6725697: par compact - rename class ChunkData to RegionData

Reviewed-by: iveresov, tonyp
This commit is contained in:
John Coomes 2008-09-30 12:20:22 -07:00
parent 2e52e9dff2
commit f2851186bb
9 changed files with 1049 additions and 1040 deletions

View file

@ -146,7 +146,7 @@ void RefProcTaskExecutor::execute(ProcessTask& task)
{
ParallelScavengeHeap* heap = PSParallelCompact::gc_heap();
uint parallel_gc_threads = heap->gc_task_manager()->workers();
ChunkTaskQueueSet* qset = ParCompactionManager::chunk_array();
RegionTaskQueueSet* qset = ParCompactionManager::region_array();
ParallelTaskTerminator terminator(parallel_gc_threads, qset);
GCTaskQueue* q = GCTaskQueue::create();
for(uint i=0; i<parallel_gc_threads; i++) {
@ -205,38 +205,38 @@ void StealMarkingTask::do_it(GCTaskManager* manager, uint which) {
}
//
// StealChunkCompactionTask
// StealRegionCompactionTask
//
StealChunkCompactionTask::StealChunkCompactionTask(ParallelTaskTerminator* t) :
_terminator(t) {};
StealRegionCompactionTask::StealRegionCompactionTask(ParallelTaskTerminator* t):
_terminator(t) {}
void StealChunkCompactionTask::do_it(GCTaskManager* manager, uint which) {
void StealRegionCompactionTask::do_it(GCTaskManager* manager, uint which) {
assert(Universe::heap()->is_gc_active(), "called outside gc");
NOT_PRODUCT(TraceTime tm("StealChunkCompactionTask",
NOT_PRODUCT(TraceTime tm("StealRegionCompactionTask",
PrintGCDetails && TraceParallelOldGCTasks, true, gclog_or_tty));
ParCompactionManager* cm =
ParCompactionManager::gc_thread_compaction_manager(which);
// Has to drain stacks first because there may be chunks on
// Has to drain stacks first because there may be regions on
// preloaded onto the stack and this thread may never have
// done a draining task. Are the draining tasks needed?
cm->drain_chunk_stacks();
cm->drain_region_stacks();
size_t chunk_index = 0;
size_t region_index = 0;
int random_seed = 17;
// If we're the termination task, try 10 rounds of stealing before
// setting the termination flag
while(true) {
if (ParCompactionManager::steal(which, &random_seed, chunk_index)) {
PSParallelCompact::fill_and_update_chunk(cm, chunk_index);
cm->drain_chunk_stacks();
if (ParCompactionManager::steal(which, &random_seed, region_index)) {
PSParallelCompact::fill_and_update_region(cm, region_index);
cm->drain_region_stacks();
} else {
if (terminator()->offer_termination()) {
break;
@ -249,11 +249,10 @@ void StealChunkCompactionTask::do_it(GCTaskManager* manager, uint which) {
UpdateDensePrefixTask::UpdateDensePrefixTask(
PSParallelCompact::SpaceId space_id,
size_t chunk_index_start,
size_t chunk_index_end) :
_space_id(space_id), _chunk_index_start(chunk_index_start),
_chunk_index_end(chunk_index_end)
{}
size_t region_index_start,
size_t region_index_end) :
_space_id(space_id), _region_index_start(region_index_start),
_region_index_end(region_index_end) {}
void UpdateDensePrefixTask::do_it(GCTaskManager* manager, uint which) {
@ -265,8 +264,8 @@ void UpdateDensePrefixTask::do_it(GCTaskManager* manager, uint which) {
PSParallelCompact::update_and_deadwood_in_dense_prefix(cm,
_space_id,
_chunk_index_start,
_chunk_index_end);
_region_index_start,
_region_index_end);
}
void DrainStacksCompactionTask::do_it(GCTaskManager* manager, uint which) {
@ -278,6 +277,6 @@ void DrainStacksCompactionTask::do_it(GCTaskManager* manager, uint which) {
ParCompactionManager* cm =
ParCompactionManager::gc_thread_compaction_manager(which);
// Process any chunks already in the compaction managers stacks.
cm->drain_chunk_stacks();
// Process any regions already in the compaction managers stacks.
cm->drain_region_stacks();
}

View file

@ -188,18 +188,18 @@ class StealMarkingTask : public GCTask {
};
//
// StealChunkCompactionTask
// StealRegionCompactionTask
//
// This task is used to distribute work to idle threads.
//
class StealChunkCompactionTask : public GCTask {
class StealRegionCompactionTask : public GCTask {
private:
ParallelTaskTerminator* const _terminator;
public:
StealChunkCompactionTask(ParallelTaskTerminator* t);
StealRegionCompactionTask(ParallelTaskTerminator* t);
char* name() { return (char *)"steal-chunk-task"; }
char* name() { return (char *)"steal-region-task"; }
ParallelTaskTerminator* terminator() { return _terminator; }
virtual void do_it(GCTaskManager* manager, uint which);
@ -215,15 +215,15 @@ class StealChunkCompactionTask : public GCTask {
class UpdateDensePrefixTask : public GCTask {
private:
PSParallelCompact::SpaceId _space_id;
size_t _chunk_index_start;
size_t _chunk_index_end;
size_t _region_index_start;
size_t _region_index_end;
public:
char* name() { return (char *)"update-dense_prefix-task"; }
UpdateDensePrefixTask(PSParallelCompact::SpaceId space_id,
size_t chunk_index_start,
size_t chunk_index_end);
size_t region_index_start,
size_t region_index_end);
virtual void do_it(GCTaskManager* manager, uint which);
};
@ -231,17 +231,17 @@ class UpdateDensePrefixTask : public GCTask {
//
// DrainStacksCompactionTask
//
// This task processes chunks that have been added to the stacks of each
// This task processes regions that have been added to the stacks of each
// compaction manager.
//
// Trying to use one draining thread does not work because there are no
// guarantees about which task will be picked up by which thread. For example,
// if thread A gets all the preloaded chunks, thread A may not get a draining
// if thread A gets all the preloaded regions, thread A may not get a draining
// task (they may all be done by other threads).
//
class DrainStacksCompactionTask : public GCTask {
public:
char* name() { return (char *)"drain-chunk-task"; }
char* name() { return (char *)"drain-region-task"; }
virtual void do_it(GCTaskManager* manager, uint which);
};

