diff -r cb913d743d09 -r 0fa27f37d4d4 src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp --- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Wed Jan 19 13:04:37 2011 -0800 +++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Wed Jan 19 19:30:42 2011 -0500 @@ -27,7 +27,7 @@ #include "gc_implementation/g1/concurrentMark.hpp" #include "gc_implementation/g1/g1RemSet.hpp" -#include "gc_implementation/g1/heapRegion.hpp" +#include "gc_implementation/g1/heapRegionSets.hpp" #include "gc_implementation/parNew/parGCAllocBuffer.hpp" #include "memory/barrierSet.hpp" #include "memory/memRegion.hpp" @@ -66,8 +66,7 @@ enum G1GCThreadGroups { G1CRGroup = 0, G1ZFGroup = 1, - G1CMGroup = 2, - G1CLGroup = 3 + G1CMGroup = 2 }; enum GCAllocPurpose { @@ -155,6 +154,7 @@ friend class RefineCardTableEntryClosure; friend class G1PrepareCompactClosure; friend class RegionSorter; + friend class RegionResetter; friend class CountRCClosure; friend class EvacPopObjClosure; friend class G1ParCleanupCTTask; @@ -178,17 +178,20 @@ // The maximum part of _g1_storage that has ever been committed. MemRegion _g1_max_committed; - // The number of regions that are completely free. - size_t _free_regions; + // The master free list. It will satisfy all new region allocations. + MasterFreeRegionList _free_list; + + // The secondary free list which contains regions that have been + // freed up during the cleanup process. This will be appended to the + // master free list when appropriate. + SecondaryFreeRegionList _secondary_free_list; + + // It keeps track of the humongous regions. + MasterHumongousRegionSet _humongous_set; // The number of regions we could create by expansion. size_t _expansion_regions; - // Return the number of free regions in the heap (by direct counting.) - size_t count_free_regions(); - // Return the number of free regions on the free and unclean lists. - size_t count_free_regions_list(); - // The block offset table for the G1 heap. G1BlockOffsetSharedArray* _bot_shared; @@ -196,9 +199,6 @@ // lists, before and after full GC. void tear_down_region_lists(); void rebuild_region_lists(); - // This sets all non-empty regions to need zero-fill (which they will if - // they are empty after full collection.) - void set_used_regions_to_need_zero_fill(); // The sequence of all heap regions in the heap. HeapRegionSeq* _hrs; @@ -231,7 +231,7 @@ // Determines PLAB size for a particular allocation purpose. static size_t desired_plab_sz(GCAllocPurpose purpose); - // When called by par thread, require par_alloc_during_gc_lock() to be held. + // When called by par thread, requires the FreeList_lock to be held. void push_gc_alloc_region(HeapRegion* hr); // This should only be called single-threaded. Undeclares all GC alloc @@ -294,10 +294,11 @@ // line number, file, etc. #define heap_locking_asserts_err_msg(__extra_message) \ - err_msg("%s : Heap_lock %slocked, %sat a safepoint", \ + err_msg("%s : Heap_lock locked: %s, at safepoint: %s, is VM thread: %s", \ (__extra_message), \ - (!Heap_lock->owned_by_self()) ? "NOT " : "", \ - (!SafepointSynchronize::is_at_safepoint()) ? "NOT " : "") + BOOL_TO_STR(Heap_lock->owned_by_self()), \ + BOOL_TO_STR(SafepointSynchronize::is_at_safepoint()), \ + BOOL_TO_STR(Thread::current()->is_VM_thread())) #define assert_heap_locked() \ do { \ @@ -305,10 +306,11 @@ heap_locking_asserts_err_msg("should be holding the Heap_lock")); \ } while (0) -#define assert_heap_locked_or_at_safepoint() \ +#define assert_heap_locked_or_at_safepoint(__should_be_vm_thread) \ do { \ assert(Heap_lock->owned_by_self() || \ - SafepointSynchronize::is_at_safepoint(), \ + (SafepointSynchronize::is_at_safepoint() && \ + ((__should_be_vm_thread) == Thread::current()->is_VM_thread())), \ heap_locking_asserts_err_msg("should be holding the Heap_lock or " \ "should be at a safepoint")); \ } while (0) @@ -335,9 +337,10 @@ "should not be at a safepoint")); \ } while (0) -#define assert_at_safepoint() \ +#define