view src/share/vm/opto/parseHelper.cpp @ 2346:e1162778c1c8

7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer. Reviewed-by: kvn, iveresov, never, tonyp, dholmes
author johnc
date Thu, 07 Apr 2011 09:53:20 -0700
parents 4b29a725c43c
children 52b5d32fbfaf 069ab3f976d3
line wrap: on
line source
 * Copyright (c) 1998, 2010, Oracle and/or its affiliates. All rights reserved.
 * 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 if you need additional information or have any
 * questions.

#include "precompiled.hpp"
#include "classfile/systemDictionary.hpp"
#include "compiler/compileLog.hpp"
#include "oops/objArrayKlass.hpp"
#include "opto/addnode.hpp"
#include "opto/memnode.hpp"
#include "opto/mulnode.hpp"
#include "opto/parse.hpp"
#include "opto/rootnode.hpp"
#include "opto/runtime.hpp"
#include "runtime/sharedRuntime.hpp"

//------------------------------make_dtrace_method_entry_exit ----------------
// Dtrace -- record entry or exit of a method if compiled with dtrace support
void GraphKit::make_dtrace_method_entry_exit(ciMethod* method, bool is_entry) {
  const TypeFunc *call_type    = OptoRuntime::dtrace_method_entry_exit_Type();
  address         call_address = is_entry ? CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_entry) :
                                            CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_exit);
  const char     *call_name    = is_entry ? "dtrace_method_entry" : "dtrace_method_exit";

  // Get base of thread-local storage area
  Node* thread = _gvn.transform( new (C, 1) ThreadLocalNode() );

  // Get method
  const TypeInstPtr* method_type = TypeInstPtr::make(TypePtr::Constant, method->klass(), true, method, 0);
  Node *method_node = _gvn.transform( ConNode::make(C, method_type) );


  // For some reason, this call reads only raw memory.
  const TypePtr* raw_adr_type = TypeRawPtr::BOTTOM;
  make_runtime_call(RC_LEAF | RC_NARROW_MEM,
                    call_type, call_address,
                    call_name, raw_adr_type,
                    thread, method_node);

void Parse::do_checkcast() {
  bool will_link;
  ciKlass* klass = iter().get_klass(will_link);

  Node *obj = peek();

  // Throw uncommon trap if class is not loaded or the value we are casting
  // _from_ is not loaded, and value is not null.  If the value _is_ NULL,
  // then the checkcast does nothing.
  const TypeInstPtr *tp = _gvn.type(obj)->isa_instptr();
  if (!will_link || (tp && !tp->is_loaded())) {
    if (C->log() != NULL) {
      if (!will_link) {
        C->log()->elem("assert_null reason='checkcast' klass='%d'",
      if (tp && !tp->is_loaded()) {
        // %%% Cannot happen?
        C->log()->elem("assert_null reason='checkcast source' klass='%d'",
    do_null_assert(obj, T_OBJECT);
    assert( stopped() || _gvn.type(peek())->higher_equal(TypePtr::NULL_PTR), "what's left behind is null" );
    if (!stopped()) {

  Node *res = gen_checkcast(obj, makecon(TypeKlassPtr::make(klass)) );

  // Pop from stack AFTER gen_checkcast because it can uncommon trap and
  // the debug info has to be correct.

void Parse::do_instanceof() {
  if (stopped())  return;
  // We would like to return false if class is not loaded, emitting a
  // dependency, but Java requires instanceof to load its operand.

  // Throw uncommon trap if class is not loaded
  bool will_link;
  ciKlass* klass = iter().get_klass(will_link);

  if (!will_link) {
    if (C->log() != NULL) {
      C->log()->elem("assert_null reason='instanceof' klass='%d'",
    do_null_assert(peek(), T_OBJECT);
    assert( stopped() || _gvn.type(peek())->higher_equal(TypePtr::NULL_PTR), "what's left behind is null" );
    if (!stopped()) {
      // The object is now known to be null.
      // Shortcut the effect of gen_instanceof and return "false" directly.
      pop();                   // pop the null
      push(_gvn.intcon(0));    // push false answer

  // Push the bool result back on stack
  Node* res = gen_instanceof(peek(), makecon(TypeKlassPtr::make(klass)));

  // Pop from stack AFTER gen_instanceof because it can uncommon trap.

