--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc/g1/g1Allocator.hpp Wed May 13 15:16:06 2015 +0200
@@ -0,0 +1,272 @@
+/*
+ * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_GC_G1_G1ALLOCATOR_HPP
+#define SHARE_VM_GC_G1_G1ALLOCATOR_HPP
+
+#include "gc/g1/g1AllocRegion.hpp"
+#include "gc/g1/g1AllocationContext.hpp"
+#include "gc/g1/g1InCSetState.hpp"
+#include "gc/shared/collectedHeap.hpp"
+#include "gc/shared/plab.hpp"
+
+class EvacuationInfo;
+
+// Base class for G1 allocators.
+class G1Allocator : public CHeapObj<mtGC> {
+ friend class VMStructs;
+protected:
+ G1CollectedHeap* _g1h;
+
+ // Outside of GC pauses, the number of bytes used in all regions other
+ // than the current allocation region.
+ size_t _summary_bytes_used;
+
+public:
+ G1Allocator(G1CollectedHeap* heap) :
+ _g1h(heap), _summary_bytes_used(0) { }
+
+ static G1Allocator* create_allocator(G1CollectedHeap* g1h);
+
+ virtual void init_mutator_alloc_region() = 0;
+ virtual void release_mutator_alloc_region() = 0;
+
+ virtual void init_gc_alloc_regions(EvacuationInfo& evacuation_info) = 0;
+ virtual void release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info) = 0;
+ virtual void abandon_gc_alloc_regions() = 0;
+
+ virtual MutatorAllocRegion* mutator_alloc_region(AllocationContext_t context) = 0;
+ virtual SurvivorGCAllocRegion* survivor_gc_alloc_region(AllocationContext_t context) = 0;
+ virtual OldGCAllocRegion* old_gc_alloc_region(AllocationContext_t context) = 0;
+ virtual size_t used() = 0;
+ virtual bool is_retained_old_region(HeapRegion* hr) = 0;
+
+ void reuse_retained_old_region(EvacuationInfo& evacuation_info,
+ OldGCAllocRegion* old,
+ HeapRegion** retained);
+
+ size_t used_unlocked() const {
+ return _summary_bytes_used;
+ }
+
+ void increase_used(size_t bytes) {
+ _summary_bytes_used += bytes;
+ }
+
+ void decrease_used(size_t bytes) {
+ assert(_summary_bytes_used >= bytes,
+ err_msg("invariant: _summary_bytes_used: "SIZE_FORMAT" should be >= bytes: "SIZE_FORMAT,
+ _summary_bytes_used, bytes));
+ _summary_bytes_used -= bytes;
+ }
+
+ void set_used(size_t bytes) {
+ _summary_bytes_used = bytes;
+ }
+
+ virtual HeapRegion* new_heap_region(uint hrs_index,
+ G1BlockOffsetSharedArray* sharedOffsetArray,
+ MemRegion mr) {
+ return new HeapRegion(hrs_index, sharedOffsetArray, mr);
+ }
+};
+
+// The default allocator for G1.
+class G1DefaultAllocator : public G1Allocator {
+protected:
+ // Alloc region used to satisfy mutator allocation requests.
+ MutatorAllocRegion _mutator_alloc_region;
+
+ // Alloc region used to satisfy allocation requests by the GC for
+ // survivor objects.
+ SurvivorGCAllocRegion _survivor_gc_alloc_region;
+
+ // Alloc region used to satisfy allocation requests by the GC for
+ // old objects.
+ OldGCAllocRegion _old_gc_alloc_region;
+
+ HeapRegion* _retained_old_gc_alloc_region;
+public:
+ G1DefaultAllocator(G1CollectedHeap* heap) : G1Allocator(heap), _retained_old_gc_alloc_region(NULL) { }
+
+ virtual void init_mutator_alloc_region();
+ virtual void release_mutator_alloc_region();
+
+ virtual void init_gc_alloc_regions(EvacuationInfo& evacuation_info);
+ virtual void release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info);
+ virtual void abandon_gc_alloc_regions();
+
+ virtual bool is_retained_old_region(HeapRegion* hr) {
+ return _retained_old_gc_alloc_region == hr;
+ }
+
+ virtual MutatorAllocRegion* mutator_alloc_region(AllocationContext_t context) {
+ return &_mutator_alloc_region;
+ }
+
+ virtual SurvivorGCAllocRegion* survivor_gc_alloc_region(AllocationContext_t context) {
+ return &_survivor_gc_alloc_region;
+ }
+
+ virtual OldGCAllocRegion* old_gc_alloc_region(AllocationContext_t context) {
+ return &_old_gc_alloc_region;
+ }
+
+ virtual size_t used() {
+ assert(Heap_lock->owner() != NULL,
+ "Should be owned on this thread's behalf.");
+ size_t result = _summary_bytes_used;
+
+ // Read only once in case it is set to NULL concurrently
+ HeapRegion* hr = mutator_alloc_region(AllocationContext::current())->get();
+ if (hr != NULL) {
+ result += hr->used();
+ }
+ return result;
+ }
+};
+
+class G1PLAB: public PLAB {
+private:
+ bool _retired;
+
+public:
+ G1PLAB(size_t gclab_word_size);
+ virtual ~G1PLAB() {
+ guarantee(_retired, "Allocation buffer has not been retired");
+ }
+
+ virtual void set_buf(HeapWord* buf) {
+ PLAB::set_buf(buf);
+ _retired = false;
+ }
+
+ virtual void retire() {
+ if (_retired) {
+ return;
+ }
+ PLAB::retire();
+ _retired = true;
+ }
+
+ virtual void flush_and_retire_stats(PLABStats* stats) {
+ PLAB::flush_and_retire_stats(stats);
+ _retired = true;
+ }
+};
+
+class G1ParGCAllocator : public CHeapObj<mtGC> {
+ friend class G1ParScanThreadState;
+protected:
+ G1CollectedHeap* _g1h;
+
+ // The survivor alignment in effect in bytes.
