src/cpu/sparc/vm/relocInfo_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) 1997, 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_RELOCINFO_SPARC_HPP
stefank@2314 26 #define CPU_SPARC_VM_RELOCINFO_SPARC_HPP
stefank@2314 27
duke@435 28 // machine-dependent parts of class relocInfo
duke@435 29 private:
duke@435 30 enum {
duke@435 31 // Since SPARC instructions are whole words,
duke@435 32 // the two low-order offset bits can always be discarded.
duke@435 33 offset_unit = 4,
duke@435 34
duke@435 35 // There is no need for format bits; the instructions are
duke@435 36 // sufficiently self-identifying.
kvn@599 37 #ifndef _LP64
duke@435 38 format_width = 0
kvn@599 39 #else
kvn@599 40 // Except narrow oops in 64-bits VM.
kvn@599 41 format_width = 1
kvn@599 42 #endif
duke@435 43 };
duke@435 44
duke@435 45
duke@435 46 //Reconciliation History
duke@435 47 // 1.3 97/10/15 15:38:36 relocInfo_i486.hpp
duke@435 48 // 1.4 97/12/08 16:01:06 relocInfo_i486.hpp
duke@435 49 // 1.5 98/01/23 01:34:55 relocInfo_i486.hpp
duke@435 50 // 1.6 98/02/27 15:44:53 relocInfo_i486.hpp
duke@435 51 // 1.6 98/03/12 14:47:13 relocInfo_i486.hpp
duke@435 52 // 1.8 99/06/22 16:37:50 relocInfo_i486.hpp
duke@435 53 // 1.9 99/07/16 11:12:11 relocInfo_i486.hpp
duke@435 54 //End
stefank@2314 55
stefank@2314 56 #endif // CPU_SPARC_VM_RELOCINFO_SPARC_HPP

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