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src/hotspot/share/gc/shared/threadLocalAllocBuffer.hpp
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rev 47590 : [mq]: heap8
rev 47592 : [mq]: heap14_rebased
*** 35,55 ****
// ThreadLocalAllocBuffer: a descriptor for thread-local storage used by
// the threads for allocation.
// It is thread-private at any time, but maybe multiplexed over
// time across multiple threads. The park()/unpark() pair is
// used to make it available for such multiplexing.
class ThreadLocalAllocBuffer: public CHeapObj<mtThread> {
friend class VMStructs;
friend class JVMCIVMStructs;
private:
HeapWord* _start; // address of TLAB
HeapWord* _top; // address after last allocation
HeapWord* _pf_top; // allocation prefetch watermark
! HeapWord* _end; // allocation end (excluding alignment_reserve)
size_t _desired_size; // desired size (including alignment_reserve)
size_t _refill_waste_limit; // hold onto tlab if free() is larger than this
size_t _allocated_before_last_gc; // total bytes allocated up until the last gc
static size_t _max_size; // maximum size of any TLAB
static int _reserve_for_allocation_prefetch; // Reserve at the end of the TLAB
static unsigned _target_refills; // expected number of refills between GCs
--- 35,67 ----
// ThreadLocalAllocBuffer: a descriptor for thread-local storage used by
// the threads for allocation.
// It is thread-private at any time, but maybe multiplexed over
// time across multiple threads. The park()/unpark() pair is
// used to make it available for such multiplexing.
+ //
+ // Heap sampling is performed via the end/actual_end fields.
+ // actual_end contains the real end of the tlab allocation,
+ // whereas end can be set to an arbitrary spot in the tlab to
+ // trip the return and sample the allocation.
+ // slow_path_end is used to track if a fast tlab refill occured
+ // between slowpath calls.
class ThreadLocalAllocBuffer: public CHeapObj<mtThread> {
friend class VMStructs;
friend class JVMCIVMStructs;
private:
HeapWord* _start; // address of TLAB
HeapWord* _top; // address after last allocation
HeapWord* _pf_top; // allocation prefetch watermark
! HeapWord* _end; // allocation end (can be the sampling end point or
! // the actual TLAB end, excluding alignment_reserve)
! HeapWord* _actual_end; // allocation actual_end (actual TLAB end, excluding alignment_reserve)
! HeapWord* _slow_path_end; // remember the end in case a fast refill occurs.
!
size_t _desired_size; // desired size (including alignment_reserve)
size_t _refill_waste_limit; // hold onto tlab if free() is larger than this
size_t _allocated_before_last_gc; // total bytes allocated up until the last gc
+ size_t _bytes_until_sample; // bytes until sample.
static size_t _max_size; // maximum size of any TLAB
static int _reserve_for_allocation_prefetch; // Reserve at the end of the TLAB
static unsigned _target_refills; // expected number of refills between GCs
*** 64,84 ****
void accumulate_statistics();
void initialize_statistics();
void set_start(HeapWord* start) { _start = start; }
void set_end(HeapWord* end) { _end = end; }
void set_top(HeapWord* top) { _top = top; }
void set_pf_top(HeapWord* pf_top) { _pf_top = pf_top; }
void set_desired_size(size_t desired_size) { _desired_size = desired_size; }
void set_refill_waste_limit(size_t waste) { _refill_waste_limit = waste; }
size_t initial_refill_waste_limit() { return desired_size() / TLABRefillWasteFraction; }
static int target_refills() { return _target_refills; }
size_t initial_desired_size();
! size_t remaining() const { return end() == NULL ? 0 : pointer_delta(hard_end(), top()); }
// Make parsable and release it.
void reset();
// Resize based on amount of allocation, etc.
--- 76,103 ----
void accumulate_statistics();
void initialize_statistics();
void set_start(HeapWord* start) { _start = start; }
void set_end(HeapWord* end) { _end = end; }
+ void set_actual_end(HeapWord* actual_end) { _actual_end = actual_end; }
+ void set_slow_path_end(HeapWord* slow_path_end) { _slow_path_end = slow_path_end; }
void set_top(HeapWord* top) { _top = top; }
void set_pf_top(HeapWord* pf_top) { _pf_top = pf_top; }
void set_desired_size(size_t desired_size) { _desired_size = desired_size; }
void set_refill_waste_limit(size_t waste) { _refill_waste_limit = waste; }
+ void set_bytes_until_sample(size_t bytes) { _bytes_until_sample = bytes; }
size_t initial_refill_waste_limit() { return desired_size() / TLABRefillWasteFraction; }
static int target_refills() { return _target_refills; }
size_t initial_desired_size();
! size_t remaining() { return end() == NULL ? 0 : pointer_delta(hard_end(), top()); }
!
! // Obtain the actual end of the TLAB.
! HeapWord* hard_end();
! void set_sample_end();
// Make parsable and release it.
void reset();
// Resize based on amount of allocation, etc.
*** 113,123 ****
static size_t max_size_in_bytes() { return max_size() * BytesPerWord; }
static void set_max_size(size_t max_size) { _max_size = max_size; }
HeapWord* start() const { return _start; }
HeapWord* end() const { return _end; }
- HeapWord* hard_end() const { return _end + alignment_reserve(); }
HeapWord* top() const { return _top; }
HeapWord* pf_top() const { return _pf_top; }
size_t desired_size() const { return _desired_size; }
size_t used() const { return pointer_delta(top(), start()); }
size_t used_bytes() const { return pointer_delta(top(), start(), 1); }
--- 132,141 ----
*** 160,169 ****
--- 178,192 ----
static void resize_all_tlabs();
void fill(HeapWord* start, HeapWord* top, size_t new_size);
void initialize();
+ void pick_next_sample(size_t diff = 0);
+ void set_back_actual_end();
+ void handle_sample(Thread* thread, HeapWord* result, size_t size);
+ bool should_sample() { return _bytes_until_sample == 0; }
+
static size_t refill_waste_limit_increment() { return TLABWasteIncrement; }
// Code generation support
static ByteSize start_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _start); }
static ByteSize end_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _end ); }
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