diff -r 5f30b5a1ce5c -r cfa71cf3564d hotspot/src/share/vm/gc_implementation/g1/g1RemSet.hpp --- a/hotspot/src/share/vm/gc_implementation/g1/g1RemSet.hpp Fri Oct 08 09:29:09 2010 -0700 +++ b/hotspot/src/share/vm/gc_implementation/g1/g1RemSet.hpp Tue Oct 12 09:36:48 2010 -0700 @@ -27,107 +27,18 @@ class G1CollectedHeap; class CardTableModRefBarrierSet; -class HRInto_G1RemSet; class ConcurrentG1Refine; +// A G1RemSet in which each heap region has a rem set that records the +// external heap references into it. Uses a mod ref bs to track updates, +// so that they can be used to update the individual region remsets. + class G1RemSet: public CHeapObj { protected: G1CollectedHeap* _g1; unsigned _conc_refine_cards; size_t n_workers(); -public: - G1RemSet(G1CollectedHeap* g1) : - _g1(g1), _conc_refine_cards(0) - {} - - // Invoke "blk->do_oop" on all pointers into the CS in object in regions - // outside the CS (having invoked "blk->set_region" to set the "from" - // region correctly beforehand.) The "worker_i" param is for the - // parallel case where the number of the worker thread calling this - // function can be helpful in partitioning the work to be done. It - // should be the same as the "i" passed to the calling thread's - // work(i) function. In the sequential case this param will be ingored. - virtual void oops_into_collection_set_do(OopsInHeapRegionClosure* blk, - int worker_i) = 0; - - // Prepare for and cleanup after an oops_into_collection_set_do - // call. Must call each of these once before and after (in sequential - // code) any threads call oops into collection set do. (This offers an - // opportunity to sequential setup and teardown of structures needed by a - // parallel iteration over the CS's RS.) - virtual void prepare_for_oops_into_collection_set_do() = 0; - virtual void cleanup_after_oops_into_collection_set_do() = 0; - - // If "this" is of the given subtype, return "this", else "NULL". - virtual HRInto_G1RemSet* as_HRInto_G1RemSet() { return NULL; } - - // Record, if necessary, the fact that *p (where "p" is in region "from", - // and is, a fortiori, required to be non-NULL) has changed to its new value. - virtual void write_ref(HeapRegion* from, oop* p) = 0; - virtual void write_ref(HeapRegion* from, narrowOop* p) = 0; - virtual void par_write_ref(HeapRegion* from, oop* p, int tid) = 0; - virtual void par_write_ref(HeapRegion* from, narrowOop* p, int tid) = 0; - - // Requires "region_bm" and "card_bm" to be bitmaps with 1 bit per region - // or card, respectively, such that a region or card with a corresponding - // 0 bit contains no part of any live object. Eliminates any remembered - // set entries that correspond to dead heap ranges. - virtual void scrub(BitMap* region_bm, BitMap* card_bm) = 0; - // Like the above, but assumes is called in parallel: "worker_num" is the - // parallel thread id of the current thread, and "claim_val" is the - // value that should be used to claim heap regions. - virtual void scrub_par(BitMap* region_bm, BitMap* card_bm, - int worker_num, int claim_val) = 0; - - // Refine the card corresponding to "card_ptr". If "sts" is non-NULL, - // join and leave around parts that must be atomic wrt GC. (NULL means - // being done at a safepoint.) - // With some implementations of this routine, when check_for_refs_into_cset - // is true, a true result may be returned if the given card contains oops - // that have references into the current collection set. - virtual bool concurrentRefineOneCard(jbyte* card_ptr, int worker_i, - bool check_for_refs_into_cset) { - return false; - } - - // Print any relevant summary info. - virtual void print_summary_info() {} - - // Prepare remebered set for verification. - virtual void prepare_for_verify() {}; -}; - - -// The simplest possible G1RemSet: iterates over all objects in non-CS -// regions, searching for pointers into the CS. -class StupidG1RemSet: public G1RemSet { -public: - StupidG1RemSet(G1CollectedHeap* g1) : G1RemSet(g1) {} - - void oops_into_collection_set_do(OopsInHeapRegionClosure* blk, - int worker_i); - - void prepare_for_oops_into_collection_set_do() {} - void cleanup_after_oops_into_collection_set_do() {} - - // Nothing is necessary in the version below. - void write_ref(HeapRegion* from, oop* p) {} - void