1 /*
   2  * Copyright (c) 1999, 2010, 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 "opto/locknode.hpp"
  27 #include "opto/parse.hpp"
  28 #include "opto/rootnode.hpp"
  29 #include "opto/runtime.hpp"
  30 
  31 //=============================================================================
  32 const RegMask &BoxLockNode::in_RegMask(uint i) const {
  33   return _inmask;
  34 }
  35 
  36 const RegMask &BoxLockNode::out_RegMask() const {
  37   return *Matcher::idealreg2regmask[Op_RegP];
  38 }
  39 
  40 uint BoxLockNode::size_of() const { return sizeof(*this); }
  41 
  42 BoxLockNode::BoxLockNode( int slot ) : Node( Compile::current()->root() ),
  43                                        _slot(slot), _is_eliminated(false) {
  44   init_class_id(Class_BoxLock);
  45   init_flags(Flag_rematerialize);
  46   OptoReg::Name reg = OptoReg::stack2reg(_slot);
  47   _inmask.Insert(reg);
  48 }
  49 
  50 //-----------------------------hash--------------------------------------------
  51 uint BoxLockNode::hash() const {
  52   return Node::hash() + _slot + (_is_eliminated ? Compile::current()->fixed_slots() : 0);
  53 }
  54 
  55 //------------------------------cmp--------------------------------------------
  56 uint BoxLockNode::cmp( const Node &n ) const {
  57   const BoxLockNode &bn = (const BoxLockNode &)n;
  58   return bn._slot == _slot && bn._is_eliminated == _is_eliminated;
  59 }
  60 
  61 OptoReg::Name BoxLockNode::stack_slot(Node* box_node) {
  62   // Chase down the BoxNode
  63   while (!box_node->is_BoxLock()) {
  64     //    if (box_node->is_SpillCopy()) {
  65     //      Node *m = box_node->in(1);
  66     //      if (m->is_Mach() && m->as_Mach()->ideal_Opcode() == Op_StoreP) {
  67     //        box_node = m->in(m->as_Mach()->operand_index(2));
  68     //        continue;
  69     //      }
  70     //    }
  71     assert(box_node->is_SpillCopy() || box_node->is_Phi(), "Bad spill of Lock.");
  72     box_node = box_node->in(1);
  73   }
  74   return box_node->in_RegMask(0).find_first_elem();
  75 }
  76 
  77 //=============================================================================
  78 //-----------------------------hash--------------------------------------------
  79 uint FastLockNode::hash() const { return NO_HASH; }
  80 
  81 //------------------------------cmp--------------------------------------------
  82 uint FastLockNode::cmp( const Node &n ) const {
  83   return (&n == this);                // Always fail except on self
  84 }
  85 
  86 //=============================================================================
  87 //-----------------------------hash--------------------------------------------
  88 uint FastUnlockNode::hash() const { return NO_HASH; }
  89 
  90 //------------------------------cmp--------------------------------------------
  91 uint FastUnlockNode::cmp( const Node &n ) const {
  92   return (&n == this);                // Always fail except on self
  93 }
  94 
  95 //
  96 // Create a counter which counts the number of times this lock is acquired
  97 //
  98 void FastLockNode::create_lock_counter(JVMState* state) {
  99   BiasedLockingNamedCounter* blnc = (BiasedLockingNamedCounter*)
 100            OptoRuntime::new_named_counter(state, NamedCounter::BiasedLockingCounter);
 101   _counters = blnc->counters();
 102 }
 103 
 104 //=============================================================================
 105 //------------------------------do_monitor_enter-------------------------------
 106 void Parse::do_monitor_enter() {
 107   kill_dead_locals();
 108 
 109   // Null check; get casted pointer.
 110   Node *obj = do_null_check(peek(), T_OBJECT);
 111   // Check for locking null object
 112   if (stopped()) return;
 113 
 114   // the monitor object is not part of debug info expression stack
 115   pop();
 116 
 117   // Insert a FastLockNode which takes as arguments the current thread pointer,
 118   // the obj pointer & the address of the stack slot pair used for the lock.
 119   shared_lock(obj);
 120 }
 121 
 122 //------------------------------do_monitor_exit--------------------------------
 123 void Parse::do_monitor_exit() {
 124   kill_dead_locals();
 125 
 126   pop();                        // Pop oop to unlock
 127   // Because monitors are guaranteed paired (else we bail out), we know
 128   // the matching Lock for this Unlock.  Hence we know there is no need
 129   // for a null check on Unlock.
 130   shared_unlock(map()->peek_monitor_box(), map()->peek_monitor_obj());
 131 }