changeset 49616:456e51e56ea2

8200169: Flatten G1Allocator class hierarchy Reviewed-by: tschatzl, sangheki
author sjohanss
date Fri, 06 Apr 2018 11:41:21 +0200
parents 9e059253786b
children 86a349234225
files src/hotspot/share/gc/g1/g1Allocator.cpp src/hotspot/share/gc/g1/g1Allocator.hpp src/hotspot/share/gc/g1/g1Allocator.inline.hpp src/hotspot/share/gc/g1/g1CollectedHeap.cpp src/hotspot/share/gc/g1/g1ParScanThreadState.cpp
diffstat 5 files changed, 137 insertions(+), 175 deletions(-) [+]
line wrap: on
line diff
--- a/src/hotspot/share/gc/g1/g1Allocator.cpp	Fri Apr 06 11:37:34 2018 +0200
+++ b/src/hotspot/share/gc/g1/g1Allocator.cpp	Fri Apr 06 11:41:21 2018 +0200
@@ -33,8 +33,8 @@
 #include "gc/g1/heapRegionType.hpp"
 #include "utilities/align.hpp"
 
-G1DefaultAllocator::G1DefaultAllocator(G1CollectedHeap* heap) :
-  G1Allocator(heap),
+G1Allocator::G1Allocator(G1CollectedHeap* heap) :
+  _g1h(heap),
   _survivor_is_full(false),
   _old_is_full(false),
   _retained_old_gc_alloc_region(NULL),
@@ -42,16 +42,20 @@
   _old_gc_alloc_region(heap->alloc_buffer_stats(InCSetState::Old)) {
 }
 
-void G1DefaultAllocator::init_mutator_alloc_region() {
+void G1Allocator::init_mutator_alloc_region() {
   assert(_mutator_alloc_region.get() == NULL, "pre-condition");
   _mutator_alloc_region.init();
 }
 
-void G1DefaultAllocator::release_mutator_alloc_region() {
+void G1Allocator::release_mutator_alloc_region() {
   _mutator_alloc_region.release();
   assert(_mutator_alloc_region.get() == NULL, "post-condition");
 }
 
+bool G1Allocator::is_retained_old_region(HeapRegion* hr) {
+  return _retained_old_gc_alloc_region == hr;
+}
+
 void G1Allocator::reuse_retained_old_region(EvacuationInfo& evacuation_info,
                                             OldGCAllocRegion* old,
                                             HeapRegion** retained_old) {
@@ -87,7 +91,7 @@
   }
 }
 
-void G1DefaultAllocator::init_gc_alloc_regions(EvacuationInfo& evacuation_info) {
+void G1Allocator::init_gc_alloc_regions(EvacuationInfo& evacuation_info) {
   assert_at_safepoint_on_vm_thread();
 
   _survivor_is_full = false;
@@ -100,7 +104,7 @@
                             &_retained_old_gc_alloc_region);
 }
 
-void G1DefaultAllocator::release_gc_alloc_regions(EvacuationInfo& evacuation_info) {
+void G1Allocator::release_gc_alloc_regions(EvacuationInfo& evacuation_info) {
   evacuation_info.set_allocation_regions(survivor_gc_alloc_region()->count() +
                                          old_gc_alloc_region()->count());
   survivor_gc_alloc_region()->release();
@@ -112,25 +116,25 @@
   _retained_old_gc_alloc_region = old_gc_alloc_region()->release();
 }
 
-void G1DefaultAllocator::abandon_gc_alloc_regions() {
+void G1Allocator::abandon_gc_alloc_regions() {
   assert(survivor_gc_alloc_region()->get() == NULL, "pre-condition");
   assert(old_gc_alloc_region()->get() == NULL, "pre-condition");
   _retained_old_gc_alloc_region = NULL;
 }
 
-bool G1DefaultAllocator::survivor_is_full() const {
+bool G1Allocator::survivor_is_full() const {
   return _survivor_is_full;
 }
 
-bool G1DefaultAllocator::old_is_full() const {
+bool G1Allocator::old_is_full() const {
   return _old_is_full;
 }
 
-void G1DefaultAllocator::set_survivor_full() {
+void G1Allocator::set_survivor_full() {
   _survivor_is_full = true;
 }
 
