--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/memory/threadLocalAllocBuffer.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,416 @@
+/*
+ * Copyright 1999-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+// Thread-Local Edens support
+
+# include "incls/_precompiled.incl"
+# include "incls/_threadLocalAllocBuffer.cpp.incl"
+
+// static member initialization
+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; 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() {
+  size_t capacity = Universe::heap()->tlab_capacity(myThread()) / HeapWordSize;
+  size_t unused   = Universe::heap()->unsafe_max_tlab_alloc(myThread()) / HeapWordSize;
+  size_t used     = capacity - unused;
+
+  // Update allocation history if a reasonable amount of eden was allocated.
+  bool update_allocation_history = used > 0.5 * capacity;
+
+  _gc_waste += (unsigned)remaining();
+
+  if (PrintTLAB && (_number_of_refills > 0 || Verbose)) {
+    print_stats("gc");
+  }
+
+  if (_number_of_refills > 0) {
+
+    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".
+      size_t allocation = _number_of_refills * desired_size();
+      double alloc_frac = allocation / (double) 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();
+    MemRegion mr(top(), hard_end());
+    SharedHeap::fill_region_with_object(mr);
+
+    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() {
+  for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
+    thread->tlab().resize();
+  }
+}
+
+void ThreadLocalAllocBuffer::resize() {
+
+  if (ResizeTLAB) {
+    // Compute the next tlab size using expected allocation amount
+    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 (primordial)
+  // 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;
+    double alloc_frac = desired_size() * target_refills() / (double) 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 (primordial) 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;
+
+  if (TLABSize > 0) {
+    init_sz = MIN2(TLABSize / HeapWordSize, max_size());
+  } else if (global_stats() == NULL) {
+    // Startup issue - main thread initialized before heap initialized.
+    init_sz = min_size();
+  } else {
+    // 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;
+}
+
+const size_t ThreadLocalAllocBuffer::max_size() {
+
+  // TLABs can't be bigger than we can fill with a int[Integer.MAX_VALUE].
+  // This restriction could be removed by enabling filling with multiple arrays.
+  // If we compute that the reasonable way as
+  //    header_size + ((sizeof(jint) * max_jint) / HeapWordSize)
+  // we'll overflow on the multiply, so we do the divide first.
+  // We actually lose a little by dividing first,
+  // but that just makes the TLAB  somewhat smaller than the biggest array,
+  // which is fine, since we'll be able to fill that.
+
+  size_t unaligned_max_size = typeArrayOopDesc::header_size(T_INT) +
+                              sizeof(jint) *
+                              ((juint) max_jint / (size_t) HeapWordSize);
+  return align_size_down(unaligned_max_size, MinObjAlignment);
+}
+
+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_capacity(thrd) -
+                      Universe::heap()->unsafe_max_tlab_alloc(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);
+}