// pull array from stack and check that the store is valid
void Parse::array_store_check() {

  // Shorthand access to array store elements
  Node *obj = stack(_sp-1);
  Node *idx = stack(_sp-2);
  Node *ary = stack(_sp-3);

  if (_gvn.type(obj) == TypePtr::NULL_PTR) {
    // There's never a type check on null values.
    // This cutout lets us avoid the uncommon_trap(Reason_array_check)
    // below, which turns into a performance liability if the
    // gen_checkcast folds up completely.

  // Extract the array klass type
  int klass_offset = oopDesc::klass_offset_in_bytes();
  Node* p = basic_plus_adr( ary, ary, klass_offset );
  // p's type is array-of-OOPS plus klass_offset
  Node* array_klass = _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), p, TypeInstPtr::KLASS) );
  // Get the array klass
  const TypeKlassPtr *tak = _gvn.type(array_klass)->is_klassptr();

  // array_klass's type is generally INexact array-of-oop.  Heroically
  // cast the array klass to EXACT array and uncommon-trap if the cast
  // fails.
  bool always_see_exact_class = false;
  if (MonomorphicArrayCheck
      && !too_many_traps(Deoptimization::Reason_array_check)) {
    always_see_exact_class = true;
    // (If no MDO at all, hope for the best, until a trap actually occurs.)

  // Is the array klass is exactly its defined type?
  if (always_see_exact_class && !tak->klass_is_exact()) {
    // Make a constant out of the inexact array klass
    const TypeKlassPtr *extak = tak->cast_to_exactness(true)->is_klassptr();
    Node* con = makecon(extak);
    Node* cmp = _gvn.transform(new (C, 3) CmpPNode( array_klass, con ));
    Node* bol = _gvn.transform(new (C, 2) BoolNode( cmp, BoolTest::eq ));
    Node* ctrl= control();
    { BuildCutout unless(this, bol, PROB_MAX);
    if (stopped()) {          // MUST uncommon-trap?
      set_control(ctrl);      // Then Don't Do It, just fall into the normal checking
    } else {                  // Cast array klass to exactness:
      // Use the exact constant value we know it is.
      CompileLog* log = C->log();
      if (log != NULL) {
        log->elem("cast_up reason='monomorphic_array' from='%d' to='(exact)'",
      array_klass = con;      // Use cast value moving forward

  // Come here for polymorphic array klasses

  // Extract the array element class
  int element_klass_offset = objArrayKlass::element_klass_offset_in_bytes() + sizeof(oopDesc);
  Node *p2 = basic_plus_adr(array_klass, array_klass, element_klass_offset);
  Node *a_e_klass = _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), p2, tak) );

  // Check (the hard way) and throw if not a subklass.
  // Result is ignored, we just need the CFG effects.
  gen_checkcast( obj, a_e_klass );

void Parse::emit_guard_for_new(ciInstanceKlass* klass) {
  // Emit guarded new
  //   if (klass->_init_thread != current_thread ||
  //       klass->_init_state != being_initialized)
  //      uncommon_trap
  Node* cur_thread = _gvn.transform( new (C, 1) ThreadLocalNode() );
  Node* merge = new (C, 3) RegionNode(3);
  _gvn.set_type(merge, Type::CONTROL);
  Node* kls = makecon(TypeKlassPtr::make(klass));

  Node* init_thread_offset = _gvn.MakeConX(instanceKlass::init_thread_offset_in_bytes() + klassOopDesc::klass_part_offset_in_bytes());
  Node* adr_node = basic_plus_adr(kls, kls, init_thread_offset);
  Node* init_thread = make_load(NULL, adr_node, TypeRawPtr::BOTTOM, T_ADDRESS);
  Node *tst   = Bool( CmpP( init_thread, cur_thread), BoolTest::eq);
  IfNode* iff = create_and_map_if(control(), tst, PROB_ALWAYS, COUNT_UNKNOWN);
  merge->set_req(1, IfFalse(iff));

