1 /* 2 * Copyright (c) 1999, 2015, 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 "runtime/thread.hpp" 31 #include "utilities/copy.hpp" 32 33 inline HeapWord* ThreadLocalAllocBuffer::allocate(size_t size) { 34 invariants(); 35 HeapWord* obj = top(); 36 if (pointer_delta(end(), obj) >= size) { 37 // successful thread-local allocation 38 #ifdef ASSERT 39 // Skip mangling the space corresponding to the object header to 40 // ensure that the returned space is not considered parsable by 41 // any concurrent GC thread. 42 size_t hdr_size = oopDesc::header_size(); 43 Copy::fill_to_words(obj + hdr_size, size - hdr_size, badHeapWordVal); 44 #endif // ASSERT 45 // This addition is safe because we know that top is 46 // at least size below end, so the add can't wrap. 47 set_top(obj + size); 48 49 invariants(); 50 return obj; 51 } 52 return NULL; 53 } 54 55 inline size_t ThreadLocalAllocBuffer::compute_size(size_t obj_size) { 56 const size_t aligned_obj_size = align_object_size(obj_size); 57 58 // Compute the size for the new TLAB. 59 // The "last" tlab may be smaller to reduce fragmentation. 60 // unsafe_max_tlab_alloc is just a hint. 61 const size_t available_size = Universe::heap()->unsafe_max_tlab_alloc(myThread()) / 62 HeapWordSize; 63 size_t new_tlab_size = MIN2(available_size, desired_size() + aligned_obj_size); 64 65 // Make sure there's enough room for object and filler int[]. 66 const size_t obj_plus_filler_size = aligned_obj_size + alignment_reserve(); 67 if (new_tlab_size < obj_plus_filler_size) { 68 // If there isn't enough room for the allocation, return failure. 69 if (PrintTLAB && Verbose) { 70 gclog_or_tty->print_cr("ThreadLocalAllocBuffer::compute_size(" SIZE_FORMAT ")" 71 " returns failure", 72 obj_size); 73 } 74 return 0; 75 } 76 if (PrintTLAB && Verbose) { 77 gclog_or_tty->print_cr("ThreadLocalAllocBuffer::compute_size(" SIZE_FORMAT ")" 78 " returns " SIZE_FORMAT, 79 obj_size, new_tlab_size); 80 } 81 return new_tlab_size; 82 } 83 84 85 void ThreadLocalAllocBuffer::record_slow_allocation(size_t obj_size) { 86 // Raise size required to bypass TLAB next time. Why? Else there's 87 // a risk that a thread that repeatedly allocates objects of one 88 // size will get stuck on this slow path. 89 90 set_refill_waste_limit(refill_waste_limit() + refill_waste_limit_increment()); 91 92 _slow_allocations++; 93 94 if (PrintTLAB && Verbose) { 95 Thread* thrd = myThread(); 96 gclog_or_tty->print("TLAB: %s thread: "INTPTR_FORMAT" [id: %2d]" 97 " obj: "SIZE_FORMAT 98 " free: "SIZE_FORMAT 99 " waste: "SIZE_FORMAT"\n", 100 "slow", p2i(thrd), thrd->osthread()->thread_id(), 101 obj_size, free(), refill_waste_limit()); 102 } 103 } 104 105 #endif // SHARE_VM_GC_SHARED_THREADLOCALALLOCBUFFER_INLINE_HPP