Sat, 01 May 2010 02:42:18 -0700
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 1997-2008 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
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23 */
25 # include "incls/_precompiled.incl"
26 # include "incls/_markOop.cpp.incl"
29 void markOopDesc::print_on(outputStream* st) const {
30 if (is_locked()) {
31 st->print("locked(0x%lx)->", value());
32 markOop(*(markOop*)value())->print_on(st);
33 } else {
34 assert(is_unlocked() || has_bias_pattern(), "just checking");
35 st->print("mark(");
36 if (has_bias_pattern()) st->print("biased,");
37 st->print("hash %#lx,", hash());
38 st->print("age %d)", age());
39 }
40 }
43 // Give advice about whether the oop that contains this markOop
44 // should be cached or not.
45 bool markOopDesc::should_not_be_cached() const {
46 // the cast is because decode_pointer() isn't marked const
47 if (is_marked() && ((markOopDesc *)this)->decode_pointer() != NULL) {
48 // If the oop containing this markOop is being forwarded, then
49 // we are in the middle of GC and we do not want the containing
50 // oop to be added to a cache. We have no way of knowing whether
51 // the cache has already been visited by the current GC phase so
52 // we don't know whether the forwarded oop will be properly
53 // processed in this phase. If the forwarded oop is not properly
54 // processed, then we'll see strange crashes or asserts during
55 // the next GC run because the markOop will contain an unexpected
56 // value.
57 //
58 // This situation has been seen when we are GC'ing a methodOop
59 // because we use the methodOop while we're GC'ing it. Scary
60 // stuff. Some of the uses the methodOop cause the methodOop to
61 // be added to the OopMapCache in the instanceKlass as a side
62 // effect. This check lets the cache maintainer know when a
63 // cache addition would not be safe.
64 return true;
65 }
67 // caching the containing oop should be just fine
68 return false;
69 }