Thu, 07 Apr 2011 09:53:20 -0700
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) 2000, 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_C1_DEFS_SPARC_HPP |
stefank@2314 | 26 | #define CPU_SPARC_VM_C1_DEFS_SPARC_HPP |
stefank@2314 | 27 | |
duke@435 | 28 | // native word offsets from memory address (big endian) |
duke@435 | 29 | enum { |
duke@435 | 30 | pd_lo_word_offset_in_bytes = BytesPerInt, |
duke@435 | 31 | pd_hi_word_offset_in_bytes = 0 |
duke@435 | 32 | }; |
duke@435 | 33 | |
duke@435 | 34 | |
duke@435 | 35 | // explicit rounding operations are not required to implement the strictFP mode |
duke@435 | 36 | enum { |
duke@435 | 37 | pd_strict_fp_requires_explicit_rounding = false |
duke@435 | 38 | }; |
duke@435 | 39 | |
duke@435 | 40 | |
duke@435 | 41 | // registers |
duke@435 | 42 | enum { |
duke@435 | 43 | pd_nof_cpu_regs_frame_map = 32, // number of registers used during code emission |
never@1363 | 44 | pd_nof_caller_save_cpu_regs_frame_map = 10, // number of cpu registers killed by calls |
duke@435 | 45 | pd_nof_cpu_regs_reg_alloc = 20, // number of registers that are visible to register allocator |
duke@435 | 46 | pd_nof_cpu_regs_linearscan = 32,// number of registers visible linear scan |
duke@435 | 47 | pd_first_cpu_reg = 0, |
duke@435 | 48 | pd_last_cpu_reg = 31, |
duke@435 | 49 | pd_last_allocatable_cpu_reg = 19, |
duke@435 | 50 | pd_first_callee_saved_reg = 0, |
duke@435 | 51 | pd_last_callee_saved_reg = 13, |
duke@435 | 52 | |
duke@435 | 53 | pd_nof_fpu_regs_frame_map = 32, // number of registers used during code emission |
duke@435 | 54 | pd_nof_caller_save_fpu_regs_frame_map = 32, // number of fpu registers killed by calls |
duke@435 | 55 | pd_nof_fpu_regs_reg_alloc = 32, // number of registers that are visible to register allocator |
duke@435 | 56 | pd_nof_fpu_regs_linearscan = 32, // number of registers visible to linear scan |
duke@435 | 57 | pd_first_fpu_reg = pd_nof_cpu_regs_frame_map, |
duke@435 | 58 | pd_last_fpu_reg = pd_nof_cpu_regs_frame_map + pd_nof_fpu_regs_frame_map - 1, |
duke@435 | 59 | |
duke@435 | 60 | pd_nof_xmm_regs_linearscan = 0, |
duke@435 | 61 | pd_nof_caller_save_xmm_regs = 0, |
duke@435 | 62 | pd_first_xmm_reg = -1, |
duke@435 | 63 | pd_last_xmm_reg = -1 |
duke@435 | 64 | }; |
duke@435 | 65 | |
duke@435 | 66 | |
duke@435 | 67 | // for debug info: a float value in a register is saved in single precision by runtime stubs |
duke@435 | 68 | enum { |
duke@435 | 69 | pd_float_saved_as_double = false |
duke@435 | 70 | }; |
stefank@2314 | 71 | |
stefank@2314 | 72 | #endif // CPU_SPARC_VM_C1_DEFS_SPARC_HPP |