assert_at_safepoint(__should_be_vm_thread) \ do { \ - assert(SafepointSynchronize::is_at_safepoint(), \ + assert(SafepointSynchronize::is_at_safepoint() && \ + ((__should_be_vm_thread) == Thread::current()->is_VM_thread()), \ heap_locking_asserts_err_msg("should be at a safepoint")); \ } while (0) @@ -362,31 +365,41 @@ // The current policy object for the collector. G1CollectorPolicy* _g1_policy; - // Parallel allocation lock to protect the current allocation region. - Mutex _par_alloc_during_gc_lock; - Mutex* par_alloc_during_gc_lock() { return &_par_alloc_during_gc_lock; } + // This is the second level of trying to allocate a new region. If + // new_region_work didn't find a region in the free_list, this call + // will check whether there's anything available in the + // secondary_free_list and/or wait for more regions to appear in that + // list, if _free_regions_coming is set. + HeapRegion* new_region_try_secondary_free_list(size_t word_size); - // If possible/desirable, allocate a new HeapRegion for normal object - // allocation sufficient for an allocation of the given "word_size". - // If "do_expand" is true, will attempt to expand the heap if necessary - // to to satisfy the request. If "zero_filled" is true, requires a - // zero-filled region. - // (Returning NULL will trigger a GC.) - virtual HeapRegion* newAllocRegion_work(size_t word_size, - bool do_expand, - bool zero_filled); + // It will try to allocate a single non-humongous HeapRegion + // sufficient for an allocation of the given word_size. If + // do_expand is true, it will attempt to expand the heap if + // necessary to satisfy the allocation request. Note that word_size + // is only used to make sure that we expand sufficiently but, given + // that the allocation request is assumed not to be humongous, + // having word_size is not strictly necessary (expanding by a single + // region will always be sufficient). But let's keep that parameter + // in case we need it in the future. + HeapRegion* new_region_work(size_t word_size, bool do_expand); - virtual HeapRegion* newAllocRegion(size_t word_size, - bool zero_filled = true) { - return newAllocRegion_work(word_size, false, zero_filled); + // It will try to allocate a new region to be used for allocation by + // mutator threads. It will not try to expand the heap if not region + // is available. + HeapRegion* new_alloc_region(size_t word_size) { + return new_region_work(word_size, false /* do_expand */); } - virtual HeapRegion* newAllocRegionWithExpansion(int purpose, - size_t word_size, - bool zero_filled = true); + + // It will try to allocate a new region to be used for allocation by + // a GC thread. It will try to expand the heap if no region is + // available. + HeapRegion* new_gc_alloc_region(int purpose, size_t word_size); + + int humongous_obj_allocate_find_first(size_t num_regions, size_t word_size); // Attempt to allocate an object of the given (very large) "word_size". // Returns "NULL" on failure. - virtual HeapWord* humongous_obj_allocate(size_t word_size); + HeapWord* humongous_obj_allocate(size_t word_size); // The following two methods, allocate_new_tlab() and // mem_allocate(), are the two main entry points from the runtime @@ -760,20 +773,29 @@ // Invoke "save_marks" on all heap regions. void save_marks(); - // Free a heap region. - void free_region(HeapRegion* hr); - // A component of "free_region", exposed for 'batching'. - // All the params after "hr" are out params: the used bytes of the freed - // region(s), the number of H regions cleared, the number of regions - // freed, and pointers to the head and tail of a list of freed contig - // regions, linked throught the "next_on_unclean_list" field. - void free_region_work(HeapRegion* hr, - size_t& pre_used, - size_t& cleared_h, - size_t& freed_regions, - UncleanRegionList* list, - bool par = false); + // It frees a non-humongous region by initializing its contents and + // adding it to the free list that's