Mercurial > hg > truffle
annotate src/share/vm/opto/locknode.cpp @ 452:00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
Summary: When we encounter marking stack overflow during precleaning of Reference lists, we were using the overflow list mechanism, which can cause problems on account of mutating the mark word of the header because of conflicts with mutator accesses and updates of that field. Instead we should use the usual mechanism for overflow handling in concurrent phases, namely dirtying of the card on which the overflowed object lies. Since precleaning effectively does a form of discovered list processing, albeit with discovery enabled, we needed to adjust some code to be correct in the face of interleaved processing and discovery.
Reviewed-by: apetrusenko, jcoomes
| author | ysr |
|---|---|
| date | Thu, 20 Nov 2008 12:27:41 -0800 |
| parents | d1605aabd0a1 |
| children | 424f9bfe6b96 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 196 | 2 * Copyright 1999-2008 Sun Microsystems, Inc. All Rights Reserved. |
| 0 | 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
| 20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
| 21 * have any questions. | |
| 22 * | |
| 23 */ | |
| 24 | |
| 25 #include "incls/_precompiled.incl" | |
| 26 #include "incls/_locknode.cpp.incl" | |
| 27 | |
| 28 //============================================================================= | |
| 29 const RegMask &BoxLockNode::in_RegMask(uint i) const { | |
| 30 return _inmask; | |
| 31 } | |
| 32 | |
| 33 const RegMask &BoxLockNode::out_RegMask() const { | |
| 34 return *Matcher::idealreg2regmask[Op_RegP]; | |
| 35 } | |
| 36 | |
| 37 uint BoxLockNode::size_of() const { return sizeof(*this); } | |
| 38 | |
|
66
6dbf1a175d6b
6672848: (Escape Analysis) improve lock elimination with EA
kvn
parents:
0
diff
changeset
|
39 BoxLockNode::BoxLockNode( int slot ) : Node( Compile::current()->root() ), |
|
6dbf1a175d6b
6672848: (Escape Analysis) improve lock elimination with EA
kvn
parents:
0
diff
changeset
|
40 _slot(slot), _is_eliminated(false) { |
| 0 | 41 init_class_id(Class_BoxLock); |
| 42 init_flags(Flag_rematerialize); | |
| 43 OptoReg::Name reg = OptoReg::stack2reg(_slot); | |
| 44 _inmask.Insert(reg); | |
| 45 } | |
| 46 | |
| 47 //------------------------------cmp-------------------------------------------- | |
| 48 uint BoxLockNode::cmp( const Node &n ) const { | |
| 49 const BoxLockNode &bn = (const BoxLockNode &)n; | |
| 50 return bn._slot == _slot; | |
| 51 } | |
| 52 | |
| 53 OptoReg::Name BoxLockNode::stack_slot(Node* box_node) { | |
| 54 // Chase down the BoxNode | |
| 55 while (!box_node->is_BoxLock()) { | |
| 56 // if (box_node->is_SpillCopy()) { | |
| 57 // Node *m = box_node->in(1); | |
| 58 // if (m->is_Mach() && m->as_Mach()->ideal_Opcode() == Op_StoreP) { | |
| 59 // box_node = m->in(m->as_Mach()->operand_index(2)); | |
| 60 // continue; | |
| 61 // } | |
| 62 // } | |
| 63 assert(box_node->is_SpillCopy() || box_node->is_Phi(), "Bad spill of Lock."); | |
| 64 box_node = box_node->in(1); | |
| 65 } | |
| 66 return box_node->in_RegMask(0).find_first_elem(); | |
| 67 } | |
| 68 | |
| 69 //============================================================================= | |
| 70 //-----------------------------hash-------------------------------------------- | |
| 71 uint FastLockNode::hash() const { return NO_HASH; } | |
| 72 | |
| 73 //------------------------------cmp-------------------------------------------- | |
| 74 uint FastLockNode::cmp( const Node &n ) const { | |
| 75 return (&n == this); // Always fail except on self | |
| 76 } | |
| 77 | |
| 78 //============================================================================= | |
| 79 //-----------------------------hash-------------------------------------------- | |
| 80 uint FastUnlockNode::hash() const { return NO_HASH; } | |
| 81 | |
| 82 //------------------------------cmp-------------------------------------------- | |
| 83 uint FastUnlockNode::cmp( const Node &n ) const { | |
| 84 return (&n == this); // Always fail except on self | |
| 85 } | |
| 86 | |
| 87 // | |
| 88 // Create a counter which counts the number of times this lock is acquired | |
| 89 // | |
| 90 void FastLockNode::create_lock_counter(JVMState* state) { | |
| 91 BiasedLockingNamedCounter* blnc = (BiasedLockingNamedCounter*) | |
| 92 OptoRuntime::new_named_counter(state, NamedCounter::BiasedLockingCounter); | |
| 93 _counters = blnc->counters(); | |
| 94 } | |
| 95 | |
| 96 //============================================================================= | |
| 97 //------------------------------do_monitor_enter------------------------------- | |
| 98 void Parse::do_monitor_enter() { | |
| 99 kill_dead_locals(); | |
| 100 | |
| 101 // Null check; get casted pointer. | |
| 102 Node *obj = do_null_check(peek(), T_OBJECT); | |
| 103 // Check for locking null object | |
| 104 if (stopped()) return; | |
| 105 | |
| 106 // the monitor object is not part of debug info expression stack | |
| 107 pop(); | |
| 108 | |
| 109 // Insert a FastLockNode which takes as arguments the current thread pointer, | |
| 110 // the obj pointer & the address of the stack slot pair used for the lock. | |
| 111 shared_lock(obj); | |
| 112 } | |
| 113 | |
| 114 //------------------------------do_monitor_exit-------------------------------- | |
| 115 void Parse::do_monitor_exit() { | |
| 116 kill_dead_locals(); | |
| 117 | |
| 118 pop(); // Pop oop to unlock | |
| 119 // Because monitors are guarenteed paired (else we bail out), we know | |
| 120 // the matching Lock for this Unlock. Hence we know there is no need | |
| 121 // for a null check on Unlock. | |
| 122 shared_unlock(map()->peek_monitor_box(), map()->peek_monitor_obj()); | |
| 123 } |