ysr@777: /*
ysr@777:  * Copyright 2001-2007 Sun Microsystems, Inc.  All Rights Reserved.
ysr@777:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ysr@777:  *
ysr@777:  * This code is free software; you can redistribute it and/or modify it
ysr@777:  * under the terms of the GNU General Public License version 2 only, as
ysr@777:  * published by the Free Software Foundation.
ysr@777:  *
ysr@777:  * This code is distributed in the hope that it will be useful, but WITHOUT
ysr@777:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ysr@777:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
ysr@777:  * version 2 for more details (a copy is included in the LICENSE file that
ysr@777:  * accompanied this code).
ysr@777:  *
ysr@777:  * You should have received a copy of the GNU General Public License version
ysr@777:  * 2 along with this work; if not, write to the Free Software Foundation,
ysr@777:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ysr@777:  *
ysr@777:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
ysr@777:  * CA 95054 USA or visit www.sun.com if you need additional information or
ysr@777:  * have any questions.
ysr@777:  *
ysr@777:  */
ysr@777: 
ysr@777: # include "incls/_precompiled.incl"
ysr@777: # include "incls/_collectionSetChooser.cpp.incl"
ysr@777: 
ysr@777: CSetChooserCache::CSetChooserCache() {
ysr@777:   for (int i = 0; i < CacheLength; ++i)
ysr@777:     _cache[i] = NULL;
ysr@777:   clear();
ysr@777: }
ysr@777: 
ysr@777: void CSetChooserCache::clear() {
ysr@777:   _occupancy = 0;
ysr@777:   _first = 0;
ysr@777:   for (int i = 0; i < CacheLength; ++i) {
ysr@777:     HeapRegion *hr = _cache[i];
ysr@777:     if (hr != NULL)
ysr@777:       hr->set_sort_index(-1);
ysr@777:     _cache[i] = NULL;
ysr@777:   }
ysr@777: }
ysr@777: 
ysr@777: #ifndef PRODUCT
ysr@777: bool CSetChooserCache::verify() {
ysr@777:   int index = _first;
ysr@777:   HeapRegion *prev = NULL;
ysr@777:   for (int i = 0; i < _occupancy; ++i) {
ysr@777:     guarantee(_cache[index] != NULL, "cache entry should not be empty");
ysr@777:     HeapRegion *hr = _cache[index];
ysr@777:     guarantee(!hr->is_young(), "should not be young!");
ysr@777:     if (prev != NULL) {
ysr@777:       guarantee(prev->gc_efficiency() >= hr->gc_efficiency(),
ysr@777:                 "cache should be correctly ordered");
ysr@777:     }
ysr@777:     guarantee(hr->sort_index() == get_sort_index(index),
ysr@777:               "sort index should be correct");
ysr@777:     index = trim_index(index + 1);
ysr@777:     prev = hr;
ysr@777:   }
ysr@777: 
ysr@777:   for (int i = 0; i < (CacheLength - _occupancy); ++i) {
ysr@777:     guarantee(_cache[index] == NULL, "cache entry should be empty");
ysr@777:     index = trim_index(index + 1);
ysr@777:   }
ysr@777: 
ysr@777:   guarantee(index == _first, "we should have reached where we started from");
ysr@777:   return true;
ysr@777: }
ysr@777: #endif // PRODUCT
ysr@777: 
ysr@777: void CSetChooserCache::insert(HeapRegion *hr) {
ysr@777:   assert(!is_full(), "cache should not be empty");
ysr@777:   hr->calc_gc_efficiency();
ysr@777: 
ysr@777:   int empty_index;
ysr@777:   if (_occupancy == 0) {
ysr@777:     empty_index = _first;
ysr@777:   } else {
ysr@777:     empty_index = trim_index(_first + _occupancy);
ysr@777:     assert(_cache[empty_index] == NULL, "last slot should be empty");
ysr@777:     int last_index = trim_index(empty_index - 1);
ysr@777:     HeapRegion *last = _cache[last_index];
ysr@777:     assert(last != NULL,"as the cache is not empty, last should not be empty");
ysr@777:     while (empty_index != _first &&
ysr@777:            last->gc_efficiency() < hr->gc_efficiency()) {
ysr@777:       _cache[empty_index] = last;
ysr@777:       last->set_sort_index(get_sort_index(empty_index));
ysr@777:       empty_index = last_index;
ysr@777:       last_index = trim_index(last_index - 1);
ysr@777:       last = _cache[last_index];
ysr@777:     }
ysr@777:   }
ysr@777:   _cache[empty_index] = hr;
ysr@777:   hr->set_sort_index(get_sort_index(empty_index));
ysr@777: 
ysr@777:   ++_occupancy;
ysr@777:   assert(verify(), "cache should be consistent");
ysr@777: }
ysr@777: 
ysr@777: HeapRegion *CSetChooserCache::remove_first() {
ysr@777:   if (_occupancy > 0) {
ysr@777:     assert(_cache[_first] != NULL, "cache should have at least one region");
ysr@777:     HeapRegion *ret = _cache[_first];
ysr@777:     _cache[_first] = NULL;
ysr@777:     ret->set_sort_index(-1);
ysr@777:     --_occupancy;
ysr@777:     _first = trim_index(_first + 1);
ysr@777:     assert(verify(), "cache should be consistent");
ysr@777:     return ret;
ysr@777:   } else {
ysr@777:     return NULL;
ysr@777:   }
ysr@777: }
ysr@777: 
ysr@777: // this is a bit expensive... but we expect that it should not be called
ysr@777: // to often.
