src/share/vm/runtime/handles.cpp

Sat, 01 Sep 2012 13:25:18 -0400

author
coleenp
date
Sat, 01 Sep 2012 13:25:18 -0400
changeset 4037
da91efe96a93
parent 3900
d2a62e0f25eb
child 4178
bdb5f8c9978b
permissions
-rw-r--r--

6964458: Reimplement class meta-data storage to use native memory
Summary: Remove PermGen, allocate meta-data in metaspace linked to class loaders, rewrite GC walking, rewrite and rename metadata to be C++ classes
Reviewed-by: jmasa, stefank, never, coleenp, kvn, brutisso, mgerdin, dholmes, jrose, twisti, roland
Contributed-by: jmasa <jon.masamitsu@oracle.com>, stefank <stefan.karlsson@oracle.com>, mgerdin <mikael.gerdin@oracle.com>, never <tom.rodriguez@oracle.com>

     1 /*
     2  * Copyright (c) 1997, 2012, 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  */
    25 #include "precompiled.hpp"
    26 #include "memory/allocation.inline.hpp"
    27 #include "oops/constantPool.hpp"
    28 #include "oops/oop.inline.hpp"
    29 #include "runtime/handles.inline.hpp"
    30 #ifdef TARGET_OS_FAMILY_linux
    31 # include "os_linux.inline.hpp"
    32 # include "thread_linux.inline.hpp"
    33 #endif
    34 #ifdef TARGET_OS_FAMILY_solaris
    35 # include "os_solaris.inline.hpp"
    36 # include "thread_solaris.inline.hpp"
    37 #endif
    38 #ifdef TARGET_OS_FAMILY_windows
    39 # include "os_windows.inline.hpp"
    40 # include "thread_windows.inline.hpp"
    41 #endif
    42 #ifdef TARGET_OS_FAMILY_bsd
    43 # include "os_bsd.inline.hpp"
    44 # include "thread_bsd.inline.hpp"
    45 #endif
    47 #ifdef ASSERT
    48 oop* HandleArea::allocate_handle(oop obj) {
    49   assert(_handle_mark_nesting > 1, "memory leak: allocating handle outside HandleMark");
    50   assert(_no_handle_mark_nesting == 0, "allocating handle inside NoHandleMark");
    51   assert(SharedSkipVerify || obj->is_oop(), "sanity check");
    52   return real_allocate_handle(obj);
    53 }
    55 Handle::Handle(Thread* thread, oop obj) {
    56   assert(thread == Thread::current(), "sanity check");
    57   if (obj == NULL) {
    58     _handle = NULL;
    59   } else {
    60     _handle = thread->handle_area()->allocate_handle(obj);
    61   }
    62 }
    64 #endif
    66 static uintx chunk_oops_do(OopClosure* f, Chunk* chunk, char* chunk_top) {
    67   oop* bottom = (oop*) chunk->bottom();
    68   oop* top    = (oop*) chunk_top;
    69   uintx handles_visited = top - bottom;
    70   assert(top >= bottom && top <= (oop*) chunk->top(), "just checking");
    71   // during GC phase 3, a handle may be a forward pointer that
    72   // is not yet valid, so loosen the assertion
    73   while (bottom < top) {
    74     // This test can be moved up but for now check every oop.
    76     assert((*bottom)->is_oop(), "handle should point to oop");
    78     f->do_oop(bottom++);
    79   }
    80   return handles_visited;
    81 }
    83 // Used for debugging handle allocation.
    84 NOT_PRODUCT(jint _nof_handlemarks  = 0;)
    86 void HandleArea::oops_do(OopClosure* f) {
    87   uintx handles_visited = 0;
    88   // First handle the current chunk. It is filled to the high water mark.
    89   handles_visited += chunk_oops_do(f, _chunk, _hwm);
    90   // Then handle all previous chunks. They are completely filled.
    91   Chunk* k = _first;
    92   while(k != _chunk) {
    93     handles_visited += chunk_oops_do(f, k, k->top());
    94     k = k->next();
    95   }
    97   // The thread local handle areas should not get very large
    98   if (TraceHandleAllocation && handles_visited > TotalHandleAllocationLimit) {
    99 #ifdef ASSERT
   100     warning("%d: Visited in HandleMark : %d",
   101       _nof_handlemarks, handles_visited);