-void G1DefaultAllocator::set_old_full() {
+void G1Allocator::set_old_full() {
   _old_is_full = true;
 }
 
@@ -151,6 +155,19 @@
   }
 }
 
+size_t G1Allocator::used_in_alloc_regions() {
+  assert(Heap_lock->owner() != NULL, "Should be owned on this thread's behalf.");
+  size_t result = 0;
+
+  // Read only once in case it is set to NULL concurrently
+  HeapRegion* hr = mutator_alloc_region()->get();
+  if (hr != NULL) {
+    result += hr->used();
+  }
+  return result;
+}
+
+
 HeapWord* G1Allocator::par_allocate_during_gc(InCSetState dest,
                                               size_t word_size) {
   size_t temp = 0;
@@ -221,13 +238,30 @@
   return result;
 }
 
+uint G1PLABAllocator::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;
+  }
+}
+
 G1PLABAllocator::G1PLABAllocator(G1Allocator* allocator) :
   _g1h(G1CollectedHeap::heap()),
   _allocator(allocator),
+  _surviving_alloc_buffer(_g1h->desired_plab_sz(InCSetState::Young)),
+  _tenured_alloc_buffer(_g1h->desired_plab_sz(InCSetState::Old)),
   _survivor_alignment_bytes(calc_survivor_alignment_bytes()) {
-  for (size_t i = 0; i < ARRAY_SIZE(_direct_allocated); i++) {
-    _direct_allocated[i] = 0;
+  for (uint state = 0; state < InCSetState::Num; state++) {
+    _direct_allocated[state] = 0;
+    _alloc_buffers[state] = NULL;
   }
+  _alloc_buffers[InCSetState::Young] = &_surviving_alloc_buffer;
+  _alloc_buffers[InCSetState::Old]  = &_tenured_alloc_buffer;
 }
 
 bool G1PLABAllocator::may_throw_away_buffer(size_t const allocation_word_sz, size_t const buffer_size) const {
@@ -282,18 +316,7 @@
   alloc_buffer(dest)->undo_allocation(obj, word_sz);
 }
 
-G1DefaultPLABAllocator::G1DefaultPLABAllocator(G1Allocator* allocator) :
-  G1PLABAllocator(allocator),
-  _surviving_alloc_buffer(_g1h->desired_plab_sz(InCSetState::Young)),
-  _tenured_alloc_buffer(_g1h->desired_plab_sz(InCSetState::Old)) {
-  for (uint state = 0; state < InCSetState::Num; state++) {
-    _alloc_buffers[state] = NULL;
-  }
-  _alloc_buffers[InCSetState::Young] = &_surviving_alloc_buffer;
-  _alloc_buffers[InCSetState::Old]  = &_tenured_alloc_buffer;
-}
-
-void G1DefaultPLABAllocator::flush_and_retire_stats() {
+void G1PLABAllocator::flush_and_retire_stats() {
   for (uint state = 0; state < InCSetState::Num; state++) {
     PLAB* const buf = _alloc_buffers[state];
     if (buf != NULL) {
@@ -305,7 +328,7 @@
   }
 }
 
-void G1DefaultPLABAllocator::waste(size_t& wasted, size_t& undo_wasted) {
+void G1PLABAllocator::waste(size_t& wasted, size_t& undo_wasted) {
   wasted = 0;
   undo_wasted = 0;
   for (uint state = 0; state < InCSetState::Num; state++) {
--- a/src/hotspot/share/gc/g1/g1Allocator.hpp	Fri Apr 06 11:37:34 2018 +0200
+++ b/src/hotspot/share/gc/g1/g1Allocator.hpp	Fri Apr 06 11:41:21 2018 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2018, 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
@@ -37,50 +37,65 @@
 // Also keeps track of retained regions across GCs.
 class G1Allocator : public CHeapObj<mtGC> {
   friend class VMStructs;
-protected:
+
+private:
   G1CollectedHeap* _g1h;
 
-  virtual MutatorAllocRegion* mutator_alloc_region() = 0;
+  bool _survivor_is_full;
+  bool _old_is_full;
 