ysr@777: void CSetChooserCache::remove(HeapRegion *hr) {
ysr@777:   assert(_occupancy > 0, "cache should not be empty");
ysr@777:   assert(hr->sort_index() < -1, "should already be in the cache");
ysr@777:   int index = get_index(hr->sort_index());
ysr@777:   assert(_cache[index] == hr, "index should be correct");
ysr@777:   int next_index = trim_index(index + 1);
ysr@777:   int last_index = trim_index(_first + _occupancy - 1);
ysr@777:   while (index != last_index) {
ysr@777:     assert(_cache[next_index] != NULL, "should not be null");
ysr@777:     _cache[index] = _cache[next_index];
ysr@777:     _cache[index]->set_sort_index(get_sort_index(index));
ysr@777: 
ysr@777:     index = next_index;
ysr@777:     next_index = trim_index(next_index+1);
ysr@777:   }
ysr@777:   assert(index == last_index, "should have reached the last one");
ysr@777:   _cache[index] = NULL;
ysr@777:   hr->set_sort_index(-1);
ysr@777:   --_occupancy;
ysr@777:   assert(verify(), "cache should be consistent");
ysr@777: }
ysr@777: 
ysr@777: static inline int orderRegions(HeapRegion* hr1, HeapRegion* hr2) {
ysr@777:   if (hr1 == NULL) {
ysr@777:     if (hr2 == NULL) return 0;
ysr@777:     else return 1;
ysr@777:   } else if (hr2 == NULL) {
ysr@777:     return -1;
ysr@777:   }
ysr@777:   if (hr2->gc_efficiency() < hr1->gc_efficiency()) return -1;
ysr@777:   else if (hr1->gc_efficiency() < hr2->gc_efficiency()) return 1;
ysr@777:   else return 0;
ysr@777: }
ysr@777: 
ysr@777: static int orderRegions(HeapRegion** hr1p, HeapRegion** hr2p) {
ysr@777:   return orderRegions(*hr1p, *hr2p);
ysr@777: }
ysr@777: 
ysr@777: CollectionSetChooser::CollectionSetChooser() :
ysr@777:   // The line below is the worst bit of C++ hackery I've ever written
ysr@777:   // (Detlefs, 11/23).  You should think of it as equivalent to
ysr@777:   // "_regions(100, true)": initialize the growable array and inform it
ysr@777:   // that it should allocate its elem array(s) on the C heap.  The first
ysr@777:   // argument, however, is actually a comma expression (new-expr, 100).
ysr@777:   // The purpose of the new_expr is to inform the growable array that it
ysr@777:   // is *already* allocated on the C heap: it uses the placement syntax to
ysr@777:   // keep it from actually doing any allocation.
