Mercurial > hg > truffle
view src/share/vm/memory/metaspaceShared.hpp @ 12301:2c022e432e10
8024974: Incorrect use of GC_locker::is_active()
Summary: SymbolTable and StringTable can make calls to GC_locker::is_active() outside a safepoint. This isn't safe because the GC_locker active state (lock count) is only updated at a safepoint and only remains valid as long as _needs_gc is true. However, outside a safepoint_needs_gc can change to false at any time, which makes it impossible to do a correct call to is_active() in that context. In this case these calls can just be removed since the input argument to basic_add() should never be on the heap and so there's no need to check the GC_locker state. This change also adjusts the assert() in is_active() to makes sure all calls to this function are always done under a safepoint.
Reviewed-by: brutisso, dcubed
Contributed-by: per.liden@oracle.com
author | stefank |
---|---|
date | Fri, 20 Sep 2013 10:53:28 +0200 |
parents | fb19af007ffc |
children | 6e0cb14ce59b |
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/* * Copyright (c) 2012, 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_MEMORY_METASPACE_SHARED_HPP #define SHARE_VM_MEMORY_METASPACE_SHARED_HPP #include "memory/allocation.hpp" #include "memory/memRegion.hpp" #include "runtime/virtualspace.hpp" #include "utilities/exceptions.hpp" #include "utilities/macros.hpp" class FileMapInfo; // Class Data Sharing Support class MetaspaceShared : AllStatic { // CDS support static ReservedSpace* _shared_rs; static int _max_alignment; public: enum { vtbl_list_size = 17, // number of entries in the shared space vtable list. num_virtuals = 200 // maximum number of virtual functions // If virtual functions are added to Metadata, // this number needs to be increased. Also, // SharedMiscCodeSize will need to be increased. }; enum { ro = 0, // read-only shared space in the heap rw = 1, // read-write shared space in the heap md = 2, // miscellaneous data for initializing tables, etc. mc = 3, // miscellaneous code - vtable replacement. n_regions = 4 }; // Accessor functions to save shared space created for metadata, which has // extra space allocated at the end for miscellaneous data and code. static void set_max_alignment(int alignment) { CDS_ONLY(_max_alignment = alignment); } static int max_alignment() { CDS_ONLY(return _max_alignment); NOT_CDS(return 0); } static void preload_and_dump(TRAPS) NOT_CDS_RETURN; static ReservedSpace* shared_rs() { CDS_ONLY(return _shared_rs); NOT_CDS(return NULL); } static void set_shared_rs(ReservedSpace* rs) { CDS_ONLY(_shared_rs = rs;) } static bool map_shared_spaces(FileMapInfo* mapinfo) NOT_CDS_RETURN_(false); static void initialize_shared_spaces() NOT_CDS_RETURN; // Return true if given address is in the mapped shared space. static bool is_in_shared_space(const void* p) NOT_CDS_RETURN_(false); static void generate_vtable_methods(void** vtbl_list, void** vtable, char** md_top, char* md_end, char** mc_top, char* mc_end); static void serialize(SerializeClosure* sc); // JVM/TI RedefineClasses() support: // Remap the shared readonly space to shared readwrite, private if // sharing is enabled. Simply returns true if sharing is not enabled // or if the remapping has already been done by a prior call. static bool remap_shared_readonly_as_readwrite() NOT_CDS_RETURN_(true); static void print_shared_spaces(); }; #endif // SHARE_VM_MEMORY_METASPACE_SHARED_HPP