  Node* init_state_offset = _gvn.MakeConX(instanceKlass::init_state_offset_in_bytes() + klassOopDesc::klass_part_offset_in_bytes());
  adr_node = basic_plus_adr(kls, kls, init_state_offset);
  Node* init_state = make_load(NULL, adr_node, TypeInt::INT, T_INT);
  Node* being_init = _gvn.intcon(instanceKlass::being_initialized);
  tst   = Bool( CmpI( init_state, being_init), BoolTest::eq);
  iff = create_and_map_if(control(), tst, PROB_ALWAYS, COUNT_UNKNOWN);
  merge->set_req(2, IfFalse(iff));

  PreserveJVMState pjvms(this);


void Parse::do_new() {

  bool will_link;
  ciInstanceKlass* klass = iter().get_klass(will_link)->as_instance_klass();
  assert(will_link, "_new: typeflow responsibility");

  // Should initialize, or throw an InstantiationError?
  if (!klass->is_initialized() && !klass->is_being_initialized() ||
      klass->is_abstract() || klass->is_interface() ||
      klass->name() == ciSymbol::java_lang_Class() ||
      iter().is_unresolved_klass()) {
  if (klass->is_being_initialized()) {

  Node* kls = makecon(TypeKlassPtr::make(klass));
  Node* obj = new_instance(kls);

  // Push resultant oop onto stack

  // Keep track of whether opportunities exist for StringBuilder
  // optimizations.
  if (OptimizeStringConcat &&
      (klass == C->env()->StringBuilder_klass() ||
       klass == C->env()->StringBuffer_klass())) {

#ifndef PRODUCT
// Debug dump of the mapping from address types to MergeMemNode indices.
void Parse::dump_map_adr_mem() const {
  tty->print_cr("--- Mapping from address types to memory Nodes ---");
  MergeMemNode *mem = map() == NULL ? NULL : (map()->memory()->is_MergeMem() ?
                                      map()->memory()->as_MergeMem() : NULL);
  for (uint i = 0; i < (uint)C->num_alias_types(); i++) {
    // Node mapping, if any
    if (mem && i < mem->req() && mem->in(i) && mem->in(i) != mem->empty_memory()) {
    } else {


// parser methods for profiling

//----------------------test_counter_against_threshold ------------------------
void Parse::test_counter_against_threshold(Node* cnt, int limit) {
  // Test the counter against the limit and uncommon trap if greater.

  // This code is largely copied from the range check code in
  // array_addressing()

  // Test invocation count vs threshold
  Node *threshold = makecon(TypeInt::make(limit));
  Node *chk   = _gvn.transform( new (C, 3) CmpUNode( cnt, threshold) );
  BoolTest::mask btest = BoolTest::lt;
  Node *tst   = _gvn.transform( new (C, 2) BoolNode( chk, btest) );
  // Branch to failure if threshold exceeded
  { BuildCutout unless(this, tst, PROB_ALWAYS);

void Parse::increment_and_test_invocation_counter(int limit) {
  if (!count_invocations()) return;

  // Get the methodOop node.
  const TypePtr* adr_type = TypeOopPtr::make_from_constant(method());
  Node *methodOop_node = makecon(adr_type);

  // Load the interpreter_invocation_counter from the methodOop.
  int offset = methodOopDesc::interpreter_invocation_counter_offset_in_bytes();
  Node* adr_node = basic_plus_adr(methodOop_node, methodOop_node, offset);
  Node* cnt = make_load(NULL, adr_node, TypeInt::INT, T_INT, adr_type);

  test_counter_against_threshold(cnt, limit);

  // Add one to the counter and store
  Node* incr = _gvn.transform(new (C, 3) AddINode(cnt, _gvn.intcon(1)));
  store_to_memory( NULL, adr_node, incr, T_INT, adr_type );

Node* Parse::method_data_addressing(ciMethodData* md, ciProfileData* data, ByteSize counter_offset, Node* idx, uint stride) {
  // Get offset within methodDataOop of the data array
  ByteSize data_offset = methodDataOopDesc::data_offset();

