handles.cpp revision 3465:d2a62e0f25eb 
1/*
2 * Copyright (c) 1997, 2010, 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/oop.inline.hpp"
28#include "runtime/handles.inline.hpp"
29#ifdef TARGET_OS_FAMILY_linux
30# include "os_linux.inline.hpp"
31# include "thread_linux.inline.hpp"
32#endif
33#ifdef TARGET_OS_FAMILY_solaris
34# include "os_solaris.inline.hpp"
35# include "thread_solaris.inline.hpp"
36#endif
37#ifdef TARGET_OS_FAMILY_windows
38# include "os_windows.inline.hpp"
39# include "thread_windows.inline.hpp"
40#endif
41#ifdef TARGET_OS_FAMILY_bsd
42# include "os_bsd.inline.hpp"
43# include "thread_bsd.inline.hpp"
44#endif
45
46#ifdef ASSERT
47oop* HandleArea::allocate_handle(oop obj) {
48  assert(_handle_mark_nesting > 1, "memory leak: allocating handle outside HandleMark");
49  assert(_no_handle_mark_nesting == 0, "allocating handle inside NoHandleMark");
50  assert(SharedSkipVerify || obj->is_oop(), "sanity check");
51  return real_allocate_handle(obj);
52}
53
54Handle::Handle(Thread* thread, oop obj) {
55  assert(thread == Thread::current(), "sanity check");
56  if (obj == NULL) {
57    _handle = NULL;
58  } else {
59    _handle = thread->handle_area()->allocate_handle(obj);
60  }
61}
62
63#endif
64
65static uintx chunk_oops_do(OopClosure* f, Chunk* chunk, char* chunk_top) {
66  oop* bottom = (oop*) chunk->bottom();
67  oop* top    = (oop*) chunk_top;
68  uintx handles_visited = top - bottom;
69  assert(top >= bottom && top <= (oop*) chunk->top(), "just checking");
70  // during GC phase 3, a handle may be a forward pointer that
71  // is not yet valid, so loosen the assertion
72  while (bottom < top) {
73//    assert((*bottom)->is_oop(), "handle should point to oop");
74      assert(Universe::heap()->is_in(*bottom), "handle should be valid heap address");
75    f->do_oop(bottom++);
76  }
77  return handles_visited;
78}
79
80// Used for debugging handle allocation.
81NOT_PRODUCT(jint _nof_handlemarks  = 0;)
82
83void HandleArea::oops_do(OopClosure* f) {
84  uintx handles_visited = 0;
85  // First handle the current chunk. It is filled to the high water mark.
86  handles_visited += chunk_oops_do(f, _chunk, _hwm);
87  // Then handle all previous chunks. They are completely filled.
88  Chunk* k = _first;
89  while(k != _chunk) {
90    handles_visited += chunk_oops_do(f, k, k->top());
91    k = k->next();
92  }
93
94  // The thread local handle areas should not get very large
95  if (TraceHandleAllocation && handles_visited > TotalHandleAllocationLimit) {
96#ifdef ASSERT
97    warning("%d: Visited in HandleMark : %d",
98      _nof_handlemarks, handles_visited);
99#else
100    warning("Visited in HandleMark : %d", handles_visited);
101#endif
102  }
103  if (_prev != NULL) _prev->oops_do(f);
104}
105
106void HandleMark::initialize(Thread* thread) {
107  _thread = thread;
108  // Save area
109  _area  = thread->handle_area();
110  // Save current top
111  _chunk = _area->_chunk;
112  _hwm   = _area->_hwm;
113  _max   = _area->_max;
114  _size_in_bytes = _area->_size_in_bytes;
115  debug_only(_area->_handle_mark_nesting++);
116  assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks");
117  debug_only(Atomic::inc(&_nof_handlemarks);)
118
119  // Link this in the thread
120  set_previous_handle_mark(thread->last_handle_mark());
121  thread->set_last_handle_mark(this);
122}
123
124
125HandleMark::~HandleMark() {
126  HandleArea* area = _area;   // help compilers with poor alias analysis
127  assert(area == _thread->handle_area(), "sanity check");
128  assert(area->_handle_mark_nesting > 0, "must stack allocate HandleMarks" );
129  debug_only(area->_handle_mark_nesting--);
130
131  // Debug code to trace the number of handles allocated per mark/
132#ifdef ASSERT
133  if (TraceHandleAllocation) {
134    size_t handles = 0;
135    Chunk *c = _chunk->next();
136    if (c == NULL) {
137      handles = area->_hwm - _hwm; // no new chunk allocated
138    } else {
139      handles = _max - _hwm;      // add rest in first chunk
140      while(c != NULL) {
141        handles += c->length();
142        c = c->next();
143      }
144      handles -= area->_max - area->_hwm; // adjust for last trunk not full
145    }
146    handles /= sizeof(void *); // Adjust for size of a handle
147    if (handles > HandleAllocationLimit) {
148      // Note: _nof_handlemarks is only set in debug mode
149      warning("%d: Allocated in HandleMark : %d", _nof_handlemarks, handles);
150    }
151  }
152#endif
153
154  // Delete later chunks
155  if( _chunk->next() ) {
156    _chunk->next_chop();
157  }
158  // Roll back arena to saved top markers
159  area->_chunk = _chunk;
160  area->_hwm = _hwm;
161  area->_max = _max;
162  area->set_size_in_bytes(_size_in_bytes);
163#ifdef ASSERT
164  // clear out first chunk (to detect allocation bugs)
165  if (ZapVMHandleArea) {
166    memset(_hwm, badHandleValue, _max - _hwm);
167  }
168  Atomic::dec(&_nof_handlemarks);
169#endif
170
171  // Unlink this from the thread
172  _thread->set_last_handle_mark(previous_handle_mark());
173}
174
175#ifdef ASSERT
176
177NoHandleMark::NoHandleMark() {
178  HandleArea* area = Thread::current()->handle_area();
179  area->_no_handle_mark_nesting++;
180  assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
181}
182
183
184NoHandleMark::~NoHandleMark() {
185  HandleArea* area = Thread::current()->handle_area();
186  assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
187  area->_no_handle_mark_nesting--;
188}
189
190
191ResetNoHandleMark::ResetNoHandleMark() {
192  HandleArea* area = Thread::current()->handle_area();
193  _no_handle_mark_nesting = area->_no_handle_mark_nesting;
194  area->_no_handle_mark_nesting = 0;
195}
196
197
198ResetNoHandleMark::~ResetNoHandleMark() {
199  HandleArea* area = Thread::current()->handle_area();
200  area->_no_handle_mark_nesting = _no_handle_mark_nesting;
201}
202
203#endif
204