src/share/vm/memory/restore.cpp

Wed, 13 Jan 2010 15:26:39 -0800

author
ysr
date
Wed, 13 Jan 2010 15:26:39 -0800
changeset 1601
7b0e9cba0307
parent 631
d1605aabd0a1
child 1907
c18cbe5936b8
permissions
-rw-r--r--

6896647: card marks can be deferred too long
Summary: Deferred card marks are now flushed during the gc prologue. Parallel[Scavege,OldGC] and SerialGC no longer defer card marks generated by COMPILER2 as a result of ReduceInitialCardMarks. For these cases, introduced a diagnostic option to defer the card marks, only for the purposes of testing and diagnostics. CMS and G1 continue to defer card marks. Potential performance concern related to single-threaded flushing of deferred card marks in the gc prologue will be addressed in the future.
Reviewed-by: never, johnc

     1 /*
     2  * Copyright 2003-2008 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 # include "incls/_precompiled.incl"
    26 # include "incls/_restore.cpp.incl"
    29 // Closure for serializing initialization data in from a data area
    30 // (oop_array) read from the shared file.
    32 class ReadClosure : public SerializeOopClosure {
    33 private:
    34   oop** _oop_array;
    36   inline oop nextOop() {
    37     return *(*_oop_array)++;
    38   }
    40 public:
    41   ReadClosure(oop** oop_array) { _oop_array = oop_array; }
    43   void do_oop(oop* p) {
    44     assert(SharedSkipVerify || *p == NULL || *p == Universe::klassKlassObj(),
    45            "initializing previously initialized oop.");
    46     oop obj = nextOop();
    47     assert(SharedSkipVerify || (intptr_t)obj >= 0 || (intptr_t)obj < -100,
    48            "hit tag while initializing oops.");
    49     assert(SharedSkipVerify || obj->is_oop_or_null(), "invalid oop");
    50     *p = obj;
    51   }
    53   void do_oop(narrowOop* p) { ShouldNotReachHere(); }
    55   void do_ptr(void** p) {
    56     assert(*p == NULL, "initializing previous initialized pointer.");
    57     void* obj = nextOop();
    58     assert((intptr_t)obj >= 0 || (intptr_t)obj < -100,
    59            "hit tag while initializing ptrs.");
    60     *p = obj;
    61   }
    63   void do_ptr(HeapWord** p) { do_ptr((void **) p); }
    65   void do_int(int* p) {
    66     *p = (int)(intptr_t)nextOop();
    67   }
    69   void do_size_t(size_t* p) {
    70     // Assumes that size_t and pointers are the same size.
    71     *p = (size_t)nextOop();
    72   }
    74   void do_tag(int tag) {
    75     int old_tag;
    76     do_int(&old_tag);
    77     FileMapInfo::assert_mark(tag == old_tag);
    78   }
    80   void do_region(u_char* start, size_t size) {
    81     assert((intptr_t)start % sizeof(oop) == 0, "bad alignment");
    82     assert(size % sizeof(oop) == 0, "bad size");
    83     do_tag((int)size);
    84     while (size > 0) {
    85       *(oop*)start = nextOop();
    86       start += sizeof(oop);
    87       size -= sizeof(oop);
    88     }
    89   }
    91   bool reading() const { return true; }
    92 };
    95 // Read the oop and miscellaneous data from the shared file, and
    96 // serialize it out to its various destinations.
    98 void CompactingPermGenGen::initialize_oops() {
    99   FileMapInfo *mapinfo = FileMapInfo::current_info();
   101   char* buffer = mapinfo->region_base(md);
   103   // Skip over (reserve space for) a list of addresses of C++ vtables
   104   // for Klass objects.  They get filled in later.
   106   // Skip over (reserve space for) dummy C++ vtables Klass objects.
   107   // They are used as is.
   109   void** vtbl_list = (void**)buffer;
   110   buffer += vtbl_list_size * sizeof(void*);
   111   intptr_t vtable_size = *(intptr_t*)buffer;
   112   buffer += sizeof(intptr_t);
   113   buffer += vtable_size;