-  virtual bool survivor_is_full() const = 0;
-  virtual bool old_is_full() const = 0;
+  // Alloc region used to satisfy mutator allocation requests.
+  MutatorAllocRegion _mutator_alloc_region;
 
-  virtual void set_survivor_full() = 0;
-  virtual void set_old_full() = 0;
+  // 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;
+
+  bool survivor_is_full() const;
+  bool old_is_full() const;
+
+  void set_survivor_full();
+  void set_old_full();
+
+  void reuse_retained_old_region(EvacuationInfo& evacuation_info,
+                                 OldGCAllocRegion* old,
+                                 HeapRegion** retained);
 
   // Accessors to the allocation regions.
-  virtual SurvivorGCAllocRegion* survivor_gc_alloc_region() = 0;
-  virtual OldGCAllocRegion* old_gc_alloc_region() = 0;
+  inline MutatorAllocRegion* mutator_alloc_region();
+  inline SurvivorGCAllocRegion* survivor_gc_alloc_region();
+  inline OldGCAllocRegion* old_gc_alloc_region();
 
   // Allocation attempt during GC for a survivor object / PLAB.
-  inline HeapWord* survivor_attempt_allocation(size_t min_word_size,
+  HeapWord* survivor_attempt_allocation(size_t min_word_size,
                                                size_t desired_word_size,
                                                size_t* actual_word_size);
+
   // Allocation attempt during GC for an old object / PLAB.
-  inline HeapWord* old_attempt_allocation(size_t min_word_size,
+  HeapWord* old_attempt_allocation(size_t min_word_size,
                                           size_t desired_word_size,
                                           size_t* actual_word_size);
 public:
-  G1Allocator(G1CollectedHeap* heap) : _g1h(heap) { }
-  virtual ~G1Allocator() { }
+  G1Allocator(G1CollectedHeap* heap);
 
 #ifdef ASSERT
   // Do we currently have an active mutator region to allocate into?
   bool has_mutator_alloc_region() { return mutator_alloc_region()->get() != NULL; }
 #endif
-  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(EvacuationInfo& evacuation_info) = 0;
-  virtual void abandon_gc_alloc_regions() = 0;
+  void init_mutator_alloc_region();
+  void release_mutator_alloc_region();
 
-  // Management of retained regions.
-
-  virtual bool is_retained_old_region(HeapRegion* hr) = 0;
-  void reuse_retained_old_region(EvacuationInfo& evacuation_info,
-                                 OldGCAllocRegion* old,
-                                 HeapRegion** retained);
+  void init_gc_alloc_regions(EvacuationInfo& evacuation_info);
+  void release_gc_alloc_regions(EvacuationInfo& evacuation_info);
+  void abandon_gc_alloc_regions();
+  bool is_retained_old_region(HeapRegion* hr);
 
   // Allocate blocks of memory during mutator time.
 
@@ -89,6 +104,7 @@
   inline HeapWord* attempt_allocation_force(size_t word_size);
 
   size_t unsafe_max_tlab_alloc();
+  size_t used_in_alloc_regions();
 
   // Allocate blocks of memory during garbage collection. Will ensure an
   // allocation region, either by picking one or expanding the
@@ -101,74 +117,6 @@
                                    size_t min_word_size,
                                    size_t desired_word_size,
                                    size_t* actual_word_size);
-
-  virtual size_t used_in_alloc_regions() = 0;
-};
-
-// The default allocation region manager for G1. Provides a single mutator, survivor
-// and old generation allocation region.
-// Can retain the (single) old generation allocation region across GCs.
-class G1DefaultAllocator : public G1Allocator {
-private:
-  bool _survivor_is_full;
-  bool _old_is_full;
-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);
-
-  virtual bool survivor_is_full() const;
-  virtual bool old_is_full() const ;
-
-  virtual void set_survivor_full();
-  virtual void set_old_full();
-
-  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(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() {
-    return &_mutator_alloc_region;
-  }
-
-  virtual SurvivorGCAllocRegion* survivor_gc_alloc_region() {
-    return &_survivor_gc_alloc_region;
-  }
-
-  virtual OldGCAllocRegion* old_gc_alloc_region() {
-    return &_old_gc_alloc_region;
-  }
-
-  virtual size_t used_in_alloc_regions() {
-    assert(Heap_lock->owner() != NULL,
-           "Should be owned on this thread's behalf.");
-    size_t result = 0;
-
-    // Read only once in case it is set to NULL concurrently
-    HeapRegion* hr = mutator_alloc_region()->get();
-    if (hr != NULL) {
-      result += hr->used();
-    }
-    return result;
-  }
 };
 
