1 /*
   2  * Copyright (c) 1999, 2012, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_MEMORY_THREADLOCALALLOCBUFFER_HPP
  26 #define SHARE_VM_MEMORY_THREADLOCALALLOCBUFFER_HPP
  27 
  28 #include "gc_implementation/shared/gcUtil.hpp"
  29 #include "oops/typeArrayOop.hpp"
  30 #include "runtime/perfData.hpp"
  31 
  32 class GlobalTLABStats;
  33 
  34 // ThreadLocalAllocBuffer: a descriptor for thread-local storage used by
  35 // the threads for allocation.
  36 //            It is thread-private at any time, but maybe multiplexed over
  37 //            time across multiple threads. The park()/unpark() pair is
  38 //            used to make it available for such multiplexing.
  39 class ThreadLocalAllocBuffer: public CHeapObj<mtThread> {
  40   friend class VMStructs;
  41 private:
  42   HeapWord* _start;                              // address of TLAB
  43   HeapWord* _top;                                // address after last allocation
  44   HeapWord* _pf_top;                             // allocation prefetch watermark
  45   HeapWord* _end;                                // allocation end (excluding alignment_reserve)
  46   size_t    _desired_size;                       // desired size   (including alignment_reserve)
  47   size_t    _refill_waste_limit;                 // hold onto tlab if free() is larger than this
  48   size_t    _allocated_before_last_gc;           // total bytes allocated up until the last gc
  49 
  50   static size_t   _max_size;                     // maximum size of any TLAB
  51   static unsigned _target_refills;               // expected number of refills between GCs
  52 
  53   unsigned  _number_of_refills;
  54   unsigned  _fast_refill_waste;
  55   unsigned  _slow_refill_waste;
  56   unsigned  _gc_waste;
  57   unsigned  _slow_allocations;
  58 
  59   AdaptiveWeightedAverage _allocation_fraction;  // fraction of eden allocated in tlabs
  60 
  61   void accumulate_statistics();
  62   void initialize_statistics();
  63 
  64   void set_start(HeapWord* start)                { _start = start; }
  65   void set_end(HeapWord* end)                    { _end = end; }
  66   void set_top(HeapWord* top)                    { _top = top; }
  67   void set_pf_top(HeapWord* pf_top)              { _pf_top = pf_top; }
  68   void set_desired_size(size_t desired_size)     { _desired_size = desired_size; }
  69   void set_refill_waste_limit(size_t waste)      { _refill_waste_limit = waste;  }
  70 
  71   size_t initial_refill_waste_limit()            { return desired_size() / TLABRefillWasteFraction; }
  72 
  73   static int    target_refills()                 { return _target_refills; }
  74   size_t initial_desired_size();
  75 
  76   size_t remaining() const                       { return end() == NULL ? 0 : pointer_delta(hard_end(), top()); }
  77 
  78   // Make parsable and release it.
  79   void reset();
  80 
  81   // Resize based on amount of allocation, etc.
  82   void resize();
  83 
  84   void invariants() const { assert(top() >= start() && top() <= end(), "invalid tlab"); }
  85 
  86   void initialize(HeapWord* start, HeapWord* top, HeapWord* end);
  87 
  88   void print_stats(const char* tag);
  89 
  90   Thread* myThread();
  91 
  92   // statistics
  93 
  94   int number_of_refills() const { return _number_of_refills; }
  95   int fast_refill_waste() const { return _fast_refill_waste; }
  96   int slow_refill_waste() const { return _slow_refill_waste; }
  97   int gc_waste() const          { return _gc_waste; }
  98   int slow_allocations() const  { return _slow_allocations; }
  99 
 100   static GlobalTLABStats* _global_stats;
 101   static GlobalTLABStats* global_stats() { return _global_stats; }
 102 
 103 public:
 104   ThreadLocalAllocBuffer() : _allocation_fraction(TLABAllocationWeight), _allocated_before_last_gc(0) {
 105     // do nothing.  tlabs must be inited by initialize() calls
 106   }
 107 
 108   static const size_t min_size()                 { return align_object_size(MinTLABSize / HeapWordSize) + alignment_reserve(); }
 109   static const size_t max_size()                 { assert(_max_size != 0, "max_size not set up"); return _max_size; }
 110   static void set_max_size(size_t max_size)      { _max_size = max_size; }
 111 
 112   HeapWord* start() const                        { return _start; }
 113   HeapWord* end() const                          { return _end; }
 114   HeapWord* hard_end() const                     { return _end + alignment_reserve(); }
 115   HeapWord* top() const                          { return _top; }
 116   HeapWord* pf_top() const                       { return _pf_top; }
 117   size_t desired_size() const                    { return _desired_size; }
 118   size_t used() const                            { return pointer_delta(top(), start()); }
 119   size_t used_bytes() const                      { return pointer_delta(top(), start(), 1); }
 120   size_t free() const                            { return pointer_delta(end(), top()); }
 121   // Don't discard tlab if remaining space is larger than this.
 122   size_t refill_waste_limit() const              { return _refill_waste_limit; }
 123 
 124   // Allocate size HeapWords. The memory is NOT initialized to zero.
 125   inline HeapWord* allocate(size_t size);
 126 
 127   // Reserve space at the end of TLAB
 128   static size_t end_reserve() {
 129     int reserve_size = typeArrayOopDesc::header_size(T_INT);
 130     return MAX2(reserve_size, VM_Version::reserve_for_allocation_prefetch());
 131   }
 132   static size_t alignment_reserve()              { return align_object_size(end_reserve()); }
 133   static size_t alignment_reserve_in_bytes()     { return alignment_reserve() * HeapWordSize; }
 134 
 135   // Return tlab size or remaining space in eden such that the
 136   // space is large enough to hold obj_size and necessary fill space.