passed as a parameter (this is + // usually a local list which will be appended to the master free + // list later). The used bytes of freed regions are accumulated in + // pre_used. If par is true, the region's RSet will not be freed + // up. The assumption is that this will be done later. + void free_region(HeapRegion* hr, + size_t* pre_used, + FreeRegionList* free_list, + bool par); + // It frees a humongous region by collapsing it into individual + // regions and calling free_region() for each of them. The freed + // regions will be added to the free list that's passed as a parameter + // (this is usually a local list which will be appended to the + // master free list later). The used bytes of freed regions are + // accumulated in pre_used. If par is true, the region's RSet will + // not be freed up. The assumption is that this will be done later. + void free_humongous_region(HeapRegion* hr, + size_t* pre_used, + FreeRegionList* free_list, + HumongousRegionSet* humongous_proxy_set, + bool par); // The concurrent marker (and the thread it runs in.) ConcurrentMark* _cm; @@ -783,9 +805,6 @@ // The concurrent refiner. ConcurrentG1Refine* _cg1r; - // The concurrent zero-fill thread. - ConcurrentZFThread* _czft; - // The parallel task queues RefToScanQueueSet *_task_queues; @@ -877,9 +896,7 @@ SubTasksDone* _process_strong_tasks; - // List of regions which require zero filling. - UncleanRegionList _unclean_region_list; - bool _unclean_regions_coming; + volatile bool _free_regions_coming; public: @@ -1002,71 +1019,64 @@ size_t max_regions(); // The number of regions that are completely free. - size_t free_regions(); + size_t free_regions() { + return _free_list.length(); + } // The number of regions that are not completely free. size_t used_regions() { return n_regions() - free_regions(); } - // True iff the ZF thread should run. - bool should_zf(); - // The number of regions available for "regular" expansion. size_t expansion_regions() { return _expansion_regions; } -#ifndef PRODUCT - bool regions_accounted_for(); - bool print_region_accounting_info(); - void print_region_counts(); -#endif + // verify_region_sets() performs verification over the region + // lists. It will be compiled in the product code to be used when + // necessary (i.e., during heap verification). + void verify_region_sets(); - HeapRegion* alloc_region_from_unclean_list(bool zero_filled); - HeapRegion* alloc_region_from_unclean_list_locked(bool zero_filled); + // verify_region_sets_optional() is planted in the code for + // list verification in non-product builds (and it can be enabled in + // product builds by definning HEAP_REGION_SET_FORCE_VERIFY to be 1). +#if HEAP_REGION_SET_FORCE_VERIFY + void verify_region_sets_optional() { + verify_region_sets(); + } +#else // HEAP_REGION_SET_FORCE_VERIFY + void verify_region_sets_optional() { } +#endif // HEAP_REGION_SET_FORCE_VERIFY - void put_region_on_unclean_list(HeapRegion* r); - void put_region_on_unclean_list_locked(HeapRegion* r); +#ifdef ASSERT + bool is_on_free_list(HeapRegion* hr) { + return hr->containing_set() == &_free_list; + } - void prepend_region_list_on_unclean_list(UncleanRegionList* list); - void prepend_region_list_on_unclean_list_locked(UncleanRegionList* list); + bool is_on_humongous_set(HeapRegion* hr) { + return hr->containing_set() == &_humongous_set; +} +#endif // ASSERT - void set_unclean_regions_coming(bool b); - void set_unclean_regions_coming_locked(bool b); - // Wait for cleanup to be complete. - void wait_for_cleanup_complete(); - // Like above, but assumes that the calling thread owns the Heap_lock. - void wait_for_cleanup_complete_locked(); + // Wrapper for the region list operations that can be called from + // methods outside this class. - // Return the head of the unclean list. - HeapRegion* peek_unclean_region_list_locked(); - // Remove and return the head of the unclean list. - HeapRegion* pop_unclean_region_list_locked(); + void