 // Manages the PLABs used during garbage collection. Interface for allocation from PLABs.
@@ -176,10 +124,14 @@
 // statistics.
 class G1PLABAllocator : public CHeapObj<mtGC> {
   friend class G1ParScanThreadState;
-protected:
+private:
   G1CollectedHeap* _g1h;
   G1Allocator* _allocator;
 
+  PLAB  _surviving_alloc_buffer;
+  PLAB  _tenured_alloc_buffer;
+  PLAB* _alloc_buffers[InCSetState::Num];
+
   // The survivor alignment in effect in bytes.
   // == 0 : don't align survivors
   // != 0 : align survivors to that alignment
@@ -190,32 +142,18 @@
   // Number of words allocated directly (not counting PLAB allocation).
   size_t _direct_allocated[InCSetState::Num];
 
-  virtual void flush_and_retire_stats() = 0;
-  virtual PLAB* alloc_buffer(InCSetState dest) = 0;
+  void flush_and_retire_stats();
+  inline PLAB* alloc_buffer(InCSetState dest);
 
   // 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;
-    }
-  }
-
-  HeapWord* allocate_new_plab(InCSetState dest,
-                              size_t word_sz);
+  static uint calc_survivor_alignment_bytes();
 
   bool may_throw_away_buffer(size_t const allocation_word_sz, size_t const buffer_size) const;
 public:
   G1PLABAllocator(G1Allocator* allocator);
-  virtual ~G1PLABAllocator() { }
 
-  virtual void waste(size_t& wasted, size_t& undo_wasted) = 0;
+  void waste(size_t& wasted, size_t& undo_wasted);
 
   // 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
@@ -230,42 +168,13 @@
   inline HeapWord* plab_allocate(InCSetState dest,
                                  size_t word_sz);
 
-  HeapWord* allocate(InCSetState dest,
-                     size_t word_sz,
-                     bool* refill_failed) {
-    HeapWord* const obj = plab_allocate(dest, word_sz);
-    if (obj != NULL) {
-      return obj;
-    }
-    return allocate_direct_or_new_plab(dest, word_sz, refill_failed);
-  }
+  inline HeapWord* allocate(InCSetState dest,
+                            size_t word_sz,
+                            bool* refill_failed);
 
   void undo_allocation(InCSetState dest, HeapWord* obj, size_t word_sz);
 };
 
-// The default PLAB allocator for G1. Keeps the current (single) PLAB for survivor
-// and old generation allocation.
-class G1DefaultPLABAllocator : public G1PLABAllocator {
-  PLAB  _surviving_alloc_buffer;
-  PLAB  _tenured_alloc_buffer;
-  PLAB* _alloc_buffers[InCSetState::Num];
-
-public:
-  G1DefaultPLABAllocator(G1Allocator* _allocator);
-
-  virtual PLAB* alloc_buffer(InCSetState dest) {
-    assert(dest.is_valid(),
-           "Allocation buffer index out-of-bounds: " CSETSTATE_FORMAT, dest.value());
-    assert(_alloc_buffers[dest.value()] != NULL,
-           "Allocation buffer is NULL: " CSETSTATE_FORMAT, dest.value());
-    return _alloc_buffers[dest.value()];
-  }
-
-  virtual void flush_and_retire_stats();
-
-  virtual void waste(size_t& wasted, size_t& undo_wasted);
-};
-
 // G1ArchiveRegionMap is a boolean array used to mark G1 regions as
 // archive regions.  This allows a quick check for whether an object
 // should not be marked because it is in an archive region.
--- a/src/hotspot/share/gc/g1/g1Allocator.inline.hpp	Fri Apr 06 11:37:34 2018 +0200
+++ b/src/hotspot/share/gc/g1/g1Allocator.inline.hpp	Fri Apr 06 11:41:21 2018 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2018, 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
@@ -29,21 +29,41 @@
 #include "gc/g1/g1AllocRegion.inline.hpp"
 #include "gc/shared/plab.inline.hpp"
 