View file

@ -30,7 +30,7 @@ ParCompactionManager** ParCompactionManager::_manager_array = NULL;
OopTaskQueueSet* ParCompactionManager::_stack_array = NULL;
ObjectStartArray* ParCompactionManager::_start_array = NULL;
ParMarkBitMap* ParCompactionManager::_mark_bitmap = NULL;
ChunkTaskQueueSet* ParCompactionManager::_chunk_array = NULL;
RegionTaskQueueSet* ParCompactionManager::_region_array = NULL;
ParCompactionManager::ParCompactionManager() :
_action(CopyAndUpdate) {
@ -46,13 +46,13 @@ ParCompactionManager::ParCompactionManager() :
// We want the overflow stack to be permanent
_overflow_stack = new (ResourceObj::C_HEAP) GrowableArray<oop>(10, true);
#ifdef USE_ChunkTaskQueueWithOverflow
chunk_stack()->initialize();
#ifdef USE_RegionTaskQueueWithOverflow
region_stack()->initialize();
#else
chunk_stack()->initialize();
region_stack()->initialize();
// We want the overflow stack to be permanent
_chunk_overflow_stack =
_region_overflow_stack =
new (ResourceObj::C_HEAP) GrowableArray<size_t>(10, true);
#endif
@ -86,18 +86,18 @@ void ParCompactionManager::initialize(ParMarkBitMap* mbm) {
_stack_array = new OopTaskQueueSet(parallel_gc_threads);
guarantee(_stack_array != NULL, "Count not initialize promotion manager");
_chunk_array = new ChunkTaskQueueSet(parallel_gc_threads);
guarantee(_chunk_array != NULL, "Count not initialize promotion manager");
_region_array = new RegionTaskQueueSet(parallel_gc_threads);
guarantee(_region_array != NULL, "Count not initialize promotion manager");
// Create and register the ParCompactionManager(s) for the worker threads.
for(uint i=0; i<parallel_gc_threads; i++) {
_manager_array[i] = new ParCompactionManager();
guarantee(_manager_array[i] != NULL, "Could not create ParCompactionManager");
stack_array()->register_queue(i, _manager_array[i]->marking_stack());
#ifdef USE_ChunkTaskQueueWithOverflow
chunk_array()->register_queue(i, _manager_array[i]->chunk_stack()->task_queue());
#ifdef USE_RegionTaskQueueWithOverflow
region_array()->register_queue(i, _manager_array[i]->region_stack()->task_queue());
#else
chunk_array()->register_queue(i, _manager_array[i]->chunk_stack());
region_array()->register_queue(i, _manager_array[i]->region_stack());
#endif
}
@ -153,31 +153,31 @@ oop ParCompactionManager::retrieve_for_scanning() {
return NULL;
}
// Save chunk on a stack
void ParCompactionManager::save_for_processing(size_t chunk_index) {
// Save region on a stack
void ParCompactionManager::save_for_processing(size_t region_index) {
#ifdef ASSERT
const ParallelCompactData& sd = PSParallelCompact::summary_data();
ParallelCompactData::ChunkData* const chunk_ptr = sd.chunk(chunk_index);
assert(chunk_ptr->claimed(), "must be claimed");
assert(chunk_ptr->_pushed++ == 0, "should only be pushed once");
ParallelCompactData::RegionData* const region_ptr = sd.region(region_index);
assert(region_ptr->claimed(), "must be claimed");
assert(region_ptr->_pushed++ == 0, "should only be pushed once");
#endif
chunk_stack_push(chunk_index);
region_stack_push(region_index);
}
void ParCompactionManager::chunk_stack_push(size_t chunk_index) {
void ParCompactionManager::region_stack_push(size_t region_index) {
#ifdef USE_ChunkTaskQueueWithOverflow
chunk_stack()->save(chunk_index);
#ifdef USE_RegionTaskQueueWithOverflow
region_stack()->save(region_index);
#else
if(!chunk_stack()->push(chunk_index)) {
chunk_overflow_stack()->push(chunk_index);
if(!region_stack()->push(region_index)) {
region_overflow_stack()->push(region_index);
}
#endif
}
bool ParCompactionManager::retrieve_for_processing(size_t& chunk_index) {
#ifdef USE_ChunkTaskQueueWithOverflow
return chunk_stack()->retrieve(chunk_index);
bool ParCompactionManager::retrieve_for_processing(size_t& region_index) {
#ifdef USE_RegionTaskQueueWithOverflow
return region_stack()->retrieve(region_index);
#else
// Should not be used in the parallel case
ShouldNotReachHere();
@ -230,14 +230,14 @@ void ParCompactionManager::drain_marking_stacks(OopClosure* blk) {
assert(overflow_stack()->length() == 0, "Sanity");
}
void ParCompactionManager::drain_chunk_overflow_stack() {
size_t chunk_index = (size_t) -1;
while(chunk_stack()->retrieve_from_overflow(chunk_index)) {
PSParallelCompact::fill_and_update_chunk(this, chunk_index);
void ParCompactionManager::drain_region_overflow_stack() {
size_t region_index = (size_t) -1;
while(region_stack()->retrieve_from_overflow(region_index)) {
PSParallelCompact::fill_and_update_region(this, region_index);
}
}
void ParCompactionManager::drain_chunk_stacks() {
void ParCompactionManager::drain_region_stacks() {
#ifdef ASSERT
ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
@ -249,42 +249,42 @@ void ParCompactionManager::drain_chunk_stacks() {
#if 1 // def DO_PARALLEL - the serial code hasn't been updated
do {
#ifdef USE_ChunkTaskQueueWithOverflow
#ifdef USE_RegionTaskQueueWithOverflow
// Drain overflow stack first, so other threads can steal from
// claimed stack while we work.
size_t chunk_index = (size_t) -1;
while(chunk_stack()->retrieve_from_overflow(chunk_index)) {
PSParallelCompact::fill_and_update_chunk(this, chunk_index);
size_t region_index = (size_t) -1;
while(region_stack()->retrieve_from_overflow(region_index)) {
PSParallelCompact::fill_and_update_region(this, region_index);
}
while (chunk_stack()->retrieve_from_stealable_queue(chunk_index)) {
PSParallelCompact::fill_and_update_chunk(this, chunk_index);
while (region_stack()->retrieve_from_stealable_queue(region_index)) {
PSParallelCompact::fill_and_update_region(this, region_index);
}
} while (!chunk_stack()->is_empty());
} while (!region_stack()->is_empty());
#else
// Drain overflow stack first, so other threads can steal from
// claimed stack while we work.
while(!chunk_overflow_stack()->is_empty()) {
size_t chunk_index = chunk_overflow_stack()->pop();
PSParallelCompact::fill_and_update_chunk(this, chunk_index);
while(!region_overflow_stack()->is_empty()) {
size_t region_index = region_overflow_stack()->pop();
PSParallelCompact::fill_and_update_region(this, region_index);
}
size_t chunk_index = -1;
size_t region_index = -1;
// obj is a reference!!!
while (chunk_stack()->pop_local(chunk_index)) {
while (region_stack()->pop_local(region_index)) {
// It would be nice to assert about the type of objects we might
// pop, but they can come from anywhere, unfortunately.
PSParallelCompact::fill_and_update_chunk(this, chunk_index);
PSParallelCompact::fill_and_update_region(this, region_index);
}
} while((chunk_stack()->size() != 0) ||
(chunk_overflow_stack()->length() != 0));
} while((region_stack()->size() != 0) ||
(region_overflow_stack()->length() != 0));
#endif
#ifdef USE_ChunkTaskQueueWithOverflow
assert(chunk_stack()->is_empty(), "Sanity");
#ifdef USE_RegionTaskQueueWithOverflow
assert(region_stack()->is_empty(), "Sanity");
#else
assert(chunk_stack()->size() == 0, "Sanity");
assert(chunk_overflow_stack()->length() == 0, "Sanity");
assert(region_stack()->size() == 0, "Sanity");
assert(region_overflow_stack()->length() == 0, "Sanity");
#endif
#else
oop obj;