ysr@777:   _markedRegions((ResourceObj::operator new (sizeof(GrowableArray<HeapRegion*>),
ysr@777:                                              (void*)&_markedRegions,
ysr@777:                                              ResourceObj::C_HEAP),
ysr@777:                   100),
ysr@777:                  true),
ysr@777:   _curMarkedIndex(0),
ysr@777:   _numMarkedRegions(0),
ysr@777:   _unmarked_age_1_returned_as_new(false),
ysr@777:   _first_par_unreserved_idx(0)
ysr@777: {}
ysr@777: 
ysr@777: 
ysr@777: 
ysr@777: #ifndef PRODUCT
ysr@777: bool CollectionSetChooser::verify() {
ysr@777:   int index = 0;
ysr@777:   guarantee(_curMarkedIndex <= _numMarkedRegions,
ysr@777:             "_curMarkedIndex should be within bounds");
ysr@777:   while (index < _curMarkedIndex) {
ysr@777:     guarantee(_markedRegions.at(index++) == NULL,
ysr@777:               "all entries before _curMarkedIndex should be NULL");
ysr@777:   }
ysr@777:   HeapRegion *prev = NULL;
ysr@777:   while (index < _numMarkedRegions) {
ysr@777:     HeapRegion *curr = _markedRegions.at(index++);
ysr@777:     if (curr != NULL) {
ysr@777:       int si = curr->sort_index();
ysr@777:       guarantee(!curr->is_young(), "should not be young!");
ysr@777:       guarantee(si > -1 && si == (index-1), "sort index invariant");
ysr@777:       if (prev != NULL) {
ysr@777:         guarantee(orderRegions(prev, curr) != 1, "regions should be sorted");
ysr@777:       }
ysr@777:       prev = curr;
ysr@777:     }
ysr@777:   }
ysr@777:   return _cache.verify();
ysr@777: }
ysr@777: #endif
ysr@777: 
ysr@777: bool
ysr@777: CollectionSetChooser::addRegionToCache() {
ysr@777:   assert(!_cache.is_full(), "cache should not be full");
ysr@777: 
ysr@777:   HeapRegion *hr = NULL;
ysr@777:   while (hr == NULL && _curMarkedIndex < _numMarkedRegions) {
ysr@777:     hr = _markedRegions.at(_curMarkedIndex++);
ysr@777:   }
ysr@777:   if (hr == NULL)
ysr@777:     return false;
ysr@777:   assert(!hr->is_young(), "should not be young!");
ysr@777:   assert(hr->sort_index() == _curMarkedIndex-1, "sort_index invariant");
ysr@777:   _markedRegions.at_put(hr->sort_index(), NULL);
ysr@777:   _cache.insert(hr);
ysr@777:   assert(!_cache.is_empty(), "cache should not be empty");
ysr@777:   assert(verify(), "cache should be consistent");
ysr@777:   return false;
ysr@777: }
ysr@777: 
ysr@777: void
ysr@777: CollectionSetChooser::fillCache() {
ysr@777:   while (!_cache.is_full() && addRegionToCache()) {
ysr@777:   }
ysr@777: }
ysr@777: 
ysr@777: void
ysr@777: CollectionSetChooser::sortMarkedHeapRegions() {
ysr@777:   guarantee(_cache.is_empty(), "cache should be empty");
ysr@777:   // First trim any unused portion of the top in the parallel case.
