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

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  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_GC_SHARED_THREADLOCALALLOCBUFFER_HPP
  26 #define SHARE_VM_GC_SHARED_THREADLOCALALLOCBUFFER_HPP
  27 
  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 
  93   Thread* myThread();
  94 
  95   // statistics
  96 
  97   int number_of_refills() const { return _number_of_refills; }
  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 


 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:




  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_GC_SHARED_THREADLOCALALLOCBUFFER_HPP
  26 #define SHARE_VM_GC_SHARED_THREADLOCALALLOCBUFFER_HPP
  27 
  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 //
  41 //            Heap sampling is performed via the end/actual_end fields.
  42 //            actual_end contains the real end of the tlab allocation,
  43 //            whereas end can be set to an arbitrary spot in the tlab to
  44 //            trip the return and sample the allocation.
  45 //            slow_path_end is used to track if a fast tlab refill occured
  46 //            between slowpath calls.
  47 class ThreadLocalAllocBuffer: public CHeapObj<mtThread> {
  48   friend class VMStructs;
  49   friend class JVMCIVMStructs;
  50 private:
  51   HeapWord* _start;                              // address of TLAB
  52   HeapWord* _top;                                // address after last allocation
  53   HeapWord* _pf_top;                             // allocation prefetch watermark
  54   HeapWord* _end;                                // allocation end (can be the sampling end point or
  55                                                  //                 the actual TLAB end, excluding alignment_reserve)
  56   HeapWord* _actual_end;                         // allocation actual_end (actual TLAB end, excluding alignment_reserve)
  57   HeapWord* _slow_path_end;                      // remember the end in case a fast refill occurs.
  58 
  59   size_t    _desired_size;                       // desired size   (including alignment_reserve)
  60   size_t    _refill_waste_limit;                 // hold onto tlab if free() is larger than this
  61   size_t    _allocated_before_last_gc;           // total bytes allocated up until the last gc
  62   size_t    _bytes_until_sample;                 // bytes until sample.
  63 
  64   static size_t   _max_size;                          // maximum size of any TLAB
  65   static int      _reserve_for_allocation_prefetch;   // Reserve at the end of the TLAB
  66   static unsigned _target_refills;                    // expected number of refills between GCs
  67 
  68   unsigned  _number_of_refills;
  69   unsigned  _fast_refill_waste;
  70   unsigned  _slow_refill_waste;
  71   unsigned  _gc_waste;
  72   unsigned  _slow_allocations;
  73 
  74   AdaptiveWeightedAverage _allocation_fraction;  // fraction of eden allocated in tlabs
  75 
  76   void accumulate_statistics();
  77   void initialize_statistics();
  78 
  79   void set_start(HeapWord* start)                { _start = start; }
  80   void set_end(HeapWord* end)                    { _end = end; }
  81   void set_actual_end(HeapWord* actual_end)      { _actual_end = actual_end; }
  82   void set_slow_path_end(HeapWord* slow_path_end)    { _slow_path_end = slow_path_end; }
  83   void set_top(HeapWord* top)                    { _top = top; }
  84   void set_pf_top(HeapWord* pf_top)              { _pf_top = pf_top; }
  85   void set_desired_size(size_t desired_size)     { _desired_size = desired_size; }
  86   void set_refill_waste_limit(size_t waste)      { _refill_waste_limit = waste;  }
  87   void set_bytes_until_sample(size_t bytes)      { _bytes_until_sample = bytes;  }
  88 
  89   size_t initial_refill_waste_limit()            { return desired_size() / TLABRefillWasteFraction; }
  90 
  91   static int    target_refills()                 { return _target_refills; }
  92   size_t initial_desired_size();
  93 
  94   size_t remaining()                             { return end() == NULL ? 0 : pointer_delta(hard_end(), top()); }
  95 
  96   // Obtain the actual end of the TLAB.
  97   void set_sample_end();
  98 
  99   // Make parsable and release it.
 100   void reset();
 101 
 102   // Resize based on amount of allocation, etc.
 103   void resize();
 104 
 105   void invariants() const { assert(top() >= start() && top() <= end(), "invalid tlab"); }
 106 
 107   void initialize(HeapWord* start, HeapWord* top, HeapWord* end);
 108 
 109   void print_stats(const char* tag);
 110 
 111   Thread* myThread();
 112 
 113   // statistics
 114 
 115   int number_of_refills() const { return _number_of_refills; }
 116   int fast_refill_waste() const { return _fast_refill_waste; }
 117   int slow_refill_waste() const { return _slow_refill_waste; }
 118   int gc_waste() const          { return _gc_waste; }
 119   int slow_allocations() const  { return _slow_allocations; }
 120 
 121   static GlobalTLABStats* _global_stats;
 122   static GlobalTLABStats* global_stats() { return _global_stats; }
 123 
 124 public:
 125   ThreadLocalAllocBuffer() : _allocation_fraction(TLABAllocationWeight), _allocated_before_last_gc(0) {
 126     // do nothing.  tlabs must be inited by initialize() calls
 127   }
 128 
 129   static size_t min_size()                       { return align_object_size(MinTLABSize / HeapWordSize) + alignment_reserve(); }
 130   static size_t max_size()                       { assert(_max_size != 0, "max_size not set up"); return _max_size; }
 131   static size_t max_size_in_bytes()              { return max_size() * BytesPerWord; }
 132   static void set_max_size(size_t max_size)      { _max_size = max_size; }
 133 
 134   HeapWord* hard_end();
 135   HeapWord* start() const                        { return _start; }
 136   HeapWord* end() const                          { return _end; }

