1 /* 2 * Copyright (c) 2017, Red Hat, Inc. and/or its affiliates. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. 7 * 8 * This code is distributed in the hope that it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 11 * version 2 for more details (a copy is included in the LICENSE file that 12 * accompanied this code). 13 * 14 * You should have received a copy of the GNU General Public License version 15 * 2 along with this work; if not, write to the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 17 * 18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 19 * or visit www.oracle.com if you need additional information or have any 20 * questions. 21 * 22 */ 23 24 #include "utilities/copy.hpp" 25 #include "gc/shared/collectedHeap.hpp" 26 #include "epsilonCollectedHeap.hpp" 27 #include "epsilonBarrierSet.hpp" 28 29 jint EpsilonCollectedHeap::initialize() { 30 size_t max_byte_size = _policy->max_heap_byte_size(); 31 size_t align = _policy->heap_alignment(); 32 33 ReservedSpace heap_rs = Universe::reserve_heap(max_byte_size, 34 align); 35 36 _start = (HeapWord *) heap_rs.base(); 37 _current = _start; 38 _end = (HeapWord *) (heap_rs.base() + heap_rs.size()); 39 40 size_t size = pointer_delta(_end, _start); 41 42 initialize_reserved_region(_start, _end); 43 os::commit_memory((char*)_start, size*HeapWordSize, align, false); 44 45 log_info(gc)("Heap space: [" PTR_FORMAT ", " PTR_FORMAT "] (" SIZE_FORMAT "M)", 46 p2i(_start), p2i(_end), size*HeapWordSize / M); 47 48 EpsilonBarrierSet* bs = new EpsilonBarrierSet(); 49 set_barrier_set(bs); 50 51 log_info(gc)("Ready to go. See you at your next OutOfMemoryError."); 52 53 return JNI_OK; 54 } 55 56 HeapWord* EpsilonCollectedHeap::allocate_new_tlab(size_t size) { 57 bool trap; 58 return mem_allocate(size, &trap); 59 } 60 61 HeapWord* EpsilonCollectedHeap::mem_allocate(size_t size, bool *gc_overhead_limit_was_exceeded) { 62 *gc_overhead_limit_was_exceeded = false; 63 do { 64 HeapWord* obj = (HeapWord *) _current; 65 if (pointer_delta(_end, obj) >= size) { 66 HeapWord* new_current = obj + size; 67 HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_current, &_current, obj); 68 if (result != obj) { 69 continue; 70 } 71 assert(is_object_aligned((intptr_t)obj), "object is aligned"); 72 assert(is_object_aligned((intptr_t)new_current), "current is aligned"); 73 return obj; 74 } else { 75 log_warning(gc)("Heap is exhausted, goodbye."); 76 vm_abort(false); // TODO: Throw the actual OOME; 77 } 78 } while (true); 79 } 80 81 void EpsilonCollectedHeap::collect_as_vm_thread(GCCause::Cause cause) { 82 log_warning(gc)("GC was triggered for VM thread with cause \"%s\", unable to handle. Goodbye.", GCCause::to_string(cause)); 83 vm_abort(false); 84 } 85 86 void EpsilonCollectedHeap::collect(GCCause::Cause cause) { 87 log_warning(gc)("GC was triggered with cause \"%s\", unable to handle. Goodbye.", GCCause::to_string(cause)); 88 vm_abort(false); 89 } 90 91 void EpsilonCollectedHeap::do_full_collection(bool clear_all_soft_refs) { 92 log_warning(gc)("Full GC was triggered, unable to handle. Goodbye."); 93 vm_abort(false); 94 }