src/share/vm/memory/resourceArea.hpp

Wed, 18 Jan 2012 09:50:16 -0800

author
johnc
date
Wed, 18 Jan 2012 09:50:16 -0800
changeset 3538
d903bf750e9f
parent 3156
f08d439fab8c
child 3900
d2a62e0f25eb
permissions
-rw-r--r--

7129514: time warp warnings after 7117303
Summary: Replace calls to os::javaTimeMillis() that are used to update the milliseconds since the last GC to an equivalent that uses a monotonically non-decreasing time source.
Reviewed-by: ysr, jmasa

duke@435 1 /*
never@3138 2 * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
trims@1907 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907 20 * or visit www.oracle.com if you need additional information or have any
trims@1907 21 * questions.
duke@435 22 *
duke@435 23 */
duke@435 24
stefank@2314 25 #ifndef SHARE_VM_MEMORY_RESOURCEAREA_HPP
stefank@2314 26 #define SHARE_VM_MEMORY_RESOURCEAREA_HPP
stefank@2314 27
stefank@2314 28 #include "memory/allocation.hpp"
stefank@2314 29 #ifdef TARGET_OS_FAMILY_linux
stefank@2314 30 # include "thread_linux.inline.hpp"
stefank@2314 31 #endif
stefank@2314 32 #ifdef TARGET_OS_FAMILY_solaris
stefank@2314 33 # include "thread_solaris.inline.hpp"
stefank@2314 34 #endif
stefank@2314 35 #ifdef TARGET_OS_FAMILY_windows
stefank@2314 36 # include "thread_windows.inline.hpp"
stefank@2314 37 #endif
never@3156 38 #ifdef TARGET_OS_FAMILY_bsd
never@3156 39 # include "thread_bsd.inline.hpp"
never@3156 40 #endif
stefank@2314 41
duke@435 42 // The resource area holds temporary data structures in the VM.
duke@435 43 // The actual allocation areas are thread local. Typical usage:
duke@435 44 //
duke@435 45 // ...
duke@435 46 // {
duke@435 47 // ResourceMark rm;
duke@435 48 // int foo[] = NEW_RESOURCE_ARRAY(int, 64);
duke@435 49 // ...
duke@435 50 // }
duke@435 51 // ...
duke@435 52
duke@435 53 //------------------------------ResourceArea-----------------------------------
duke@435 54 // A ResourceArea is an Arena that supports safe usage of ResourceMark.
duke@435 55 class ResourceArea: public Arena {
duke@435 56 friend class ResourceMark;
duke@435 57 friend class DeoptResourceMark;
never@3138 58 friend class VMStructs;
duke@435 59 debug_only(int _nesting;) // current # of nested ResourceMarks
duke@435 60 debug_only(static int _warned;) // to suppress multiple warnings
duke@435 61
duke@435 62 public:
duke@435 63 ResourceArea() {
duke@435 64 debug_only(_nesting = 0;)
duke@435 65 }
duke@435 66
duke@435 67 ResourceArea(size_t init_size) : Arena(init_size) {
duke@435 68 debug_only(_nesting = 0;);
duke@435 69 }
duke@435 70
duke@435 71 char* allocate_bytes(size_t size) {
duke@435 72 #ifdef ASSERT
duke@435 73 if (_nesting < 1 && !_warned++)
duke@435 74 fatal("memory leak: allocating without ResourceMark");
duke@435 75 if (UseMallocOnly) {
duke@435 76 // use malloc, but save pointer in res. area for later freeing
duke@435 77 char** save = (char**)internal_malloc_4(sizeof(char*));
duke@435 78 return (*save = (char*)os::malloc(size));
duke@435 79 }
duke@435 80 #endif
duke@435 81 return (char*)Amalloc(size);
duke@435 82 }
duke@435 83
duke@435 84 debug_only(int nesting() const { return _nesting; });
duke@435 85 };
duke@435 86
duke@435 87
duke@435 88 //------------------------------ResourceMark-----------------------------------
duke@435 89 // A resource mark releases all resources allocated after it was constructed
duke@435 90 // when the destructor is called. Typically used as a local variable.
duke@435 91 class ResourceMark: public StackObj {
duke@435 92 protected:
duke@435 93 ResourceArea *_area; // Resource area to stack allocate