View file

@ -52,7 +52,7 @@ class ParCompactionManager : public CHeapObj {
friend class ParallelTaskTerminator;
friend class ParMarkBitMap;
friend class PSParallelCompact;
friend class StealChunkCompactionTask;
friend class StealRegionCompactionTask;
friend class UpdateAndFillClosure;
friend class RefProcTaskExecutor;
@ -75,20 +75,20 @@ class ParCompactionManager : public CHeapObj {
static ParCompactionManager** _manager_array;
static OopTaskQueueSet* _stack_array;
static ObjectStartArray* _start_array;
static ChunkTaskQueueSet* _chunk_array;
static RegionTaskQueueSet* _region_array;
static PSOldGen* _old_gen;
OopTaskQueue _marking_stack;
GrowableArray<oop>* _overflow_stack;
// Is there a way to reuse the _marking_stack for the
// saving empty chunks? For now just create a different
// saving empty regions? For now just create a different
// type of TaskQueue.
#ifdef USE_ChunkTaskQueueWithOverflow
ChunkTaskQueueWithOverflow _chunk_stack;
#ifdef USE_RegionTaskQueueWithOverflow
RegionTaskQueueWithOverflow _region_stack;
#else
ChunkTaskQueue _chunk_stack;
GrowableArray<size_t>* _chunk_overflow_stack;
RegionTaskQueue _region_stack;
GrowableArray<size_t>* _region_overflow_stack;
#endif
#if 1 // does this happen enough to need a per thread stack?
@ -106,15 +106,16 @@ class ParCompactionManager : public CHeapObj {
protected:
// Array of tasks. Needed by the ParallelTaskTerminator.
static ChunkTaskQueueSet* chunk_array() { return _chunk_array; }
static RegionTaskQueueSet* region_array() { return _region_array; }
OopTaskQueue* marking_stack() { return &_marking_stack; }
GrowableArray<oop>* overflow_stack() { return _overflow_stack; }
#ifdef USE_ChunkTaskQueueWithOverflow
ChunkTaskQueueWithOverflow* chunk_stack() { return &_chunk_stack; }
#ifdef USE_RegionTaskQueueWithOverflow
RegionTaskQueueWithOverflow* region_stack() { return &_region_stack; }
#else
ChunkTaskQueue* chunk_stack() { return &_chunk_stack; }
GrowableArray<size_t>* chunk_overflow_stack() { return _chunk_overflow_stack; }
RegionTaskQueue* region_stack() { return &_region_stack; }
GrowableArray<size_t>* region_overflow_stack() {
return _region_overflow_stack;
}
#endif
// Pushes onto the marking stack. If the marking stack is full,
@ -123,9 +124,9 @@ class ParCompactionManager : public CHeapObj {
// Do not implement an equivalent stack_pop. Deal with the
// marking stack and overflow stack directly.
// Pushes onto the chunk stack. If the chunk stack is full,
// pushes onto the chunk overflow stack.
void chunk_stack_push(size_t chunk_index);
// Pushes onto the region stack. If the region stack is full,
// pushes onto the region overflow stack.
void region_stack_push(size_t region_index);
public:
Action action() { return _action; }
@ -160,10 +161,10 @@ class ParCompactionManager : public CHeapObj {
// Get a oop for scanning. If returns null, no oop were found.
oop retrieve_for_scanning();
// Save chunk for later processing. Must not fail.
void save_for_processing(size_t chunk_index);
// Get a chunk for processing. If returns null, no chunk were found.
bool retrieve_for_processing(size_t& chunk_index);
// Save region for later processing. Must not fail.
void save_for_processing(size_t region_index);
// Get a region for processing. If returns null, no region were found.
bool retrieve_for_processing(size_t& region_index);
// Access function for compaction managers
static ParCompactionManager* gc_thread_compaction_manager(int index);
@ -172,18 +173,18 @@ class ParCompactionManager : public CHeapObj {
return stack_array()->steal(queue_num, seed, t);
}
static bool steal(int queue_num, int* seed, ChunkTask& t) {
return chunk_array()->steal(queue_num, seed, t);
static bool steal(int queue_num, int* seed, RegionTask& t) {
return region_array()->steal(queue_num, seed, t);
}
// Process tasks remaining on any stack
void drain_marking_stacks(OopClosure *blk);
// Process tasks remaining on any stack
void drain_chunk_stacks();
void drain_region_stacks();
// Process tasks remaining on any stack
void drain_chunk_overflow_stack();
void drain_region_overflow_stack();
// Debugging support
#ifdef ASSERT

