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src/hotspot/share/gc/g1/g1AllocRegion.hpp
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rev 49850 : imported patch 8191471-region-logging-waste
rev 49852 : imported patch 8191471-g1-retained-mutator-region
rev 49854 : [mq]: 8191471-tschatzl-comments-move-wasted
@@ -78,10 +78,24 @@
// == end()). When we don't have a valid active region we make
// _alloc_region point to this. This allows us to skip checking
// whether the _alloc_region is NULL or not.
static HeapRegion* _dummy_region;
+ // After a region is allocated by alloc_new_region, this
+ // method is used to set it as the active alloc_region
+ void update_alloc_region(HeapRegion* alloc_region);
+
+ // Allocate a new active region and use it to perform a word_size
+ // allocation. The force parameter will be passed on to
+ // G1CollectedHeap::allocate_new_alloc_region() and tells it to try
+ // to allocate a new region even if the max has been reached.
+ HeapWord* new_alloc_region_and_allocate(size_t word_size, bool force);
+
+protected:
+ // Reset the alloc region to point a the dummy region.
+ void reset_alloc_region();
+
// Perform a non-MT-safe allocation out of the given region.
inline HeapWord* allocate(HeapRegion* alloc_region,
size_t word_size);
// Perform a MT-safe allocation out of the given region.
@@ -100,27 +114,18 @@
// so that noone else can allocate out of it any more.
// Returns the number of bytes that have been wasted by filled up
// the space.
size_t fill_up_remaining_space(HeapRegion* alloc_region);
- // After a region is allocated by alloc_new_region, this
- // method is used to set it as the active alloc_region
- void update_alloc_region(HeapRegion* alloc_region);
-
- // Allocate a new active region and use it to perform a word_size
- // allocation. The force parameter will be passed on to
- // G1CollectedHeap::allocate_new_alloc_region() and tells it to try
- // to allocate a new region even if the max has been reached.
- HeapWord* new_alloc_region_and_allocate(size_t word_size, bool force);
-
-protected:
// Retire the active allocating region. If fill_up is true then make
// sure that the region is full before we retire it so that no one
// else can allocate out of it.
// Returns the number of bytes that have been filled up during retire.
virtual size_t retire(bool fill_up);
+ size_t retire_internal(HeapRegion* alloc_region, bool fill_up);
+
// For convenience as subclasses use it.
static G1CollectedHeap* _g1h;
virtual HeapRegion* allocate_new_region(size_t word_size, bool force) = 0;
virtual void retire_region(HeapRegion* alloc_region,
@@ -175,11 +180,11 @@
// allocation attempts have failed and we are not holding a valid
// active region.
inline HeapWord* attempt_allocation_force(size_t word_size);
// Should be called before we start using this object.
- void init();
+ virtual void init();
// This can be used to set the active region to a specific
// region. (Use Example: we try to retain the last old GC alloc
// region that we've used during a GC and we can use set() to
// re-instate it at the beginning of the next GC.)
@@ -195,18 +200,53 @@
size_t actual_word_size = 0,
HeapWord* result = NULL) PRODUCT_RETURN;
};
class MutatorAllocRegion : public G1AllocRegion {
+private:
+ // Keeps track of the total waste generated during the current
+ // mutator phase.
+ size_t _wasted_bytes;
+
+ // Retained allocation region. Used to lower the waste generated
+ // during mutation by having two active regions if the free space
+ // in a region about to be retired still could fit a TLAB.
+ HeapRegion* volatile _retained_alloc_region;
+
+ // Decide if the region should be retained, based on the free size
+ // in it and the free size in the currently retained region, if any.
+ bool should_retain(HeapRegion* region);
protected:
virtual HeapRegion* allocate_new_region(size_t word_size, bool force);
virtual void retire_region(HeapRegion* alloc_region, size_t allocated_bytes);
+ virtual size_t retire(bool fill_up);
public:
MutatorAllocRegion()
- : G1AllocRegion("Mutator Alloc Region", false /* bot_updates */) { }
-};
+ : G1AllocRegion("Mutator Alloc Region", false /* bot_updates */),
+ _wasted_bytes(0),
+ _retained_alloc_region(NULL) { }
+
+ // Returns the combined used memory in the current alloc region and
+ // the retained alloc region.
+ size_t used_in_alloc_regions();
+
+ // Perform an allocation out of the retained allocation region, with the given
+ // minimum and desired size. Returns the actual size allocated (between
+ // minimum and desired size) in actual_word_size if the allocation has been
+ // successful.
+ // Should be called without holding a lock. It will try to allocate lock-free
+ // out of the retained region, or return NULL if it was unable to.
+ inline HeapWord* attempt_retained_allocation(size_t min_word_size,
+ size_t desired_word_size,
+ size_t* actual_word_size);
+
+ // This specialization of release() makes sure that the retained alloc
+ // region is retired and set to NULL.
+ virtual HeapRegion* release();
+ virtual void init();
+};
// Common base class for allocation regions used during GC.
class G1GCAllocRegion : public G1AllocRegion {
protected:
G1EvacStats* _stats;
InCSetState::in_cset_state_t _purpose;
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