1 /*
   2  * Copyright (c) 1999, 2010, 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_INLINE_HPP
  26 #define SHARE_VM_MEMORY_THREADLOCALALLOCBUFFER_INLINE_HPP
  27 
  28 #include "gc_interface/collectedHeap.hpp"
  29 #include "memory/threadLocalAllocBuffer.hpp"
  30 #include "runtime/atomic.hpp"
  31 #include "runtime/thread.hpp"
  32 #include "utilities/copy.hpp"
  33 
  34 inline HeapWord* ThreadLocalAllocBuffer::allocate(size_t size) {
  35   invariants();
  36   HeapWord* obj = top();
  37   if (pointer_delta(end(), obj) >= size) {
  38     // successful thread-local allocation
  39 #ifdef ASSERT
  40     // Skip mangling the space corresponding to the object header to
  41     // ensure that the returned space is not considered parsable by
  42     // any concurrent GC thread.
  43     size_t hdr_size = oopDesc::header_size();
  44     Copy::fill_to_words(obj + hdr_size, size - hdr_size, badHeapWordVal);
  45 #endif // ASSERT
  46     // This addition is safe because we know that top is
  47     // at least size below end, so the add can't wrap.
  48     set_top(obj + size);
  49 
  50     invariants();
  51     return obj;
  52   }
  53   return NULL;
  54 }
  55 
  56 inline size_t ThreadLocalAllocBuffer::compute_size(size_t obj_size) {
  57   const size_t aligned_obj_size = align_object_size(obj_size);
  58 
  59   // Compute the size for the new TLAB.
  60   // The "last" tlab may be smaller to reduce fragmentation.
  61   // unsafe_max_tlab_alloc is just a hint.
  62   const size_t available_size = Universe::heap()->unsafe_max_tlab_alloc(myThread()) /
  63                                                   HeapWordSize;
  64   size_t new_tlab_size = MIN2(available_size, desired_size() + aligned_obj_size);
  65 
  66   // Make sure there's enough room for object and filler int[].
  67   const size_t obj_plus_filler_size = aligned_obj_size + alignment_reserve();
  68   if (new_tlab_size < obj_plus_filler_size) {
  69     // If there isn't enough room for the allocation, return failure.
  70     if (PrintTLAB && Verbose) {
  71       gclog_or_tty->print_cr("ThreadLocalAllocBuffer::compute_size(" SIZE_FORMAT ")"
  72                     " returns failure",
  73                     obj_size);
  74     }
  75     return 0;
  76   }
  77   if (PrintTLAB && Verbose) {
  78     gclog_or_tty->print_cr("ThreadLocalAllocBuffer::compute_size(" SIZE_FORMAT ")"
  79                   " returns " SIZE_FORMAT,
  80                   obj_size, new_tlab_size);
  81   }
  82   return new_tlab_size;
  83 }
  84 
  85 
  86 void ThreadLocalAllocBuffer::record_slow_allocation(size_t obj_size) {
  87   // Raise size required to bypass TLAB next time. Why? Else there's
  88   // a risk that a thread that repeatedly allocates objects of one
  89   // size will get stuck on this slow path.
  90 
  91   set_refill_waste_limit(refill_waste_limit() + refill_waste_limit_increment());
  92 
  93   _slow_allocations++;
  94 
  95   if (PrintTLAB && Verbose) {
  96     Thread* thrd = myThread();
  97     gclog_or_tty->print("TLAB: %s thread: "INTPTR_FORMAT" [id: %2d]"
  98                         " obj: "SIZE_FORMAT
  99                         " free: "SIZE_FORMAT
 100                         " waste: "SIZE_FORMAT"\n",
 101                         "slow", p2i(thrd), thrd->osthread()->thread_id(),
 102                         obj_size, free(), refill_waste_limit());
 103   }
 104 }
 105 
 106 #endif // SHARE_VM_MEMORY_THREADLOCALALLOCBUFFER_INLINE_HPP