set_next(Atomic::load(&_table[h])); |
| // Make sure that concurrent readers not taking the mutex observe the writing of "next". |
| Atomic::release_store(&_table[h], s); |
| } |
| |
| VtableStub* VtableStubs::entry_point(address pc) { |
| MutexLocker ml(VtableStubs_lock, Mutex::_no_safepoint_check_flag); |
| VtableStub* stub = (VtableStub*)(pc - VtableStub::entry_offset()); |
| uint hash = VtableStubs::hash(stub->is_vtable_stub(), stub->index()); |
| VtableStub* s; |
| for (s = Atomic::load(&_table[hash]); s != nullptr && s != stub; s = s->next()) {} |
| return (s == stub) ? s : nullptr; |
| } |
| |
| bool VtableStubs::is_icholder_entry(address pc) { |
| assert(contains(pc), "must contain all vtable blobs"); |
| VtableStub* stub = (VtableStub*)(pc - VtableStub::entry_offset()); |
| // itable stubs use CompiledICHolder. |
| return stub->is_itable_stub(); |
| } |
| |
| bool VtableStubs::contains(address pc) { |
| // simple solution for now - we may want to use |
| // a faster way if this function is called often |
| return stub_containing(pc) != nullptr; |
| } |
| |
| |
| VtableStub* VtableStubs::stub_containing(address pc) { |
| for (int i = 0; i < N; i++) { |
| for (VtableStub* s = Atomic::load_acquire(&_table[i]); s != nullptr; s = s->next()) { |
| if (s->contains(pc)) return s; |
| } |
| } |
| return nullptr; |
| } |
| |
| void vtableStubs_init() { |
| VtableStubs::initialize(); |
| } |
| |
| void VtableStubs::vtable_stub_do(void f(VtableStub*)) { |
| for (int i = 0; i < N; i++) { |
| for (VtableStub* s = Atomic::load_acquire(&_table[i]); s != nullptr; s = s->next()) { |
| f(s); |
| } |
| } |
| } |
| |
| |
| //----------------------------------------------------------------------------------------------------- |
| // Non-product code |
| #ifndef PRODUCT |
| |
| extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index) { |
| ResourceMark rm; |
| Klass* klass = receiver->klass(); |
| InstanceKlass* ik = InstanceKlass::cast(klass); |
| klassVtable vt = ik->vtable(); |
| ik->print(); |
| fatal("bad compiled vtable dispatch: receiver " INTPTR_FORMAT ", " |
| "index %d (vtable length %d)", |
| p2i(receiver), index, vt.length()); |
| } |
| |
| #endif // PRODUCT |
