src/share/vm/oops/markOop.inline.hpp

Sat, 01 May 2010 02:42:18 -0700

author
jrose
date
Sat, 01 May 2010 02:42:18 -0700
changeset 1862
cd5dbf694d45
parent 777
37f87013dfd8
child 1907
c18cbe5936b8
permissions
-rw-r--r--

6939134: JSR 292 adjustments to method handle invocation
Summary: split MethodHandle.invoke into invokeExact and invokeGeneric; also clean up JVM-to-Java interfaces
Reviewed-by: twisti

     1 /*
     2  * Copyright 2006 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 // Should this header be preserved during GC?
    26 inline bool markOopDesc::must_be_preserved_with_bias(oop obj_containing_mark) const {
    27   assert(UseBiasedLocking, "unexpected");
    28   if (has_bias_pattern()) {
    29     // Will reset bias at end of collection
    30     // Mark words of biased and currently locked objects are preserved separately
    31     return false;
    32   }
    33   markOop prototype_header = prototype_for_object(obj_containing_mark);
    34   if (prototype_header->has_bias_pattern()) {
    35     // Individual instance which has its bias revoked; must return
    36     // true for correctness
    37     return true;
    38   }
    39   return (!is_unlocked() || !has_no_hash());
    40 }
    42 inline bool markOopDesc::must_be_preserved(oop obj_containing_mark) const {
    43   if (!UseBiasedLocking)
    44     return (!is_unlocked() || !has_no_hash());
    45   return must_be_preserved_with_bias(obj_containing_mark);
    46 }
    48 // Should this header (including its age bits) be preserved in the
    49 // case of a promotion failure during scavenge?
    50 inline bool markOopDesc::must_be_preserved_with_bias_for_promotion_failure(oop obj_containing_mark) const {
    51   assert(UseBiasedLocking, "unexpected");
    52   // We don't explicitly save off the mark words of biased and
    53   // currently-locked objects during scavenges, so if during a
    54   // promotion failure we encounter either a biased mark word or a
    55   // klass which still has a biasable prototype header, we have to
    56   // preserve the mark word. This results in oversaving, but promotion
    57   // failures are rare, and this avoids adding more complex logic to
    58   // the scavengers to call new variants of
    59   // BiasedLocking::preserve_marks() / restore_marks() in the middle
    60   // of a scavenge when a promotion failure has first been detected.
    61   if (has_bias_pattern() ||
    62       prototype_for_object(obj_containing_mark)->has_bias_pattern()) {
    63     return true;
    64   }
    65   return (this != prototype());
    66 }
    68 inline bool markOopDesc::must_be_preserved_for_promotion_failure(oop obj_containing_mark) const {
    69   if (!UseBiasedLocking)
    70     return (this != prototype());
    71   return must_be_preserved_with_bias_for_promotion_failure(obj_containing_mark);
    72 }
    75 // Should this header (including its age bits) be preserved in the
    76 // case of a scavenge in which CMS is the old generation?
    77 inline bool markOopDesc::must_be_preserved_with_bias_for_cms_scavenge(klassOop klass_of_obj_containing_mark) const {
    78   assert(UseBiasedLocking, "unexpected");
    79   // CMS scavenges preserve mark words in similar fashion to promotion failures; see above
    80   if (has_bias_pattern() ||
    81       klass_of_obj_containing_mark->klass_part()->prototype_header()->has_bias_pattern()) {
    82     return true;
    83   }
    84   return (this != prototype());
    85 }
    86 inline bool markOopDesc::must_be_preserved_for_cms_scavenge(klassOop klass_of_obj_containing_mark) const {
    87   if (!UseBiasedLocking)
    88     return (this != prototype());
    89   return must_be_preserved_with_bias_for_cms_scavenge(klass_of_obj_containing_mark);
    90 }
    92 inline markOop markOopDesc::prototype_for_object(oop obj) {
    93 #ifdef ASSERT
    94   markOop prototype_header = obj->klass()->klass_part()->prototype_header();
    95   assert(prototype_header == prototype() || prototype_header->has_bias_pattern(), "corrupt prototype header");
    96 #endif
    97   return obj->klass()->klass_part()->prototype_header();
    98 }

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