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view src/share/vm/runtime/relocator.hpp @ 3979:4dfb2df418f2
6484982: G1: process references during evacuation pauses
Summary: G1 now uses two reference processors - one is used by concurrent marking and the other is used by STW GCs (both full and incremental evacuation pauses). In an evacuation pause, the reference processor is embedded into the closures used to scan objects. Doing so causes causes reference objects to be 'discovered' by the reference processor. At the end of the evacuation pause, these discovered reference objects are processed - preserving (and copying) referent objects (and their reachable graphs) as appropriate.
Reviewed-by: ysr, jwilhelm, brutisso, stefank, tonyp
author | johnc |
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date | Thu, 22 Sep 2011 10:57:37 -0700 |
parents | b92c45f2bc75 |
children | da91efe96a93 |
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/* * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #ifndef SHARE_VM_RUNTIME_RELOCATOR_HPP #define SHARE_VM_RUNTIME_RELOCATOR_HPP #include "interpreter/bytecodes.hpp" #include "oops/methodOop.hpp" #ifdef TARGET_ARCH_x86 # include "bytes_x86.hpp" #endif #ifdef TARGET_ARCH_sparc # include "bytes_sparc.hpp" #endif #ifdef TARGET_ARCH_zero # include "bytes_zero.hpp" #endif #ifdef TARGET_ARCH_arm # include "bytes_arm.hpp" #endif #ifdef TARGET_ARCH_ppc # include "bytes_ppc.hpp" #endif // This code has been converted from the 1.1E java virtual machine // Thanks to the JavaTopics group for using the code class ChangeItem; // Callback object for code relocations class RelocatorListener : public StackObj { public: RelocatorListener() {}; virtual void relocated(int bci, int delta, int new_method_size) = 0; }; class Relocator : public ResourceObj { public: Relocator(methodHandle method, RelocatorListener* listener); methodHandle insert_space_at(int bci, int space, u_char inst_buffer[], TRAPS); // Callbacks from ChangeItem's bool handle_code_changes(); bool handle_widen (int bci, int new_ilen, u_char inst_buffer[]); // handles general instructions void push_jump_widen (int bci, int delta, int new_delta); // pushes jumps bool handle_jump_widen (int bci, int delta); // handles jumps bool handle_switch_pad (int bci, int old_pad, bool is_lookup_switch); // handles table and lookup switches private: unsigned char* _code_array; int _code_array_length; int _code_length; unsigned char* _compressed_line_number_table; int _compressed_line_number_table_size; methodHandle _method; u_char _overwrite[3]; // stores overwritten bytes for shrunken instructions GrowableArray<ChangeItem*>* _changes; unsigned char* code_array() const { return _code_array; } void set_code_array(unsigned char* array) { _code_array = array; } int code_length() const { return _code_length; } void set_code_length(int length) { _code_length = length; } int code_array_length() const { return _code_array_length; } void set_code_array_length(int length) { _code_array_length = length; } unsigned char* compressed_line_number_table() const { return _compressed_line_number_table; } void set_compressed_line_number_table(unsigned char* table) { _compressed_line_number_table = table; } int compressed_line_number_table_size() const { return _compressed_line_number_table_size; } void set_compressed_line_number_table_size(int size) { _compressed_line_number_table_size = size; } methodHandle method() const { return _method; } void set_method(methodHandle method) { _method = method; } // This will return a raw bytecode, which is possibly rewritten. Bytecodes::Code code_at(int bci) const { return (Bytecodes::Code) code_array()[bci]; } void code_at_put(int bci, Bytecodes::Code code) { code_array()[bci] = (char) code; } // get and set signed integers in the code_array inline int int_at(int bci) const { return Bytes::get_Java_u4(&code_array()[bci]); } inline void int_at_put(int bci, int value) { Bytes::put_Java_u4(&code_array()[bci], value); } // get and set signed shorts in the code_array inline short short_at(int bci) const { return (short)Bytes::get_Java_u2(&code_array()[bci]); } inline void short_at_put(int bci, short value) { Bytes::put_Java_u2((address) &code_array()[bci], value); } // get the address of in the code_array inline char* addr_at(int bci) const { return (char*) &code_array()[bci]; } int instruction_length_at(int bci) { return Bytecodes::length_at(NULL, code_array() + bci); } // Helper methods int align(int n) const { return (n+3) & ~3; } int code_slop_pct() const { return 25; } bool is_opcode_lookupswitch(Bytecodes::Code bc); // basic relocation methods bool relocate_code (int bci, int ilen, int delta); void change_jumps (int break_bci, int delta); void change_jump (int bci, int offset, bool is_short, int break_bci, int delta); void adjust_exception_table(int bci, int delta); void adjust_line_no_table (int bci, int delta); void adjust_local_var_table(int bci, int delta); void adjust_stack_map_table(int bci, int delta); int get_orig_switch_pad (int bci, bool is_lookup_switch); int rc_instr_len (int bci); bool expand_code_array (int delta); // Callback support RelocatorListener *_listener; void notify(int bci, int delta, int new_code_length) { if (_listener != NULL) _listener->relocated(bci, delta, new_code_length); } }; #endif // SHARE_VM_RUNTIME_RELOCATOR_HPP