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7145441: G1: collection set chooser-related cleanup

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Cleanup of the CSet chooser class: standardize on uints for region num and indexes (instead of int, jint, etc.), make the method / field naming style more consistent, remove a lot of dead code.

Reviewed-by: johnc, brutisso
This commit is contained in:
Antonios Printezis 2012-04-18 13:39:55 -04:00
parent 01ea4199c7
commit 0afaaf8d36
9 changed files with 147 additions and 578 deletions
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255
hotspot/src/share/vm/gc_implementation/g1/collectionSetChooser.cpp
View file

@ -29,102 +29,6 @@
#include "gc_implementation/g1/g1ErgoVerbose.hpp"
#include "memory/space.inline.hpp"
CSetChooserCache::CSetChooserCache() {
for (int i = 0; i < CacheLength; ++i)
_cache[i] = NULL;
clear();
}
void CSetChooserCache::clear() {
_occupancy = 0;
_first = 0;
for (int i = 0; i < CacheLength; ++i) {
HeapRegion *hr = _cache[i];
if (hr != NULL)
hr->set_sort_index(-1);
_cache[i] = NULL;
}
}
#ifndef PRODUCT
bool CSetChooserCache::verify() {
guarantee(false, "CSetChooserCache::verify(): don't call this any more");
int index = _first;
HeapRegion *prev = NULL;
for (int i = 0; i < _occupancy; ++i) {
guarantee(_cache[index] != NULL, "cache entry should not be empty");
HeapRegion *hr = _cache[index];
guarantee(!hr->is_young(), "should not be young!");
if (prev != NULL) {
guarantee(prev->gc_efficiency() >= hr->gc_efficiency(),
"cache should be correctly ordered");
}
guarantee(hr->sort_index() == get_sort_index(index),
"sort index should be correct");
index = trim_index(index + 1);
prev = hr;
}
for (int i = 0; i < (CacheLength - _occupancy); ++i) {
guarantee(_cache[index] == NULL, "cache entry should be empty");
index = trim_index(index + 1);
}
guarantee(index == _first, "we should have reached where we started from");
return true;
}
#endif // PRODUCT
void CSetChooserCache::insert(HeapRegion *hr) {
guarantee(false, "CSetChooserCache::insert(): don't call this any more");
assert(!is_full(), "cache should not be empty");
hr->calc_gc_efficiency();
int empty_index;
if (_occupancy == 0) {
empty_index = _first;
} else {
empty_index = trim_index(_first + _occupancy);
assert(_cache[empty_index] == NULL, "last slot should be empty");
int last_index = trim_index(empty_index - 1);
HeapRegion *last = _cache[last_index];
assert(last != NULL,"as the cache is not empty, last should not be empty");
while (empty_index != _first &&
last->gc_efficiency() < hr->gc_efficiency()) {
_cache[empty_index] = last;
last->set_sort_index(get_sort_index(empty_index));
empty_index = last_index;
last_index = trim_index(last_index - 1);
last = _cache[last_index];
}
}
_cache[empty_index] = hr;
hr->set_sort_index(get_sort_index(empty_index));
++_occupancy;
assert(verify(), "cache should be consistent");
}
HeapRegion *CSetChooserCache::remove_first() {
guarantee(false, "CSetChooserCache::remove_first(): "
"don't call this any more");
if (_occupancy > 0) {
assert(_cache[_first] != NULL, "cache should have at least one region");
HeapRegion *ret = _cache[_first];
_cache[_first] = NULL;
ret->set_sort_index(-1);
--_occupancy;
_first = trim_index(_first + 1);
assert(verify(), "cache should be consistent");
return ret;
} else {
return NULL;
}
}
// Even though we don't use the GC efficiency in our heuristics as
// much as we used to, we still order according to GC efficiency. This
// will cause regions with a lot of live objects and large RSets to
@ -134,7 +38,7 @@ HeapRegion *CSetChooserCache::remove_first() {
// the ones we'll skip are ones with both large RSets and a lot of
// live objects, not the ones with just a lot of live objects if we
// ordered according to the amount of reclaimable bytes per region.
