jdk-sandbox: hotspot/src/share/vm/oops/markOop.cpp@ec745a0fe922 (annotated)

1 489c9b5090e2 Initial load duke parents: diff changeset	1	/*
489c9b5090e2 Initial load duke parents: diff changeset	2	* Copyright 1997-1999 Sun Microsystems, Inc. All Rights Reserved.
489c9b5090e2 Initial load duke parents: diff changeset	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
489c9b5090e2 Initial load duke parents: diff changeset	4	*
489c9b5090e2 Initial load duke parents: diff changeset	5	* This code is free software; you can redistribute it and/or modify it
489c9b5090e2 Initial load duke parents: diff changeset	6	* under the terms of the GNU General Public License version 2 only, as
489c9b5090e2 Initial load duke parents: diff changeset	7	* published by the Free Software Foundation.
489c9b5090e2 Initial load duke parents: diff changeset	8	*
489c9b5090e2 Initial load duke parents: diff changeset	9	* This code is distributed in the hope that it will be useful, but WITHOUT
489c9b5090e2 Initial load duke parents: diff changeset	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
489c9b5090e2 Initial load duke parents: diff changeset	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
489c9b5090e2 Initial load duke parents: diff changeset	12	* version 2 for more details (a copy is included in the LICENSE file that
489c9b5090e2 Initial load duke parents: diff changeset	13	* accompanied this code).
489c9b5090e2 Initial load duke parents: diff changeset	14	*
489c9b5090e2 Initial load duke parents: diff changeset	15	* You should have received a copy of the GNU General Public License version
489c9b5090e2 Initial load duke parents: diff changeset	16	* 2 along with this work; if not, write to the Free Software Foundation,
489c9b5090e2 Initial load duke parents: diff changeset	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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489c9b5090e2 Initial load duke parents: diff changeset	19	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
489c9b5090e2 Initial load duke parents: diff changeset	20	* CA 95054 USA or visit www.sun.com if you need additional information or
489c9b5090e2 Initial load duke parents: diff changeset	21	* have any questions.
489c9b5090e2 Initial load duke parents: diff changeset	22	*
489c9b5090e2 Initial load duke parents: diff changeset	23	*/
489c9b5090e2 Initial load duke parents: diff changeset	24
489c9b5090e2 Initial load duke parents: diff changeset	25	# include "incls/_precompiled.incl"
489c9b5090e2 Initial load duke parents: diff changeset	26	# include "incls/_markOop.cpp.incl"
489c9b5090e2 Initial load duke parents: diff changeset	27
489c9b5090e2 Initial load duke parents: diff changeset	28
489c9b5090e2 Initial load duke parents: diff changeset	29	void markOopDesc::print_on(outputStream* st) const {
489c9b5090e2 Initial load duke parents: diff changeset	30	if (is_locked()) {
489c9b5090e2 Initial load duke parents: diff changeset	31	st->print("locked(0x%lx)->", value());
489c9b5090e2 Initial load duke parents: diff changeset	32	markOop((markOop)value())->print_on(st);
489c9b5090e2 Initial load duke parents: diff changeset	33	} else {
489c9b5090e2 Initial load duke parents: diff changeset	34	assert(is_unlocked(), "just checking");
489c9b5090e2 Initial load duke parents: diff changeset	35	st->print("mark(");
489c9b5090e2 Initial load duke parents: diff changeset	36	st->print("hash %#lx,", hash());
489c9b5090e2 Initial load duke parents: diff changeset	37	st->print("age %d)", age());
489c9b5090e2 Initial load duke parents: diff changeset	38	}
489c9b5090e2 Initial load duke parents: diff changeset	39	}
221 ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	40
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	41
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	42	// Give advice about whether the oop that contains this markOop
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	43	// should be cached or not.
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	44	bool markOopDesc::should_not_be_cached() const {
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	45	// the cast is because decode_pointer() isn't marked const
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	46	if (is_marked() && ((markOopDesc *)this)->decode_pointer() != NULL) {
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	47	// If the oop containing this markOop is being forwarded, then
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	48	// we are in the middle of GC and we do not want the containing
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	49	// oop to be added to a cache. We have no way of knowing whether
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	50	// the cache has already been visited by the current GC phase so
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	51	// we don't know whether the forwarded oop will be properly
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	52	// processed in this phase. If the forwarded oop is not properly
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	53	// processed, then we'll see strange crashes or asserts during
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	54	// the next GC run because the markOop will contain an unexpected
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	55	// value.
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	56	//
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	57	// This situation has been seen when we are GC'ing a methodOop
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	58	// because we use the methodOop while we're GC'ing it. Scary
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	59	// stuff. Some of the uses the methodOop cause the methodOop to
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	60	// be added to the OopMapCache in the instanceKlass as a side
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	61	// effect. This check lets the cache maintainer know when a
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	62	// cache addition would not be safe.
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	63	return true;
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	64	}
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	65
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	66	// caching the containing oop should be just fine
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	67	return false;
ec745a0fe922 6599425: 4/3 OopMapCache::lookup() can cause later crash or assert() failure dcubed parents: 1 diff changeset	68	}

author	dcubed
	Wed, 12 Mar 2008 18:07:46 -0700
changeset 221	ec745a0fe922
parent 1	489c9b5090e2
child 670	ddf3e9583f2f
permissions	-rw-r--r--