View file

@ -76,87 +76,87 @@ class ParallelCompactData
{
public:
// Sizes are in HeapWords, unless indicated otherwise.
static const size_t Log2ChunkSize;
static const size_t ChunkSize;
static const size_t ChunkSizeBytes;
static const size_t Log2RegionSize;
static const size_t RegionSize;
static const size_t RegionSizeBytes;
// Mask for the bits in a size_t to get an offset within a chunk.
static const size_t ChunkSizeOffsetMask;
// Mask for the bits in a pointer to get an offset within a chunk.
static const size_t ChunkAddrOffsetMask;
// Mask for the bits in a pointer to get the address of the start of a chunk.
static const size_t ChunkAddrMask;
// Mask for the bits in a size_t to get an offset within a region.
static const size_t RegionSizeOffsetMask;
// Mask for the bits in a pointer to get an offset within a region.
static const size_t RegionAddrOffsetMask;
// Mask for the bits in a pointer to get the address of the start of a region.
static const size_t RegionAddrMask;
static const size_t Log2BlockSize;
static const size_t BlockSize;
static const size_t BlockOffsetMask;
static const size_t BlockMask;
static const size_t BlocksPerChunk;
static const size_t BlocksPerRegion;
class ChunkData
class RegionData
{
public:
// Destination address of the chunk.
// Destination address of the region.
HeapWord* destination() const { return _destination; }
// The first chunk containing data destined for this chunk.
size_t source_chunk() const { return _source_chunk; }
// The first region containing data destined for this region.
size_t source_region() const { return _source_region; }
// The object (if any) starting in this chunk and ending in a different
// chunk that could not be updated during the main (parallel) compaction
// The object (if any) starting in this region and ending in a different
// region that could not be updated during the main (parallel) compaction
// phase. This is different from _partial_obj_addr, which is an object that
// extends onto a source chunk. However, the two uses do not overlap in
// extends onto a source region. However, the two uses do not overlap in
// time, so the same field is used to save space.
HeapWord* deferred_obj_addr() const { return _partial_obj_addr; }
// The starting address of the partial object extending onto the chunk.
// The starting address of the partial object extending onto the region.
HeapWord* partial_obj_addr() const { return _partial_obj_addr; }
// Size of the partial object extending onto the chunk (words).
// Size of the partial object extending onto the region (words).
size_t partial_obj_size() const { return _partial_obj_size; }
// Size of live data that lies within this chunk due to objects that start
// in this chunk (words). This does not include the partial object
// extending onto the chunk (if any), or the part of an object that extends
// onto the next chunk (if any).
// Size of live data that lies within this region due to objects that start
// in this region (words). This does not include the partial object
// extending onto the region (if any), or the part of an object that extends
// onto the next region (if any).
size_t live_obj_size() const { return _dc_and_los & los_mask; }
// Total live data that lies within the chunk (words).
// Total live data that lies within the region (words).
size_t data_size() const { return partial_obj_size() + live_obj_size(); }
// The destination_count is the number of other chunks to which data from
// this chunk will be copied. At the end of the summary phase, the valid
// The destination_count is the number of other regions to which data from
// this region will be copied. At the end of the summary phase, the valid
// values of destination_count are
//
// 0 - data from the chunk will be compacted completely into itself, or the
// chunk is empty. The chunk can be claimed and then filled.
// 1 - data from the chunk will be compacted into 1 other chunk; some
// data from the chunk may also be compacted into the chunk itself.
// 2 - data from the chunk will be copied to 2 other chunks.
// 0 - data from the region will be compacted completely into itself, or the
// region is empty. The region can be claimed and then filled.
// 1 - data from the region will be compacted into 1 other region; some
// data from the region may also be compacted into the region itself.
// 2 - data from the region will be copied to 2 other regions.
//
// During compaction as chunks are emptied, the destination_count is
// During compaction as regions are emptied, the destination_count is
// decremented (atomically) and when it reaches 0, it can be claimed and
// then filled.
//
// A chunk is claimed for processing by atomically changing the
// destination_count to the claimed value (dc_claimed). After a chunk has
// A region is claimed for processing by atomically changing the
// destination_count to the claimed value (dc_claimed). After a region has
// been filled, the destination_count should be set to the completed value
// (dc_completed).
inline uint destination_count() const;
inline uint destination_count_raw() const;
// The location of the java heap data that corresponds to this chunk.
// The location of the java heap data that corresponds to this region.
inline HeapWord* data_location() const;
// The highest address referenced by objects in this chunk.
// The highest address referenced by objects in this region.
inline HeapWord* highest_ref() const;
// Whether this chunk is available to be claimed, has been claimed, or has
// Whether this region is available to be claimed, has been claimed, or has
// been completed.
//
// Minor subtlety: claimed() returns true if the chunk is marked
// completed(), which is desirable since a chunk must be claimed before it
// Minor subtlety: claimed() returns true if the region is marked
// completed(), which is desirable since a region must be claimed before it
// can be completed.
bool available() const { return _dc_and_los < dc_one; }
bool claimed() const { return _dc_and_los >= dc_claimed; }
@ -164,11 +164,11 @@ public:
// These are not atomic.
void set_destination(HeapWord* addr) { _destination = addr; }
void set_source_chunk(size_t chunk) { _source_chunk = chunk; }
void set_source_region(size_t region) { _source_region = region; }
void set_deferred_obj_addr(HeapWord* addr) { _partial_obj_addr = addr; }
void set_partial_obj_addr(HeapWord* addr) { _partial_obj_addr = addr; }
void set_partial_obj_size(size_t words) {
_partial_obj_size = (chunk_sz_t) words;
_partial_obj_size = (region_sz_t) words;
}
inline void set_destination_count(uint count);
@ -184,24 +184,24 @@ public:
inline bool claim();
private:
// The type used to represent object sizes within a chunk.
typedef uint chunk_sz_t;
// The type used to represent object sizes within a region.
typedef uint region_sz_t;
// Constants for manipulating the _dc_and_los field, which holds both the
// destination count and live obj size. The live obj size lives at the
// least significant end so no masking is necessary when adding.
static const chunk_sz_t dc_shift; // Shift amount.
static const chunk_sz_t dc_mask; // Mask for destination count.
static const chunk_sz_t dc_one; // 1, shifted appropriately.
static const chunk_sz_t dc_claimed; // Chunk has been claimed.
static const chunk_sz_t dc_completed; // Chunk has been completed.
static const chunk_sz_t los_mask; // Mask for live obj size.
static const region_sz_t dc_shift; // Shift amount.
static const region_sz_t dc_mask; // Mask for destination count.
static const region_sz_t dc_one; // 1, shifted appropriately.
static const region_sz_t dc_claimed; // Region has been claimed.
static const region_sz_t dc_completed; // Region has been completed.
static const region_sz_t los_mask; // Mask for live obj size.
HeapWord* _destination;
size_t _source_chunk;
size_t _source_region;
HeapWord* _partial_obj_addr;
chunk_sz_t _partial_obj_size;
chunk_sz_t volatile _dc_and_los;
region_sz_t _partial_obj_size;
region_sz_t volatile _dc_and_los;
#ifdef ASSERT
// These enable optimizations that are only partially implemented. Use
// debug builds to prevent the code fragments from breaking.
@ -211,17 +211,17 @@ public:
#ifdef ASSERT
public:
uint _pushed; // 0 until chunk is pushed onto a worker's stack
uint _pushed; // 0 until region is pushed onto a worker's stack
private:
#endif
};
// 'Blocks' allow shorter sections of the bitmap to be searched. Each Block
// holds an offset, which is the amount of live data in the Chunk to the left
// holds an offset, which is the amount of live data in the Region to the left
// of the first live object in the Block. This amount of live data will
// include any object extending into the block. The first block in
// a chunk does not include any partial object extending into the
// the chunk.
// a region does not include any partial object extending into the
// the region.
//
// The offset also encodes the
// 'parity' of the first 1 bit in the Block: a positive offset means the
@ -286,27 +286,27 @@ public:
ParallelCompactData();
bool initialize(MemRegion covered_region);
size_t chunk_count() const { return _chunk_count; }
size_t region_count() const { return _region_count; }
// Convert chunk indices to/from ChunkData pointers.
inline ChunkData* chunk(size_t chunk_idx) const;
inline size_t chunk(const ChunkData* const chunk_ptr) const;
// Convert region indices to/from RegionData pointers.
inline RegionData* region(size_t region_idx) const;
inline size_t region(const RegionData* const region_ptr) const;
// Returns true if the given address is contained within the chunk
bool chunk_contains(size_t chunk_index, HeapWord* addr);
// Returns true if the given address is contained within the region
bool region_contains(size_t region_index, HeapWord* addr);
size_t block_count() const { return _block_count; }
inline BlockData* block(size_t n) const;
// Returns true if the given block is in the given chunk.
static bool chunk_contains_block(size_t chunk_index, size_t block_index);
// Returns true if the given block is in the given region.
static bool region_contains_block(size_t region_index, size_t block_index);
void add_obj(HeapWord* addr, size_t len);