  // Get cell offset of the ProfileData within data array
  int cell_offset = md->dp_to_di(data->dp());

  // Add in counter_offset, the # of bytes into the ProfileData of counter or flag
  int offset = in_bytes(data_offset) + cell_offset + in_bytes(counter_offset);

  const TypePtr* adr_type = TypeOopPtr::make_from_constant(md);
  Node* mdo = makecon(adr_type);
  Node* ptr = basic_plus_adr(mdo, mdo, offset);

  if (stride != 0) {
    Node* str = _gvn.MakeConX(stride);
    Node* scale = _gvn.transform( new (C, 3) MulXNode( idx, str ) );
    ptr   = _gvn.transform( new (C, 4) AddPNode( mdo, ptr, scale ) );

  return ptr;

void Parse::increment_md_counter_at(ciMethodData* md, ciProfileData* data, ByteSize counter_offset, Node* idx, uint stride) {
  Node* adr_node = method_data_addressing(md, data, counter_offset, idx, stride);

  const TypePtr* adr_type = _gvn.type(adr_node)->is_ptr();
  Node* cnt  = make_load(NULL, adr_node, TypeInt::INT, T_INT, adr_type);
  Node* incr = _gvn.transform(new (C, 3) AddINode(cnt, _gvn.intcon(DataLayout::counter_increment)));
  store_to_memory(NULL, adr_node, incr, T_INT, adr_type );

void Parse::test_for_osr_md_counter_at(ciMethodData* md, ciProfileData* data, ByteSize counter_offset, int limit) {
  Node* adr_node = method_data_addressing(md, data, counter_offset);

  const TypePtr* adr_type = _gvn.type(adr_node)->is_ptr();
  Node* cnt  = make_load(NULL, adr_node, TypeInt::INT, T_INT, adr_type);

  test_counter_against_threshold(cnt, limit);

void Parse::set_md_flag_at(ciMethodData* md, ciProfileData* data, int flag_constant) {
  Node* adr_node = method_data_addressing(md, data, DataLayout::flags_offset());

  const TypePtr* adr_type = _gvn.type(adr_node)->is_ptr();
  Node* flags = make_load(NULL, adr_node, TypeInt::BYTE, T_BYTE, adr_type);
  Node* incr = _gvn.transform(new (C, 3) OrINode(flags, _gvn.intcon(flag_constant)));
  store_to_memory(NULL, adr_node, incr, T_BYTE, adr_type);

void Parse::profile_taken_branch(int target_bci, bool force_update) {
  // This is a potential osr_site if we have a backedge.
  int cur_bci = bci();
  bool osr_site =
    (target_bci <= cur_bci) && count_invocations() && UseOnStackReplacement;

  // If we are going to OSR, restart at the target bytecode.

  // To do: factor out the the limit calculations below. These duplicate
  // the similar limit calculations in the interpreter.

  if (method_data_update() || force_update) {
    ciMethodData* md = method()->method_data();
    assert(md != NULL, "expected valid ciMethodData");
    ciProfileData* data = md->bci_to_data(cur_bci);
    assert(data->is_JumpData(), "need JumpData for taken branch");
    increment_md_counter_at(md, data, JumpData::taken_offset());

  // In the new tiered system this is all we need to do. In the old
  // (c2 based) tiered sytem we must do the code below.
#ifndef TIERED
  if (method_data_update()) {
    ciMethodData* md = method()->method_data();
    if (osr_site) {
      ciProfileData* data = md->bci_to_data(cur_bci);
      int limit = (CompileThreshold
                   * (OnStackReplacePercentage - InterpreterProfilePercentage)) / 100;
      test_for_osr_md_counter_at(md, data, JumpData::taken_offset(), limit);
  } else {
    // With method data update off, use the invocation counter to trigger an
    // OSR compilation, as done in the interpreter.
    if (osr_site) {
      int limit = (CompileThreshold * OnStackReplacePercentage) / 100;
#endif // TIERED

  // Restore the original bytecode.

