# HG changeset patch # User blacklion # Date 1213880540 25200 # Node ID 66cdb30329a6fef07b489e6c3fed45b64b3177f9 # Parent f139919897d29ca73b2d0716fc7d2a6973a69483# Parent 4f91c08b3e4498213a9c5a24898f7d9c38cf86fb Merge diff -r f139919897d2 -r 66cdb30329a6 .hgtags --- a/.hgtags Tue Jun 17 09:59:59 2008 -0700 +++ b/.hgtags Thu Jun 19 06:02:20 2008 -0700 @@ -2,3 +2,4 @@ 7836be3e92d0a4f9ee7566f602c91f5609534e66 jdk7-b25 ad0b851458ff9d1d490ed2d79bb84f75a9fdb753 jdk7-b26 e3d2692f8442e2d951166dc9bd9a330684754438 jdk7-b27 +c14dab40ed9bf45ad21150bd70c9c80cdf655415 jdk7-b28 diff -r f139919897d2 -r 66cdb30329a6 agent/src/share/classes/sun/jvm/hotspot/memory/CompactibleFreeListSpace.java --- a/agent/src/share/classes/sun/jvm/hotspot/memory/CompactibleFreeListSpace.java Tue Jun 17 09:59:59 2008 -0700 +++ b/agent/src/share/classes/sun/jvm/hotspot/memory/CompactibleFreeListSpace.java Thu Jun 19 06:02:20 2008 -0700 @@ -189,7 +189,7 @@ cur = cur.addOffsetTo(adjustObjectSizeInBytes(size)); } - if (FreeChunk.secondWordIndicatesFreeChunk(dbg.getAddressValue(klassOop))) { + if (FreeChunk.indicatesFreeChunk(cur)) { if (! cur.equals(regionStart)) { res.add(new MemRegion(regionStart, cur)); } diff -r f139919897d2 -r 66cdb30329a6 agent/src/share/classes/sun/jvm/hotspot/memory/FreeChunk.java --- a/agent/src/share/classes/sun/jvm/hotspot/memory/FreeChunk.java Tue Jun 17 09:59:59 2008 -0700 +++ b/agent/src/share/classes/sun/jvm/hotspot/memory/FreeChunk.java Thu Jun 19 06:02:20 2008 -0700 @@ -28,6 +28,7 @@ import sun.jvm.hotspot.debugger.*; import sun.jvm.hotspot.types.*; import sun.jvm.hotspot.runtime.*; +import sun.jvm.hotspot.oops.*; public class FreeChunk extends VMObject { static { @@ -42,13 +43,13 @@ Type type = db.lookupType("FreeChunk"); nextField = type.getAddressField("_next"); prevField = type.getAddressField("_prev"); - sizeField = type.getCIntegerField("_size"); + sizeField = type.getAddressField("_size"); } // Fields private static AddressField nextField; private static AddressField prevField; - private static CIntegerField sizeField; + private static AddressField sizeField; // Accessors public FreeChunk next() { @@ -61,20 +62,34 @@ } public long size() { - return sizeField.getValue(addr); + if (VM.getVM().isCompressedOopsEnabled()) { + Mark mark = new Mark(sizeField.getValue(addr)); + return mark.getSize(); + } else { + Address size = sizeField.getValue(addr); + Debugger dbg = VM.getVM().getDebugger(); + return dbg.getAddressValue(size); + } } public FreeChunk(Address addr) { super(addr); } - public static boolean secondWordIndicatesFreeChunk(long word) { - return (word & 0x1L) == 0x1L; + public static boolean indicatesFreeChunk(Address cur) { + FreeChunk f = new FreeChunk(cur); + return f.isFree(); } public boolean isFree() { - Debugger dbg = VM.getVM().getDebugger(); - Address prev = prevField.getValue(addr); - return secondWordIndicatesFreeChunk(dbg.getAddressValue(prev)); + if (VM.getVM().isCompressedOopsEnabled()) { + Mark mark = new Mark(sizeField.getValue(addr)); + return mark.isCmsFreeChunk(); + } else { + Address prev = prevField.getValue(addr); + Debugger dbg = VM.getVM().getDebugger(); + long word = dbg.getAddressValue(prev); + return (word & 0x1L) == 0x1L; + } } } diff -r f139919897d2 -r 66cdb30329a6 agent/src/share/classes/sun/jvm/hotspot/oops/Mark.java --- a/agent/src/share/classes/sun/jvm/hotspot/oops/Mark.java Tue Jun 17 09:59:59 2008 -0700 +++ b/agent/src/share/classes/sun/jvm/hotspot/oops/Mark.java Thu Jun 19 06:02:20 2008 -0700 @@ -79,6 +79,11 @@ noHashInPlace = db.lookupLongConstant("markOopDesc::no_hash_in_place").longValue(); noLockInPlace = db.lookupLongConstant("markOopDesc::no_lock_in_place").longValue(); maxAge = db.lookupLongConstant("markOopDesc::max_age").longValue(); + + /* Constants in markOop used by CMS. */ + cmsShift = db.lookupLongConstant("markOopDesc::cms_shift").longValue(); + cmsMask = db.lookupLongConstant("markOopDesc::cms_mask").longValue(); + sizeShift = db.lookupLongConstant("markOopDesc::size_shift").longValue(); } // Field accessors @@ -120,6 +125,11 @@ private static long maxAge; + /* Constants in markOop used by CMS. */ + private static long cmsShift; + private static long cmsMask; + private static long sizeShift; + public Mark(Address addr) { super(addr); } @@ -290,4 +300,11 @@ // // // Recover address of oop from encoded form used in mark // inline void* decode_pointer() { return clear_lock_bits(); } + + // Copy markOop methods for CMS here. + public boolean isCmsFreeChunk() { + return isUnlocked() && + (Bits.maskBitsLong(value() >> cmsShift, cmsMask) & 0x1L) == 0x1L; + } + public long getSize() { return (long)(value() >> sizeShift); } } diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/classfile/vmSymbols.hpp --- a/src/share/vm/classfile/vmSymbols.hpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/classfile/vmSymbols.hpp Thu Jun 19 06:02:20 2008 -0700 @@ -283,6 +283,7 @@ template(cache_field_name, "cache") \ template(value_name, "value") \ template(frontCacheEnabled_name, "frontCacheEnabled") \ + template(stringCacheEnabled_name, "stringCacheEnabled") \ \ /* non-intrinsic name/signature pairs: */ \ template(register_method_name, "register") \ diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp --- a/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp Thu Jun 19 06:02:20 2008 -0700 @@ -805,28 +805,30 @@ // This must be volatile, or else there is a danger that the compiler // will compile the code below into a sometimes-infinite loop, by keeping // the value read the first time in a register. - oop o = (oop)p; - volatile oop* second_word_addr = o->klass_addr(); while (true) { - klassOop k = (klassOop)(*second_word_addr); // We must do this until we get a consistent view of the object. - if (FreeChunk::secondWordIndicatesFreeChunk((intptr_t)k)) { - FreeChunk* fc = (FreeChunk*)p; - volatile size_t* sz_addr = (volatile size_t*)(fc->size_addr()); - size_t res = (*sz_addr); - klassOop k2 = (klassOop)(*second_word_addr); // Read to confirm. - if (k == k2) { + if (FreeChunk::indicatesFreeChunk(p)) { + volatile FreeChunk* fc = (volatile FreeChunk*)p; + size_t res = fc->size(); + // If the object is still a free chunk, return the size, else it + // has been allocated so try again. + if (FreeChunk::indicatesFreeChunk(p)) { assert(res != 0, "Block size should not be 0"); return res; } - } else if (k != NULL) { - assert(k->is_oop(true /* ignore mark word */), "Should really be klass oop."); - assert(o->is_parsable(), "Should be parsable"); - assert(o->is_oop(true /* ignore mark word */), "Should be an oop."); - size_t res = o->size_given_klass(k->klass_part()); - res = adjustObjectSize(res); - assert(res != 0, "Block size should not be 0"); - return res; + } else { + // must read from what 'p' points to in each loop. + klassOop k = ((volatile oopDesc*)p)->klass_or_null(); + if (k != NULL) { + assert(k->is_oop(true /* ignore mark word */), "Should really be klass oop."); + oop o = (oop)p; + assert(o->is_parsable(), "Should be parsable"); + assert(o->is_oop(true /* ignore mark word */), "Should be an oop."); + size_t res = o->size_given_klass(k->klass_part()); + res = adjustObjectSize(res); + assert(res != 0, "Block size should not be 0"); + return res; + } } } } @@ -845,31 +847,31 @@ // This must be volatile, or else there is a danger that the compiler // will compile the code below into a sometimes-infinite loop, by keeping // the value read the first time in a register. - oop o = (oop)p; - volatile oop* second_word_addr = o->klass_addr(); DEBUG_ONLY(uint loops = 0;) while (true) { - klassOop k = (klassOop)(*second_word_addr); // We must do this until we get a consistent view of the object. - if (FreeChunk::secondWordIndicatesFreeChunk((intptr_t)k)) { - FreeChunk* fc = (FreeChunk*)p; - volatile size_t* sz_addr = (volatile size_t*)(fc->size_addr()); - size_t res = (*sz_addr); - klassOop k2 = (klassOop)(*second_word_addr); // Read to confirm. - if (k == k2) { + if (FreeChunk::indicatesFreeChunk(p)) { + volatile FreeChunk* fc = (volatile FreeChunk*)p; + size_t res = fc->size(); + if (FreeChunk::indicatesFreeChunk(p)) { assert(res != 0, "Block size should not be 0"); assert(loops == 0, "Should be 0"); return res; } - } else if (k != NULL && o->is_parsable()) { - assert(k->is_oop(), "Should really be klass oop."); - assert(o->is_oop(), "Should be an oop"); - size_t res = o->size_given_klass(k->klass_part()); - res = adjustObjectSize(res); - assert(res != 0, "Block size should not be 0"); - return res; } else { - return c->block_size_if_printezis_bits(p); + // must read from what 'p' points to in each loop. + klassOop k = ((volatile oopDesc*)p)->klass_or_null(); + if (k != NULL && ((oopDesc*)p)->is_parsable()) { + assert(k->is_oop(), "Should really be klass oop."); + oop o = (oop)p; + assert(o->is_oop(), "Should be an oop"); + size_t res = o->size_given_klass(k->klass_part()); + res = adjustObjectSize(res); + assert(res != 0, "Block size should not be 0"); + return res; + } else { + return c->block_size_if_printezis_bits(p); + } } assert(loops == 0, "Can loop at most once"); DEBUG_ONLY(loops++;) @@ -907,9 +909,8 @@ // and those objects (if garbage) may have been modified to hold // live range information. // assert(ParallelGCThreads > 0 || _bt.block_start(p) == p, "Should be a block boundary"); - klassOop k = oop(p)->klass(); - intptr_t ki = (intptr_t)k; - if (FreeChunk::secondWordIndicatesFreeChunk(ki)) return false; + if (FreeChunk::indicatesFreeChunk(p)) return false; + klassOop k = oop(p)->klass_or_null(); if (k != NULL) { // Ignore mark word because it may have been used to // chain together promoted objects (the last one @@ -1027,7 +1028,7 @@ FreeChunk* fc = (FreeChunk*)res; fc->markNotFree(); assert(!fc->isFree(), "shouldn't be marked free"); - assert(oop(fc)->klass() == NULL, "should look uninitialized"); + assert(oop(fc)->klass_or_null() == NULL, "should look uninitialized"); // Verify that the block offset table shows this to // be a single block, but not one which is unallocated. _bt.verify_single_block(res, size); @@ -2593,7 +2594,7 @@ } res->markNotFree(); assert(!res->isFree(), "shouldn't be marked free"); - assert(oop(res)->klass() == NULL, "should look uninitialized"); + assert(oop(res)->klass_or_null() == NULL, "should look uninitialized"); // mangle a just allocated object with a distinct pattern. debug_only(res->mangleAllocated(word_sz)); return (HeapWord*)res; diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp --- a/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Thu Jun 19 06:02:20 2008 -0700 @@ -190,7 +190,8 @@ // depends on this property. debug_only( FreeChunk* junk = NULL; - assert(junk->prev_addr() == (void*)(oop(junk)->klass_addr()), + assert(UseCompressedOops || + junk->prev_addr() == (void*)(oop(junk)->klass_addr()), "Offset of FreeChunk::_prev within FreeChunk must match" " that of OopDesc::_klass within OopDesc"); ) @@ -1039,7 +1040,7 @@ // mark end of object } // check that oop looks uninitialized - assert(oop(start)->klass() == NULL, "_klass should be NULL"); + assert(oop(start)->klass_or_null() == NULL, "_klass should be NULL"); } void CMSCollector::promoted(bool par, HeapWord* start, @@ -1309,17 +1310,25 @@ } } oop obj = oop(obj_ptr); - assert(obj->klass() == NULL, "Object should be uninitialized here."); + assert(obj->klass_or_null() == NULL, "Object should be uninitialized here."); // Otherwise, copy the object. Here we must be careful to insert the // klass pointer last, since this marks the block as an allocated object. + // Except with compressed oops it's the mark word. HeapWord* old_ptr = (HeapWord*)old; if (word_sz > (size_t)oopDesc::header_size()) { Copy::aligned_disjoint_words(old_ptr + oopDesc::header_size(), obj_ptr + oopDesc::header_size(), word_sz - oopDesc::header_size()); } + + if (UseCompressedOops) { + // Copy gap missed by (aligned) header size calculation above + obj->set_klass_gap(old->klass_gap()); + } + // Restore the mark word copied above. obj->set_mark(m); + // Now we can track the promoted object, if necessary. We take care // To delay the transition from uninitialized to full object // (i.e., insertion of klass pointer) until after, so that it @@ -1327,7 +1336,8 @@ if (promoInfo->tracking()) { promoInfo->track((PromotedObject*)obj, old->klass()); } - // Finally, install the klass pointer. + + // Finally, install the klass pointer (this should be volatile). obj->set_klass(old->klass()); assert(old->is_oop(), "Will dereference klass ptr below"); @@ -6165,7 +6175,7 @@ HeapWord* CMSCollector::next_card_start_after_block(HeapWord* addr) const { size_t sz = 0; oop p = (oop)addr; - if (p->klass() != NULL && p->is_parsable()) { + if (p->klass_or_null() != NULL && p->is_parsable()) { sz = CompactibleFreeListSpace::adjustObjectSize(p->size()); } else { sz = block_size_using_printezis_bits(addr); @@ -6602,7 +6612,7 @@ } if (_bitMap->isMarked(addr)) { // it's marked; is it potentially uninitialized? - if (p->klass() != NULL) { + if (p->klass_or_null() != NULL) { if (CMSPermGenPrecleaningEnabled && !p->is_parsable()) { // Signal precleaning to redirty the card since // the klass pointer is already installed. @@ -6615,11 +6625,8 @@ if (p->is_objArray()) { // objArrays are precisely marked; restrict scanning // to dirty cards only. - size = p->oop_iterate(_scanningClosure, mr); - assert(size == CompactibleFreeListSpace::adjustObjectSize(size), - "adjustObjectSize should be the identity for array sizes, " - "which are necessarily larger than minimum object size of " - "two heap words"); + size = CompactibleFreeListSpace::adjustObjectSize( + p->oop_iterate(_scanningClosure, mr)); } else { // A non-array may have been imprecisely marked; we need // to scan object in its entirety. @@ -6653,7 +6660,7 @@ } } else { // Either a not yet marked object or an uninitialized object - if (p->klass() == NULL || !p->is_parsable()) { + if (p->klass_or_null() == NULL || !p->is_parsable()) { // An uninitialized object, skip to the next card, since // we may not be able to read its P-bits yet. assert(size == 0, "Initial value"); @@ -6710,7 +6717,7 @@ HeapWord* addr = (HeapWord*)p; DEBUG_ONLY(_collector->verify_work_stacks_empty();) assert(!_span.contains(addr), "we are scanning the survivor spaces"); - assert(p->klass() != NULL, "object should be initializd"); + assert(p->klass_or_null() != NULL, "object should be initializd"); assert(p->is_parsable(), "must be parsable."); // an initialized object; ignore mark word in verification below // since we are running concurrent with mutators @@ -6868,7 +6875,7 @@ assert(_skipBits == 0, "tautology"); _skipBits = 2; // skip next two marked bits ("Printezis-marks") oop p = oop(addr); - if (p->klass() == NULL || !p->is_parsable()) { + if (p->klass_or_null() == NULL || !p->is_parsable()) { DEBUG_ONLY(if (!_verifying) {) // We re-dirty the cards on which this object lies and increase // the _threshold so that we'll come back to scan this object @@ -6890,7 +6897,7 @@ if (_threshold < end_card_addr) { _threshold = end_card_addr; } - if (p->klass() != NULL) { + if (p->klass_or_null() != NULL) { // Redirty the range of cards... _mut->mark_range(redirty_range); } // ...else the setting of klass will dirty the card anyway. @@ -7048,7 +7055,7 @@ assert(_skip_bits == 0, "tautology"); _skip_bits = 2; // skip next two marked bits ("Printezis-marks") oop p = oop(addr); - if (p->klass() == NULL || !p->is_parsable()) { + if (p->klass_or_null() == NULL || !p->is_parsable()) { // in the case of Clean-on-Enter optimization, redirty card // and avoid clearing card by increasing the threshold. return; @@ -8023,7 +8030,7 @@ "alignment problem"); #ifdef DEBUG - if (oop(addr)->klass() != NULL && + if (oop(addr)->klass_or_null() != NULL && ( !_collector->should_unload_classes() || oop(addr)->is_parsable())) { // Ignore mark word because we are running concurrent with mutators @@ -8036,7 +8043,7 @@ } else { // This should be an initialized object that's alive. - assert(oop(addr)->klass() != NULL && + assert(oop(addr)->klass_or_null() != NULL && (!_collector->should_unload_classes() || oop(addr)->is_parsable()), "Should be an initialized object"); diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/gc_implementation/concurrentMarkSweep/freeBlockDictionary.hpp --- a/src/share/vm/gc_implementation/concurrentMarkSweep/freeBlockDictionary.hpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/freeBlockDictionary.hpp Thu Jun 19 06:02:20 2008 -0700 @@ -22,88 +22,6 @@ * */ -// -// Free block maintenance for Concurrent Mark Sweep Generation -// -// The main data structure for free blocks are -// . an indexed array of small free blocks, and -// . a dictionary of large free blocks -// - -// No virtuals in FreeChunk (don't want any vtables). - -// A FreeChunk is merely a chunk that can be in a doubly linked list -// and has a size field. NOTE: FreeChunks are distinguished from allocated -// objects in two ways (by the sweeper). The second word (prev) has the -// LSB set to indicate a free chunk; allocated objects' klass() pointers -// don't have their LSB set. The corresponding bit in the CMSBitMap is -// set when the chunk is allocated. There are also blocks that "look free" -// but are not part of the free list and should not be coalesced into larger -// free blocks. These free blocks have their two LSB's set. - -class FreeChunk VALUE_OBJ_CLASS_SPEC { - friend class VMStructs; - FreeChunk* _next; - FreeChunk* _prev; - size_t _size; - - public: - NOT_PRODUCT(static const size_t header_size();) - // Returns "true" if the "wrd", which is required to be the second word - // of a block, indicates that the block represents a free chunk. - static bool secondWordIndicatesFreeChunk(intptr_t wrd) { - return (wrd & 0x1) == 0x1; - } - bool isFree() const { - return secondWordIndicatesFreeChunk((intptr_t)_prev); - } - bool cantCoalesce() const { return (((intptr_t)_prev) & 0x3) == 0x3; } - FreeChunk* next() const { return _next; } - FreeChunk* prev() const { return (FreeChunk*)(((intptr_t)_prev) & ~(0x3)); } - debug_only(void* prev_addr() const { return (void*)&_prev; }) - - void linkAfter(FreeChunk* ptr) { - linkNext(ptr); - if (ptr != NULL) ptr->linkPrev(this); - } - void linkAfterNonNull(FreeChunk* ptr) { - assert(ptr != NULL, "precondition violation"); - linkNext(ptr); - ptr->linkPrev(this); - } - void linkNext(FreeChunk* ptr) { _next = ptr; } - void linkPrev(FreeChunk* ptr) { _prev = (FreeChunk*)((intptr_t)ptr | 0x1); } - void clearPrev() { _prev = NULL; } - void clearNext() { _next = NULL; } - void dontCoalesce() { - // the block should be free - assert(isFree(), "Should look like a free block"); - _prev = (FreeChunk*)(((intptr_t)_prev) | 0x2); - } - void markFree() { _prev = (FreeChunk*)((intptr_t)_prev | 0x1); } - void