duke@435 94 Chunk *_chunk; // saved arena chunk
duke@435 95 char *_hwm, *_max;
duke@435 96 NOT_PRODUCT(size_t _size_in_bytes;)
duke@435 97
duke@435 98 void initialize(Thread *thread) {
duke@435 99 _area = thread->resource_area();
duke@435 100 _chunk = _area->_chunk;
duke@435 101 _hwm = _area->_hwm;
duke@435 102 _max= _area->_max;
duke@435 103 NOT_PRODUCT(_size_in_bytes = _area->size_in_bytes();)
duke@435 104 debug_only(_area->_nesting++;)
duke@435 105 assert( _area->_nesting > 0, "must stack allocate RMs" );
duke@435 106 }
duke@435 107
duke@435 108 public:
duke@435 109
duke@435 110 #ifndef ASSERT
duke@435 111 ResourceMark(Thread *thread) {
duke@435 112 assert(thread == Thread::current(), "not the current thread");
duke@435 113 initialize(thread);
duke@435 114 }
duke@435 115 #else
duke@435 116 ResourceMark(Thread *thread);
duke@435 117 #endif // ASSERT
duke@435 118
duke@435 119 ResourceMark() { initialize(Thread::current()); }
duke@435 120
duke@435 121 ResourceMark( ResourceArea *r ) :
duke@435 122 _area(r), _chunk(r->_chunk), _hwm(r->_hwm), _max(r->_max) {
duke@435 123 NOT_PRODUCT(_size_in_bytes = _area->size_in_bytes();)
duke@435 124 debug_only(_area->_nesting++;)
duke@435 125 assert( _area->_nesting > 0, "must stack allocate RMs" );
duke@435 126 }
duke@435 127
duke@435 128 void reset_to_mark() {
duke@435 129 if (UseMallocOnly) free_malloced_objects();
duke@435 130
duke@435 131 if( _chunk->next() ) // Delete later chunks
duke@435 132 _chunk->next_chop();
duke@435 133 _area->_chunk = _chunk; // Roll back arena to saved chunk
duke@435 134 _area->_hwm = _hwm;
duke@435 135 _area->_max = _max;
duke@435 136
duke@435 137 // clear out this chunk (to detect allocation bugs)
duke@435 138 if (ZapResourceArea) memset(_hwm, badResourceValue, _max - _hwm);
duke@435 139 _area->set_size_in_bytes(size_in_bytes());
duke@435 140 }
duke@435 141
duke@435 142 ~ResourceMark() {
duke@435 143 assert( _area->_nesting > 0, "must stack allocate RMs" );
duke@435 144 debug_only(_area->_nesting--;)
duke@435 145 reset_to_mark();
duke@435 146 }
duke@435 147
duke@435 148
duke@435 149 private:
duke@435 150 void free_malloced_objects() PRODUCT_RETURN;
duke@435 151 size_t size_in_bytes() NOT_PRODUCT({ return _size_in_bytes; }) PRODUCT_RETURN0;
duke@435 152 };
duke@435 153
duke@435 154 //------------------------------DeoptResourceMark-----------------------------------
duke@435 155 // A deopt resource mark releases all resources allocated after it was constructed
duke@435 156 // when the destructor is called. Typically used as a local variable. It differs
duke@435 157 // from a typical resource more in that it is C-Heap allocated so that deoptimization
duke@435 158 // can use data structures that are arena based but are not amenable to vanilla
duke@435 159 // ResourceMarks because deoptimization can not use a stack allocated mark. During
duke@435 160 // deoptimization we go thru the following steps:
duke@435 161 //
duke@435 162 // 0: start in assembly stub and call either uncommon_trap/fetch_unroll_info
duke@435 163 // 1: create the vframeArray (contains pointers to Resource allocated structures)
duke@435 164 // This allocates the DeoptResourceMark.
duke@435 165 // 2: return to assembly stub and remove stub frame and deoptee frame and create
duke@435 166 // the new skeletal frames.
duke@435 167 // 3: push new stub frame and call unpack_frames
duke@435 168 // 4: retrieve information from the vframeArray to populate the skeletal frames
duke@435 169 // 5: release the DeoptResourceMark
duke@435 170 // 6: return to stub and eventually to interpreter