void Parse::profile_not_taken_branch(bool force_update) {

  if (method_data_update() || force_update) {
    ciMethodData* md = method()->method_data();
    assert(md != NULL, "expected valid ciMethodData");
    ciProfileData* data = md->bci_to_data(bci());
    assert(data->is_BranchData(), "need BranchData for not taken branch");
    increment_md_counter_at(md, data, BranchData::not_taken_offset());


void Parse::profile_call(Node* receiver) {
  if (!method_data_update()) return;

  switch (bc()) {
  case Bytecodes::_invokevirtual:
  case Bytecodes::_invokeinterface:
  case Bytecodes::_invokestatic:
  case Bytecodes::_invokedynamic:
  case Bytecodes::_invokespecial:
  default: fatal("unexpected call bytecode");

void Parse::profile_generic_call() {
  assert(method_data_update(), "must be generating profile code");

  ciMethodData* md = method()->method_data();
  assert(md != NULL, "expected valid ciMethodData");
  ciProfileData* data = md->bci_to_data(bci());
  assert(data->is_CounterData(), "need CounterData for not taken branch");
  increment_md_counter_at(md, data, CounterData::count_offset());

void Parse::profile_receiver_type(Node* receiver) {
  assert(method_data_update(), "must be generating profile code");

  ciMethodData* md = method()->method_data();
  assert(md != NULL, "expected valid ciMethodData");
  ciProfileData* data = md->bci_to_data(bci());
  assert(data->is_ReceiverTypeData(), "need ReceiverTypeData here");

  // Skip if we aren't tracking receivers
  if (TypeProfileWidth < 1) {
    increment_md_counter_at(md, data, CounterData::count_offset());
  ciReceiverTypeData* rdata = (ciReceiverTypeData*)data->as_ReceiverTypeData();

  Node* method_data = method_data_addressing(md, rdata, in_ByteSize(0));

  // Using an adr_type of TypePtr::BOTTOM to work around anti-dep problems.
  // A better solution might be to use TypeRawPtr::BOTTOM with RC_NARROW_MEM.
  make_runtime_call(RC_LEAF, OptoRuntime::profile_receiver_type_Type(),
                    method_data, receiver);

void Parse::profile_ret(int target_bci) {
  if (!method_data_update()) return;

  // Skip if we aren't tracking ret targets
  if (TypeProfileWidth < 1) return;

  ciMethodData* md = method()->method_data();
  assert(md != NULL, "expected valid ciMethodData");
  ciProfileData* data = md->bci_to_data(bci());
  assert(data->is_RetData(), "need RetData for ret");
  ciRetData* ret_data = (ciRetData*)data->as_RetData();

  // Look for the target_bci is already in the table
  uint row;
  bool table_full = true;
  for (row = 0; row < ret_data->row_limit(); row++) {
    int key = ret_data->bci(row);
    table_full &= (key != RetData::no_bci);
    if (key == target_bci) break;

  if (row >= ret_data->row_limit()) {
    // The target_bci was not found in the table.
    if (!table_full) {
      // XXX: Make slow call to update RetData

  // the target_bci is already in the table
  increment_md_counter_at(md, data, RetData::bci_count_offset(row));

void Parse::profile_null_checkcast() {
  // Set the null-seen flag, done in conjunction with the usual null check. We
  // never unset the flag, so this is a one-way switch.
  if (!method_data_update()) return;

  ciMethodData* md = method()->method_data();
  assert(md != NULL, "expected valid ciMethodData");
  ciProfileData* data = md->bci_to_data(bci());
  assert(data->is_BitData(), "need BitData for checkcast");
  set_md_flag_at(md, data, BitData::null_seen_byte_constant());

void Parse::profile_switch_case(int table_index) {
  if (!method_data_update()) return;

  ciMethodData* md = method()->method_data();
  assert(md != NULL, "expected valid ciMethodData");

  ciProfileData* data = md->bci_to_data(bci());
  assert(data->is_MultiBranchData(), "need MultiBranchData for switch case");
  if (table_index >= 0) {
    increment_md_counter_at(md, data, MultiBranchData::case_count_offset(table_index));
  } else {
    increment_md_counter_at(md, data, MultiBranchData::default_count_offset());