ysr@777:   if (_first_par_unreserved_idx > 0) {
ysr@777:     if (G1PrintParCleanupStats) {
ysr@777:       gclog_or_tty->print("     Truncating _markedRegions from %d to %d.\n",
ysr@777:                           _markedRegions.length(), _first_par_unreserved_idx);
ysr@777:     }
ysr@777:     assert(_first_par_unreserved_idx <= _markedRegions.length(),
ysr@777:            "Or we didn't reserved enough length");
ysr@777:     _markedRegions.trunc_to(_first_par_unreserved_idx);
ysr@777:   }
ysr@777:   _markedRegions.sort(orderRegions);
ysr@777:   assert(_numMarkedRegions <= _markedRegions.length(), "Requirement");
ysr@777:   assert(_numMarkedRegions == 0
ysr@777:          || _markedRegions.at(_numMarkedRegions-1) != NULL,
ysr@777:          "Testing _numMarkedRegions");
ysr@777:   assert(_numMarkedRegions == _markedRegions.length()
ysr@777:          || _markedRegions.at(_numMarkedRegions) == NULL,
ysr@777:          "Testing _numMarkedRegions");
ysr@777:   if (G1PrintParCleanupStats) {
ysr@777:     gclog_or_tty->print_cr("     Sorted %d marked regions.", _numMarkedRegions);
ysr@777:   }
ysr@777:   for (int i = 0; i < _numMarkedRegions; i++) {
ysr@777:     assert(_markedRegions.at(i) != NULL, "Should be true by sorting!");
ysr@777:     _markedRegions.at(i)->set_sort_index(i);
ysr@777:     if (G1PrintRegionLivenessInfo > 0) {
ysr@777:       if (i == 0) gclog_or_tty->print_cr("Sorted marked regions:");
ysr@777:       if (i < G1PrintRegionLivenessInfo ||
ysr@777:           (_numMarkedRegions-i) < G1PrintRegionLivenessInfo) {
ysr@777:         HeapRegion* hr = _markedRegions.at(i);
ysr@777:         size_t u = hr->used();
ysr@777:         gclog_or_tty->print_cr("  Region %d: %d used, %d max live, %5.2f%%.",
ysr@777:                       i, u, hr->max_live_bytes(),
ysr@777:                       100.0*(float)hr->max_live_bytes()/(float)u);
ysr@777:       }
ysr@777:     }
ysr@777:   }
ysr@777:   if (G1PolicyVerbose > 1)
ysr@777:     printSortedHeapRegions();
ysr@777:   assert(verify(), "should now be sorted");
ysr@777: }
ysr@777: 
ysr@777: void
ysr@777: printHeapRegion(HeapRegion *hr) {
ysr@777:   if (hr->isHumongous())
ysr@777:     gclog_or_tty->print("H: ");
ysr@777:   if (hr->in_collection_set())
ysr@777:     gclog_or_tty->print("CS: ");
ysr@777:   gclog_or_tty->print_cr("Region " PTR_FORMAT " (%s%s) "
ysr@777:                          "[" PTR_FORMAT ", " PTR_FORMAT"] "
ysr@777:                          "Used: " SIZE_FORMAT "K, garbage: " SIZE_FORMAT "K.",
ysr@777:                          hr, hr->is_young() ? "Y " : "  ",
ysr@777:                          hr->is_marked()? "M1" : "M0",
ysr@777:                          hr->bottom(), hr->end(),
ysr@777:                          hr->used()/K, hr->garbage_bytes()/K);
ysr@777: }
ysr@777: 
ysr@777: void
ysr@777: CollectionSetChooser::addMarkedHeapRegion(HeapRegion* hr) {
ysr@777:   assert(!hr->isHumongous(),
ysr@777:          "Humongous regions shouldn't be added to the collection set");
ysr@777:   assert(!hr->is_young(), "should not be young!");
ysr@777:   _markedRegions.append(hr);
ysr@777:   _numMarkedRegions++;
ysr@777:   hr->calc_gc_efficiency();
ysr@777: }
ysr@777: 
ysr@777: void
ysr@777: CollectionSetChooser::
ysr@777: prepareForAddMarkedHeapRegionsPar(size_t n_regions, size_t chunkSize) {
ysr@777:   _first_par_unreserved_idx = 0;
ysr@777:   size_t max_waste = ParallelGCThreads * chunkSize;
ysr@777:   // it should be aligned with respect to chunkSize
ysr@777:   size_t aligned_n_regions =
ysr@777:                      (n_regions + (chunkSize - 1)) / chunkSize * chunkSize;
ysr@777:   assert( aligned_n_regions % chunkSize == 0, "should be aligned" );
ysr@777:   _markedRegions.at_put_grow((int)(aligned_n_regions + max_waste - 1), NULL);
ysr@777: }
ysr@777: 
ysr@777: jint
ysr@777: CollectionSetChooser::getParMarkedHeapRegionChunk(jint n_regions) {