 137   // Otherwise return 0;
 138   inline size_t compute_size(size_t obj_size);
 139 
 140   // Record slow allocation
 141   inline void record_slow_allocation(size_t obj_size);
 142 
 143   // Initialization at startup
 144   static void startup_initialization();
 145 
 146   // Make an in-use tlab parsable, optionally also retiring it.
 147   void make_parsable(bool retire);
 148 
 149   // Retire in-use tlab before allocation of a new tlab
 150   void clear_before_allocation();
 151 
 152   // Accumulate statistics across all tlabs before gc
 153   static void accumulate_statistics_before_gc();
 154 
 155   // Resize tlabs for all threads
 156   static void resize_all_tlabs();
 157 
 158   void fill(HeapWord* start, HeapWord* top, size_t new_size);
 159   void initialize();
 160 
 161   static size_t refill_waste_limit_increment()   { return TLABWasteIncrement; }
 162 
 163   // Code generation support
 164   static ByteSize start_offset()                 { return byte_offset_of(ThreadLocalAllocBuffer, _start); }
 165   static ByteSize end_offset()                   { return byte_offset_of(ThreadLocalAllocBuffer, _end  ); }
 166   static ByteSize top_offset()                   { return byte_offset_of(ThreadLocalAllocBuffer, _top  ); }
 167   static ByteSize pf_top_offset()                { return byte_offset_of(ThreadLocalAllocBuffer, _pf_top  ); }
 168   static ByteSize size_offset()                  { return byte_offset_of(ThreadLocalAllocBuffer, _desired_size ); }
 169   static ByteSize refill_waste_limit_offset()    { return byte_offset_of(ThreadLocalAllocBuffer, _refill_waste_limit ); }
 170 
 171   static ByteSize number_of_refills_offset()     { return byte_offset_of(ThreadLocalAllocBuffer, _number_of_refills ); }
 172   static ByteSize fast_refill_waste_offset()     { return byte_offset_of(ThreadLocalAllocBuffer, _fast_refill_waste ); }
 173   static ByteSize slow_allocations_offset()      { return byte_offset_of(ThreadLocalAllocBuffer, _slow_allocations ); }
 174 
 175   void verify();
 176 };
 177 
 178 class GlobalTLABStats: public CHeapObj<mtThread> {
 179 private:
 180 
 181   // Accumulate perfdata in private variables because
 182   // PerfData should be write-only for security reasons
 183   // (see perfData.hpp)
 184   unsigned _allocating_threads;
 185   unsigned _total_refills;
 186   unsigned _max_refills;
 187   size_t   _total_allocation;
 188   size_t   _total_gc_waste;
 189   size_t   _max_gc_waste;
 190   size_t   _total_slow_refill_waste;
 191   size_t   _max_slow_refill_waste;
 192   size_t   _total_fast_refill_waste;
 193   size_t   _max_fast_refill_waste;
 194   unsigned _total_slow_allocations;
 195   unsigned _max_slow_allocations;
 196 
 197   PerfVariable* _perf_allocating_threads;
 198   PerfVariable* _perf_total_refills;
 199   PerfVariable* _perf_max_refills;
 200   PerfVariable* _perf_allocation;
 201   PerfVariable* _perf_gc_waste;
 202   PerfVariable* _perf_max_gc_waste;
 203   PerfVariable* _perf_slow_refill_waste;
 204   PerfVariable* _perf_max_slow_refill_waste;
 205   PerfVariable* _perf_fast_refill_waste;
 206   PerfVariable* _perf_max_fast_refill_waste;
 207   PerfVariable* _perf_slow_allocations;
 208   PerfVariable* _perf_max_slow_allocations;
 209 
 210   AdaptiveWeightedAverage _allocating_threads_avg;
 211 
 212 public:
 213   GlobalTLABStats();
 214 
 215   // Initialize all counters
 216   void initialize();
 217 
 218   // Write all perf counters to the perf_counters
 219   void publish();
 220 
 221   void print();
 222 
 223   // Accessors
 224   unsigned allocating_threads_avg() {
 225     return MAX2((unsigned)(_allocating_threads_avg.average() + 0.5), 1U);
 226   }
 227 
 228   size_t allocation() {
 229     return _total_allocation;
 230   }
 231 
 232   // Update methods
 233 
 234   void update_allocating_threads() {
 235     _allocating_threads++;
 236   }
 237   void update_number_of_refills(unsigned value) {
 238     _total_refills += value;
 239     _max_refills    = MAX2(_max_refills, value);
 240   }
 241   void update_allocation(size_t value) {
 242     _total_allocation += value;
 243   }
 244   void update_gc_waste(size_t value) {
 245     _total_gc_waste += value;
 246     _max_gc_waste    = MAX2(_max_gc_waste, value);
 247   }
 248   void update_fast_refill_waste(size_t value) {
 249     _total_fast_refill_waste += value;
 250     _max_fast_refill_waste    = MAX2(_max_fast_refill_waste, value);
 251   }
 252   void update_slow_refill_waste(size_t value) {
 253     _total_slow_refill_waste += value;
 254     _max_slow_refill_waste    = MAX2(_max_slow_refill_waste, value);
 255   }
 256   void update_slow_allocations(unsigned value) {
 257     _total_slow_allocations += value;
 258     _max_slow_allocations    = MAX2(_max_slow_allocations, value);
 259   }
 260 };
 261 
 262 #endif // SHARE_VM_MEMORY_THREADLOCALALLOCBUFFER_HPP