jdk8-mips64-public/hotspot: src/share/vm/code/vtableStubs.cpp@82f9d3b7e317 (annotated)

src/share/vm/code/vtableStubs.cpp@82f9d3b7e317 (annotated)

src/share/vm/code/vtableStubs.cpp

Fri, 30 Mar 2018 20:09:45 +0000

author: poonam
date: Fri, 30 Mar 2018 20:09:45 +0000
changeset 9185: 82f9d3b7e317
parent 6680: 78bbf4d43a14
child 9203: 53eec13fbaa5
child 9834: bb1da64b0492
permissions: -rw-r--r--

8199406: Performance drop with Java JDK 1.8.0_162-b32
Summary: Improve the nmethod unloading times by optimizing the search for an itable stub in VtableStubs array
Reviewed-by: kvn, coleenp, tschatzl

 /*
  * Copyright (c) 1997, 2018, 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/disassembler.hpp"
 #include "memory/allocation.inline.hpp"
 #include "memory/resourceArea.hpp"
 #include "oops/instanceKlass.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"
 #ifdef COMPILER2
 #include "opto/matcher.hpp"
 #endif
 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
 // -----------------------------------------------------------------------------------------
 // Implementation of VtableStub
 address VtableStub::_chunk             = NULL;
 address VtableStub::_chunk_end         = NULL;
 VMReg   VtableStub::_receiver_location = VMRegImpl::Bad();
 void* VtableStub::operator new(size_t size, int code_size) throw() {
   assert(size == sizeof(VtableStub), "mismatched size");
   // compute real VtableStub size (rounded to nearest word)
   const int real_size = round_to(code_size + sizeof(VtableStub), wordSize);
   // malloc them in chunks to minimize header overhead
   const int chunk_factor = 32;
   if (_chunk == NULL || _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 == NULL) {
       return NULL;
     }
     _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 = %d, code = [" INTPTR_FORMAT ", " INTPTR_FORMAT "[)",
              index(), receiver_location(), code_begin(), code_end());
 }
 // -----------------------------------------------------------------------------------------
 // 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* VtableStubs::_table[VtableStubs::N];
 int VtableStubs::_number_of_vtable_stubs = 0;
 void VtableStubs::initialize() {
   VtableStub::_receiver_location = SharedRuntime::name_for_receiver();
   {
     MutexLocker ml(VtableStubs_lock);
     assert(_number_of_vtable_stubs == 0, "potential performance bug: VtableStubs initialized more than once");
     assert(is_power_of_2(N), "N must be a power of 2");
     for (int i = 0; i < N; i++) {
       _table[i] = NULL;
     }
   }
 }
 address VtableStubs::find_stub(bool is_vtable_stub, int vtable_index) {
   assert(vtable_index >= 0, "must be positive");
   VtableStub* s = ShareVtableStubs ? lookup(is_vtable_stub, vtable_index) : NULL;
   if (s == NULL) {
     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 == NULL) {
       return NULL;
     }
     enter(is_vtable_stub, vtable_index, s);
     if (PrintAdapterHandlers) {
       tty->print_cr("Decoding VtableStub %s[%d]@%d",
                     is_vtable_stub? "vtbl": "itbl", vtable_index, VtableStub::receiver_location());
       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.
     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) {
   MutexLocker ml(VtableStubs_lock);
   unsigned hash = VtableStubs::hash(is_vtable_stub, vtable_index);
   VtableStub* s = _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) {
   MutexLocker ml(VtableStubs_lock);
   assert(s->matches(is_vtable_stub, vtable_index), "bad vtable stub");
   unsigned int h = VtableStubs::hash(is_vtable_stub, vtable_index);
   // enter s at the beginning of the corresponding list
   s->set_next(_table[h]);
   _table[h] = s;
   _number_of_vtable_stubs++;
 }
 VtableStub* VtableStubs::entry_point(address pc) {
   MutexLocker ml(VtableStubs_lock);
   VtableStub* stub = (VtableStub*)(pc - VtableStub::entry_offset());
   uint hash = VtableStubs::hash(stub->is_vtable_stub(), stub->index());
   VtableStub* s;
   for (s = _table[hash]; s != NULL && s != stub; s = s->next()) {}
   if (s == stub) {
     return s;
   }
   return NULL;
 }
 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) != NULL;
 }
 VtableStub* VtableStubs::stub_containing(address pc) {
   // Note: No locking needed since any change to the data structure
   //       happens with an atomic store into it (we don't care about
   //       consistency with the _number_of_vtable_stubs counter).
   for (int i = 0; i < N; i++) {
     for (VtableStub* s = _table[i]; s != NULL; s = s->next()) {
       if (s->contains(pc)) return s;
     }
   }
   return NULL;
 }
 void vtableStubs_init() {
   VtableStubs::initialize();
 }
 void VtableStubs::vtable_stub_do(void f(VtableStub*)) {
     for (int i = 0; i < N; i++) {
         for (VtableStub* s = _table[i]; s != NULL; 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;
   HandleMark hm;
   Klass* klass = receiver->klass();
   InstanceKlass* ik = InstanceKlass::cast(klass);
   klassVtable* vt = ik->vtable();
   ik->print();
   fatal(err_msg("bad compiled vtable dispatch: receiver " INTPTR_FORMAT ", "
                 "index %d (vtable length %d)",
                 (address)receiver, index, vt->length()));
 }
 #endif // Product

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/code/vtableStubs.cpp@82f9d3b7e317 (annotated)

src/share/vm/code/vtableStubs.cpp