   102 #else
   103     warning("Visited in HandleMark : %d", handles_visited);
   104 #endif
   105   }
   106   if (_prev != NULL) _prev->oops_do(f);
   107 }
   109 void HandleMark::initialize(Thread* thread) {
   110   _thread = thread;
   111   // Save area
   112   _area  = thread->handle_area();
   113   // Save current top
   114   _chunk = _area->_chunk;
   115   _hwm   = _area->_hwm;
   116   _max   = _area->_max;
   117   _size_in_bytes = _area->_size_in_bytes;
   118   debug_only(_area->_handle_mark_nesting++);
   119   assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks");
   120   debug_only(Atomic::inc(&_nof_handlemarks);)
   122   // Link this in the thread
   123   set_previous_handle_mark(thread->last_handle_mark());
   124   thread->set_last_handle_mark(this);
   125 }
   128 HandleMark::~HandleMark() {
   129   HandleArea* area = _area;   // help compilers with poor alias analysis
   130   assert(area == _thread->handle_area(), "sanity check");
   131   assert(area->_handle_mark_nesting > 0, "must stack allocate HandleMarks" );
   132   debug_only(area->_handle_mark_nesting--);
   134   // Debug code to trace the number of handles allocated per mark/
   135 #ifdef ASSERT
   136   if (TraceHandleAllocation) {
   137     size_t handles = 0;
   138     Chunk *c = _chunk->next();
   139     if (c == NULL) {
   140       handles = area->_hwm - _hwm; // no new chunk allocated
   141     } else {
   142       handles = _max - _hwm;      // add rest in first chunk
   143       while(c != NULL) {
   144         handles += c->length();
   145         c = c->next();
   146       }
   147       handles -= area->_max - area->_hwm; // adjust for last trunk not full
   148     }
   149     handles /= sizeof(void *); // Adjust for size of a handle
   150     if (handles > HandleAllocationLimit) {
   151       // Note: _nof_handlemarks is only set in debug mode
   152       warning("%d: Allocated in HandleMark : %d", _nof_handlemarks, handles);
   153     }
   155     tty->print_cr("Handles %d", handles);
   156   }
   157 #endif
   159   // Delete later chunks
   160   if( _chunk->next() ) {
   161     _chunk->next_chop();
   162   }
   163   // Roll back arena to saved top markers
   164   area->_chunk = _chunk;
   165   area->_hwm = _hwm;
   166   area->_max = _max;
   167   area->set_size_in_bytes(_size_in_bytes);
   168 #ifdef ASSERT
   169   // clear out first chunk (to detect allocation bugs)
   170   if (ZapVMHandleArea) {
   171     memset(_hwm, badHandleValue, _max - _hwm);
   172   }
   173   Atomic::dec(&_nof_handlemarks);
   174 #endif
   176   // Unlink this from the thread
   177   _thread->set_last_handle_mark(previous_handle_mark());
   178 }
   180 #ifdef ASSERT
   182 NoHandleMark::NoHandleMark() {
   183   HandleArea* area = Thread::current()->handle_area();
   184   area->_no_handle_mark_nesting++;
   185   assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
   186 }
   189 NoHandleMark::~NoHandleMark() {
   190   HandleArea* area = Thread::current()->handle_area();
   191   assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
   192   area->_no_handle_mark_nesting--;
   193 }
   196 ResetNoHandleMark::ResetNoHandleMark() {
   197   HandleArea* area = Thread::current()->handle_area();
   198   _no_handle_mark_nesting = area->_no_handle_mark_nesting;
   199   area->_no_handle_mark_nesting = 0;
   200 }
   203 ResetNoHandleMark::~ResetNoHandleMark() {
   204   HandleArea* area = Thread::current()->handle_area();
   205   area->_no_handle_mark_nesting = _no_handle_mark_nesting;
   206 }
   208 #endif

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