void add_obj(oop p, size_t len) { add_obj((HeapWord*)p, len); }
// Fill in the chunks covering [beg, end) so that no data moves; i.e., the
// destination of chunk n is simply the start of chunk n. The argument beg
// must be chunk-aligned; end need not be.
// Fill in the regions covering [beg, end) so that no data moves; i.e., the
// destination of region n is simply the start of region n. The argument beg
// must be region-aligned; end need not be.
void summarize_dense_prefix(HeapWord* beg, HeapWord* end);
bool summarize(HeapWord* target_beg, HeapWord* target_end,
@ -314,27 +314,27 @@ public:
HeapWord** target_next, HeapWord** source_next = 0);
void clear();
void clear_range(size_t beg_chunk, size_t end_chunk);
void clear_range(size_t beg_region, size_t end_region);
void clear_range(HeapWord* beg, HeapWord* end) {
clear_range(addr_to_chunk_idx(beg), addr_to_chunk_idx(end));
clear_range(addr_to_region_idx(beg), addr_to_region_idx(end));
}
// Return the number of words between addr and the start of the chunk
// Return the number of words between addr and the start of the region
// containing addr.
inline size_t chunk_offset(const HeapWord* addr) const;
inline size_t region_offset(const HeapWord* addr) const;
// Convert addresses to/from a chunk index or chunk pointer.
inline size_t addr_to_chunk_idx(const HeapWord* addr) const;
inline ChunkData* addr_to_chunk_ptr(const HeapWord* addr) const;
inline HeapWord* chunk_to_addr(size_t chunk) const;
inline HeapWord* chunk_to_addr(size_t chunk, size_t offset) const;
inline HeapWord* chunk_to_addr(const ChunkData* chunk) const;
// Convert addresses to/from a region index or region pointer.
inline size_t addr_to_region_idx(const HeapWord* addr) const;
inline RegionData* addr_to_region_ptr(const HeapWord* addr) const;
inline HeapWord* region_to_addr(size_t region) const;
inline HeapWord* region_to_addr(size_t region, size_t offset) const;
inline HeapWord* region_to_addr(const RegionData* region) const;
inline HeapWord* chunk_align_down(HeapWord* addr) const;
inline HeapWord* chunk_align_up(HeapWord* addr) const;
inline bool is_chunk_aligned(HeapWord* addr) const;
inline HeapWord* region_align_down(HeapWord* addr) const;
inline HeapWord* region_align_up(HeapWord* addr) const;
inline bool is_region_aligned(HeapWord* addr) const;
// Analogous to chunk_offset() for blocks.
// Analogous to region_offset() for blocks.
size_t block_offset(const HeapWord* addr) const;
size_t addr_to_block_idx(const HeapWord* addr) const;
size_t addr_to_block_idx(const oop obj) const {
@ -344,7 +344,7 @@ public:
inline HeapWord* block_to_addr(size_t block) const;
// Return the address one past the end of the partial object.
HeapWord* partial_obj_end(size_t chunk_idx) const;
HeapWord* partial_obj_end(size_t region_idx) const;
// Return the new location of the object p after the
// the compaction.
@ -353,8 +353,8 @@ public:
// Same as calc_new_pointer() using blocks.
HeapWord* block_calc_new_pointer(HeapWord* addr);
// Same as calc_new_pointer() using chunks.
HeapWord* chunk_calc_new_pointer(HeapWord* addr);
// Same as calc_new_pointer() using regions.
HeapWord* region_calc_new_pointer(HeapWord* addr);
HeapWord* calc_new_pointer(oop p) {
return calc_new_pointer((HeapWord*) p);
@ -364,7 +364,7 @@ public:
klassOop calc_new_klass(klassOop);
// Given a block returns true if the partial object for the
// corresponding chunk ends in the block. Returns false, otherwise
// corresponding region ends in the block. Returns false, otherwise
// If there is no partial object, returns false.
bool partial_obj_ends_in_block(size_t block_index);
@ -378,7 +378,7 @@ public:
private:
bool initialize_block_data(size_t region_size);
bool initialize_chunk_data(size_t region_size);
bool initialize_region_data(size_t region_size);
PSVirtualSpace* create_vspace(size_t count, size_t element_size);
private:
@ -387,9 +387,9 @@ private:
HeapWord* _region_end;
#endif // #ifdef ASSERT
PSVirtualSpace* _chunk_vspace;
ChunkData* _chunk_data;
size_t _chunk_count;
PSVirtualSpace* _region_vspace;
RegionData* _region_data;
size_t _region_count;
PSVirtualSpace* _block_vspace;
BlockData* _block_data;
@ -397,64 +397,64 @@ private:
};
inline uint
ParallelCompactData::ChunkData::destination_count_raw() const
ParallelCompactData::RegionData::destination_count_raw() const
{
return _dc_and_los & dc_mask;
}
inline uint
ParallelCompactData::ChunkData::destination_count() const
ParallelCompactData::RegionData::destination_count() const
{
return destination_count_raw() >> dc_shift;
}
inline void
ParallelCompactData::ChunkData::set_destination_count(uint count)
ParallelCompactData::RegionData::set_destination_count(uint count)
{
assert(count <= (dc_completed >> dc_shift), "count too large");
const chunk_sz_t live_sz = (chunk_sz_t) live_obj_size();
const region_sz_t live_sz = (region_sz_t) live_obj_size();
_dc_and_los = (count << dc_shift) | live_sz;
}
inline void ParallelCompactData::ChunkData::set_live_obj_size(size_t words)
inline void ParallelCompactData::RegionData::set_live_obj_size(size_t words)
{
assert(words <= los_mask, "would overflow");
_dc_and_los = destination_count_raw() | (chunk_sz_t)words;
_dc_and_los = destination_count_raw() | (region_sz_t)words;
}
inline void ParallelCompactData::ChunkData::decrement_destination_count()
inline void ParallelCompactData::RegionData::decrement_destination_count()
{
assert(_dc_and_los < dc_claimed, "already claimed");
assert(_dc_and_los >= dc_one, "count would go negative");
Atomic::add((int)dc_mask, (volatile int*)&_dc_and_los);
}
inline HeapWord* ParallelCompactData::ChunkData::data_location() const
inline HeapWord* ParallelCompactData::RegionData::data_location() const
{
DEBUG_ONLY(return _data_location;)
NOT_DEBUG(return NULL;)
}
inline HeapWord* ParallelCompactData::ChunkData::highest_ref() const
inline HeapWord* ParallelCompactData::RegionData::highest_ref() const
{
DEBUG_ONLY(return _highest_ref;)
NOT_DEBUG(return NULL;)
}
inline void ParallelCompactData::ChunkData::set_data_location(HeapWord* addr)
inline void ParallelCompactData::RegionData::set_data_location(HeapWord* addr)
{
DEBUG_ONLY(_data_location = addr;)
}
inline void ParallelCompactData::ChunkData::set_completed()
inline void ParallelCompactData::RegionData::set_completed()
{
assert(claimed(), "must be claimed first");
_dc_and_los = dc_completed | (chunk_sz_t) live_obj_size();
_dc_and_los = dc_completed | (region_sz_t) live_obj_size();
}
// MT-unsafe claiming of a chunk. Should only be used during single threaded
// MT-unsafe claiming of a region. Should only be used during single threaded
// execution.
inline bool ParallelCompactData::ChunkData::claim_unsafe()
inline bool ParallelCompactData::RegionData::claim_unsafe()
{
if (available()) {
_dc_and_los |= dc_claimed;
@ -463,13 +463,13 @@ inline bool ParallelCompactData::ChunkData::claim_unsafe()
return false;
}
inline void ParallelCompactData::ChunkData::add_live_obj(size_t words)
inline void ParallelCompactData::RegionData::add_live_obj(size_t words)
{
assert(words <= (size_t)los_mask - live_obj_size(), "overflow");
Atomic::add((int) words, (volatile int*) &_dc_and_los);
}
inline void ParallelCompactData::ChunkData::set_highest_ref(HeapWord* addr)
inline void ParallelCompactData::RegionData::set_highest_ref(HeapWord* addr)
{
#ifdef ASSERT
HeapWord* tmp = _highest_ref;
@ -479,7 +479,7 @@ inline void ParallelCompactData::ChunkData::set_highest_ref(HeapWord* addr)
#endif // #ifdef ASSERT
}
inline bool ParallelCompactData::ChunkData::claim()
inline bool ParallelCompactData::RegionData::claim()
{
const int los = (int) live_obj_size();
const int old = Atomic::cmpxchg(dc_claimed | los,
@ -487,19 +487,19 @@ inline bool ParallelCompactData::ChunkData::claim()
return old == los;
}
inline ParallelCompactData::ChunkData*
ParallelCompactData::chunk(size_t chunk_idx) const
inline ParallelCompactData::RegionData*
ParallelCompactData::region(size_t region_idx) const
{
assert(chunk_idx <= chunk_count(), "bad arg");
return _chunk_data + chunk_idx;
assert(region_idx <= region_count(), "bad arg");
return _region_data + region_idx;
}
inline size_t
ParallelCompactData::chunk(const ChunkData* const chunk_ptr) const
ParallelCompactData::region(const RegionData* const region_ptr) const
{
assert(chunk_ptr >= _chunk_data, "bad arg");
assert(chunk_ptr <= _chunk_data + chunk_count(), "bad arg");
return pointer_delta(chunk_ptr, _chunk_data, sizeof(ChunkData));
assert(region_ptr >= _region_data, "bad arg");
assert(region_ptr <= _region_data + region_count(), "bad arg");
return pointer_delta(region_ptr, _region_data, sizeof(RegionData));
}
inline ParallelCompactData::BlockData*
@ -509,68 +509,69 @@ ParallelCompactData::block(size_t n) const {
}
inline size_t
ParallelCompactData::chunk_offset(const HeapWord* addr) const
ParallelCompactData::region_offset(const HeapWord* addr) const
{
assert(addr >= _region_start, "bad addr");
assert(addr <= _region_end, "bad addr");
return (size_t(addr) & ChunkAddrOffsetMask) >> LogHeapWordSize;
return (size_t(addr) & RegionAddrOffsetMask) >> LogHeapWordSize;
}
inline size_t
ParallelCompactData::addr_to_chunk_idx(const HeapWord* addr) const
ParallelCompactData::addr_to_region_idx(const HeapWord* addr) const
{
assert(addr >= _region_start, "bad addr");
assert(addr <= _region_end, "bad addr");
return pointer_delta(addr, _region_start) >> Log2ChunkSize;
return pointer_delta(addr, _region_start) >> Log2RegionSize;
}
inline ParallelCompactData::ChunkData*
ParallelCompactData::addr_to_chunk_ptr(const HeapWord* addr) const
inline ParallelCompactData::RegionData*
ParallelCompactData::addr_to_region_ptr(const HeapWord* addr) const
{
return chunk(addr_to_chunk_idx(addr));
return region(addr_to_region_idx(addr));
}
inline HeapWord*
ParallelCompactData::chunk_to_addr(size_t chunk) const
ParallelCompactData::region_to_addr(size_t region) const
{
assert(chunk <= _chunk_count, "chunk out of range");
return _region_start + (chunk << Log2ChunkSize);
assert(region <= _region_count, "region out of range");
return _region_start + (region << Log2RegionSize);
}
inline HeapWord*
ParallelCompactData::chunk_to_addr(const ChunkData* chunk) const
