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 /*

  * Copyright (c) 1999, 2020, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  *

  */

 #include "precompiled.hpp"

 #include "memory/genCollectedHeap.hpp"

 #include "memory/resourceArea.hpp"

 #include "memory/threadLocalAllocBuffer.inline.hpp"

 #include "memory/universe.inline.hpp"

 #include "oops/oop.inline.hpp"

 #include "runtime/thread.inline.hpp"

 #include "utilities/copy.hpp"

 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC

 // Thread-Local Edens support

 // static member initialization

 size_t           ThreadLocalAllocBuffer::_max_size       = 0;

 unsigned         ThreadLocalAllocBuffer::_target_refills = 0;

 GlobalTLABStats* ThreadLocalAllocBuffer::_global_stats   = NULL;

 void ThreadLocalAllocBuffer::clear_before_allocation() {

   _slow_refill_waste += (unsigned)remaining();

   make_parsable(true);   // also retire the TLAB

 }

 void ThreadLocalAllocBuffer::accumulate_statistics_before_gc() {

   global_stats()->initialize();

   for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) {

     thread->tlab().accumulate_statistics();

     thread->tlab().initialize_statistics();

   }

   // Publish new stats if some allocation occurred.

   if (global_stats()->allocation() != 0) {

     global_stats()->publish();

     if (PrintTLAB) {

       global_stats()->print();

     }

   }

 }

 void ThreadLocalAllocBuffer::accumulate_statistics() {

   Thread* thread = myThread();

   size_t capacity = Universe::heap()->tlab_capacity(thread);

   size_t used     = Universe::heap()->tlab_used(thread);

   _gc_waste += (unsigned)remaining();

   size_t total_allocated = thread->allocated_bytes();

   size_t allocated_since_last_gc = total_allocated - _allocated_before_last_gc;

   _allocated_before_last_gc = total_allocated;

   if (PrintTLAB && (_number_of_refills > 0 || Verbose)) {

     print_stats("gc");

   }

   if (_number_of_refills > 0) {

     // Update allocation history if a reasonable amount of eden was allocated.

     bool update_allocation_history = used > 0.5 * capacity;

     if (update_allocation_history) {

       // Average the fraction of eden allocated in a tlab by this

       // thread for use in the next resize operation.

       // _gc_waste is not subtracted because it's included in

       // "used".

       // The result can be larger than 1.0 due to direct to old allocations.

       // These allocations should ideally not be counted but since it is not possible

       // to filter them out here we just cap the fraction to be at most 1.0.

       // Keep alloc_frac as float and not double to avoid the double to float conversion

       float alloc_frac = MIN2(1.0f, allocated_since_last_gc / (float) used);

       _allocation_fraction.sample(alloc_frac);

     }

     global_stats()->update_allocating_threads();

     global_stats()->update_number_of_refills(_number_of_refills);

     global_stats()->update_allocation(_number_of_refills * desired_size());

     global_stats()->update_gc_waste(_gc_waste);

     global_stats()->update_slow_refill_waste(_slow_refill_waste);

     global_stats()->update_fast_refill_waste(_fast_refill_waste);

   } else {

     assert(_number_of_refills == 0 && _fast_refill_waste == 0 &&

            _slow_refill_waste == 0 && _gc_waste          == 0,

            "tlab stats == 0");

   }

   global_stats()->update_slow_allocations(_slow_allocations);

 }

 // Fills the current tlab with a dummy filler array to create

 // an illusion of a contiguous Eden and optionally retires the tlab.

 // Waste accounting should be done in caller as appropriate; see,

 // for example, clear_before_allocation().

 void ThreadLocalAllocBuffer::make_parsable(bool retire) {

   if (end() != NULL) {

     invariants();

     if (retire) {

       myThread()->incr_allocated_bytes(used_bytes());

     }

     CollectedHeap::fill_with_object(top(), hard_end(), retire);

     if (retire || ZeroTLAB) {  // "Reset" the TLAB

       set_start(NULL);

       set_top(NULL);

       set_pf_top(NULL);

       set_end(NULL);

     }

   }

   assert(!(retire || ZeroTLAB)  ||

          (start() == NULL && end() == NULL && top() == NULL),

          "TLAB must be reset");

 }

 void ThreadLocalAllocBuffer::resize_all_tlabs() {

   if (ResizeTLAB) {

     for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) {

       thread->tlab().resize();

     }

   }

 }

 void ThreadLocalAllocBuffer::resize() {

   // Compute the next tlab size using expected allocation amount

   assert(ResizeTLAB, "Should not call this otherwise");

   size_t alloc = (size_t)(_allocation_fraction.average() *

                           (Universe::heap()->tlab_capacity(myThread()) / HeapWordSize));

   size_t new_size = alloc / _target_refills;

   new_size = MIN2(MAX2(new_size, min_size()), max_size());

   size_t aligned_new_size = align_object_size(new_size);

   if (PrintTLAB && Verbose) {

     gclog_or_tty->print("TLAB new size: thread: " INTPTR_FORMAT " [id: %2d]"

