Mercurial > hg > graal-compiler
view src/share/vm/runtime/stubCodeGenerator.hpp @ 3917:eca1193ca245
4965777: GC changes to support use of discovered field for pending references
Summary: If and when the reference handler thread is able to use the discovered field to link reference objects in its pending list, so will GC. In that case, GC will scan through this field once a reference object has been placed on the pending list, but not scan that field before that stage, as the field is used by the concurrent GC thread to link discovered objects. When ReferenceHandleR thread does not use the discovered field for the purpose of linking the elements in the pending list, as would be the case in older JDKs, the JVM will fall back to the old behaviour of using the next field for that purpose.
Reviewed-by: jcoomes, mchung, stefank
author | ysr |
---|---|
date | Wed, 07 Sep 2011 13:55:42 -0700 |
parents | f8c9417e3571 |
children | d2a62e0f25eb |
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/* * Copyright (c) 1997, 2010, 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_STUBCODEGENERATOR_HPP #define SHARE_VM_RUNTIME_STUBCODEGENERATOR_HPP #include "asm/assembler.hpp" #include "memory/allocation.hpp" // All the basic framework for stubcode generation/debugging/printing. // A StubCodeDesc describes a piece of generated code (usually stubs). // This information is mainly useful for debugging and printing. // Currently, code descriptors are simply chained in a linked list, // this may have to change if searching becomes too slow. class StubCodeDesc: public CHeapObj { protected: static StubCodeDesc* _list; // the list of all descriptors static int _count; // length of list StubCodeDesc* _next; // the next element in the linked list const char* _group; // the group to which the stub code belongs const char* _name; // the name assigned to the stub code int _index; // serial number assigned to the stub address _begin; // points to the first byte of the stub code (included) address _end; // points to the first byte after the stub code (excluded) void set_end(address end) { assert(_begin <= end, "begin & end not properly ordered"); _end = end; } void set_begin(address begin) { assert(begin >= _begin, "begin may not decrease"); assert(_end == NULL || begin <= _end, "begin & end not properly ordered"); _begin = begin; } friend class StubCodeMark; friend class StubCodeGenerator; public: static StubCodeDesc* desc_for(address pc); // returns the code descriptor for the code containing pc or NULL static StubCodeDesc* desc_for_index(int); // returns the code descriptor for the index or NULL static const char* name_for(address pc); // returns the name of the code containing pc or NULL StubCodeDesc(const char* group, const char* name, address begin) { assert(name != NULL, "no name specified"); _next = _list; _group = group; _name = name; _index = ++_count; // (never zero) _begin = begin; _end = NULL; _list = this; }; const char* group() const { return _group; } const char* name() const { return _name; } int index() const { return _index; } address begin() const { return _begin; } address end() const { return _end; } int size_in_bytes() const { return _end - _begin; } bool contains(address pc) const { return _begin <= pc && pc < _end; } void print_on(outputStream* st) const; void print() const { print_on(tty); } }; // The base class for all stub-generating code generators. // Provides utility functions. class StubCodeGenerator: public StackObj { protected: MacroAssembler* _masm; StubCodeDesc* _first_stub; StubCodeDesc* _last_stub; bool _print_code; public: StubCodeGenerator(CodeBuffer* code, bool print_code = false); ~StubCodeGenerator(); MacroAssembler* assembler() const { return _masm; } virtual void stub_prolog(StubCodeDesc* cdesc); // called by StubCodeMark constructor virtual void stub_epilog(StubCodeDesc* cdesc); // called by StubCodeMark destructor }; // Stack-allocated helper class used to assciate a stub code with a name. // All stub code generating functions that use a StubCodeMark will be registered // in the global StubCodeDesc list and the generated stub code can be identified // later via an address pointing into it. class StubCodeMark: public StackObj { protected: StubCodeGenerator* _cgen; StubCodeDesc* _cdesc; public: StubCodeMark(StubCodeGenerator* cgen, const char* group, const char* name); ~StubCodeMark(); }; #endif // SHARE_VM_RUNTIME_STUBCODEGENERATOR_HPP