ParallelCompactData::region_to_addr(const RegionData* region) const
{
return chunk_to_addr(pointer_delta(chunk, _chunk_data, sizeof(ChunkData)));
return region_to_addr(pointer_delta(region, _region_data,
sizeof(RegionData)));
}
inline HeapWord*
ParallelCompactData::chunk_to_addr(size_t chunk, size_t offset) const
ParallelCompactData::region_to_addr(size_t region, size_t offset) const
{
assert(chunk <= _chunk_count, "chunk out of range");
assert(offset < ChunkSize, "offset too big"); // This may be too strict.
return chunk_to_addr(chunk) + offset;
assert(region <= _region_count, "region out of range");
assert(offset < RegionSize, "offset too big"); // This may be too strict.
return region_to_addr(region) + offset;
}
inline HeapWord*
ParallelCompactData::chunk_align_down(HeapWord* addr) const
ParallelCompactData::region_align_down(HeapWord* addr) const
{
assert(addr >= _region_start, "bad addr");
assert(addr < _region_end + ChunkSize, "bad addr");
return (HeapWord*)(size_t(addr) & ChunkAddrMask);
assert(addr < _region_end + RegionSize, "bad addr");
return (HeapWord*)(size_t(addr) & RegionAddrMask);
}
inline HeapWord*
ParallelCompactData::chunk_align_up(HeapWord* addr) const
ParallelCompactData::region_align_up(HeapWord* addr) const
{
assert(addr >= _region_start, "bad addr");
assert(addr <= _region_end, "bad addr");
return chunk_align_down(addr + ChunkSizeOffsetMask);
return region_align_down(addr + RegionSizeOffsetMask);
}
inline bool
ParallelCompactData::is_chunk_aligned(HeapWord* addr) const
ParallelCompactData::is_region_aligned(HeapWord* addr) const
{
return chunk_offset(addr) == 0;
return region_offset(addr) == 0;
}
inline size_t
@ -692,40 +693,39 @@ class BitBlockUpdateClosure: public ParMarkBitMapClosure {
// ParallelCompactData::BlockData::blk_ofs_t _live_data_left;
size_t _live_data_left;
size_t _cur_block;
HeapWord* _chunk_start;
HeapWord* _chunk_end;
size_t _chunk_index;
HeapWord* _region_start;
HeapWord* _region_end;
size_t _region_index;
public:
BitBlockUpdateClosure(ParMarkBitMap* mbm,
ParCompactionManager* cm,
size_t chunk_index);
size_t region_index);
size_t cur_block() { return _cur_block; }
size_t chunk_index() { return _chunk_index; }
size_t region_index() { return _region_index; }
size_t live_data_left() { return _live_data_left; }
// Returns true the first bit in the current block (cur_block) is
// a start bit.
// Returns true if the current block is within the chunk for the closure;
bool chunk_contains_cur_block();
// Returns true if the current block is within the region for the closure;
bool region_contains_cur_block();
// Set the chunk index and related chunk values for
// a new chunk.
void reset_chunk(size_t chunk_index);
// Set the region index and related region values for
// a new region.
void reset_region(size_t region_index);
virtual IterationStatus do_addr(HeapWord* addr, size_t words);
};
// The UseParallelOldGC collector is a stop-the-world garbage
// collector that does parts of the collection using parallel threads.
// The collection includes the tenured generation and the young
// generation. The permanent generation is collected at the same
// time as the other two generations but the permanent generation
// is collect by a single GC thread. The permanent generation is
// collected serially because of the requirement that during the
// processing of a klass AAA, any objects reference by AAA must
// already have been processed. This requirement is enforced by
// a left (lower address) to right (higher address) sliding compaction.
// The UseParallelOldGC collector is a stop-the-world garbage collector that
// does parts of the collection using parallel threads. The collection includes
// the tenured generation and the young generation. The permanent generation is
// collected at the same time as the other two generations but the permanent
// generation is collect by a single GC thread. The permanent generation is
// collected serially because of the requirement that during the processing of a
// klass AAA, any objects reference by AAA must already have been processed.
// This requirement is enforced by a left (lower address) to right (higher
// address) sliding compaction.
//
// There are four phases of the collection.
//
@ -740,80 +740,75 @@ class BitBlockUpdateClosure: public ParMarkBitMapClosure {
// - move the objects to their destination
// - update some references and reinitialize some variables
//
// These three phases are invoked in PSParallelCompact::invoke_no_policy().
// The marking phase is implemented in PSParallelCompact::marking_phase()
// and does a complete marking of the heap.
// The summary phase is implemented in PSParallelCompact::summary_phase().
// The move and update phase is implemented in PSParallelCompact::compact().
// These three phases are invoked in PSParallelCompact::invoke_no_policy(). The
// marking phase is implemented in PSParallelCompact::marking_phase() and does a
// complete marking of the heap. The summary phase is implemented in
// PSParallelCompact::summary_phase(). The move and update phase is implemented
// in PSParallelCompact::compact().
//
// A space that is being collected is divided into chunks and with
// each chunk is associated an object of type ParallelCompactData.
// Each chunk is of a fixed size and typically will contain more than
// 1 object and may have parts of objects at the front and back of the
// chunk.
// A space that is being collected is divided into regions and with each region
// is associated an object of type ParallelCompactData. Each region is of a
// fixed size and typically will contain more than 1 object and may have parts
// of objects at the front and back of the region.
//
// chunk -----+---------------------+----------
// region -----+---------------------+----------
// objects covered [ AAA )[ BBB )[ CCC )[ DDD )
//
// The marking phase does a complete marking of all live objects in the
// heap. The marking also compiles the size of the data for
// all live objects covered by the chunk. This size includes the
// part of any live object spanning onto the chunk (part of AAA
// if it is live) from the front, all live objects contained in the chunk
// (BBB and/or CCC if they are live), and the part of any live objects
// covered by the chunk that extends off the chunk (part of DDD if it is
// live). The marking phase uses multiple GC threads and marking is
// done in a bit array of type ParMarkBitMap. The marking of the
// bit map is done atomically as is the accumulation of the size of the
// live objects covered by a chunk.
// The marking phase does a complete marking of all live objects in the heap.
// The marking also compiles the size of the data for all live objects covered
// by the region. This size includes the part of any live object spanning onto
// the region (part of AAA if it is live) from the front, all live objects
// contained in the region (BBB and/or CCC if they are live), and the part of
// any live objects covered by the region that extends off the region (part of
// DDD if it is live). The marking phase uses multiple GC threads and marking
// is done in a bit array of type ParMarkBitMap. The marking of the bit map is
// done atomically as is the accumulation of the size of the live objects
// covered by a region.
//
// The summary phase calculates the total live data to the left of
// each chunk XXX. Based on that total and the bottom of the space,
// it can calculate the starting location of the live data in XXX.
// The summary phase calculates for each chunk XXX quantites such as
// The summary phase calculates the total live data to the left of each region
// XXX. Based on that total and the bottom of the space, it can calculate the
// starting location of the live data in XXX. The summary phase calculates for
// each region XXX quantites such as
//
// - the amount of live data at the beginning of a chunk from an object
// entering the chunk.
// - the location of the first live data on the chunk
// - a count of the number of chunks receiving live data from XXX.
// - the amount of live data at the beginning of a region from an object
// entering the region.
// - the location of the first live data on the region
// - a count of the number of regions receiving live data from XXX.
//
// See ParallelCompactData for precise details. The summary phase also
// calculates the dense prefix for the compaction. The dense prefix
// is a portion at the beginning of the space that is not moved. The
// objects in the dense prefix do need to have their object references
// updated. See method summarize_dense_prefix().
// calculates the dense prefix for the compaction. The dense prefix is a
// portion at the beginning of the space that is not moved. The objects in the
// dense prefix do need to have their object references updated. See method
// summarize_dense_prefix().
//
// The summary phase is done using 1 GC thread.
//
// The compaction phase moves objects to their new location and updates
// all references in the object.
// The compaction phase moves objects to their new location and updates all
// references in the object.
//
// A current exception is that objects that cross a chunk boundary
// are moved but do not have their references updated. References are
// not updated because it cannot easily be determined if the klass
// pointer KKK for the object AAA has been updated. KKK likely resides
// in a chunk to the left of the chunk containing AAA. These AAA's
// have there references updated at the end in a clean up phase.
// See the method PSParallelCompact::update_deferred_objects(). An
// alternate strategy is being investigated for this deferral of updating.
//
// Compaction is done on a chunk basis. A chunk that is ready to be
// filled is put on a ready list and GC threads take chunk off the list
// and fill them. A chunk is ready to be filled if it
// empty of live objects. Such a chunk may have been initially
// empty (only contained
// dead objects) or may have had all its live objects copied out already.
// A chunk that compacts into itself is also ready for filling. The
// ready list is initially filled with empty chunks and chunks compacting