static int orderRegions(HeapRegion* hr1, HeapRegion* hr2) {
static int order_regions(HeapRegion* hr1, HeapRegion* hr2) {
if (hr1 == NULL) {
if (hr2 == NULL) {
return 0;
@ -156,8 +60,8 @@ static int orderRegions(HeapRegion* hr1, HeapRegion* hr2) {
}
}
static int orderRegions(HeapRegion** hr1p, HeapRegion** hr2p) {
return orderRegions(*hr1p, *hr2p);
static int order_regions(HeapRegion** hr1p, HeapRegion** hr2p) {
return order_regions(*hr1p, *hr2p);
}
CollectionSetChooser::CollectionSetChooser() :
@ -175,105 +79,74 @@ CollectionSetChooser::CollectionSetChooser() :
//
// Note: containing object is allocated on C heap since it is CHeapObj.
//
_markedRegions((ResourceObj::set_allocation_type((address)&_markedRegions,
_regions((ResourceObj::set_allocation_type((address) &_regions,
ResourceObj::C_HEAP),
100), true /* C_Heap */),
_curr_index(0), _length(0),
_regionLiveThresholdBytes(0), _remainingReclaimableBytes(0),
_first_par_unreserved_idx(0) {
_regionLiveThresholdBytes =
_curr_index(0), _length(0), _first_par_unreserved_idx(0),
_region_live_threshold_bytes(0), _remaining_reclaimable_bytes(0) {
_region_live_threshold_bytes =
HeapRegion::GrainBytes * (size_t) G1OldCSetRegionLiveThresholdPercent / 100;
}
#ifndef PRODUCT
bool CollectionSetChooser::verify() {
guarantee(_length >= 0, err_msg("_length: %d", _length));
guarantee(0 <= _curr_index && _curr_index <= _length,
err_msg("_curr_index: %d _length: %d", _curr_index, _length));
int index = 0;
void CollectionSetChooser::verify() {
guarantee(_length <= regions_length(),
err_msg("_length: %u regions length: %u", _length, regions_length()));
guarantee(_curr_index <= _length,
err_msg("_curr_index: %u _length: %u", _curr_index, _length));
uint index = 0;
size_t sum_of_reclaimable_bytes = 0;
while (index < _curr_index) {
guarantee(_markedRegions.at(index) == NULL,
guarantee(regions_at(index) == NULL,
"all entries before _curr_index should be NULL");
index += 1;
}
HeapRegion *prev = NULL;
while (index < _length) {
HeapRegion *curr = _markedRegions.at(index++);
guarantee(curr != NULL, "Regions in _markedRegions array cannot be NULL");
int si = curr->sort_index();
HeapRegion *curr = regions_at(index++);
guarantee(curr != NULL, "Regions in _regions array cannot be NULL");
guarantee(!curr->is_young(), "should not be young!");
guarantee(!curr->isHumongous(), "should not be humongous!");
guarantee(si > -1 && si == (index-1), "sort index invariant");
if (prev != NULL) {
guarantee(orderRegions(prev, curr) != 1,
guarantee(order_regions(prev, curr) != 1,
err_msg("GC eff prev: %1.4f GC eff curr: %1.4f",
prev->gc_efficiency(), curr->gc_efficiency()));
}
sum_of_reclaimable_bytes += curr->reclaimable_bytes();
prev = curr;
}
guarantee(sum_of_reclaimable_bytes == _remainingReclaimableBytes,
guarantee(sum_of_reclaimable_bytes == _remaining_reclaimable_bytes,
err_msg("reclaimable bytes inconsistent, "
"remaining: "SIZE_FORMAT" sum: "SIZE_FORMAT,
_remainingReclaimableBytes, sum_of_reclaimable_bytes));
return true;
_remaining_reclaimable_bytes, sum_of_reclaimable_bytes));
}
#endif
#endif // !PRODUCT
void CollectionSetChooser::fillCache() {
guarantee(false, "fillCache: don't call this any more");
while (!_cache.is_full() && (_curr_index < _length)) {
HeapRegion* hr = _markedRegions.at(_curr_index);
assert(hr != NULL,
err_msg("Unexpected NULL hr in _markedRegions at index %d",
_curr_index));
_curr_index += 1;
assert(!hr->is_young(), "should not be young!");
assert(hr->sort_index() == _curr_index-1, "sort_index invariant");
_markedRegions.at_put(hr->sort_index(), NULL);
_cache.insert(hr);
assert(!_cache.is_empty(), "cache should not be empty");
}
assert(verify(), "cache should be consistent");
}
void CollectionSetChooser::sortMarkedHeapRegions() {
void CollectionSetChooser::sort_regions() {
// First trim any unused portion of the top in the parallel case.
