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 if (ShenandoahVerifyReadsToFromSpace) {
40 obj = oopDesc::bs()->read_barrier(obj);
41 }
42 assert(obj->is_oop(), err_msg("not an oop: " INTPTR_FORMAT, (intptr_t*) obj));
43 return real_allocate_handle(obj);
44 }
45
46 Handle::Handle(Thread* thread, oop obj) {
47 assert(thread == Thread::current(), "sanity check");
48 if (obj == NULL) {
49 _handle = NULL;
50 } else {
51 _handle = thread->handle_area()->allocate_handle(obj);
52 }
53 }
54
55 #endif
56
57 static uintx chunk_oops_do(OopClosure* f, Chunk* chunk, char* chunk_top) {
58 oop* bottom = (oop*) chunk->bottom();
59 oop* top = (oop*) chunk_top;
60 uintx handles_visited = top - bottom;
61 assert(top >= bottom && top <= (oop*) chunk->top(), "just checking");
62 // during GC phase 3, a handle may be a forward pointer that
63 // is not yet valid, so loosen the assertion
64 while (bottom < top) {
65 // This test can be moved up but for now check every oop.
66
67 assert((*bottom)->is_oop(), "handle should point to oop");
68
69 f->do_oop(bottom++);
70 }
71 return handles_visited;
72 }
73
74 // Used for debugging handle allocation.
75 NOT_PRODUCT(jint _nof_handlemarks = 0;)
76
77 void HandleArea::oops_do(OopClosure* f) {
78 uintx handles_visited = 0;
79 // First handle the current chunk. It is filled to the high water mark.
80 handles_visited += chunk_oops_do(f, _chunk, _hwm);
81 // Then handle all previous chunks. They are completely filled.
82 Chunk* k = _first;
83 while(k != _chunk) {
84 handles_visited += chunk_oops_do(f, k, k->top());
85 k = k->next();
86 }
87
88 // The thread local handle areas should not get very large
89 if (TraceHandleAllocation && (size_t)handles_visited > TotalHandleAllocationLimit) {
90 #ifdef ASSERT
91 warning("%d: Visited in HandleMark : %d",
92 _nof_handlemarks, handles_visited);
93 #else
94 warning("Visited in HandleMark : %d", handles_visited);
95 #endif
96 }
97 if (_prev != NULL) _prev->oops_do(f);
98 }
99
100 void HandleMark::initialize(Thread* thread) {
101 _thread = thread;
102 // Save area
103 _area = thread->handle_area();
104 // Save current top
105 _chunk = _area->_chunk;
106 _hwm = _area->_hwm;
107 _max = _area->_max;
108 _size_in_bytes = _area->_size_in_bytes;
109 debug_only(_area->_handle_mark_nesting++);
110 assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks");
111 debug_only(Atomic::inc(&_nof_handlemarks);)
112
113 // Link this in the thread
114 set_previous_handle_mark(thread->last_handle_mark());
115 thread->set_last_handle_mark(this);
116 }
117
118
119 HandleMark::~HandleMark() {
120 HandleArea* area = _area; // help compilers with poor alias analysis
121 assert(area == _thread->handle_area(), "sanity check");
122 assert(area->_handle_mark_nesting > 0, "must stack allocate HandleMarks" );
123 debug_only(area->_handle_mark_nesting--);
124
125 // Debug code to trace the number of handles allocated per mark/
126 #ifdef ASSERT
127 if (TraceHandleAllocation) {
128 size_t handles = 0;
129 Chunk *c = _chunk->next();
130 if (c == NULL) {
131 handles = area->_hwm - _hwm; // no new chunk allocated
132 } else {
133 handles = _max - _hwm; // add rest in first chunk
134 while(c != NULL) {
135 handles += c->length();
136 c = c->next();
137 }
138 handles -= area->_max - area->_hwm; // adjust for last trunk not full
139 }
140 handles /= sizeof(void *); // Adjust for size of a handle
141 if (handles > HandleAllocationLimit) {
142 // Note: _nof_handlemarks is only set in debug mode
143 warning("%d: Allocated in HandleMark : %d", _nof_handlemarks, handles);
144 }
145
146 tty->print_cr("Handles %d", handles);
147 }
148 #endif
149
150 // Delete later chunks
151 if( _chunk->next() ) {
152 // reset arena size before delete chunks. Otherwise, the total
153 // arena size could exceed total chunk size
154 assert(area->size_in_bytes() > size_in_bytes(), "Sanity check");
155 area->set_size_in_bytes(size_in_bytes());
156 _chunk->next_chop();
157 } else {
158 assert(area->size_in_bytes() == size_in_bytes(), "Sanity check");
159 }
160 // Roll back arena to saved top markers
161 area->_chunk = _chunk;
162 area->_hwm = _hwm;
163 area->_max = _max;
164 #ifdef ASSERT
165 // clear out first chunk (to detect allocation bugs)
166 if (ZapVMHandleArea) {
167 memset(_hwm, badHandleValue, _max - _hwm);
168 }
169 Atomic::dec(&_nof_handlemarks);
170 #endif
171
172 // Unlink this from the thread
173 _thread->set_last_handle_mark(previous_handle_mark());
174 }
175
176 void* HandleMark::operator new(size_t size) throw() {
177 return AllocateHeap(size, mtThread);
178 }
179
180 void* HandleMark::operator new [] (size_t size) throw() {
181 return AllocateHeap(size, mtThread);
182 }
183
184 void HandleMark::operator delete(void* p) {
185 FreeHeap(p);
186 }
187
188 void HandleMark::operator delete[](void* p) {
189 FreeHeap(p);
190 }
191
192 #ifdef ASSERT
193
194 NoHandleMark::NoHandleMark() {
195 HandleArea* area = Thread::current()->handle_area();
196 area->_no_handle_mark_nesting++;
197 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
198 }
199
200
201 NoHandleMark::~NoHandleMark() {
202 HandleArea* area = Thread::current()->handle_area();
203 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
204 area->_no_handle_mark_nesting--;
205 }
206
207
208 ResetNoHandleMark::ResetNoHandleMark() {
209 HandleArea* area = Thread::current()->handle_area();
210 _no_handle_mark_nesting = area->_no_handle_mark_nesting;
211 area->_no_handle_mark_nesting = 0;
212 }
213
214
215 ResetNoHandleMark::~ResetNoHandleMark() {
216 HandleArea* area = Thread::current()->handle_area();
217 area->_no_handle_mark_nesting = _no_handle_mark_nesting;
218 }
219
220 bool instanceKlassHandle::is_instanceKlass(const Klass* k) {
221 return k->oop_is_instance();
222 }
223
224 #endif