// into themselves. There is always at least 1 chunk that can be put on
// the ready list. The chunks are atomically added and removed from
// the ready list.
// A current exception is that objects that cross a region boundary are moved
// but do not have their references updated. References are not updated because
// it cannot easily be determined if the klass pointer KKK for the object AAA
// has been updated. KKK likely resides in a region to the left of the region
// containing AAA. These AAA's have there references updated at the end in a
// clean up phase. See the method PSParallelCompact::update_deferred_objects().
// An alternate strategy is being investigated for this deferral of updating.
//
// Compaction is done on a region basis. A region that is ready to be filled is
// put on a ready list and GC threads take region off the list and fill them. A
// region is ready to be filled if it empty of live objects. Such a region may
// have been initially empty (only contained dead objects) or may have had all
// its live objects copied out already. A region that compacts into itself is
// also ready for filling. The ready list is initially filled with empty
// regions and regions compacting into themselves. There is always at least 1
// region that can be put on the ready list. The regions are atomically added
// and removed from the ready list.
class PSParallelCompact : AllStatic {
public:
// Convenient access to type names.
typedef ParMarkBitMap::idx_t idx_t;
typedef ParallelCompactData::ChunkData ChunkData;
typedef ParallelCompactData::RegionData RegionData;
typedef ParallelCompactData::BlockData BlockData;
typedef enum {
@ -977,26 +972,26 @@ class PSParallelCompact : AllStatic {
// not reclaimed).
static double dead_wood_limiter(double density, size_t min_percent);
// Find the first (left-most) chunk in the range [beg, end) that has at least
// Find the first (left-most) region in the range [beg, end) that has at least
// dead_words of dead space to the left. The argument beg must be the first
// chunk in the space that is not completely live.
static ChunkData* dead_wood_limit_chunk(const ChunkData* beg,
const ChunkData* end,
// region in the space that is not completely live.
static RegionData* dead_wood_limit_region(const RegionData* beg,
const RegionData* end,
size_t dead_words);
// Return a pointer to the first chunk in the range [beg, end) that is not
// Return a pointer to the first region in the range [beg, end) that is not
// completely full.
static ChunkData* first_dead_space_chunk(const ChunkData* beg,
const ChunkData* end);
static RegionData* first_dead_space_region(const RegionData* beg,
const RegionData* end);
// Return a value indicating the benefit or 'yield' if the compacted region
// were to start (or equivalently if the dense prefix were to end) at the
// candidate chunk. Higher values are better.
// candidate region. Higher values are better.
//
// The value is based on the amount of space reclaimed vs. the costs of (a)
// updating references in the dense prefix plus (b) copying objects and
// updating references in the compacted region.
static inline double reclaimed_ratio(const ChunkData* const candidate,
static inline double reclaimed_ratio(const RegionData* const candidate,
HeapWord* const bottom,
HeapWord* const top,
HeapWord* const new_top);
@ -1005,9 +1000,9 @@ class PSParallelCompact : AllStatic {
static HeapWord* compute_dense_prefix(const SpaceId id,
bool maximum_compaction);
// Return true if dead space crosses onto the specified Chunk; bit must be the
// bit index corresponding to the first word of the Chunk.
static inline bool dead_space_crosses_boundary(const ChunkData* chunk,
// Return true if dead space crosses onto the specified Region; bit must be
// the bit index corresponding to the first word of the Region.
static inline bool dead_space_crosses_boundary(const RegionData* region,
idx_t bit);
// Summary phase utility routine to fill dead space (if any) at the dense
@ -1038,16 +1033,16 @@ class PSParallelCompact : AllStatic {
static void compact_perm(ParCompactionManager* cm);
static void compact();
// Add available chunks to the stack and draining tasks to the task queue.
static void enqueue_chunk_draining_tasks(GCTaskQueue* q,
// Add available regions to the stack and draining tasks to the task queue.
static void enqueue_region_draining_tasks(GCTaskQueue* q,
uint parallel_gc_threads);
// Add dense prefix update tasks to the task queue.
static void enqueue_dense_prefix_tasks(GCTaskQueue* q,
uint parallel_gc_threads);
// Add chunk stealing tasks to the task queue.
static void enqueue_chunk_stealing_tasks(
// Add region stealing tasks to the task queue.
static void enqueue_region_stealing_tasks(
GCTaskQueue* q,
ParallelTaskTerminator* terminator_ptr,
uint parallel_gc_threads);
@ -1154,56 +1149,56 @@ class PSParallelCompact : AllStatic {
// Move and update the live objects in the specified space.
static void move_and_update(ParCompactionManager* cm, SpaceId space_id);
// Process the end of the given chunk range in the dense prefix.
// Process the end of the given region range in the dense prefix.
// This includes saving any object not updated.
static void dense_prefix_chunks_epilogue(ParCompactionManager* cm,
size_t chunk_start_index,
size_t chunk_end_index,
static void dense_prefix_regions_epilogue(ParCompactionManager* cm,
size_t region_start_index,
size_t region_end_index,
idx_t exiting_object_offset,
idx_t chunk_offset_start,
idx_t chunk_offset_end);
idx_t region_offset_start,
idx_t region_offset_end);
// Update a chunk in the dense prefix. For each live object
// in the chunk, update it's interior references. For each
// Update a region in the dense prefix. For each live object
// in the region, update it's interior references. For each
// dead object, fill it with deadwood. Dead space at the end
// of a chunk range will be filled to the start of the next
// live object regardless of the chunk_index_end. None of the
// of a region range will be filled to the start of the next
// live object regardless of the region_index_end. None of the
// objects in the dense prefix move and dead space is dead
// (holds only dead objects that don't need any processing), so
// dead space can be filled in any order.
static void update_and_deadwood_in_dense_prefix(ParCompactionManager* cm,
SpaceId space_id,
size_t chunk_index_start,
size_t chunk_index_end);
size_t region_index_start,
size_t region_index_end);
// Return the address of the count + 1st live word in the range [beg, end).
static HeapWord* skip_live_words(HeapWord* beg, HeapWord* end, size_t count);
// Return the address of the word to be copied to dest_addr, which must be
// aligned to a chunk boundary.
// aligned to a region boundary.
static HeapWord* first_src_addr(HeapWord* const dest_addr,
size_t src_chunk_idx);
size_t src_region_idx);
// Determine the next source chunk, set closure.source() to the start of the
// new chunk return the chunk index. Parameter end_addr is the address one
// Determine the next source region, set closure.source() to the start of the
// new region return the region index. Parameter end_addr is the address one
// beyond the end of source range just processed. If necessary, switch to a
// new source space and set src_space_id (in-out parameter) and src_space_top
// (out parameter) accordingly.
static size_t next_src_chunk(MoveAndUpdateClosure& closure,
static size_t next_src_region(MoveAndUpdateClosure& closure,
SpaceId& src_space_id,
HeapWord*& src_space_top,
HeapWord* end_addr);
// Decrement the destination count for each non-empty source chunk in the
// range [beg_chunk, chunk(chunk_align_up(end_addr))).
// Decrement the destination count for each non-empty source region in the
// range [beg_region, region(region_align_up(end_addr))).
static void decrement_destination_counts(ParCompactionManager* cm,
size_t beg_chunk,
size_t beg_region,
HeapWord* end_addr);
// Fill a chunk, copying objects from one or more source chunks.
static void fill_chunk(ParCompactionManager* cm, size_t chunk_idx);
static void fill_and_update_chunk(ParCompactionManager* cm, size_t chunk) {
fill_chunk(cm, chunk);
// Fill a region, copying objects from one or more source regions.
static void fill_region(ParCompactionManager* cm, size_t region_idx);
static void fill_and_update_region(ParCompactionManager* cm, size_t region) {
fill_region(cm, region);
}
// Update the deferred objects in the space.
@ -1259,7 +1254,7 @@ class PSParallelCompact : AllStatic {
#ifndef PRODUCT
// Debugging support.
static const char* space_names[last_space_id];
static void print_chunk_ranges();
static void print_region_ranges();
static void print_dense_prefix_stats(const char* const algorithm,
const SpaceId id,
const bool maximum_compaction,
@ -1267,7 +1262,7 @@ class PSParallelCompact : AllStatic {
#endif // #ifndef PRODUCT
#ifdef ASSERT
// Verify that all the chunks have been emptied.
// Verify that all the regions have been emptied.
static void verify_complete(SpaceId space_id);
#endif // #ifdef ASSERT
};
@ -1376,17 +1371,17 @@ inline double PSParallelCompact::normal_distribution(double density) {
}
inline bool
PSParallelCompact::dead_space_crosses_boundary(const ChunkData* chunk,
PSParallelCompact::dead_space_crosses_boundary(const RegionData* region,
idx_t bit)
{
assert(bit > 0, "cannot call this for the first bit/chunk");
assert(_summary_data.chunk_to_addr(chunk) == _mark_bitmap.bit_to_addr(bit),
assert(bit > 0, "cannot call this for the first bit/region");
assert(_summary_data.region_to_addr(region) == _mark_bitmap.bit_to_addr(bit),
"sanity check");
// Dead space crosses the boundary if (1) a partial object does not extend
// onto the chunk, (2) an object does not start at the beginning of the chunk,
// and (3) an object does not end at the end of the prior chunk.
return chunk->partial_obj_size() == 0 &&
// onto the region, (2) an object does not start at the beginning of the
// region, and (3) an object does not end at the end of the prior region.
return region->partial_obj_size() == 0 &&
!_mark_bitmap.is_obj_beg(bit) &&
!_mark_bitmap.is_obj_end(bit - 1);
}

