handles.cpp revision 9099:115188e14c15
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#ifdef ASSERT 34oop* HandleArea::allocate_handle(oop obj) { 35 assert(_handle_mark_nesting > 1, "memory leak: allocating handle outside HandleMark"); 36 assert(_no_handle_mark_nesting == 0, "allocating handle inside NoHandleMark"); 37 assert(obj->is_oop(), "not an oop: " INTPTR_FORMAT, p2i(obj)); 38 return real_allocate_handle(obj); 39} 40 41Handle::Handle(Thread* thread, oop obj) { 42 assert(thread == Thread::current(), "sanity check"); 43 if (obj == NULL) { 44 _handle = NULL; 45 } else { 46 _handle = thread->handle_area()->allocate_handle(obj); 47 } 48} 49 50#endif 51 52static uintx chunk_oops_do(OopClosure* f, Chunk* chunk, char* chunk_top) { 53 oop* bottom = (oop*) chunk->bottom(); 54 oop* top = (oop*) chunk_top; 55 uintx handles_visited = top - bottom; 56 assert(top >= bottom && top <= (oop*) chunk->top(), "just checking"); 57 // during GC phase 3, a handle may be a forward pointer that 58 // is not yet valid, so loosen the assertion 59 while (bottom < top) { 60 // This test can be moved up but for now check every oop. 61 62 assert((*bottom)->is_oop(), "handle should point to oop"); 63 64 f->do_oop(bottom++); 65 } 66 return handles_visited; 67} 68 69// Used for debugging handle allocation. 70NOT_PRODUCT(jint _nof_handlemarks = 0;) 71 72void HandleArea::oops_do(OopClosure* f) { 73 uintx handles_visited = 0; 74 // First handle the current chunk. It is filled to the high water mark. 75 handles_visited += chunk_oops_do(f, _chunk, _hwm); 76 // Then handle all previous chunks. They are completely filled. 77 Chunk* k = _first; 78 while(k != _chunk) { 79 handles_visited += chunk_oops_do(f, k, k->top()); 80 k = k->next(); 81 } 82 83 // The thread local handle areas should not get very large 84 if (TraceHandleAllocation && (size_t)handles_visited > TotalHandleAllocationLimit) { 85#ifdef ASSERT 86 warning("%d: Visited in HandleMark : " SIZE_FORMAT, _nof_handlemarks, handles_visited); 87#else 88 warning("Visited in HandleMark : " SIZE_FORMAT, handles_visited); 89#endif 90 } 91 if (_prev != NULL) _prev->oops_do(f); 92} 93 94void HandleMark::initialize(Thread* thread) { 95 _thread = thread; 96 // Save area 97 _area = thread->handle_area(); 98 // Save current top 99 _chunk = _area->_chunk; 100 _hwm = _area->_hwm; 101 _max = _area->_max; 102 _size_in_bytes = _area->_size_in_bytes; 103 debug_only(_area->_handle_mark_nesting++); 104 assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks"); 105 debug_only(Atomic::inc(&_nof_handlemarks);) 106 107 // Link this in the thread 108 set_previous_handle_mark(thread->last_handle_mark()); 109 thread->set_last_handle_mark(this); 110} 111 112 113HandleMark::~HandleMark() { 114 HandleArea* area = _area; // help compilers with poor alias analysis 115 assert(area == _thread->handle_area(), "sanity check"); 116 assert(area->_handle_mark_nesting > 0, "must stack allocate HandleMarks" ); 117 debug_only(area->_handle_mark_nesting--); 118 119 // Debug code to trace the number of handles allocated per mark/ 120#ifdef ASSERT 121 if (TraceHandleAllocation) { 122 size_t handles = 0; 123 Chunk *c = _chunk->next(); 124 if (c == NULL) { 125 handles = area->_hwm - _hwm; // no new chunk allocated 126 } else { 127 handles = _max - _hwm; // add rest in first chunk 128 while(c != NULL) { 129 handles += c->length(); 130 c = c->next(); 131 } 132 handles -= area->_max - area->_hwm; // adjust for last trunk not full 133 } 134 handles /= sizeof(void *); // Adjust for size of a handle 135 if (handles > HandleAllocationLimit) { 136 // Note: _nof_handlemarks is only set in debug mode 137 warning("%d: Allocated in HandleMark : " SIZE_FORMAT, _nof_handlemarks, handles); 138 } 139 140 tty->print_cr("Handles " SIZE_FORMAT, handles); 141 } 142#endif 143 144 // Delete later chunks 145 if( _chunk->next() ) { 146 // reset arena size before delete chunks. Otherwise, the total 147 // arena size could exceed total chunk size 148 assert(area->size_in_bytes() > size_in_bytes(), "Sanity check"); 149 area->set_size_in_bytes(size_in_bytes()); 150 _chunk->next_chop(); 151 } else { 152 assert(area->size_in_bytes() == size_in_bytes(), "Sanity check"); 153 } 154 // Roll back arena to saved top markers 155 area->_chunk = _chunk; 156 area->_hwm = _hwm; 157 area->_max = _max; 158#ifdef ASSERT 159 // clear out first chunk (to detect allocation bugs) 160 if (ZapVMHandleArea) { 161 memset(_hwm, badHandleValue, _max - _hwm); 162 } 163 Atomic::dec(&_nof_handlemarks); 164#endif 165 166 // Unlink this from the thread 167 _thread->set_last_handle_mark(previous_handle_mark()); 168} 169 170void* HandleMark::operator new(size_t size) throw() { 171 return AllocateHeap(size, mtThread); 172} 173 174void* HandleMark::operator new [] (size_t size) throw() { 175 return AllocateHeap(size, mtThread); 176} 177 178void HandleMark::operator delete(void* p) { 179 FreeHeap(p); 180} 181 182void HandleMark::operator delete[](void* p) { 183 FreeHeap(p); 184} 185 186#ifdef ASSERT 187 188NoHandleMark::NoHandleMark() { 189 HandleArea* area = Thread::current()->handle_area(); 190 area->_no_handle_mark_nesting++; 191 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" ); 192} 193 194 195NoHandleMark::~NoHandleMark() { 196 HandleArea* area = Thread::current()->handle_area(); 197 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" ); 198 area->_no_handle_mark_nesting--; 199} 200 201 202ResetNoHandleMark::ResetNoHandleMark() { 203 HandleArea* area = Thread::current()->handle_area(); 204 _no_handle_mark_nesting = area->_no_handle_mark_nesting; 205 area->_no_handle_mark_nesting = 0; 206} 207 208 209ResetNoHandleMark::~ResetNoHandleMark() { 210 HandleArea* area = Thread::current()->handle_area(); 211 area->_no_handle_mark_nesting = _no_handle_mark_nesting; 212} 213 214bool instanceKlassHandle::is_instanceKlass(const Klass* k) { 215 return k->oop_is_instance(); 216} 217 218#endif 219