-HeapWord* G1Allocator::attempt_allocation(size_t word_size) {
+inline MutatorAllocRegion* G1Allocator::mutator_alloc_region() {
+  return &_mutator_alloc_region;
+}
+
+inline SurvivorGCAllocRegion* G1Allocator::survivor_gc_alloc_region() {
+  return &_survivor_gc_alloc_region;
+}
+
+inline OldGCAllocRegion* G1Allocator::old_gc_alloc_region() {
+  return &_old_gc_alloc_region;
+}
+
+inline HeapWord* G1Allocator::attempt_allocation(size_t word_size) {
   return mutator_alloc_region()->attempt_allocation(word_size);
 }
 
-HeapWord* G1Allocator::attempt_allocation_locked(size_t word_size) {
+inline HeapWord* G1Allocator::attempt_allocation_locked(size_t word_size) {
   HeapWord* result = mutator_alloc_region()->attempt_allocation_locked(word_size);
   assert(result != NULL || mutator_alloc_region()->get() == NULL,
          "Must not have a mutator alloc region if there is no memory, but is " PTR_FORMAT, p2i(mutator_alloc_region()->get()));
   return result;
 }
 
-HeapWord* G1Allocator::attempt_allocation_force(size_t word_size) {
+inline HeapWord* G1Allocator::attempt_allocation_force(size_t word_size) {
   return mutator_alloc_region()->attempt_allocation_force(word_size);
 }
 
+inline PLAB* G1PLABAllocator::alloc_buffer(InCSetState dest) {
+  assert(dest.is_valid(),
+         "Allocation buffer index out-of-bounds: " CSETSTATE_FORMAT, dest.value());
+  assert(_alloc_buffers[dest.value()] != NULL,
+         "Allocation buffer is NULL: " CSETSTATE_FORMAT, dest.value());
+  return _alloc_buffers[dest.value()];
+}
+
 inline HeapWord* G1PLABAllocator::plab_allocate(InCSetState dest,
                                                 size_t word_sz) {
   PLAB* buffer = alloc_buffer(dest);
@@ -54,6 +74,16 @@
   }
 }
 
+inline HeapWord* G1PLABAllocator::allocate(InCSetState dest,
+                                           size_t word_sz,
+                                           bool* refill_failed) {
+  HeapWord* const obj = plab_allocate(dest, word_sz);
+  if (obj != NULL) {
+    return obj;
+  }
+  return allocate_direct_or_new_plab(dest, word_sz, refill_failed);
+}
+
 // Create the maps which is used to identify archive objects.
 inline void G1ArchiveAllocator::enable_archive_object_check() {
   if (_archive_check_enabled) {
--- a/src/hotspot/share/gc/g1/g1CollectedHeap.cpp	Fri Apr 06 11:37:34 2018 +0200
+++ b/src/hotspot/share/gc/g1/g1CollectedHeap.cpp	Fri Apr 06 11:41:21 2018 +0200
@@ -1426,7 +1426,7 @@
   _workers->initialize_workers();
   _verifier = new G1HeapVerifier(this);
 
-  _allocator = new G1DefaultAllocator(this);
+  _allocator = new G1Allocator(this);
 
   _heap_sizing_policy = G1HeapSizingPolicy::create(this, _g1_policy->analytics());
 
--- a/src/hotspot/share/gc/g1/g1ParScanThreadState.cpp	Fri Apr 06 11:37:34 2018 +0200
+++ b/src/hotspot/share/gc/g1/g1ParScanThreadState.cpp	Fri Apr 06 11:41:21 2018 +0200
@@ -66,7 +66,7 @@
   _surviving_young_words = _surviving_young_words_base + PADDING_ELEM_NUM;
   memset(_surviving_young_words, 0, real_length * sizeof(size_t));
 
-  _plab_allocator = new G1DefaultPLABAllocator(_g1h->allocator());
+  _plab_allocator = new G1PLABAllocator(_g1h->allocator());
 
   _dest[InCSetState::NotInCSet]    = InCSetState::NotInCSet;
   // The dest for Young is used when the objects are aged enough to