1 /* 2 * Copyright (c) 1997, 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 #include "precompiled.hpp" 26 #include "memory/allocation.inline.hpp" 27 #include "oops/constantPool.hpp" 28 #include "oops/oop.inline.hpp" 29 #include "runtime/atomic.inline.hpp" 30 #include "runtime/handles.inline.hpp" 31 #include "runtime/thread.inline.hpp" 32 33 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 34 35 #ifdef ASSERT 36 oop* HandleArea::allocate_handle(oop obj) { 37 assert(_handle_mark_nesting > 1, "memory leak: allocating handle outside HandleMark"); 38 assert(_no_handle_mark_nesting == 0, "allocating handle inside NoHandleMark"); 39 assert(obj->is_oop(), "not an oop: " INTPTR_FORMAT, (intptr_t*) obj); 40 return real_allocate_handle(obj); 41 } 42 43 Handle::Handle(Thread* thread, oop obj) { 44 assert(thread == Thread::current(), "sanity check"); 45 if (obj == NULL) { 46 _handle = NULL; 47 } else { 48 _handle = thread->handle_area()->allocate_handle(obj); 49 } 50 } 51 52 #endif 53 54 static uintx chunk_oops_do(OopClosure* f, Chunk* chunk, char* chunk_top) { 55 oop* bottom = (oop*) chunk->bottom(); 56 oop* top = (oop*) chunk_top; 57 uintx handles_visited = top - bottom; 58 assert(top >= bottom && top <= (oop*) chunk->top(), "just checking"); 59 // during GC phase 3, a handle may be a forward pointer that 60 // is not yet valid, so loosen the assertion 61 while (bottom < top) { 62 // This test can be moved up but for now check every oop. 63 64 assert((*bottom)->is_oop(), "handle should point to oop"); 65 66 f->do_oop(bottom++); 67 } 68 return handles_visited; 69 } 70 71 // Used for debugging handle allocation. 72 NOT_PRODUCT(jint _nof_handlemarks = 0;) 73 74 void HandleArea::oops_do(OopClosure* f) { 75 uintx handles_visited = 0; 76 // First handle the current chunk. It is filled to the high water mark. 77 handles_visited += chunk_oops_do(f, _chunk, _hwm); 78 // Then handle all previous chunks. They are completely filled. 79 Chunk* k = _first; 80 while(k != _chunk) { 81 handles_visited += chunk_oops_do(f, k, k->top()); 82 k = k->next(); 83 } 84 85 // The thread local handle areas should not get very large 86 if (TraceHandleAllocation && (size_t)handles_visited > TotalHandleAllocationLimit) { 87 #ifdef ASSERT 88 warning("%d: Visited in HandleMark : %d", 89 _nof_handlemarks, handles_visited); 90 #else 91 warning("Visited in HandleMark : %d", handles_visited); 92 #endif 93 } 94 if (_prev != NULL) _prev->oops_do(f); 95 } 96 97 void HandleMark::initialize(Thread* thread) { 98 _thread = thread; 99 // Save area 100 _area = thread->handle_area(); 101 // Save current top 102 _chunk = _area->_chunk; 103 _hwm = _area->_hwm; 104 _max = _area->_max; 105 _size_in_bytes = _area->_size_in_bytes; 106 debug_only(_area->_handle_mark_nesting++); 107 assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks"); 108 debug_only(Atomic::inc(&_nof_handlemarks);) 109 110 // Link this in the thread 111 set_previous_handle_mark(thread->last_handle_mark()); 112 thread->set_last_handle_mark(this); 113 } 114 115 116 HandleMark::~HandleMark() { 117 HandleArea* area = _area; // help compilers with poor alias analysis 118 assert(area == _thread->handle_area(), "sanity check"); 119 assert(area->_handle_mark_nesting > 0, "must stack allocate HandleMarks" ); 120 debug_only(area->_handle_mark_nesting--); 121 122 // Debug code to trace the number of handles allocated per mark/ 123 #ifdef ASSERT 124 if (TraceHandleAllocation) { 125 size_t handles = 0; 126 Chunk *c = _chunk->next(); 127 if (c == NULL) { 128 handles = area->_hwm - _hwm; // no new chunk allocated 129 } else { 130 handles = _max - _hwm; // add rest in first chunk 131 while(c != NULL) { 132 handles += c->length(); 133 c = c->next(); 134 } 135 handles -= area->_max - area->_hwm; // adjust for last trunk not full 136 } 137 handles /= sizeof(void *); // Adjust for size of a handle 138 if (handles > HandleAllocationLimit) { 139 // Note: _nof_handlemarks is only set in debug mode 140 warning("%d: Allocated in HandleMark : %d", _nof_handlemarks, handles); 141 } 142 143 tty->print_cr("Handles %d", handles); 144 } 145 #endif 146 147 // Delete later chunks 148 if( _chunk->next() ) { 149 // reset arena size before delete chunks. Otherwise, the total 150 // arena size could exceed total chunk size 151 assert(area->size_in_bytes() > size_in_bytes(), "Sanity check"); 152 area->set_size_in_bytes(size_in_bytes()); 153 _chunk->next_chop(); 154 } else { 155 assert(area->size_in_bytes() == size_in_bytes(), "Sanity check"); 156 } 157 // Roll back arena to saved top markers 158 area->_chunk = _chunk; 159 area->_hwm = _hwm; 160 area->_max = _max; 161 #ifdef ASSERT 162 // clear out first chunk (to detect allocation bugs) 163 if (ZapVMHandleArea) { 164 memset(_hwm, badHandleValue, _max - _hwm); 165 } 166 Atomic::dec(&_nof_handlemarks); 167 #endif 168 169 // Unlink this from the thread 170 _thread->set_last_handle_mark(previous_handle_mark()); 171 } 172 173 void* HandleMark::operator new(size_t size) throw() { 174 return AllocateHeap(size, mtThread); 175 } 176 177 void* HandleMark::operator new [] (size_t size) throw() { 178 return AllocateHeap(size, mtThread); 179 } 180 181 void HandleMark::operator delete(void* p) { 182 FreeHeap(p); 183 } 184 185 void HandleMark::operator delete[](void* p) { 186 FreeHeap(p); 187 } 188 189 #ifdef ASSERT 190 191 NoHandleMark::NoHandleMark() { 192 HandleArea* area = Thread::current()->handle_area(); 193 area->_no_handle_mark_nesting++; 194 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" ); 195 } 196 197 198 NoHandleMark::~NoHandleMark() { 199 HandleArea* area = Thread::current()->handle_area(); 200 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" ); 201 area->_no_handle_mark_nesting--; 202 } 203 204 205 ResetNoHandleMark::ResetNoHandleMark() { 206 HandleArea* area = Thread::current()->handle_area(); 207 _no_handle_mark_nesting = area->_no_handle_mark_nesting; 208 area->_no_handle_mark_nesting = 0; 209 } 210 211 212 ResetNoHandleMark::~ResetNoHandleMark() { 213 HandleArea* area = Thread::current()->handle_area(); 214 area->_no_handle_mark_nesting = _no_handle_mark_nesting; 215 } 216 217 bool instanceKlassHandle::is_instanceKlass(const Klass* k) { 218 return k->oop_is_instance(); 219 } 220 221 #endif