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src/share/vm/gc/shared/threadLocalAllocBuffer.hpp

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  28 #include "gc/shared/gcUtil.hpp"
  29 #include "oops/typeArrayOop.hpp"
  30 #include "runtime/perfData.hpp"
  31 #include "runtime/vm_version.hpp"
  32 
  33 class GlobalTLABStats;
  34 
  35 // ThreadLocalAllocBuffer: a descriptor for thread-local storage used by
  36 // the threads for allocation.
  37 //            It is thread-private at any time, but maybe multiplexed over
  38 //            time across multiple threads. The park()/unpark() pair is
  39 //            used to make it available for such multiplexing.
  40 class ThreadLocalAllocBuffer: public CHeapObj<mtThread> {
  41   friend class VMStructs;
  42   friend class JVMCIVMStructs;
  43 private:
  44   HeapWord* _start;                              // address of TLAB
  45   HeapWord* _top;                                // address after last allocation
  46   HeapWord* _pf_top;                             // allocation prefetch watermark
  47   HeapWord* _end;                                // allocation end (excluding alignment_reserve)

  48   size_t    _desired_size;                       // desired size   (including alignment_reserve)
  49   size_t    _refill_waste_limit;                 // hold onto tlab if free() is larger than this
  50   size_t    _allocated_before_last_gc;           // total bytes allocated up until the last gc
  51 
  52   static size_t   _max_size;                          // maximum size of any TLAB
  53   static int      _reserve_for_allocation_prefetch;   // Reserve at the end of the TLAB
  54   static unsigned _target_refills;                    // expected number of refills between GCs


  55 
  56   unsigned  _number_of_refills;
  57   unsigned  _fast_refill_waste;
  58   unsigned  _slow_refill_waste;
  59   unsigned  _gc_waste;
  60   unsigned  _slow_allocations;
  61 
  62   AdaptiveWeightedAverage _allocation_fraction;  // fraction of eden allocated in tlabs
  63 
  64   void accumulate_statistics();
  65   void initialize_statistics();
  66 
  67   void set_start(HeapWord* start)                { _start = start; }
  68   void set_end(HeapWord* end)                    { _end = end; }

  69   void set_top(HeapWord* top)                    { _top = top; }
  70   void set_pf_top(HeapWord* pf_top)              { _pf_top = pf_top; }
  71   void set_desired_size(size_t desired_size)     { _desired_size = desired_size; }
  72   void set_refill_waste_limit(size_t waste)      { _refill_waste_limit = waste;  }

  73 
  74   size_t initial_refill_waste_limit()            { return desired_size() / TLABRefillWasteFraction; }
  75 
  76   static int    target_refills()                 { return _target_refills; }
  77   size_t initial_desired_size();
  78 
  79   size_t remaining() const                       { return end() == NULL ? 0 : pointer_delta(hard_end(), top()); }
  80 
  81   // Make parsable and release it.
  82   void reset();
  83 
  84   // Resize based on amount of allocation, etc.
  85   void resize();
  86 
  87   void invariants() const { assert(top() >= start() && top() <= end(), "invalid tlab"); }
  88 
  89   void initialize(HeapWord* start, HeapWord* top, HeapWord* end);
  90 
  91   void print_stats(const char* tag);
  92 


  98   int fast_refill_waste() const { return _fast_refill_waste; }
  99   int slow_refill_waste() const { return _slow_refill_waste; }
 100   int gc_waste() const          { return _gc_waste; }
 101   int slow_allocations() const  { return _slow_allocations; }
 102 
 103   static GlobalTLABStats* _global_stats;
 104   static GlobalTLABStats* global_stats() { return _global_stats; }
 105 
 106 public:
 107   ThreadLocalAllocBuffer() : _allocation_fraction(TLABAllocationWeight), _allocated_before_last_gc(0) {
 108     // do nothing.  tlabs must be inited by initialize() calls
 109   }
 110 
 111   static size_t min_size()                       { return align_object_size(MinTLABSize / HeapWordSize) + alignment_reserve(); }
 112   static size_t max_size()                       { assert(_max_size != 0, "max_size not set up"); return _max_size; }
 113   static size_t max_size_in_bytes()              { return max_size() * BytesPerWord; }
 114   static void set_max_size(size_t max_size)      { _max_size = max_size; }
 115 
 116   HeapWord* start() const                        { return _start; }
 117   HeapWord* end() const                          { return _end; }
 118   HeapWord* hard_end() const                     { return _end + alignment_reserve(); }
 119   HeapWord* top() const                          { return _top; }
 120   HeapWord* pf_top() const                       { return _pf_top; }
 121   size_t desired_size() const                    { return _desired_size; }
 122   size_t used() const                            { return pointer_delta(top(), start()); }
 123   size_t used_bytes() const                      { return pointer_delta(top(), start(), 1); }
 124   size_t free() const                            { return pointer_delta(end(), top()); }