markNotFree() { _prev = NULL; } - - size_t size() const { return _size; } - void setSize(size_t size) { _size = size; } - - // For volatile reads: - size_t* size_addr() { return &_size; } - - // Return the address past the end of this chunk - HeapWord* end() const { return ((HeapWord*) this) + _size; } - - // debugging - void verify() const PRODUCT_RETURN; - void verifyList() const PRODUCT_RETURN; - void mangleAllocated(size_t size) PRODUCT_RETURN; - void mangleFreed(size_t size) PRODUCT_RETURN; -}; - -// Alignment helpers etc. -#define numQuanta(x,y) ((x+y-1)/y) -enum AlignmentConstants { - MinChunkSize = numQuanta(sizeof(FreeChunk), MinObjAlignmentInBytes) * MinObjAlignment -}; // A FreeBlockDictionary is an abstract superclass that will allow // a number of alternative implementations in the future. diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/gc_implementation/concurrentMarkSweep/freeChunk.cpp --- a/src/share/vm/gc_implementation/concurrentMarkSweep/freeChunk.cpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/freeChunk.cpp Thu Jun 19 06:02:20 2008 -0700 @@ -47,15 +47,15 @@ Copy::fill_to_words(addr + hdr, size - hdr, baadbabeHeapWord); } -void FreeChunk::mangleFreed(size_t size) { +void FreeChunk::mangleFreed(size_t sz) { assert(baadbabeHeapWord != deadbeefHeapWord, "Need distinct patterns"); // mangle all but the header of a just-freed block of storage // just prior to passing it to the storage dictionary - assert(size >= MinChunkSize, "smallest size of object"); - assert(size == _size, "just checking"); + assert(sz >= MinChunkSize, "smallest size of object"); + assert(sz == size(), "just checking"); HeapWord* addr = (HeapWord*)this; size_t hdr = header_size(); - Copy::fill_to_words(addr + hdr, size - hdr, deadbeefHeapWord); + Copy::fill_to_words(addr + hdr, sz - hdr, deadbeefHeapWord); } void FreeChunk::verifyList() const { diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/gc_implementation/concurrentMarkSweep/freeChunk.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/freeChunk.hpp Thu Jun 19 06:02:20 2008 -0700 @@ -0,0 +1,137 @@ +/* + * Copyright 2001-2005 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +// +// Free block maintenance for Concurrent Mark Sweep Generation +// +// The main data structure for free blocks are +// . an indexed array of small free blocks, and +// . a dictionary of large free blocks +// + +// No virtuals in FreeChunk (don't want any vtables). + +// A FreeChunk is merely a chunk that can be in a doubly linked list +// and has a size field. NOTE: FreeChunks are distinguished from allocated +// objects in two ways (by the sweeper), depending on whether the VM is 32 or +// 64 bits. +// In 32 bits or 64 bits without CompressedOops, the second word (prev) has the +// LSB set to indicate a free chunk; allocated objects' klass() pointers +// don't have their LSB set. The corresponding bit in the CMSBitMap is +// set when the chunk is allocated. There are also blocks that "look free" +// but are not part of the free list and should not be coalesced into larger +// free blocks. These free blocks have their two LSB's set. + +class FreeChunk VALUE_OBJ_CLASS_SPEC { + friend class VMStructs; + // For 64 bit compressed oops, the markOop encodes both the size and the + // indication that this is a FreeChunk and not an object. + volatile size_t _size; + FreeChunk* _prev; + FreeChunk* _next; + + markOop mark() const volatile { return (markOop)_size; } + void set_mark(markOop m) { _size = (size_t)m; } + + public: + NOT_PRODUCT(static const size_t header_size();) + + // Returns "true" if the address indicates that the block represents + // a free chunk. + static bool indicatesFreeChunk(const HeapWord* addr) { + // Force volatile read from addr because value might change between + // calls. We really want the read of _mark and _prev from this pointer + // to be volatile but making the fields volatile causes all sorts of + // compilation errors. + return ((volatile FreeChunk*)addr)->isFree(); + } + + bool isFree() const volatile { + LP64_ONLY(if (UseCompressedOops) return mark()->is_cms_free_chunk(); else) + return (((intptr_t)_prev) & 0x1) == 0x1; + } + bool cantCoalesce() const { + assert(isFree(), "can't get coalesce bit on not free"); + return (((intptr_t)_prev) & 0x2) == 0x2; + } + void dontCoalesce() { + // the block should be free + assert(isFree(), "Should look like a free block"); + _prev = (FreeChunk*)(((intptr_t)_prev) | 0x2); + } + FreeChunk* prev() const { + return (FreeChunk*)(((intptr_t)_prev) & ~(0x3)); + } + + debug_only(void* prev_addr() const { return (void*)&_prev; }) + + size_t size() const volatile { + LP64_ONLY(if (UseCompressedOops) return mark()->get_size(); else ) + return _size; + } + void setSize(size_t sz) { + LP64_ONLY(if (UseCompressedOops) set_mark(markOopDesc::set_size_and_free(sz)); else ) + _size = sz; + } + + FreeChunk* next() const { return _next; } + + void linkAfter(FreeChunk* ptr) { + linkNext(ptr); + if (ptr != NULL) ptr->linkPrev(this); + } + void linkAfterNonNull(FreeChunk* ptr) { + assert(ptr != NULL, "precondition violation"); + linkNext(ptr); + ptr->linkPrev(this); + } + void linkNext(FreeChunk* ptr) { _next = ptr; } + void linkPrev(FreeChunk* ptr) { + LP64_ONLY(if (UseCompressedOops) _prev = ptr; else) + _prev = (FreeChunk*)((intptr_t)ptr | 0x1); + } + void clearPrev() { _prev = NULL; } + void clearNext() { _next = NULL; } + void markNotFree() { + LP64_ONLY(if (UseCompressedOops) set_mark(markOopDesc::prototype());) + // Also set _prev to null + _prev = NULL; + } + + // Return the address past the end of this chunk + HeapWord* end() const { return ((HeapWord*) this) + size(); } + + // debugging + void verify() const PRODUCT_RETURN; + void verifyList() const PRODUCT_RETURN; + void mangleAllocated(size_t size) PRODUCT_RETURN; + void mangleFreed(size_t size) PRODUCT_RETURN; +}; + +// Alignment helpers etc. +#define numQuanta(x,y) ((x+y-1)/y) +enum AlignmentConstants { + MinChunkSize = numQuanta(sizeof(FreeChunk), MinObjAlignmentInBytes) * MinObjAlignment +}; + diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/gc_implementation/concurrentMarkSweep/vmStructs_cms.hpp --- a/src/share/vm/gc_implementation/concurrentMarkSweep/vmStructs_cms.hpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/vmStructs_cms.hpp