 137   HeapWord* top() const                          { return _top; }
 138   HeapWord* pf_top() const                       { return _pf_top; }
 139   size_t desired_size() const                    { return _desired_size; }
 140   size_t used() const                            { return pointer_delta(top(), start()); }
 141   size_t used_bytes() const                      { return pointer_delta(top(), start(), 1); }
 142   size_t free() const                            { return pointer_delta(end(), top()); }
 143   // Don't discard tlab if remaining space is larger than this.
 144   size_t refill_waste_limit() const              { return _refill_waste_limit; }
 145 
 146   // Allocate size HeapWords. The memory is NOT initialized to zero.
 147   inline HeapWord* allocate(size_t size);
 148 
 149   // Reserve space at the end of TLAB
 150   static size_t end_reserve() {
 151     int reserve_size = typeArrayOopDesc::header_size(T_INT);
 152     return MAX2(reserve_size, _reserve_for_allocation_prefetch);
 153   }
 154   static size_t alignment_reserve()              { return align_object_size(end_reserve()); }
 155   static size_t alignment_reserve_in_bytes()     { return alignment_reserve() * HeapWordSize; }
 156 


 162   // Record slow allocation
 163   inline void record_slow_allocation(size_t obj_size);
 164 
 165   // Initialization at startup
 166   static void startup_initialization();
 167 
 168   // Make an in-use tlab parsable, optionally retiring and/or zapping it.
 169   void make_parsable(bool retire, bool zap = true);
 170 
 171   // Retire in-use tlab before allocation of a new tlab
 172   void clear_before_allocation();
 173 
 174   // Accumulate statistics across all tlabs before gc
 175   static void accumulate_statistics_before_gc();
 176 
 177   // Resize tlabs for all threads
 178   static void resize_all_tlabs();
 179 
 180   void fill(HeapWord* start, HeapWord* top, size_t new_size);
 181   void initialize();
 182 
 183   void pick_next_sample(size_t diff = 0);
 184   void set_back_actual_end();
 185   void handle_sample(Thread* thread, HeapWord* result, size_t size);
 186   bool should_sample() { return _bytes_until_sample == 0; }
 187 
 188   static size_t refill_waste_limit_increment()   { return TLABWasteIncrement; }
 189 
 190   // Code generation support
 191   static ByteSize start_offset()                 { return byte_offset_of(ThreadLocalAllocBuffer, _start); }
 192   static ByteSize end_offset()                   { return byte_offset_of(ThreadLocalAllocBuffer, _end  ); }
 193   static ByteSize top_offset()                   { return byte_offset_of(ThreadLocalAllocBuffer, _top  ); }
 194   static ByteSize pf_top_offset()                { return byte_offset_of(ThreadLocalAllocBuffer, _pf_top  ); }
 195   static ByteSize size_offset()                  { return byte_offset_of(ThreadLocalAllocBuffer, _desired_size ); }
 196   static ByteSize refill_waste_limit_offset()    { return byte_offset_of(ThreadLocalAllocBuffer, _refill_waste_limit ); }
 197 
 198   static ByteSize number_of_refills_offset()     { return byte_offset_of(ThreadLocalAllocBuffer, _number_of_refills ); }
 199   static ByteSize fast_refill_waste_offset()     { return byte_offset_of(ThreadLocalAllocBuffer, _fast_refill_waste ); }
 200   static ByteSize slow_allocations_offset()      { return byte_offset_of(ThreadLocalAllocBuffer, _slow_allocations ); }
 201 
 202   void verify();
 203 };
 204 
 205 class GlobalTLABStats: public CHeapObj<mtThread> {
 206 private:


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