1 /* 2 * Copyright (c) 1999, 2016, 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_GC_SHARED_THREADLOCALALLOCBUFFER_INLINE_HPP 26 #define SHARE_VM_GC_SHARED_THREADLOCALALLOCBUFFER_INLINE_HPP 27 28 #include "gc/shared/collectedHeap.hpp" 29 #include "gc/shared/threadLocalAllocBuffer.hpp" 30 #include "logging/log.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 // Compute the size for the new TLAB. 58 // The "last" tlab may be smaller to reduce fragmentation. 59 // unsafe_max_tlab_alloc is just a hint. 60 const size_t available_size = Universe::heap()->unsafe_max_tlab_alloc(myThread()) / 61 HeapWordSize; 62 size_t new_tlab_size = MIN3(available_size, desired_size() + align_object_size(obj_size), max_size()); 63 64 // Make sure there's enough room for object and filler int[]. 65 if (new_tlab_size < compute_min_size(obj_size)) { 66 // If there isn't enough room for the allocation, return failure. 67 log_trace(gc, tlab)("ThreadLocalAllocBuffer::compute_size(" SIZE_FORMAT ") returns failure", 68 obj_size); 69 return 0; 70 } 71 log_trace(gc, tlab)("ThreadLocalAllocBuffer::compute_size(" SIZE_FORMAT ") returns " SIZE_FORMAT, 72 obj_size, new_tlab_size); 73 return new_tlab_size; 74 } 75 76 inline size_t ThreadLocalAllocBuffer::compute_min_size(size_t obj_size) { 77 const size_t aligned_obj_size = align_object_size(obj_size); 78 const size_t size_with_reserve = aligned_obj_size + alignment_reserve(); 79 return MAX2(size_with_reserve, MinTLABSize); 80 } 81 82 void ThreadLocalAllocBuffer::record_slow_allocation(size_t obj_size) { 83 // Raise size required to bypass TLAB next time. Why? Else there's 84 // a risk that a thread that repeatedly allocates objects of one 85 // size will get stuck on this slow path. 86 87 set_refill_waste_limit(refill_waste_limit() + refill_waste_limit_increment()); 88 89 _slow_allocations++; 90 91 log_develop_trace(gc, tlab)("TLAB: %s thread: " INTPTR_FORMAT " [id: %2d]" 92 " obj: " SIZE_FORMAT 93 " free: " SIZE_FORMAT 94 " waste: " SIZE_FORMAT, 95 "slow", p2i(myThread()), myThread()->osthread()->thread_id(), 96 obj_size, free(), refill_waste_limit()); 97 } 98 99 #endif // SHARE_VM_GC_SHARED_THREADLOCALALLOCBUFFER_INLINE_HPP