 125   // Don't discard tlab if remaining space is larger than this.
 126   size_t refill_waste_limit() const              { return _refill_waste_limit; }
 127 
 128   // Allocate size HeapWords. The memory is NOT initialized to zero.
 129   inline HeapWord* allocate(size_t size);
 130 
 131   // Reserve space at the end of TLAB
 132   static size_t end_reserve() {
 133     int reserve_size = typeArrayOopDesc::header_size(T_INT);
 134     return MAX2(reserve_size, _reserve_for_allocation_prefetch);
 135   }
 136   static size_t alignment_reserve()              { return align_object_size(end_reserve()); }
 137   static size_t alignment_reserve_in_bytes()     { return alignment_reserve() * HeapWordSize; }
 138 
 139   // Return tlab size or remaining space in eden such that the
 140   // space is large enough to hold obj_size and necessary fill space.
 141   // Otherwise return 0;
 142   inline size_t compute_size(size_t obj_size);
 143 
 144   // Record slow allocation
 145   inline void record_slow_allocation(size_t obj_size);
 146 
 147   // Initialization at startup
 148   static void startup_initialization();
 149 
 150   // Make an in-use tlab parsable, optionally retiring and/or zapping it.
 151   void make_parsable(bool retire, bool zap = true);
 152 
 153   // Retire in-use tlab before allocation of a new tlab
 154   void clear_before_allocation();
 155 
 156   // Accumulate statistics across all tlabs before gc
 157   static void accumulate_statistics_before_gc();
 158 
 159   // Resize tlabs for all threads
 160   static void resize_all_tlabs();
 161 

 162   void fill(HeapWord* start, HeapWord* top, size_t new_size);
 163   void initialize();
 164 






 165   static size_t refill_waste_limit_increment()   { return TLABWasteIncrement; }
 166 
 167   // Code generation support
 168   static ByteSize start_offset()                 { return byte_offset_of(ThreadLocalAllocBuffer, _start); }
 169   static ByteSize end_offset()                   { return byte_offset_of(ThreadLocalAllocBuffer, _end  ); }

 170   static ByteSize top_offset()                   { return byte_offset_of(ThreadLocalAllocBuffer, _top  ); }
 171   static ByteSize pf_top_offset()                { return byte_offset_of(ThreadLocalAllocBuffer, _pf_top  ); }
 172   static ByteSize size_offset()                  { return byte_offset_of(ThreadLocalAllocBuffer, _desired_size ); }
 173   static ByteSize refill_waste_limit_offset()    { return byte_offset_of(ThreadLocalAllocBuffer, _refill_waste_limit ); }
 174 
 175   static ByteSize number_of_refills_offset()     { return byte_offset_of(ThreadLocalAllocBuffer, _number_of_refills ); }
 176   static ByteSize fast_refill_waste_offset()     { return byte_offset_of(ThreadLocalAllocBuffer, _fast_refill_waste ); }
 177   static ByteSize slow_allocations_offset()      { return byte_offset_of(ThreadLocalAllocBuffer, _slow_allocations ); }
 178 
 179   void verify();
 180 };
 181 
 182 class GlobalTLABStats: public CHeapObj<mtThread> {
 183 private:
 184 
 185   // Accumulate perfdata in private variables because
 186   // PerfData should be write-only for security reasons
 187   // (see perfData.hpp)
 188   unsigned _allocating_threads;
 189   unsigned _total_refills;