Thu Jun 19 06:02:20 2008 -0700 @@ -23,6 +23,7 @@ */ #define VM_STRUCTS_CMS(nonstatic_field, \ + volatile_nonstatic_field, \ static_field) \ nonstatic_field(CompactibleFreeListSpace, _collector, CMSCollector*) \ nonstatic_field(CompactibleFreeListSpace, _bt, BlockOffsetArrayNonContigSpace) \ @@ -36,9 +37,9 @@ nonstatic_field(CMSCollector, _markBitMap, CMSBitMap) \ nonstatic_field(ConcurrentMarkSweepGeneration, _cmsSpace, CompactibleFreeListSpace*) \ static_field(ConcurrentMarkSweepThread, _collector, CMSCollector*) \ + volatile_nonstatic_field(FreeChunk, _size, size_t) \ nonstatic_field(FreeChunk, _next, FreeChunk*) \ nonstatic_field(FreeChunk, _prev, FreeChunk*) \ - nonstatic_field(FreeChunk, _size, size_t) \ nonstatic_field(LinearAllocBlock, _word_size, size_t) \ nonstatic_field(FreeList, _size, size_t) \ nonstatic_field(FreeList, _count, ssize_t) \ diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/gc_implementation/includeDB_gc_concurrentMarkSweep --- a/src/share/vm/gc_implementation/includeDB_gc_concurrentMarkSweep Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/gc_implementation/includeDB_gc_concurrentMarkSweep Thu Jun 19 06:02:20 2008 -0700 @@ -206,6 +206,7 @@ freeBlockDictionary.hpp allocation.hpp freeBlockDictionary.hpp debug.hpp +freeBlockDictionary.hpp freeChunk.hpp freeBlockDictionary.hpp globalDefinitions.hpp freeBlockDictionary.hpp memRegion.hpp freeBlockDictionary.hpp mutex.hpp @@ -214,6 +215,14 @@ freeChunk.cpp copy.hpp freeChunk.cpp freeBlockDictionary.hpp +freeChunk.hpp allocation.hpp +freeChunk.hpp debug.hpp +freeChunk.hpp globalDefinitions.hpp +freeChunk.hpp markOop.hpp +freeChunk.hpp memRegion.hpp +freeChunk.hpp mutex.hpp +freeChunk.hpp ostream.hpp + freeList.cpp freeBlockDictionary.hpp freeList.cpp freeList.hpp freeList.cpp globals.hpp diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/gc_implementation/shared/immutableSpace.cpp --- a/src/share/vm/gc_implementation/shared/immutableSpace.cpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/gc_implementation/shared/immutableSpace.cpp Thu Jun 19 06:02:20 2008 -0700 @@ -66,7 +66,7 @@ #endif -void ImmutableSpace::verify(bool allow_dirty) const { +void ImmutableSpace::verify(bool allow_dirty) { HeapWord* p = bottom(); HeapWord* t = end(); HeapWord* prev_p = NULL; diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/gc_implementation/shared/immutableSpace.hpp --- a/src/share/vm/gc_implementation/shared/immutableSpace.hpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/gc_implementation/shared/immutableSpace.hpp Thu Jun 19 06:02:20 2008 -0700 @@ -59,5 +59,5 @@ // Debugging virtual void print() const PRODUCT_RETURN; virtual void print_short() const PRODUCT_RETURN; - virtual void verify(bool allow_dirty) const; + virtual void verify(bool allow_dirty); }; diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/gc_implementation/shared/mutableNUMASpace.cpp --- a/src/share/vm/gc_implementation/shared/mutableNUMASpace.cpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/gc_implementation/shared/mutableNUMASpace.cpp Thu Jun 19 06:02:20 2008 -0700 @@ -599,12 +599,28 @@ // Mark the the holes in chunks below the top() as invalid. void MutableNUMASpace::set_top(HeapWord* value) { bool found_top = false; - for (int i = 0; i < lgrp_spaces()->length(); i++) { + for (int i = 0; i < lgrp_spaces()->length();) { LGRPSpace *ls = lgrp_spaces()->at(i); MutableSpace *s = ls->space(); HeapWord *top = MAX2((HeapWord*)round_down((intptr_t)s->top(), page_size()), s->bottom()); if (s->contains(value)) { + // Check if setting the chunk's top to a given value would create a hole less than + // a minimal object; assuming that's not the last chunk in which case we don't care. + if (i < lgrp_spaces()->length() - 1) { + size_t remainder = pointer_delta(s->end(), value); + const size_t minimal_object_size = oopDesc::header_size(); + if (remainder < minimal_object_size && remainder > 0) { + // Add a filler object of a minimal size, it will cross the chunk boundary. + SharedHeap::fill_region_with_object(MemRegion(value, minimal_object_size)); + value += minimal_object_size; + assert(!s->contains(value), "Should be in the next chunk"); + // Restart the loop from the same chunk, since the value has moved + // to the next one. + continue; + } + } + if (!os::numa_has_static_binding() && top < value && top < s->end()) { ls->add_invalid_region(MemRegion(top, value)); } @@ -620,6 +636,7 @@ s->set_top(s->end()); } } + i++; } MutableSpace::set_top(value); } @@ -700,12 +717,14 @@ MutableSpace *s = lgrp_spaces()->at(i)->space(); HeapWord *p = s->cas_allocate(size); if (p != NULL) { - size_t remainder = pointer_delta(s->end(), p); + size_t remainder = pointer_delta(s->end(), p + size); if (remainder < (size_t)oopDesc::header_size() && remainder > 0) { if (s->cas_deallocate(p, size)) { // We were the last to allocate and created a fragment less than // a minimal object. p = NULL; + } else { + guarantee(false, "Deallocation should always succeed"); } } } @@ -761,10 +780,12 @@ } } -void MutableNUMASpace::verify(bool allow_dirty) const { - for (int i = 0; i < lgrp_spaces()->length(); i++) { - lgrp_spaces()->at(i)->space()->verify(allow_dirty); - } +void MutableNUMASpace::verify(bool allow_dirty) { + // This can be called after setting an arbitary value to the space's top, + // so an object can cross the chunk boundary. We ensure the parsablity + // of the space and just walk the objects in linear fashion. + ensure_parsability(); + MutableSpace::verify(allow_dirty); } // Scan pages and gather stats about page placement and size. diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/gc_implementation/shared/mutableNUMASpace.hpp --- a/src/share/vm/gc_implementation/shared/mutableNUMASpace.hpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/gc_implementation/shared/mutableNUMASpace.hpp Thu Jun 19 06:02:20 2008 -0700 @@ -192,7 +192,7 @@ // Debugging virtual void print_on(outputStream* st) const; virtual void print_short_on(outputStream* st) const; - virtual void verify(bool allow_dirty) const; + virtual void verify(bool allow_dirty); virtual void set_top(HeapWord* value); }; diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/gc_implementation/shared/mutableSpace.cpp --- a/src/share/vm/gc_implementation/shared/mutableSpace.cpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/gc_implementation/shared/mutableSpace.cpp Thu Jun 19 06:02:20 2008 -0700 @@ -118,7 +118,7 @@ bottom(), top(), end()); } -void MutableSpace::verify(bool allow_dirty) const { +void MutableSpace::verify(bool allow_dirty) { HeapWord* p = bottom(); HeapWord* t = top(); HeapWord* prev_p = NULL; diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/gc_implementation/shared/mutableSpace.hpp --- a/src/share/vm/gc_implementation/shared/mutableSpace.hpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/gc_implementation/shared/mutableSpace.hpp Thu Jun 19 06:02:20 2008 -0700 @@ -98,5 +98,5 @@ virtual void print_on(outputStream* st) const; virtual void print_short() const; virtual void print_short_on(outputStream* st) const; - virtual void verify(bool allow_dirty) const; + virtual void verify(bool allow_dirty); }; diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/oops/markOop.hpp --- a/src/share/vm/oops/markOop.hpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/oops/markOop.hpp Thu Jun 19 06:02:20 2008 -0700 @@ -29,8 +29,10 @@ // // Bit-format of an object header (most significant first): // -// -// unused:0/25 hash:25/31 age:4 biased_lock:1 lock:2 = 32/64 bits +// 32 bits: unused:0 hash:25 age:4 biased_lock:1 lock:2 +// 64 bits: unused:24 hash:31 cms:2 age:4 biased_lock:1 lock:2 +// unused:20 size:35 cms:2 age:4 biased_lock:1 lock:2 (if cms +// free chunk) // // - hash contains the identity hash value: largest value is // 31 bits, see os::random(). Also, 64-bit vm's require @@ -91,6 +93,7 @@ biased_lock_bits = 1, max_hash_bits = BitsPerWord - age_bits - lock_bits - biased_lock_bits, hash_bits = max_hash_bits > 31 ? 31 : max_hash_bits, + cms_bits = LP64_ONLY(1) NOT_LP64(0), epoch_bits = 2 }; @@ -106,7 +109,8 @@ enum { lock_shift = 0, biased_lock_shift = lock_bits, age_shift = lock_bits + biased_lock_bits, - hash_shift = lock_bits + biased_lock_bits + age_bits, + cms_shift = age_shift + age_bits, + hash_shift = cms_shift + cms_bits, epoch_shift = hash_shift }; @@ -118,7 +122,9 @@ age_mask = right_n_bits(age_bits), age_mask_in_place = age_mask << age_shift, epoch_mask = right_n_bits(epoch_bits), - epoch_mask_in_place = epoch_mask << epoch_shift + epoch_mask_in_place = epoch_mask << epoch_shift, + cms_mask = right_n_bits(cms_bits), + cms_mask_in_place = cms_mask << cms_shift #ifndef _WIN64 ,hash_mask = right_n_bits(hash_bits), hash_mask_in_place = (address_word)hash_mask << hash_shift @@ -360,4 +366,40 @@ // see the definition in markOop.cpp for the gory details bool should_not_be_cached() const; + + // These markOops indicate cms free chunk blocks and not objects. + // In 64 bit, the markOop is set to distinguish them from oops. + // These are defined in 32 bit mode for vmStructs. + const static uintptr_t cms_free_chunk_pattern = 0x1; + + // Constants for the size field. + enum { size_shift = cms_shift + cms_bits, + size_bits = 35 // need for compressed oops 32G + }; + // These values are too big for Win64 + const static uintptr_t size_mask = LP64_ONLY(right_n_bits(size_bits)) + NOT_LP64(0); + const static uintptr_t size_mask_in_place = + (address_word)size_mask << size_shift; + +#ifdef _LP64 + static markOop cms_free_prototype() { + return markOop(((intptr_t)prototype() & ~cms_mask_in_place) | + ((cms_free_chunk_pattern & cms_mask) << cms_shift)); + } + uintptr_t cms_encoding() const { + return mask_bits(value() >> cms_shift, cms_mask); + } + bool is_cms_free_chunk() const { + return is_neutral() && + (cms_encoding() & cms_free_chunk_pattern) == cms_free_chunk_pattern; + } + + size_t get_size() const { return (size_t)(value() >> size_shift); } + static markOop set_size_and_free(size_t size) { + assert((size & ~size_mask) == 0, "shouldn't overflow size field"); + return markOop(((intptr_t)cms_free_prototype() & ~size_mask_in_place) | + (((intptr_t)size & size_mask) << size_shift)); + } +#endif // _LP64 }; diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/oops/methodDataOop.hpp --- a/src/share/vm/oops/methodDataOop.hpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/oops/methodDataOop.hpp Thu Jun 19 06:02:20 2008 -0700 @@ -158,7 +158,6 @@ assert(ProfileTraps, "used only under +ProfileTraps"); uint old_flags = (_header._struct._flags & flag_mask); _header._struct._flags = (new_state << trap_shift) | old_flags; - assert(trap_state() == new_state, "sanity"); } u1 flags() { diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/opto/memnode.cpp --- a/src/share/vm/opto/memnode.cpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/opto/memnode.cpp Thu Jun 19 06:02:20 2008 -0700 @@ -253,11 +253,17 @@ if (dom == NULL || dom->is_top() || sub == NULL || sub->is_top()) return false; // Conservative answer for dead code - // Check 'dom'. + // Check 'dom'. Skip Proj and CatchProj nodes. dom = dom->find_exact_control(dom); if (dom == NULL || dom->is_top()) return false; // Conservative answer for dead code + if (dom == sub) { + // For the case when, for example, 'sub' is Initialize and the original + // 'dom' is Proj node of the 'sub'. + return false; + } + if (dom->is_Con() || dom->is_Start() || dom->is_Root() || dom == sub) return true; @@ -271,6 +277,7 @@ sub->is_Region(), "expecting only these nodes"); // Get control edge of 'sub'. + Node* orig_sub = sub; sub = sub->find_exact_control(sub->in(0)); if (sub == NULL || sub->is_top()) return false; // Conservative answer for dead code @@ -296,14 +303,16 @@ for (uint next = 0; next < dom_list.size(); next++) { Node* n = dom_list.at(next); + if (n == orig_sub) + return false; // One of dom's inputs dominated by sub. if (!n->is_CFG() && n->pinned()) { // Check only own control edge for pinned non-control nodes. n = n->find_exact_control(n->in(0)); if (n == NULL || n->is_top()) return false; // Conservative answer for dead code assert(n->is_CFG(), "expecting control"); - } - if (n->is_Con() || n->is_Start() || n->is_Root()) { + dom_list.push(n); + } else if (n->is_Con() || n->is_Start() || n->is_Root()) { only_dominating_controls = true; } else if (n->is_CFG()) { if (n->dominates(sub, nlist)) diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/opto/node.cpp --- a/src/share/vm/opto/node.cpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/opto/node.cpp Thu Jun 19 06:02:20 2008 -0700 @@ -1039,6 +1039,9 @@ //--------------------------dominates------------------------------------------ // Helper function for MemNode::all_controls_dominate(). // Check if 'this' control node dominates or equal to 'sub' control node. +// We already know that if any path back to Root or Start reaches 'this', +// then all paths so, so this is a simple search for one example, +// not an exhaustive search for a counterexample. bool Node::dominates(Node* sub, Node_List &nlist) { assert(this->is_CFG(), "expecting control"); assert(sub != NULL && sub->is_CFG(), "expecting control"); @@ -1047,110 +1050,115 @@ int iterations_without_region_limit = DominatorSearchLimit; Node* orig_sub = sub; + Node* dom = this; + bool met_dom = false; nlist.clear(); - bool this_dominates = false; - bool result = false; // Conservative answer - while (sub != NULL) { // walk 'sub' up the chain to 'this' - if (sub == this) { + // Walk 'sub' backward up the chain to 'dom', watching for regions. + // After seeing 'dom', continue up to Root or Start. + // If we hit a region (backward split point), it may be a loop head. + // Keep going through one of the region's inputs. If we reach the + // same region again, go through a different input. Eventually we + // will either exit through the loop head, or give up. + // (If we get confused, break out and return a conservative 'false'.) + while (sub != NULL) { + if (sub->is_top()) break; // Conservative answer for dead code. + if (sub == dom) { if (nlist.size() == 0) { // No Region nodes except loops were visited before and the EntryControl // path was taken for loops: it did not walk in a cycle. - result = true; - break; - } else if (this_dominates) { - result = false; // already met before: walk in a cycle - break; + return true; + } else if (met_dom) { + break; // already met before: walk in a cycle } else { // Region nodes were visited. Continue walk up to Start or Root // to make sure that it did not walk in a cycle. - this_dominates = true; // first time meet + met_dom = true; // first time meet iterations_without_region_limit = DominatorSearchLimit; // Reset } } if (sub->is_Start() || sub->is_Root()) { - result = this_dominates; - break; + // Success if we met 'dom' along a path to Start or Root. + // We assume there are no alternative paths that avoid 'dom'. + // (This assumption is up to the caller to ensure!) + return met_dom; } - Node* up = sub->find_exact_control(sub->in(0)); - if (up == NULL || up->is_top()) { - result = false; // Conservative answer for dead code - break; - } - if (sub == up && (sub->is_Loop() || sub->is_Region() && sub->req() != 3)) { - // Take first valid path on the way up to 'this'. + Node* up = sub->in(0); + // Normalize simple pass-through regions and projections: + up = sub->find_exact_control(up); + // If sub == up, we found a self-loop. Try to push past it. + if (sub == up && sub->is_Loop()) { + // Take loop entry path on the way up to 'dom'. up = sub->in(1); // in(LoopNode::EntryControl); + } else if (sub == up && sub->is_Region() && sub->req() != 3) { + // Always take in(1) path on the way up to 'dom' for clone regions + // (with only one input) or regions which merge > 2 paths + // (usually used to merge fast/slow paths). + up = sub->in(1); } else if (sub == up && sub->is_Region()) { - assert(sub->req() == 3, "sanity"); + // Try both paths for Regions with 2 input paths (it may be a loop head). + // It could give conservative 'false' answer without information + // which region's input is the entry path. iterations_without_region_limit = DominatorSearchLimit; // Reset - // Try both paths for such Regions. - // It is not accurate without regions dominating information. - // With such information the other path should be checked for - // the most dominating Region which was visited before. bool region_was_visited_before = false; - uint i = 1; - uint size = nlist.size(); - if (size == 0) { - // No such Region nodes were visited before. - // Take first valid path on the way up to 'this'. - } else { - // Was this Region node visited before? - intptr_t ni; - int j = size - 1; - for (; j >= 0; j--) { - ni = (intptr_t)nlist.at(j); - if ((Node*)(ni & ~1) == sub) { - if ((ni & 1) != 0) { - break; // Visited 2 paths. Give up. - } else { - // The Region node was visited before only once. - nlist.remove(j); - region_was_visited_before = true; - for (; i < sub->req(); i++) { - Node* in = sub->in(i); - if (in != NULL && !in->is_top() && in != sub) { - break; - } - } - i++; // Take other path. - break; - } + // Was this Region node visited before? + // If so, we have reached it because we accidentally took a + // loop-back edge from 'sub' back into the body of the loop, + // and worked our way up again to the loop header 'sub'. + // So, take the first unexplored path on the way up to 'dom'. + for (int j = nlist.size() - 1; j >= 0; j--) { + intptr_t ni = (intptr_t)nlist.at(j); + Node* visited = (Node*)(ni & ~1); + bool visited_twice_already = ((ni & 1) != 0); + if (visited == sub) { + if (visited_twice_already) { + // Visited 2 paths, but still stuck in loop body. Give up. + return false; } - } - if (j >= 0 && (ni & 1) != 0) { - result = false; // Visited 2 paths. Give up. - break; - } - // The Region node was not visited before. - } - for (; i < sub->req(); i++) { - Node* in = sub->in(i); - if (in != NULL && !in->is_top() && in != sub) { + // The Region node was visited before only once. + // (We will repush with the low bit set, below.) + nlist.remove(j); + // We will find a new edge and re-insert. + region_was_visited_before = true; break; } } - if (i < sub->req()) { - up = sub->in(i); - if (region_was_visited_before && sub != up) { - // Set 0 bit to indicate that both paths were taken. - nlist.push((Node*)((intptr_t)sub + 1)); - } else { - nlist.push(sub); + + // Find an incoming edge which has not been seen yet; walk through it. + assert(up == sub, ""); + uint skip = region_was_visited_before ? 