   115   // Create the symbol table using the bucket array at this spot in the
   116   // misc data space.  Since the symbol table is often modified, this
   117   // region (of mapped pages) will be copy-on-write.
   119   int symbolTableLen = *(intptr_t*)buffer;
   120   buffer += sizeof(intptr_t);
   121   int number_of_entries = *(intptr_t*)buffer;
   122   buffer += sizeof(intptr_t);
   123   SymbolTable::create_table((HashtableBucket*)buffer, symbolTableLen,
   124                             number_of_entries);
   125   buffer += symbolTableLen;
   127   // Create the string table using the bucket array at this spot in the
   128   // misc data space.  Since the string table is often modified, this
   129   // region (of mapped pages) will be copy-on-write.
   131   int stringTableLen = *(intptr_t*)buffer;
   132   buffer += sizeof(intptr_t);
   133   number_of_entries = *(intptr_t*)buffer;
   134   buffer += sizeof(intptr_t);
   135   StringTable::create_table((HashtableBucket*)buffer, stringTableLen,
   136                             number_of_entries);
   137   buffer += stringTableLen;
   139   // Create the shared dictionary using the bucket array at this spot in
   140   // the misc data space.  Since the shared dictionary table is never
   141   // modified, this region (of mapped pages) will be (effectively, if
   142   // not explicitly) read-only.
   144   int sharedDictionaryLen = *(intptr_t*)buffer;
   145   buffer += sizeof(intptr_t);
   146   number_of_entries = *(intptr_t*)buffer;
   147   buffer += sizeof(intptr_t);
   148   SystemDictionary::set_shared_dictionary((HashtableBucket*)buffer,
   149                                           sharedDictionaryLen,
   150                                           number_of_entries);
   151   buffer += sharedDictionaryLen;
   153   // Create the package info table using the bucket array at this spot in
   154   // the misc data space.  Since the package info table is never
   155   // modified, this region (of mapped pages) will be (effectively, if
   156   // not explicitly) read-only.
   158   int pkgInfoLen = *(intptr_t*)buffer;
   159   buffer += sizeof(intptr_t);
   160   number_of_entries = *(intptr_t*)buffer;
   161   buffer += sizeof(intptr_t);
   162   ClassLoader::create_package_info_table((HashtableBucket*)buffer, pkgInfoLen,
   163                                          number_of_entries);
   164   buffer += pkgInfoLen;
   165   ClassLoader::verify();
   167   // The following data in the shared misc data region are the linked
   168   // list elements (HashtableEntry objects) for the symbol table, string
   169   // table, and shared dictionary.  The heap objects refered to by the
   170   // symbol table, string table, and shared dictionary are permanent and
   171   // unmovable.  Since new entries added to the string and symbol tables
   172   // are always added at the beginning of the linked lists, THESE LINKED
   173   // LIST ELEMENTS ARE READ-ONLY.
   175   int len = *(intptr_t*)buffer; // skip over symbol table entries
   176   buffer += sizeof(intptr_t);
   177   buffer += len;
   179   len = *(intptr_t*)buffer;     // skip over string table entries
   180   buffer += sizeof(intptr_t);
   181   buffer += len;
   183   len = *(intptr_t*)buffer;     // skip over shared dictionary entries
   184   buffer += sizeof(intptr_t);
   185   buffer += len;
   187   len = *(intptr_t*)buffer;     // skip over package info table entries
   188   buffer += sizeof(intptr_t);
   189   buffer += len;
   191   len = *(intptr_t*)buffer;     // skip over package info table char[] arrays.
   192   buffer += sizeof(intptr_t);
   193   buffer += len;
   195   oop* oop_array = (oop*)buffer;
   196   ReadClosure rc(&oop_array);
   197   serialize_oops(&rc);
   198 }

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