+ // == 0 : don't align survivors
+ // != 0 : align survivors to that alignment
+ // These values were chosen to favor the non-alignment case since some
+ // architectures have a special compare against zero instructions.
+ const uint _survivor_alignment_bytes;
+
+ virtual void retire_alloc_buffers() = 0;
+ virtual G1PLAB* alloc_buffer(InCSetState dest, AllocationContext_t context) = 0;
+
+ // Calculate the survivor space object alignment in bytes. Returns that or 0 if
+ // there are no restrictions on survivor alignment.
+ static uint calc_survivor_alignment_bytes() {
+ assert(SurvivorAlignmentInBytes >= ObjectAlignmentInBytes, "sanity");
+ if (SurvivorAlignmentInBytes == ObjectAlignmentInBytes) {
+ // No need to align objects in the survivors differently, return 0
+ // which means "survivor alignment is not used".
+ return 0;
+ } else {
+ assert(SurvivorAlignmentInBytes > 0, "sanity");
+ return SurvivorAlignmentInBytes;
+ }
+ }
+
+public:
+ G1ParGCAllocator(G1CollectedHeap* g1h) :
+ _g1h(g1h), _survivor_alignment_bytes(calc_survivor_alignment_bytes()) { }
+ virtual ~G1ParGCAllocator() { }
+
+ static G1ParGCAllocator* create_allocator(G1CollectedHeap* g1h);
+
+ virtual void waste(size_t& wasted, size_t& undo_wasted) = 0;
+
+ // Allocate word_sz words in dest, either directly into the regions or by
+ // allocating a new PLAB. Returns the address of the allocated memory, NULL if
+ // not successful.
+ HeapWord* allocate_direct_or_new_plab(InCSetState dest,
+ size_t word_sz,
+ AllocationContext_t context);
+
+ // Allocate word_sz words in the PLAB of dest. Returns the address of the
+ // allocated memory, NULL if not successful.
+ HeapWord* plab_allocate(InCSetState dest,
+ size_t word_sz,
+ AllocationContext_t context) {
+ G1PLAB* buffer = alloc_buffer(dest, context);
+ if (_survivor_alignment_bytes == 0) {
+ return buffer->allocate(word_sz);
+ } else {
+ return buffer->allocate_aligned(word_sz, _survivor_alignment_bytes);
+ }
+ }
+
+ HeapWord* allocate(InCSetState dest, size_t word_sz,
+ AllocationContext_t context) {
+ HeapWord* const obj = plab_allocate(dest, word_sz, context);
+ if (obj != NULL) {
+ return obj;
+ }
+ return allocate_direct_or_new_plab(dest, word_sz, context);
+ }
+
+ void undo_allocation(InCSetState dest, HeapWord* obj, size_t word_sz, AllocationContext_t context) {
+ alloc_buffer(dest, context)->undo_allocation(obj, word_sz);
+ }
+};
+
+class G1DefaultParGCAllocator : public G1ParGCAllocator {
+ G1PLAB _surviving_alloc_buffer;
+ G1PLAB _tenured_alloc_buffer;
+ G1PLAB* _alloc_buffers[InCSetState::Num];
+
+public:
+ G1DefaultParGCAllocator(G1CollectedHeap* g1h);
+
+ virtual G1PLAB* alloc_buffer(InCSetState dest, AllocationContext_t context) {
+ assert(dest.is_valid(),
+ err_msg("Allocation buffer index out-of-bounds: " CSETSTATE_FORMAT, dest.value()));
+ assert(_alloc_buffers[dest.value()] != NULL,
+ err_msg("Allocation buffer is NULL: " CSETSTATE_FORMAT, dest.value()));
+ return _alloc_buffers[dest.value()];
+ }
+
+ virtual void retire_alloc_buffers();
+
+ virtual void waste(size_t& wasted, size_t& undo_wasted);
+};
+
+#endif // SHARE_VM_GC_G1_G1ALLOCATOR_HPP