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src/cpu/sparc/vm/javaFrameAnchor_sparc.hpp@e1162778c1c8 (annotated)

src/cpu/sparc/vm/javaFrameAnchor_sparc.hpp

Thu, 07 Apr 2011 09:53:20 -0700

author

johnc

date

Thu, 07 Apr 2011 09:53:20 -0700

changeset 2781

e1162778c1c8

parent 2314

f95d63e2154a

child 6876

710a3c8b516e

permissions

-rw-r--r--

7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error
Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer.
Reviewed-by: kvn, iveresov, never, tonyp, dholmes

duke@435	1	/*
stefank@2314	2	* Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
duke@435	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435	4	*
duke@435	5	* This code is free software; you can redistribute it and/or modify it
duke@435	6	* under the terms of the GNU General Public License version 2 only, as
duke@435	7	* published by the Free Software Foundation.
duke@435	8	*
duke@435	9	* This code is distributed in the hope that it will be useful, but WITHOUT
duke@435	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435	12	* version 2 for more details (a copy is included in the LICENSE file that
duke@435	13	* accompanied this code).
duke@435	14	*
duke@435	15	* You should have received a copy of the GNU General Public License version
duke@435	16	* 2 along with this work; if not, write to the Free Software Foundation,
duke@435	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435	18	*
trims@1907	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907	20	* or visit www.oracle.com if you need additional information or have any
trims@1907	21	* questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
stefank@2314	25	#ifndef CPU_SPARC_VM_JAVAFRAMEANCHOR_SPARC_HPP
stefank@2314	26	#define CPU_SPARC_VM_JAVAFRAMEANCHOR_SPARC_HPP
stefank@2314	27
duke@435	28	private:
duke@435	29	volatile int _flags;
duke@435	30
duke@435	31	public:
duke@435	32
duke@435	33	enum pd_Constants {
duke@435	34	flushed = 1 // winodows have flushed
duke@435	35	};
duke@435	36
duke@435	37	int flags(void) { return _flags; }
duke@435	38	void set_flags(int flags) { _flags = flags; }
duke@435	39
duke@435	40	static ByteSize flags_offset() { return byte_offset_of(JavaFrameAnchor, _flags); }
duke@435	41
duke@435	42	// Each arch must define clear, copy
duke@435	43	// These are used by objects that only care about:
duke@435	44	// 1 - initializing a new state (thread creation, javaCalls)
duke@435	45	// 2 - saving a current state (javaCalls)
duke@435	46	// 3 - restoring an old state (javaCalls)
duke@435	47
duke@435	48	void clear(void) {
duke@435	49	// clearing _last_Java_sp must be first
duke@435	50	_last_Java_sp = NULL;
duke@435	51	// fence?
duke@435	52	_flags = 0;
duke@435	53	_last_Java_pc = NULL;
duke@435	54	}
duke@435	55
duke@435	56	void copy(JavaFrameAnchor* src) {
duke@435	57	// In order to make sure the transition state is valid for "this"
duke@435	58	// We must clear _last_Java_sp before copying the rest of the new data
duke@435	59	//
duke@435	60	// Hack Alert: Temporary bugfix for 4717480/4721647
duke@435	61	// To act like previous version (pd_cache_state) don't NULL _last_Java_sp
duke@435	62	// unless the value is changing
duke@435	63	//
duke@435	64	if (_last_Java_sp != src->_last_Java_sp)
duke@435	65	_last_Java_sp = NULL;
duke@435	66
duke@435	67	_flags = src->_flags;
duke@435	68	_last_Java_pc = src->_last_Java_pc;
duke@435	69	// Must be last so profiler will always see valid frame if has_last_frame() is true
duke@435	70	_last_Java_sp = src->_last_Java_sp;
duke@435	71	}
duke@435	72
duke@435	73	// Is stack walkable
duke@435	74	inline bool walkable( void) {
duke@435	75	return _flags & flushed;
duke@435	76	}
duke@435	77
duke@435	78	void make_walkable(JavaThread* thread);
duke@435	79
duke@435	80	void set_last_Java_sp(intptr_t* sp) { _last_Java_sp = sp; }
duke@435	81
bobv@2036	82	address last_Java_pc(void) { return _last_Java_pc; }
bobv@2036	83
duke@435	84	// These are only used by friends
duke@435	85	private:
duke@435	86
duke@435	87	intptr_t* last_Java_sp() const {
duke@435	88	// _last_Java_sp will always be a an unbiased stack pointer
duke@435	89	// if is is biased then some setter screwed up. This is
duke@435	90	// deadly.
duke@435	91	#ifdef _LP64
duke@435	92	assert(((intptr_t)_last_Java_sp & 0xF) == 0, "Biased last_Java_sp");
duke@435	93	#endif
duke@435	94	return _last_Java_sp;
duke@435	95	}
duke@435	96
duke@435	97	void capture_last_Java_pc(intptr_t* sp);
duke@435	98
duke@435	99	void set_window_flushed( void) {
duke@435	100	_flags |= flushed;
duke@435	101	OrderAccess::fence();
duke@435	102	}
stefank@2314	103
stefank@2314	104	#endif // CPU_SPARC_VM_JAVAFRAMEANCHOR_SPARC_HPP