write_ref(HeapRegion* from, narrowOop* p) {} - void par_write_ref(HeapRegion* from, oop* p, int tid) {} - void par_write_ref(HeapRegion* from, narrowOop* p, int tid) {} - - void scrub(BitMap* region_bm, BitMap* card_bm) {} - void scrub_par(BitMap* region_bm, BitMap* card_bm, - int worker_num, int claim_val) {} - -}; - -// A G1RemSet in which each heap region has a rem set that records the -// external heap references into it. Uses a mod ref bs to track updates, -// so that they can be used to update the individual region remsets. - -class HRInto_G1RemSet: public G1RemSet { protected: enum SomePrivateConstants { UpdateRStoMergeSync = 0, @@ -175,28 +86,32 @@ // scanned. void cleanupHRRS(); - HRInto_G1RemSet(G1CollectedHeap* g1, CardTableModRefBS* ct_bs); - ~HRInto_G1RemSet(); + G1RemSet(G1CollectedHeap* g1, CardTableModRefBS* ct_bs); + ~G1RemSet(); + // Invoke "blk->do_oop" on all pointers into the CS in objects in regions + // outside the CS (having invoked "blk->set_region" to set the "from" + // region correctly beforehand.) The "worker_i" param is for the + // parallel case where the number of the worker thread calling this + // function can be helpful in partitioning the work to be done. It + // should be the same as the "i" passed to the calling thread's + // work(i) function. In the sequential case this param will be ingored. void oops_into_collection_set_do(OopsInHeapRegionClosure* blk, int worker_i); + // Prepare for and cleanup after an oops_into_collection_set_do + // call. Must call each of these once before and after (in sequential + // code) any threads call oops_into_collection_set_do. (This offers an + // opportunity to sequential setup and teardown of structures needed by a + // parallel iteration over the CS's RS.) void prepare_for_oops_into_collection_set_do(); void cleanup_after_oops_into_collection_set_do(); + void scanRS(OopsInHeapRegionClosure* oc, int worker_i); - template void scanNewRefsRS_work(OopsInHeapRegionClosure* oc, int worker_i); - void scanNewRefsRS(OopsInHeapRegionClosure* oc, int worker_i) { - if (UseCompressedOops) { - scanNewRefsRS_work(oc, worker_i); - } else { - scanNewRefsRS_work(oc, worker_i); - } - } void updateRS(DirtyCardQueue* into_cset_dcq, int worker_i); + HeapRegion* calculateStartRegion(int i); - HRInto_G1RemSet* as_HRInto_G1RemSet() { return this; } - CardTableModRefBS* ct_bs() { return _ct_bs; } size_t cardsScanned() { return _total_cards_scanned; } @@ -219,17 +134,31 @@ bool self_forwarded(oop obj); + // Requires "region_bm" and "card_bm" to be bitmaps with 1 bit per region + // or card, respectively, such that a region or card with a corresponding + // 0 bit contains no part of any live object. Eliminates any remembered + // set entries that correspond to dead heap ranges. void scrub(BitMap* region_bm, BitMap* card_bm); + + // Like the above, but assumes is called in parallel: "worker_num" is the + // parallel thread id of the current thread, and "claim_val" is the + // value that should be used to claim heap regions. void scrub_par(BitMap* region_bm, BitMap* card_bm, int worker_num, int claim_val); - // If check_for_refs_into_cset is true then a true result is returned - // if the card contains oops that have references into the current - // collection set. + // Refine the card corresponding to "card_ptr". If "sts" is non-NULL, + // join and leave around parts that must be atomic wrt GC. (NULL means + // being done at a safepoint.) + // If check_for_refs_into_cset is true, a true result is returned + // if the given card contains oops that have references into the + // current collection set. virtual bool concurrentRefineOneCard(jbyte* card_ptr, int worker_i, bool check_for_refs_into_cset); + // Print any relevant summary info. virtual void print_summary_info(); + + // Prepare remembered set for verification. virtual void prepare_for_verify(); }; @@ -250,13 +179,13 @@ class UpdateRSOopClosure: public OopClosure { HeapRegion* _from; - HRInto_G1RemSet* _rs; + G1RemSet* _rs; int _worker_i; template void do_oop_work(T* p); public: - UpdateRSOopClosure(HRInto_G1RemSet* rs, int worker_i = 0) : + UpdateRSOopClosure(G1RemSet* rs, int worker_i = 0) : _from(NULL), _rs(rs), _worker_i(worker_i) { guarantee(_rs != NULL, "Requires an HRIntoG1RemSet"); }