if (_first_par_unreserved_idx > 0) {
if (G1PrintParCleanupStats) {
gclog_or_tty->print(" Truncating _markedRegions from %d to %d.\n",
_markedRegions.length(), _first_par_unreserved_idx);
}
assert(_first_par_unreserved_idx <= _markedRegions.length(),
assert(_first_par_unreserved_idx <= regions_length(),
"Or we didn't reserved enough length");
_markedRegions.trunc_to(_first_par_unreserved_idx);
regions_trunc_to(_first_par_unreserved_idx);
}
_markedRegions.sort(orderRegions);
assert(_length <= _markedRegions.length(), "Requirement");
assert(_length == 0 || _markedRegions.at(_length - 1) != NULL,
"Testing _length");
assert(_length == _markedRegions.length() ||
_markedRegions.at(_length) == NULL, "Testing _length");
if (G1PrintParCleanupStats) {
gclog_or_tty->print_cr(" Sorted %d marked regions.", _length);
}
for (int i = 0; i < _length; i++) {
assert(_markedRegions.at(i) != NULL, "Should be true by sorting!");
_markedRegions.at(i)->set_sort_index(i);
_regions.sort(order_regions);
assert(_length <= regions_length(), "Requirement");
#ifdef ASSERT
for (uint i = 0; i < _length; i++) {
assert(regions_at(i) != NULL, "Should be true by sorting!");
}
#endif // ASSERT
if (G1PrintRegionLivenessInfo) {
G1PrintRegionLivenessInfoClosure cl(gclog_or_tty, "Post-Sorting");
for (int i = 0; i < _length; ++i) {
HeapRegion* r = _markedRegions.at(i);
for (uint i = 0; i < _length; ++i) {
HeapRegion* r = regions_at(i);
cl.doHeapRegion(r);
}
}
assert(verify(), "CSet chooser verification");
verify();
}
uint CollectionSetChooser::calcMinOldCSetLength() {
uint CollectionSetChooser::calc_min_old_cset_length() {
// The min old CSet region bound is based on the maximum desired
// number of mixed GCs after a cycle. I.e., even if some old regions
// look expensive, we should add them to the CSet anyway to make
@ -294,7 +167,7 @@ uint CollectionSetChooser::calcMinOldCSetLength() {
return (uint) result;
}
uint CollectionSetChooser::calcMaxOldCSetLength() {
uint CollectionSetChooser::calc_max_old_cset_length() {
// The max old CSet region bound is based on the threshold expressed
// as a percentage of the heap size. I.e., it should bound the
// number of old regions added to the CSet irrespective of how many
@ -311,18 +184,18 @@ uint CollectionSetChooser::calcMaxOldCSetLength() {
return (uint) result;
}
void CollectionSetChooser::addMarkedHeapRegion(HeapRegion* hr) {
void CollectionSetChooser::add_region(HeapRegion* hr) {
assert(!hr->isHumongous(),
"Humongous regions shouldn't be added to the collection set");
assert(!hr->is_young(), "should not be young!");
_markedRegions.append(hr);
_regions.append(hr);
_length++;
_remainingReclaimableBytes += hr->reclaimable_bytes();
_remaining_reclaimable_bytes += hr->reclaimable_bytes();
hr->calc_gc_efficiency();
}
void CollectionSetChooser::prepareForAddMarkedHeapRegionsPar(uint n_regions,
uint chunkSize) {
void CollectionSetChooser::prepare_for_par_region_addition(uint n_regions,
uint chunk_size) {
_first_par_unreserved_idx = 0;
uint n_threads = (uint) ParallelGCThreads;
