src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp
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rev 4803 : imported patch thomas-comments-2
*** 31,40 ****
--- 31,41 ----
#include "memory/allocation.hpp"
#include "memory/space.inline.hpp"
#include "oops/oop.inline.hpp"
#include "utilities/bitMap.inline.hpp"
#include "utilities/globalDefinitions.hpp"
+ #include "utilities/growableArray.hpp"
class PerRegionTable: public CHeapObj<mtGC> {
friend class OtherRegionsTable;
friend class HeapRegionRemSetIterator;
*** 847,857 ****
return (int)MAX2(DirtyCardQueueSet::num_par_ids() + ConcurrentG1Refine::thread_num(), ParallelGCThreads);
}
HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa,
HeapRegion* hr)
! : _bosa(bosa), _other_regions(hr) {
reset_for_par_iteration();
}
void HeapRegionRemSet::setup_remset_size() {
// Setup sparse and fine-grain tables sizes.
--- 848,858 ----
return (int)MAX2(DirtyCardQueueSet::num_par_ids() + ConcurrentG1Refine::thread_num(), ParallelGCThreads);
}
HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa,
HeapRegion* hr)
! : _bosa(bosa), _strong_code_roots_list(NULL), _other_regions(hr) {
reset_for_par_iteration();
}
void HeapRegionRemSet::setup_remset_size() {
// Setup sparse and fine-grain tables sizes.
*** 906,915 ****
--- 907,922 ----
void HeapRegionRemSet::cleanup() {
SparsePRT::cleanup_all();
}
void HeapRegionRemSet::clear() {
+ if (_strong_code_roots_list != NULL) {
+ delete _strong_code_roots_list;
+ }
+ _strong_code_roots_list = new (ResourceObj::C_HEAP, mtGC)
+ GrowableArray<nmethod*>(10, 0, NULL, true);
+
_other_regions.clear();
assert(occupied() == 0, "Should be clear.");
reset_for_par_iteration();
}
*** 923,932 ****
--- 930,1051 ----
void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs,
BitMap* region_bm, BitMap* card_bm) {
_other_regions.scrub(ctbs, region_bm, card_bm);
}
+
+ // Code roots support
+
+ void HeapRegionRemSet::add_strong_code_root(nmethod* nm) {
+ assert(nm != NULL, "sanity");
+ // Search for the code blob from the RHS to avoid
+ // duplicate entries as much as possible
+ if (_strong_code_roots_list->find_from_end(nm) < 0) {
+ // Code blob isn't already in the list
+ _strong_code_roots_list->push(nm);
+ }
+ }
+
+ void HeapRegionRemSet::remove_strong_code_root(nmethod* nm) {
+ assert(nm != NULL, "sanity");
+ int idx = _strong_code_roots_list->find(nm);
+ if (idx >= 0) {
+ _strong_code_roots_list->remove_at(idx);
+ }
+ // Check that there were no duplicates
+ guarantee(_strong_code_roots_list->find(nm) < 0, "duplicate entry found");
+ }
+
+ class NMethodMigrationOopClosure : public OopClosure {
+ G1CollectedHeap* _g1h;
+ HeapRegion* _from;
+ nmethod* _nm;
+
+ uint _num_self_forwarded;
+
+ template <class T> void do_oop_work(T* p) {
+ T heap_oop = oopDesc::load_heap_oop(p);
+ if (!oopDesc::is_null(heap_oop)) {
+ oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
+ if (_from->is_in(obj)) {
+ // Reference still points into the source region.
+ // Since roots are immediately evacuated this means that
+ // we must have self forwarded the object
+ assert(obj->is_forwarded(),
+ err_msg("code roots should be immediately evacuated. "
+ "Ref: "PTR_FORMAT", "
+ "Obj: "PTR_FORMAT", "
+ "Region: "HR_FORMAT,
+ p, (void*) obj, HR_FORMAT_PARAMS(_from)));
+ assert(obj->forwardee() == obj,
+ err_msg("not self forwarded? obj = "PTR_FORMAT, (void*)obj));
+
+ // The object has been self forwarded.
+ // Note, if we're during an initial mark pause, there is
+ // no need to explicitly mark object. It will be marked
+ // during the regular evacuation failure handling code.
+ _num_self_forwarded++;
+ } else {
+ // The reference points into a promotion or to-space region
+ HeapRegion* to = _g1h->heap_region_containing(obj);
+ to->rem_set()->add_strong_code_root(_nm);
+ }
+ }
+ }
+
+ public:
+ NMethodMigrationOopClosure(G1CollectedHeap* g1h, HeapRegion* from, nmethod* nm):
+ _g1h(g1h), _from(from), _nm(nm), _num_self_forwarded(0) {}
+
+ void do_oop(narrowOop* p) { do_oop_work(p); }
+ void do_oop(oop* p) { do_oop_work(p); }
+
+ uint retain() { return _num_self_forwarded > 0; }
+ };
+
+ void HeapRegionRemSet::migrate_strong_code_roots() {
+ assert(hr()->in_collection_set(), "only collection set regions");
+ assert(!hr()->isHumongous(), "not humongous regions");
+
+ ResourceMark rm;
+
+ // List of code blobs to retain for this region
+ GrowableArray<nmethod*> to_be_retained(10);
+ G1CollectedHeap* g1h = G1CollectedHeap::heap();
+
+ while (_strong_code_roots_list->is_nonempty()) {
+ nmethod *nm = _strong_code_roots_list->pop();
+ if (nm != NULL) {
+ NMethodMigrationOopClosure oop_cl(g1h, hr(), nm);
+ nm->oops_do(&oop_cl);
+ if (oop_cl.retain()) {
+ to_be_retained.push(nm);
+ }
+ }
+ }
+
+ // Now push any code roots we need to retain
+ // FIXME: assert that region got an evacuation failure if non-empty
+ while (to_be_retained.is_nonempty()) {
+ nmethod* nm = to_be_retained.pop();
+ assert(nm != NULL, "sanity");
+ add_strong_code_root(nm);
+ }
+ }
+
+ void HeapRegionRemSet::strong_code_roots_do(CodeBlobClosure* blk) const {
+ for (int i = 0; i < _strong_code_roots_list->length(); i += 1) {
+ nmethod* nm = _strong_code_roots_list->at(i);
+ blk->do_code_blob(nm);
+ }
+ }
+
+ size_t HeapRegionRemSet::strong_code_roots_mem_size() {
+ return sizeof(GrowableArray<nmethod*>) +
+ _strong_code_roots_list->max_length() * sizeof(nmethod*);
+ }
+
//-------------------- Iteration --------------------
HeapRegionRemSetIterator:: HeapRegionRemSetIterator(const HeapRegionRemSet* hrrs) :
_hrrs(hrrs),
_g1h(G1CollectedHeap::heap()),