1 : 0; + for (uint i = 1; i < sub->req(); i++) { + Node* in = sub->in(i); + if (in != NULL && !in->is_top() && in != sub) { + if (skip == 0) { + up = in; + break; + } + --skip; // skip this nontrivial input } } + + // Set 0 bit to indicate that both paths were taken. + nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0))); } - if (sub == up) { - result = false; // some kind of tight cycle - break; + + if (up == sub) { + break; // some kind of tight cycle + } + if (up == orig_sub && met_dom) { + // returned back after visiting 'dom' + break; // some kind of cycle } if (--iterations_without_region_limit < 0) { - result = false; // dead cycle - break; + break; // dead cycle } sub = up; } - return result; + + // Did not meet Root or Start node in pred. chain. + // Conservative answer for dead code. + return false; } //------------------------------remove_dead_region----------------------------- diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/runtime/arguments.cpp --- a/src/share/vm/runtime/arguments.cpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/runtime/arguments.cpp Thu Jun 19 06:02:20 2008 -0700 @@ -1174,7 +1174,7 @@ // field offset to determine free list chunk markers. // Check that UseCompressedOops can be set with the max heap size allocated // by ergonomics. - if (!UseConcMarkSweepGC && MaxHeapSize <= max_heap_for_compressed_oops()) { + if (MaxHeapSize <= max_heap_for_compressed_oops()) { if (FLAG_IS_DEFAULT(UseCompressedOops)) { // Leave compressed oops off by default. Uncomment // the following line to return it to default status. diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/runtime/globals.hpp --- a/src/share/vm/runtime/globals.hpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/runtime/globals.hpp Thu Jun 19 06:02:20 2008 -0700 @@ -2246,6 +2246,9 @@ product(bool, AggressiveOpts, false, \ "Enable aggressive optimizations - see arguments.cpp") \ \ + product(bool, UseStringCache, false, \ + "Enable String cache capabilities on String.java") \ + \ /* statistics */ \ develop(bool, UseVTune, false, \ "enable support for Intel's VTune profiler") \ diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/runtime/thread.cpp --- a/src/share/vm/runtime/thread.cpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/runtime/thread.cpp Thu Jun 19 06:02:20 2008 -0700 @@ -2926,21 +2926,42 @@ } if (AggressiveOpts) { - // Forcibly initialize java/util/HashMap and mutate the private - // static final "frontCacheEnabled" field before we start creating instances + { + // Forcibly initialize java/util/HashMap and mutate the private + // static final "frontCacheEnabled" field before we start creating instances #ifdef ASSERT - klassOop tmp_k = SystemDictionary::find(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0); - assert(tmp_k == NULL, "java/util/HashMap should not be loaded yet"); + klassOop tmp_k = SystemDictionary::find(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0); + assert(tmp_k == NULL, "java/util/HashMap should not be loaded yet"); #endif - klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0); - KlassHandle k = KlassHandle(THREAD, k_o); - guarantee(k.not_null(), "Must find java/util/HashMap"); - instanceKlassHandle ik = instanceKlassHandle(THREAD, k()); - ik->initialize(CHECK_0); - fieldDescriptor fd; - // Possible we might not find this field; if so, don't break - if (ik->find_local_field(vmSymbols::frontCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) { - k()->bool_field_put(fd.offset(), true); + klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_util_HashMap(), Handle(), Handle(), CHECK_0); + KlassHandle k = KlassHandle(THREAD, k_o); + guarantee(k.not_null(), "Must find java/util/HashMap"); + instanceKlassHandle ik = instanceKlassHandle(THREAD, k()); + ik->initialize(CHECK_0); + fieldDescriptor fd; + // Possible we might not find this field; if so, don't break + if (ik->find_local_field(vmSymbols::frontCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) { + k()->bool_field_put(fd.offset(), true); + } + } + + if (UseStringCache) { + // Forcibly initialize java/lang/String and mutate the private + // static final "stringCacheEnabled" field before we start creating instances +#ifdef ASSERT + klassOop tmp_k = SystemDictionary::find(vmSymbolHandles::java_lang_String(), Handle(), Handle(), CHECK_0); + assert(tmp_k == NULL, "java/lang/String should not be loaded yet"); +#endif + klassOop k_o = SystemDictionary::resolve_or_null(vmSymbolHandles::java_lang_String(), Handle(), Handle(), CHECK_0); + KlassHandle k = KlassHandle(THREAD, k_o); + guarantee(k.not_null(), "Must find java/lang/String"); + instanceKlassHandle ik = instanceKlassHandle(THREAD, k()); + ik->initialize(CHECK_0); + fieldDescriptor fd; + // Possible we might not find this field; if so, don't break + if (ik->find_local_field(vmSymbols::stringCacheEnabled_name(), vmSymbols::bool_signature(), &fd)) { + k()->bool_field_put(fd.offset(), true); + } } } diff -r f139919897d2 -r 66cdb30329a6 src/share/vm/runtime/vmStructs.cpp --- a/src/share/vm/runtime/vmStructs.cpp Tue Jun 17 09:59:59 2008 -0700 +++ b/src/share/vm/runtime/vmStructs.cpp Thu Jun 19 06:02:20 2008 -0700 @@ -1695,7 +1695,12 @@ declare_constant(markOopDesc::no_hash) \ declare_constant(markOopDesc::no_hash_in_place) \ declare_constant(markOopDesc::no_lock_in_place) \ - declare_constant(markOopDesc::max_age) + declare_constant(markOopDesc::max_age) \ + \ + /* Constants in markOop used by CMS. */ \ + declare_constant(markOopDesc::cms_shift) \ + declare_constant(markOopDesc::cms_mask) \ + declare_constant(markOopDesc::size_shift) \ /* NOTE that we do not use the last_entry() macro here; it is used */ /* in vmStructs__.hpp's VM_LONG_CONSTANTS_OS_CPU macro (and */ @@ -1959,6 +1964,7 @@ GENERATE_STATIC_VM_STRUCT_ENTRY) VM_STRUCTS_CMS(GENERATE_NONSTATIC_VM_STRUCT_ENTRY, \ + GENERATE_NONSTATIC_VM_STRUCT_ENTRY, \ GENERATE_STATIC_VM_STRUCT_ENTRY) #endif // SERIALGC @@ -2100,6 +2106,7 @@ CHECK_STATIC_VM_STRUCT_ENTRY); VM_STRUCTS_CMS(CHECK_NONSTATIC_VM_STRUCT_ENTRY, + CHECK_VOLATILE_NONSTATIC_VM_STRUCT_ENTRY, CHECK_STATIC_VM_STRUCT_ENTRY); #endif // SERIALGC @@ -2204,6 +2211,7 @@ debug_only(VM_STRUCTS_PARALLELGC(ENSURE_FIELD_TYPE_PRESENT, \ ENSURE_FIELD_TYPE_PRESENT)); debug_only(VM_STRUCTS_CMS(ENSURE_FIELD_TYPE_PRESENT, \ + ENSURE_FIELD_TYPE_PRESENT, \ ENSURE_FIELD_TYPE_PRESENT)); #endif // SERIALGC debug_only(VM_STRUCTS_CPU(ENSURE_FIELD_TYPE_PRESENT, \