secondary_free_list_add_as_tail(FreeRegionList* list) { + _secondary_free_list.add_as_tail(list); + } - // List of regions which are zero filled and ready for allocation. - HeapRegion* _free_region_list; - // Number of elements on the free list. - size_t _free_region_list_size; + void append_secondary_free_list() { + _free_list.add_as_tail(&_secondary_free_list); + } - // If the head of the unclean list is ZeroFilled, move it to the free - // list. - bool move_cleaned_region_to_free_list_locked(); - bool move_cleaned_region_to_free_list(); + void append_secondary_free_list_if_not_empty() { + if (!_secondary_free_list.is_empty()) { + MutexLockerEx x(SecondaryFreeList_lock, Mutex::_no_safepoint_check_flag); + append_secondary_free_list(); + } + } - void put_free_region_on_list_locked(HeapRegion* r); - void put_free_region_on_list(HeapRegion* r); - - // Remove and return the head element of the free list. - HeapRegion* pop_free_region_list_locked(); - - // If "zero_filled" is true, we first try the free list, then we try the - // unclean list, zero-filling the result. If "zero_filled" is false, we - // first try the unclean list, then the zero-filled list. - HeapRegion* alloc_free_region_from_lists(bool zero_filled); - - // Verify the integrity of the region lists. - void remove_allocated_regions_from_lists(); - bool verify_region_lists(); - bool verify_region_lists_locked(); - size_t unclean_region_list_length(); - size_t free_region_list_length(); + void set_free_regions_coming(); + void reset_free_regions_coming(); + bool free_regions_coming() { return _free_regions_coming; } + void wait_while_free_regions_coming(); // Perform a collection of the heap; intended for use in implementing // "System.gc". This probably implies as full a collection as the @@ -1085,23 +1095,24 @@ // True iff a evacuation has failed in the most-recent collection. bool evacuation_failed() { return _evacuation_failed; } - // Free a region if it is totally full of garbage. Returns the number of - // bytes freed (0 ==> didn't free it). - size_t free_region_if_totally_empty(HeapRegion *hr); - void free_region_if_totally_empty_work(HeapRegion *hr, - size_t& pre_used, - size_t& cleared_h_regions, - size_t& freed_regions, - UncleanRegionList* list, - bool par = false); + // It will free a region if it has allocated objects in it that are + // all dead. It calls either free_region() or + // free_humongous_region() depending on the type of the region that + // is passed to it. + void free_region_if_totally_empty(HeapRegion* hr, + size_t* pre_used, + FreeRegionList* free_list, + HumongousRegionSet* humongous_proxy_set, + bool par); - // If we've done free region work that yields the given changes, update - // the relevant global variables. - void finish_free_region_work(size_t pre_used, - size_t cleared_h_regions, - size_t freed_regions, - UncleanRegionList* list); - + // It appends the free list to the master free list and updates the + // master humongous list according to the contents of the proxy + // list. It also adjusts the total used bytes according to pre_used + // (if par is true, it will do so by taking the ParGCRareEvent_lock). + void update_sets_after_freeing_regions(size_t pre_used, + FreeRegionList* free_list, + HumongousRegionSet* humongous_proxy_set, + bool par); // Returns "TRUE" iff "p" points into the allocated area of the heap. virtual bool is_in(const void* p) const; @@ -1314,8 +1325,6 @@ return true; } - virtual bool allocs_are_zero_filled(); - // The boundary between a "large" and "small" array of primitives, in // words. virtual size_t large_typearray_limit(); @@ -1546,13 +1555,6 @@ protected: size_t _max_heap_capacity; - -public: - // Temporary: call to mark things unimplemented for the G1 heap (e.g., - // MemoryService). In productization, we can make this assert false - // to catch such places (as well as searching for calls to this...) - static void g1_unimplemented(); - }; #define use_local_bitmaps 1