duke@435 171 //
duke@435 172 // With old style eager deoptimization the vframeArray was created by the vmThread there
duke@435 173 // was no way for the vframeArray to contain resource allocated objects and so
duke@435 174 // a complex set of data structures to simulate an array of vframes in CHeap memory
duke@435 175 // was used. With new style lazy deoptimization the vframeArray is created in the
duke@435 176 // the thread that will use it and we can use a much simpler scheme for the vframeArray
duke@435 177 // leveraging existing data structures if we simply create a way to manage this one
duke@435 178 // special need for a ResourceMark. If ResourceMark simply inherited from CHeapObj
duke@435 179 // then existing ResourceMarks would work fine since no one use new to allocate them
duke@435 180 // and they would be stack allocated. This leaves open the possibilty of accidental
duke@435 181 // misuse so we simple duplicate the ResourceMark functionality here.
duke@435 182
duke@435 183 class DeoptResourceMark: public CHeapObj {
duke@435 184 protected:
duke@435 185 ResourceArea *_area; // Resource area to stack allocate
duke@435 186 Chunk *_chunk; // saved arena chunk
duke@435 187 char *_hwm, *_max;
duke@435 188 NOT_PRODUCT(size_t _size_in_bytes;)
duke@435 189
duke@435 190 void initialize(Thread *thread) {
duke@435 191 _area = thread->resource_area();
duke@435 192 _chunk = _area->_chunk;
duke@435 193 _hwm = _area->_hwm;
duke@435 194 _max= _area->_max;
duke@435 195 NOT_PRODUCT(_size_in_bytes = _area->size_in_bytes();)
duke@435 196 debug_only(_area->_nesting++;)
duke@435 197 assert( _area->_nesting > 0, "must stack allocate RMs" );
duke@435 198 }
duke@435 199
duke@435 200 public:
duke@435 201
duke@435 202 #ifndef ASSERT
duke@435 203 DeoptResourceMark(Thread *thread) {
duke@435 204 assert(thread == Thread::current(), "not the current thread");
duke@435 205 initialize(thread);
duke@435 206 }
duke@435 207 #else
duke@435 208 DeoptResourceMark(Thread *thread);
duke@435 209 #endif // ASSERT
duke@435 210
duke@435 211 DeoptResourceMark() { initialize(Thread::current()); }
duke@435 212
duke@435 213 DeoptResourceMark( ResourceArea *r ) :
duke@435 214 _area(r), _chunk(r->_chunk), _hwm(r->_hwm), _max(r->_max) {
duke@435 215 NOT_PRODUCT(_size_in_bytes = _area->size_in_bytes();)
duke@435 216 debug_only(_area->_nesting++;)
duke@435 217 assert( _area->_nesting > 0, "must stack allocate RMs" );
duke@435 218 }
duke@435 219
duke@435 220 void reset_to_mark() {
duke@435 221 if (UseMallocOnly) free_malloced_objects();
duke@435 222
duke@435 223 if( _chunk->next() ) // Delete later chunks
duke@435 224 _chunk->next_chop();
duke@435 225 _area->_chunk = _chunk; // Roll back arena to saved chunk
duke@435 226 _area->_hwm = _hwm;
duke@435 227 _area->_max = _max;
duke@435 228
duke@435 229 // clear out this chunk (to detect allocation bugs)
duke@435 230 if (ZapResourceArea) memset(_hwm, badResourceValue, _max - _hwm);
duke@435 231 _area->set_size_in_bytes(size_in_bytes());
duke@435 232 }
duke@435 233
duke@435 234 ~DeoptResourceMark() {
duke@435 235 assert( _area->_nesting > 0, "must stack allocate RMs" );
duke@435 236 debug_only(_area->_nesting--;)
duke@435 237 reset_to_mark();
duke@435 238 }
duke@435 239
duke@435 240
duke@435 241 private:
duke@435 242 void free_malloced_objects() PRODUCT_RETURN;
duke@435 243 size_t size_in_bytes() NOT_PRODUCT({ return _size_in_bytes; }) PRODUCT_RETURN0;
duke@435 244 };
stefank@2314 245
stefank@2314 246 #endif // SHARE_VM_MEMORY_RESOURCEAREA_HPP

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