View file

@ -1157,9 +1157,9 @@ class CommandLineFlags {
"In the Parallel Old garbage collector use parallel dense" \
" prefix update") \
\
develop(bool, UseParallelOldGCChunkPointerCalc, true, \
"In the Parallel Old garbage collector use chucks to calculate" \
" new object locations") \
develop(bool, UseParallelOldGCRegionPointerCalc, true, \
"In the Parallel Old garbage collector use regions to calculate" \
"new object locations") \
\
product(uintx, HeapMaximumCompactionInterval, 20, \
"How often should we maximally compact the heap (not allowing " \
@ -1195,8 +1195,8 @@ class CommandLineFlags {
develop(bool, ParallelOldMTUnsafeUpdateLiveData, false, \
"Use the Parallel Old MT unsafe in update of live size") \
\
develop(bool, TraceChunkTasksQueuing, false, \
"Trace the queuing of the chunk tasks") \
develop(bool, TraceRegionTasksQueuing, false, \
"Trace the queuing of the region tasks") \
\
product(uintx, ParallelMarkingThreads, 0, \
"Number of marking threads concurrent gc will use") \

View file

@ -109,72 +109,72 @@ void ParallelTaskTerminator::reset_for_reuse() {
}
}
bool ChunkTaskQueueWithOverflow::is_empty() {
return (_chunk_queue.size() == 0) &&
bool RegionTaskQueueWithOverflow::is_empty() {
return (_region_queue.size() == 0) &&
(_overflow_stack->length() == 0);
}
bool ChunkTaskQueueWithOverflow::stealable_is_empty() {
return _chunk_queue.size() == 0;
bool RegionTaskQueueWithOverflow::stealable_is_empty() {
return _region_queue.size() == 0;
}
bool ChunkTaskQueueWithOverflow::overflow_is_empty() {
bool RegionTaskQueueWithOverflow::overflow_is_empty() {
return _overflow_stack->length() == 0;
}
void ChunkTaskQueueWithOverflow::initialize() {
_chunk_queue.initialize();
void RegionTaskQueueWithOverflow::initialize() {
_region_queue.initialize();
assert(_overflow_stack == 0, "Creating memory leak");
_overflow_stack =
new (ResourceObj::C_HEAP) GrowableArray<ChunkTask>(10, true);
new (ResourceObj::C_HEAP) GrowableArray<RegionTask>(10, true);
}
void ChunkTaskQueueWithOverflow::save(ChunkTask t) {
if (TraceChunkTasksQueuing && Verbose) {
void RegionTaskQueueWithOverflow::save(RegionTask t) {
if (TraceRegionTasksQueuing && Verbose) {
gclog_or_tty->print_cr("CTQ: save " PTR_FORMAT, t);
}
if(!_chunk_queue.push(t)) {
if(!_region_queue.push(t)) {
_overflow_stack->push(t);
}
}
// Note that using this method will retrieve all chunks
// Note that using this method will retrieve all regions
// that have been saved but that it will always check
// the overflow stack. It may be more efficient to
// check the stealable queue and the overflow stack
// separately.
bool ChunkTaskQueueWithOverflow::retrieve(ChunkTask& chunk_task) {
bool result = retrieve_from_overflow(chunk_task);
bool RegionTaskQueueWithOverflow::retrieve(RegionTask& region_task) {
bool result = retrieve_from_overflow(region_task);
if (!result) {
result = retrieve_from_stealable_queue(chunk_task);
result = retrieve_from_stealable_queue(region_task);
}
if (TraceChunkTasksQueuing && Verbose && result) {
if (TraceRegionTasksQueuing && Verbose && result) {
gclog_or_tty->print_cr(" CTQ: retrieve " PTR_FORMAT, result);
}
return result;
}
bool ChunkTaskQueueWithOverflow::retrieve_from_stealable_queue(
ChunkTask& chunk_task) {
bool result = _chunk_queue.pop_local(chunk_task);
if (TraceChunkTasksQueuing && Verbose) {
gclog_or_tty->print_cr("CTQ: retrieve_stealable " PTR_FORMAT, chunk_task);
bool RegionTaskQueueWithOverflow::retrieve_from_stealable_queue(
RegionTask& region_task) {
bool result = _region_queue.pop_local(region_task);
if (TraceRegionTasksQueuing && Verbose) {
gclog_or_tty->print_cr("CTQ: retrieve_stealable " PTR_FORMAT, region_task);
}
return result;
}
bool ChunkTaskQueueWithOverflow::retrieve_from_overflow(
ChunkTask& chunk_task) {
bool
RegionTaskQueueWithOverflow::retrieve_from_overflow(RegionTask& region_task) {
bool result;
if (!_overflow_stack->is_empty()) {
chunk_task = _overflow_stack->pop();
region_task = _overflow_stack->pop();
result = true;
} else {
chunk_task = (ChunkTask) NULL;
region_task = (RegionTask) NULL;
result = false;
}
if (TraceChunkTasksQueuing && Verbose) {
gclog_or_tty->print_cr("CTQ: retrieve_stealable " PTR_FORMAT, chunk_task);
if (TraceRegionTasksQueuing && Verbose) {
gclog_or_tty->print_cr("CTQ: retrieve_stealable " PTR_FORMAT, region_task);
}
return result;
}

View file

@ -557,32 +557,32 @@ class StarTask {
typedef GenericTaskQueue<StarTask> OopStarTaskQueue;
typedef GenericTaskQueueSet<StarTask> OopStarTaskQueueSet;
typedef size_t ChunkTask; // index for chunk
typedef GenericTaskQueue<ChunkTask> ChunkTaskQueue;
typedef GenericTaskQueueSet<ChunkTask> ChunkTaskQueueSet;
typedef size_t RegionTask; // index for region
typedef GenericTaskQueue<RegionTask> RegionTaskQueue;
typedef GenericTaskQueueSet<RegionTask> RegionTaskQueueSet;
class ChunkTaskQueueWithOverflow: public CHeapObj {
class RegionTaskQueueWithOverflow: public CHeapObj {
protected:
ChunkTaskQueue _chunk_queue;
GrowableArray<ChunkTask>* _overflow_stack;
RegionTaskQueue _region_queue;
GrowableArray<RegionTask>* _overflow_stack;
public:
ChunkTaskQueueWithOverflow() : _overflow_stack(NULL) {}
RegionTaskQueueWithOverflow() : _overflow_stack(NULL) {}
// Initialize both stealable queue and overflow
void initialize();
// Save first to stealable queue and then to overflow
void save(ChunkTask t);
void save(RegionTask t);
// Retrieve first from overflow and then from stealable queue
bool retrieve(ChunkTask& chunk_index);
bool retrieve(RegionTask& region_index);
// Retrieve from stealable queue
bool retrieve_from_stealable_queue(ChunkTask& chunk_index);
bool retrieve_from_stealable_queue(RegionTask& region_index);
// Retrieve from overflow
bool retrieve_from_overflow(ChunkTask& chunk_index);
bool retrieve_from_overflow(RegionTask& region_index);
bool is_empty();
bool stealable_is_empty();
bool overflow_is_empty();
juint stealable_size() { return _chunk_queue.size(); }
ChunkTaskQueue* task_queue() { return &_chunk_queue; }
juint stealable_size() { return _region_queue.size(); }
RegionTaskQueue* task_queue() { return &_region_queue; }
};
#define USE_ChunkTaskQueueWithOverflow
#define USE_RegionTaskQueueWithOverflow