Mercurial > hg > graal-jvmci-8
view src/share/vm/opto/stringopts.hpp @ 3249:e1162778c1c8
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
author | johnc |
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date | Thu, 07 Apr 2011 09:53:20 -0700 |
parents | f95d63e2154a |
children | 8f972594effc |
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/* * Copyright (c) 2009, 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_OPTO_STRINGOPTS_HPP #define SHARE_VM_OPTO_STRINGOPTS_HPP #include "opto/node.hpp" #include "opto/phaseX.hpp" class StringConcat; class PhaseStringOpts : public Phase { friend class StringConcat; private: PhaseGVN* _gvn; // List of dead nodes to clean up aggressively at the end Unique_Node_List dead_worklist; // Memory slices needed for code gen int char_adr_idx; int value_field_idx; int count_field_idx; int offset_field_idx; // Integer.sizeTable - used for int to String conversion ciField* size_table_field; // A set for use by various stages VectorSet _visited; // Collect a list of all SB.toString calls Node_List collect_toString_calls(); // Examine the use of the SB alloc to see if it can be replace with // a single string construction. StringConcat* build_candidate(CallStaticJavaNode* call); // Replace all the SB calls in concat with an optimization String allocation void replace_string_concat(StringConcat* concat); // Load the value of a static field, performing any constant folding. Node* fetch_static_field(GraphKit& kit, ciField* field); // Compute the number of characters required to represent the int value Node* int_stringSize(GraphKit& kit, Node* value); // Copy the characters representing value into char_array starting at start void int_getChars(GraphKit& kit, Node* value, Node* char_array, Node* start, Node* end); // Copy of the contents of the String str into char_array starting at index start. Node* copy_string(GraphKit& kit, Node* str, Node* char_array, Node* start); // Clean up any leftover nodes void record_dead_node(Node* node); void remove_dead_nodes(); PhaseGVN* gvn() { return _gvn; } enum { // max length of constant string copy unrolling in copy_string unroll_string_copy_length = 6 }; public: PhaseStringOpts(PhaseGVN* gvn, Unique_Node_List* worklist); }; #endif // SHARE_VM_OPTO_STRINGOPTS_HPP