  28 #include "gc/shared/gcUtil.hpp"
  29 #include "oops/typeArrayOop.hpp"
  30 #include "runtime/perfData.hpp"
  31 #include "runtime/vm_version.hpp"
  32 
  33 class GlobalTLABStats;
  34 
  35 // ThreadLocalAllocBuffer: a descriptor for thread-local storage used by
  36 // the threads for allocation.
  37 //            It is thread-private at any time, but maybe multiplexed over
  38 //            time across multiple threads. The park()/unpark() pair is
  39 //            used to make it available for such multiplexing.
  40 class ThreadLocalAllocBuffer: public CHeapObj<mtThread> {
  41   friend class VMStructs;
  42   friend class JVMCIVMStructs;
  43 private:
  44   HeapWord* _start;                              // address of TLAB
  45   HeapWord* _top;                                // address after last allocation
  46   HeapWord* _pf_top;                             // allocation prefetch watermark
  47   HeapWord* _end;                                // allocation end (excluding alignment_reserve)
  48   HeapWord* _actual_end;                         // allocation actual_end (excluding alignment_reserve)
  49   size_t    _desired_size;                       // desired size   (including alignment_reserve)
  50   size_t    _refill_waste_limit;                 // hold onto tlab if free() is larger than this
  51   size_t    _allocated_before_last_gc;           // total bytes allocated up until the last gc
  52 
  53   static size_t   _max_size;                          // maximum size of any TLAB
  54   static int      _reserve_for_allocation_prefetch;   // Reserve at the end of the TLAB
  55   static unsigned _target_refills;                    // expected number of refills between GCs
  56   size_t _bytes_until_sample;                         // bytes until sample.
  57   size_t _extra_space;                                // extra space due to sampling logic.
  58 
  59   unsigned  _number_of_refills;
  60   unsigned  _fast_refill_waste;
  61   unsigned  _slow_refill_waste;
  62   unsigned  _gc_waste;
  63   unsigned  _slow_allocations;
  64 
  65   AdaptiveWeightedAverage _allocation_fraction;  // fraction of eden allocated in tlabs
  66 
  67   void accumulate_statistics();
  68   void initialize_statistics();
  69 
  70   void set_start(HeapWord* start)                { _start = start; }
  71   void set_end(HeapWord* end)                    { _end = end; }
  72   void set_actual_end(HeapWord* actual_end)      { _actual_end = actual_end; }
  73   void set_top(HeapWord* top)                    { _top = top; }
  74   void set_pf_top(HeapWord* pf_top)              { _pf_top = pf_top; }
  75   void set_desired_size(size_t desired_size)     { _desired_size = desired_size; }
  76   void set_refill_waste_limit(size_t waste)      { _refill_waste_limit = waste;  }
  77   void set_bytes_until_sample(size_t bytes)      { _bytes_until_sample = bytes;  }
  78 
  79   size_t initial_refill_waste_limit()            { return desired_size() / TLABRefillWasteFraction; }
  80 
  81   static int    target_refills()                 { return _target_refills; }
  82   size_t initial_desired_size();
  83 
  84   size_t remaining() const                       { return end() == NULL ? 0 : pointer_delta(hard_end(), top()); }
  85 
  86   // Make parsable and release it.
  87   void reset();
  88 
  89   // Resize based on amount of allocation, etc.
  90   void resize();
  91 
  92   void invariants() const { assert(top() >= start() && top() <= end(), "invalid tlab"); }
  93 
  94   void initialize(HeapWord* start, HeapWord* top, HeapWord* end);
  95 
  96   void print_stats(const char* tag);
  97 