ysr@777:   jint res = Atomic::add(n_regions, &_first_par_unreserved_idx);
ysr@777:   assert(_markedRegions.length() > res + n_regions - 1,
ysr@777:          "Should already have been expanded");
ysr@777:   return res - n_regions;
ysr@777: }
ysr@777: 
ysr@777: void
ysr@777: CollectionSetChooser::setMarkedHeapRegion(jint index, HeapRegion* hr) {
ysr@777:   assert(_markedRegions.at(index) == NULL, "precondition");
ysr@777:   assert(!hr->is_young(), "should not be young!");
ysr@777:   _markedRegions.at_put(index, hr);
ysr@777:   hr->calc_gc_efficiency();
ysr@777: }
ysr@777: 
ysr@777: void
ysr@777: CollectionSetChooser::incNumMarkedHeapRegions(jint inc_by) {
ysr@777:   (void)Atomic::add(inc_by, &_numMarkedRegions);
ysr@777: }
ysr@777: 
ysr@777: void
ysr@777: CollectionSetChooser::clearMarkedHeapRegions(){
ysr@777:   for (int i = 0; i < _markedRegions.length(); i++) {
ysr@777:     HeapRegion* r =   _markedRegions.at(i);
ysr@777:     if (r != NULL) r->set_sort_index(-1);
ysr@777:   }
ysr@777:   _markedRegions.clear();
ysr@777:   _curMarkedIndex = 0;
ysr@777:   _numMarkedRegions = 0;
ysr@777:   _cache.clear();
ysr@777: };
ysr@777: 
ysr@777: void
ysr@777: CollectionSetChooser::updateAfterFullCollection() {
ysr@777:   G1CollectedHeap* g1h = G1CollectedHeap::heap();
ysr@777:   clearMarkedHeapRegions();
ysr@777: }
ysr@777: 
ysr@777: void
ysr@777: CollectionSetChooser::printSortedHeapRegions() {
ysr@777:   gclog_or_tty->print_cr("Printing %d Heap Regions sorted by amount of known garbage",
ysr@777:                 _numMarkedRegions);
ysr@777:   for (int i = 0; i < _markedRegions.length(); i++) {
ysr@777:     printHeapRegion(_markedRegions.at(i));
ysr@777:   }
ysr@777:   gclog_or_tty->print_cr("Done sorted heap region print");
ysr@777: }
ysr@777: 
ysr@777: void CollectionSetChooser::removeRegion(HeapRegion *hr) {
ysr@777:   int si = hr->sort_index();
ysr@777:   assert(si == -1 || hr->is_marked(), "Sort index not valid.");
ysr@777:   if (si > -1) {
ysr@777:     assert(_markedRegions.at(si) == hr, "Sort index not valid." );
ysr@777:     _markedRegions.at_put(si, NULL);
ysr@777:   } else if (si < -1) {
ysr@777:     assert(_cache.region_in_cache(hr), "should be in the cache");
ysr@777:     _cache.remove(hr);
ysr@777:     assert(hr->sort_index() == -1, "sort index invariant");
ysr@777:   }
ysr@777:   hr->set_sort_index(-1);
ysr@777: }
ysr@777: 
ysr@777: // if time_remaining < 0.0, then this method should try to return
ysr@777: // a region, whether it fits within the remaining time or not
ysr@777: HeapRegion*
ysr@777: CollectionSetChooser::getNextMarkedRegion(double time_remaining,
ysr@777:                                           double avg_prediction) {
ysr@777:   G1CollectedHeap* g1h = G1CollectedHeap::heap();
ysr@777:   G1CollectorPolicy* g1p = g1h->g1_policy();
ysr@777:   fillCache();
ysr@777:   if (_cache.is_empty()) {
ysr@777:     assert(_curMarkedIndex == _numMarkedRegions,
ysr@777:            "if cache is empty, list should also be empty");
ysr@777:     return NULL;
ysr@777:   }
ysr@777: 
ysr@777:   HeapRegion *hr = _cache.get_first();
ysr@777:   assert(hr != NULL, "if cache not empty, first entry should be non-null");
ysr@777:   double predicted_time = g1h->predict_region_elapsed_time_ms(hr, false);
ysr@777: 
ysr@777:   if (g1p->adaptive_young_list_length()) {
ysr@777:     if (time_remaining - predicted_time < 0.0) {
ysr@777:       g1h->check_if_region_is_too_expensive(predicted_time);
ysr@777:       return NULL;
ysr@777:     }
ysr@777:   } else {
ysr@777:     if (predicted_time > 2.0 * avg_prediction) {
ysr@777:       return NULL;
ysr@777:     }
ysr@777:   }
ysr@777: 
ysr@777:   HeapRegion *hr2 = _cache.remove_first();
ysr@777:   assert(hr == hr2, "cache contents should not have changed");
ysr@777: 
ysr@777:   return hr;
ysr@777: }