                         " refills %d  alloc: %8.6f desired_size: " SIZE_FORMAT " -> " SIZE_FORMAT "\n",

                         myThread(), myThread()->osthread()->thread_id(),

                         _target_refills, _allocation_fraction.average(), desired_size(), aligned_new_size);

   }

   set_desired_size(aligned_new_size);

   set_refill_waste_limit(initial_refill_waste_limit());

 }

 void ThreadLocalAllocBuffer::initialize_statistics() {

     _number_of_refills = 0;

     _fast_refill_waste = 0;

     _slow_refill_waste = 0;

     _gc_waste          = 0;

     _slow_allocations  = 0;

 }

 void ThreadLocalAllocBuffer::fill(HeapWord* start,

                                   HeapWord* top,

                                   size_t    new_size) {

   _number_of_refills++;

   if (PrintTLAB && Verbose) {

     print_stats("fill");

   }

   assert(top <= start + new_size - alignment_reserve(), "size too small");

   initialize(start, top, start + new_size - alignment_reserve());

   // Reset amount of internal fragmentation

   set_refill_waste_limit(initial_refill_waste_limit());

 }

 void ThreadLocalAllocBuffer::initialize(HeapWord* start,

                                         HeapWord* top,

                                         HeapWord* end) {

   set_start(start);

   set_top(top);

   set_pf_top(top);

   set_end(end);

   invariants();

 }

 void ThreadLocalAllocBuffer::initialize() {

   initialize(NULL,                    // start

              NULL,                    // top

              NULL);                   // end

   set_desired_size(initial_desired_size());

   // Following check is needed because at startup the main

   // thread is initialized before the heap is.  The initialization for

   // this thread is redone in startup_initialization below.

   if (Universe::heap() != NULL) {

     size_t capacity   = Universe::heap()->tlab_capacity(myThread()) / HeapWordSize;

     // Keep alloc_frac as float and not double to avoid the double to float conversion

     float alloc_frac = desired_size() * target_refills() / (float) capacity;

     _allocation_fraction.sample(alloc_frac);

   }

   set_refill_waste_limit(initial_refill_waste_limit());

   initialize_statistics();

 }

 void ThreadLocalAllocBuffer::startup_initialization() {

   // Assuming each thread's active tlab is, on average,

   // 1/2 full at a GC

   _target_refills = 100 / (2 * TLABWasteTargetPercent);

   _target_refills = MAX2(_target_refills, (unsigned)1U);

   _global_stats = new GlobalTLABStats();

   // During jvm startup, the main thread is initialized

   // before the heap is initialized.  So reinitialize it now.

   guarantee(Thread::current()->is_Java_thread(), "tlab initialization thread not Java thread");

   Thread::current()->tlab().initialize();

   if (PrintTLAB && Verbose) {

     gclog_or_tty->print("TLAB min: " SIZE_FORMAT " initial: " SIZE_FORMAT " max: " SIZE_FORMAT "\n",

                         min_size(), Thread::current()->tlab().initial_desired_size(), max_size());

   }

 }

 size_t ThreadLocalAllocBuffer::initial_desired_size() {

   size_t init_sz = 0;

   if (TLABSize > 0) {

     init_sz = TLABSize / HeapWordSize;

   } else if (global_stats() != NULL) {

     // Initial size is a function of the average number of allocating threads.

     unsigned nof_threads = global_stats()->allocating_threads_avg();

     init_sz  = (Universe::heap()->tlab_capacity(myThread()) / HeapWordSize) /

                       (nof_threads * target_refills());

     init_sz = align_object_size(init_sz);

   }

   init_sz = MIN2(MAX2(init_sz, min_size()), max_size());

   return init_sz;

 }

 void ThreadLocalAllocBuffer::print_stats(const char* tag) {

   Thread* thrd = myThread();

   size_t waste = _gc_waste + _slow_refill_waste + _fast_refill_waste;

   size_t alloc = _number_of_refills * _desired_size;

   double waste_percent = alloc == 0 ? 0.0 :

                       100.0 * waste / alloc;

   size_t tlab_used  = Universe::heap()->tlab_used(thrd);

   gclog_or_tty->print("TLAB: %s thread: " INTPTR_FORMAT " [id: %2d]"

                       " desired_size: " SIZE_FORMAT "KB"

                       " slow allocs: %d  refill waste: " SIZE_FORMAT "B"

                       " alloc:%8.5f %8.0fKB refills: %d waste %4.1f%% gc: %dB"

                       " slow: %dB fast: %dB\n",

                       tag, thrd, thrd->osthread()->thread_id(),

                       _desired_size / (K / HeapWordSize),

                       _slow_allocations, _refill_waste_limit * HeapWordSize,

                       _allocation_fraction.average(),

                       _allocation_fraction.average() * tlab_used / K,

                       _number_of_refills, waste_percent,

                       _gc_waste * HeapWordSize,

                       _slow_refill_waste * HeapWordSize,

                       _fast_refill_waste * HeapWordSize);

 }

 void ThreadLocalAllocBuffer::verify() {

   HeapWord* p = start();

   HeapWord* t = top();

   HeapWord* prev_p = NULL;

   while (p < t) {

     oop(p)->verify();

     prev_p = p;

     p += oop(p)->size();