if (UseDynamicNumberOfGCThreads) {
@ -335,56 +208,46 @@ void CollectionSetChooser::prepareForAddMarkedHeapRegionsPar(uint n_regions,
n_threads = MAX2(G1CollectedHeap::heap()->workers()->active_workers(),
1U);
}
uint max_waste = n_threads * chunkSize;
// it should be aligned with respect to chunkSize
uint aligned_n_regions = (n_regions + chunkSize - 1) / chunkSize * chunkSize;
assert(aligned_n_regions % chunkSize == 0, "should be aligned");
_markedRegions.at_put_grow((int) (aligned_n_regions + max_waste - 1), NULL);
uint max_waste = n_threads * chunk_size;
// it should be aligned with respect to chunk_size
uint aligned_n_regions = (n_regions + chunk_size - 1) / chunk_size * chunk_size;
assert(aligned_n_regions % chunk_size == 0, "should be aligned");
regions_at_put_grow(aligned_n_regions + max_waste - 1, NULL);
}
jint CollectionSetChooser::getParMarkedHeapRegionChunk(jint n_regions) {
// Don't do this assert because this can be called at a point
// where the loop up stream will not execute again but might
// try to claim more chunks (loop test has not been done yet).
// assert(_markedRegions.length() > _first_par_unreserved_idx,
// "Striding beyond the marked regions");
jint res = Atomic::add(n_regions, &_first_par_unreserved_idx);
assert(_markedRegions.length() > res + n_regions - 1,
uint CollectionSetChooser::claim_array_chunk(uint chunk_size) {
uint res = (uint) Atomic::add((jint) chunk_size,
(volatile jint*) &_first_par_unreserved_idx);
assert(regions_length() > res + chunk_size - 1,
"Should already have been expanded");
return res - n_regions;
return res - chunk_size;
}
void CollectionSetChooser::setMarkedHeapRegion(jint index, HeapRegion* hr) {
assert(_markedRegions.at(index) == NULL, "precondition");
void CollectionSetChooser::set_region(uint index, HeapRegion* hr) {
assert(regions_at(index) == NULL, "precondition");
assert(!hr->is_young(), "should not be young!");
_markedRegions.at_put(index, hr);
regions_at_put(index, hr);
hr->calc_gc_efficiency();
}
void CollectionSetChooser::updateTotals(jint region_num,
size_t reclaimable_bytes) {
void CollectionSetChooser::update_totals(uint region_num,
size_t reclaimable_bytes) {
// Only take the lock if we actually need to update the totals.
if (region_num > 0) {
assert(reclaimable_bytes > 0, "invariant");
// We could have just used atomics instead of taking the
// lock. However, we currently don't have an atomic add for size_t.
MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
_length += (int) region_num;
_remainingReclaimableBytes += reclaimable_bytes;
_length += region_num;
_remaining_reclaimable_bytes += reclaimable_bytes;
} else {
assert(reclaimable_bytes == 0, "invariant");
}
}
void CollectionSetChooser::clearMarkedHeapRegions() {
for (int i = 0; i < _markedRegions.length(); i++) {
HeapRegion* r = _markedRegions.at(i);
if (r != NULL) {
r->set_sort_index(-1);
}
}
_markedRegions.clear();
void CollectionSetChooser::clear() {
_regions.clear();
_curr_index = 0;
_length = 0;
_remainingReclaimableBytes = 0;
_remaining_reclaimable_bytes = 0;
};