 103   int fast_refill_waste() const { return _fast_refill_waste; }
 104   int slow_refill_waste() const { return _slow_refill_waste; }
 105   int gc_waste() const          { return _gc_waste; }
 106   int slow_allocations() const  { return _slow_allocations; }
 107 
 108   static GlobalTLABStats* _global_stats;
 109   static GlobalTLABStats* global_stats() { return _global_stats; }
 110 
 111 public:
 112   ThreadLocalAllocBuffer() : _allocation_fraction(TLABAllocationWeight), _allocated_before_last_gc(0) {
 113     // do nothing.  tlabs must be inited by initialize() calls
 114   }
 115 
 116   static size_t min_size()                       { return align_object_size(MinTLABSize / HeapWordSize) + alignment_reserve(); }
 117   static size_t max_size()                       { assert(_max_size != 0, "max_size not set up"); return _max_size; }
 118   static size_t max_size_in_bytes()              { return max_size() * BytesPerWord; }
 119   static void set_max_size(size_t max_size)      { _max_size = max_size; }
 120 
 121   HeapWord* start() const                        { return _start; }
 122   HeapWord* end() const                          { return _end; }
 123   HeapWord* hard_end() const                     { return _actual_end + alignment_reserve(); }
 124   HeapWord* top() const                          { return _top; }
 125   HeapWord* pf_top() const                       { return _pf_top; }
 126   size_t desired_size() const                    { return _desired_size; }
 127   size_t used() const                            { return pointer_delta(top(), start()); }
 128   size_t used_bytes() const                      { return pointer_delta(top(), start(), 1); }
 129   size_t free() const                            { return pointer_delta(end(), top()); }
 130 
 131   // Don't discard tlab if remaining space is larger than this.
 132   size_t refill_waste_limit() const              { return _refill_waste_limit; }
 133 
 134   // Allocate size HeapWords. The memory is NOT initialized to zero.
 135   inline HeapWord* allocate(size_t size);
 136 
 137   // Reserve space at the end of TLAB
 138   static size_t end_reserve() {
 139     int reserve_size = typeArrayOopDesc::header_size(T_INT);
 140     return MAX2(reserve_size, _reserve_for_allocation_prefetch);
 141   }
 142   static size_t alignment_reserve()              { return align_object_size(end_reserve()); }
 143   static size_t alignment_reserve_in_bytes()     { return alignment_reserve() * HeapWordSize; }
 144 
 145   // Return tlab size or remaining space in eden such that the
 146   // space is large enough to hold obj_size and necessary fill space.
 147   // Otherwise return 0;
 148   inline size_t compute_size(size_t obj_size);
 149 
 150   // Record slow allocation
 151   inline void record_slow_allocation(size_t obj_size);
 152 
 153   // Initialization at startup
 154   static void startup_initialization();
 155 
 156   // Make an in-use tlab parsable, optionally retiring and/or zapping it.
 157   void make_parsable(bool retire, bool zap = true);
 158 
 159   // Retire in-use tlab before allocation of a new tlab
 160   void clear_before_allocation();
 161 
 162   // Accumulate statistics across all tlabs before gc
 163   static void accumulate_statistics_before_gc();
 164 
 165   // Resize tlabs for all threads
 166   static void resize_all_tlabs();
 167 
 168   void set_back_actual_end() { _end = _actual_end; }
 169   void fill(HeapWord* start, HeapWord* top, size_t new_size);
 170   void initialize();
 171 
 172   void pick_next_sample();
 173   void handle_sample(Thread* thread, HeapWord* result, size_t size);
 174   size_t bytes_until_sample() { return _bytes_until_sample; }
 175   size_t *bytes_until_sample_addr() { return &_bytes_until_sample; }
 176   bool should_sample() { return bytes_until_sample() == 0; }
 177 
 178   static size_t refill_waste_limit_increment()   { return TLABWasteIncrement; }
 179 
 180   // Code generation support
 181   static ByteSize start_offset()                 { return byte_offset_of(ThreadLocalAllocBuffer, _start); }
 182   static ByteSize end_offset()                   { return byte_offset_of(ThreadLocalAllocBuffer, _end  ); }
 183   static ByteSize actual_end_offset()            { return byte_offset_of(ThreadLocalAllocBuffer, _actual_end  ); }
 184   static ByteSize top_offset()                   { return byte_offset_of(ThreadLocalAllocBuffer, _top  ); }
 185   static ByteSize pf_top_offset()                { return byte_offset_of(ThreadLocalAllocBuffer, _pf_top  ); }
 186   static ByteSize size_offset()                  { return byte_offset_of(ThreadLocalAllocBuffer, _desired_size ); }
 187   static ByteSize refill_waste_limit_offset()    { return byte_offset_of(ThreadLocalAllocBuffer, _refill_waste_limit ); }
 188 
 189   static ByteSize number_of_refills_offset()     { return byte_offset_of(ThreadLocalAllocBuffer, _number_of_refills ); }
 190   static ByteSize fast_refill_waste_offset()     { return byte_offset_of(ThreadLocalAllocBuffer, _fast_refill_waste ); }
 191   static ByteSize slow_allocations_offset()      { return byte_offset_of(ThreadLocalAllocBuffer, _slow_allocations ); }
 192 
 193   void verify();
 194 };
 195 
 196 class GlobalTLABStats: public CHeapObj<mtThread> {
 197 private:
 198 
 199   // Accumulate perfdata in private variables because
 200   // PerfData should be write-only for security reasons
 201   // (see perfData.hpp)
 202   unsigned _allocating_threads;
 203   unsigned _total_refills;


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