   }

   guarantee(p == top(), "end of last object must match end of space");

 }

 Thread* ThreadLocalAllocBuffer::myThread() {

   return (Thread*)(((char *)this) +

                    in_bytes(start_offset()) -

                    in_bytes(Thread::tlab_start_offset()));

 }

 GlobalTLABStats::GlobalTLABStats() :

   _allocating_threads_avg(TLABAllocationWeight) {

   initialize();

   _allocating_threads_avg.sample(1); // One allocating thread at startup

   if (UsePerfData) {

     EXCEPTION_MARK;

     ResourceMark rm;

     char* cname = PerfDataManager::counter_name("tlab", "allocThreads");

     _perf_allocating_threads =

       PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_None, CHECK);

     cname = PerfDataManager::counter_name("tlab", "fills");

     _perf_total_refills =

       PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_None, CHECK);

     cname = PerfDataManager::counter_name("tlab", "maxFills");

     _perf_max_refills =

       PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_None, CHECK);

     cname = PerfDataManager::counter_name("tlab", "alloc");

     _perf_allocation =

       PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_Bytes, CHECK);

     cname = PerfDataManager::counter_name("tlab", "gcWaste");

     _perf_gc_waste =

       PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_Bytes, CHECK);

     cname = PerfDataManager::counter_name("tlab", "maxGcWaste");

     _perf_max_gc_waste =

       PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_Bytes, CHECK);

     cname = PerfDataManager::counter_name("tlab", "slowWaste");

     _perf_slow_refill_waste =

       PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_Bytes, CHECK);

     cname = PerfDataManager::counter_name("tlab", "maxSlowWaste");

     _perf_max_slow_refill_waste =

       PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_Bytes, CHECK);

     cname = PerfDataManager::counter_name("tlab", "fastWaste");

     _perf_fast_refill_waste =

       PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_Bytes, CHECK);

     cname = PerfDataManager::counter_name("tlab", "maxFastWaste");

     _perf_max_fast_refill_waste =

       PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_Bytes, CHECK);

     cname = PerfDataManager::counter_name("tlab", "slowAlloc");

     _perf_slow_allocations =

       PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_None, CHECK);

     cname = PerfDataManager::counter_name("tlab", "maxSlowAlloc");

     _perf_max_slow_allocations =

       PerfDataManager::create_variable(SUN_GC, cname, PerfData::U_None, CHECK);

   }

 }

 void GlobalTLABStats::initialize() {

   // Clear counters summarizing info from all threads

   _allocating_threads      = 0;

   _total_refills           = 0;

   _max_refills             = 0;

   _total_allocation        = 0;

   _total_gc_waste          = 0;

   _max_gc_waste            = 0;

   _total_slow_refill_waste = 0;

   _max_slow_refill_waste   = 0;

   _total_fast_refill_waste = 0;

   _max_fast_refill_waste   = 0;

   _total_slow_allocations  = 0;

   _max_slow_allocations    = 0;

 }

 void GlobalTLABStats::publish() {

   _allocating_threads_avg.sample(_allocating_threads);

   if (UsePerfData) {

     _perf_allocating_threads   ->set_value(_allocating_threads);

     _perf_total_refills        ->set_value(_total_refills);

     _perf_max_refills          ->set_value(_max_refills);

     _perf_allocation           ->set_value(_total_allocation);

     _perf_gc_waste             ->set_value(_total_gc_waste);

     _perf_max_gc_waste         ->set_value(_max_gc_waste);

     _perf_slow_refill_waste    ->set_value(_total_slow_refill_waste);

     _perf_max_slow_refill_waste->set_value(_max_slow_refill_waste);

     _perf_fast_refill_waste    ->set_value(_total_fast_refill_waste);

     _perf_max_fast_refill_waste->set_value(_max_fast_refill_waste);

     _perf_slow_allocations     ->set_value(_total_slow_allocations);

     _perf_max_slow_allocations ->set_value(_max_slow_allocations);

   }

 }

 void GlobalTLABStats::print() {

   size_t waste = _total_gc_waste + _total_slow_refill_waste + _total_fast_refill_waste;

   double waste_percent = _total_allocation == 0 ? 0.0 :

                          100.0 * waste / _total_allocation;

   gclog_or_tty->print("TLAB totals: thrds: %d  refills: %d max: %d"

                       " slow allocs: %d max %d waste: %4.1f%%"

                       " gc: " SIZE_FORMAT "B max: " SIZE_FORMAT "B"

                       " slow: " SIZE_FORMAT "B max: " SIZE_FORMAT "B"

                       " fast: " SIZE_FORMAT "B max: " SIZE_FORMAT "B\n",

                       _allocating_threads,

                       _total_refills, _max_refills,

                       _total_slow_allocations, _max_slow_allocations,

                       waste_percent,

                       _total_gc_waste * HeapWordSize,

                       _max_gc_waste * HeapWordSize,

                       _total_slow_refill_waste * HeapWordSize,

                       _max_slow_refill_waste * HeapWordSize,

                       _total_fast_refill_waste * HeapWordSize,

                       _max_fast_refill_waste * HeapWordSize);

 }