diff -r 000000000000 -r f90c822e73f8 src/share/vm/code/vtableStubs.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/code/vtableStubs.hpp Wed Apr 27 01:25:04 2016 +0800 @@ -0,0 +1,137 @@ +/* + * Copyright (c) 1997, 2013, 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_CODE_VTABLESTUBS_HPP +#define SHARE_VM_CODE_VTABLESTUBS_HPP + +#include "code/vmreg.hpp" +#include "memory/allocation.hpp" + +// A VtableStub holds an individual code stub for a pair (vtable index, #args) for either itables or vtables +// There's a one-to-one relationship between a VtableStub and such a pair. + +class VtableStub { + private: + friend class VtableStubs; + + static address _chunk; // For allocation + static address _chunk_end; // For allocation + static VMReg _receiver_location; // Where to find receiver + + VtableStub* _next; // Pointer to next entry in hash table + const short _index; // vtable index + short _ame_offset; // Where an AbstractMethodError might occur + short _npe_offset; // Where a NullPointerException might occur + bool _is_vtable_stub; // True if vtable stub, false, is itable stub + /* code follows here */ // The vtableStub code + + void* operator new(size_t size, int code_size) throw(); + + VtableStub(bool is_vtable_stub, int index) + : _next(NULL), _is_vtable_stub(is_vtable_stub), + _index(index), _ame_offset(-1), _npe_offset(-1) {} + VtableStub* next() const { return _next; } + int index() const { return _index; } + static VMReg receiver_location() { return _receiver_location; } + void set_next(VtableStub* n) { _next = n; } + + public: + address code_begin() const { return (address)(this + 1); } + address code_end() const { return code_begin() + pd_code_size_limit(_is_vtable_stub); } + address entry_point() const { return code_begin(); } + static int entry_offset() { return sizeof(class VtableStub); } + + bool matches(bool is_vtable_stub, int index) const { + return _index == index && _is_vtable_stub == is_vtable_stub; + } + bool contains(address pc) const { return code_begin() <= pc && pc < code_end(); } + + private: + void set_exception_points(address npe_addr, address ame_addr) { + _npe_offset = npe_addr - code_begin(); + _ame_offset = ame_addr - code_begin(); + assert(is_abstract_method_error(ame_addr), "offset must be correct"); + assert(is_null_pointer_exception(npe_addr), "offset must be correct"); + assert(!is_abstract_method_error(npe_addr), "offset must be correct"); + assert(!is_null_pointer_exception(ame_addr), "offset must be correct"); + } + + // platform-dependent routines + static int pd_code_size_limit(bool is_vtable_stub); + static int pd_code_alignment(); + // CNC: Removed because vtable stubs are now made with an ideal graph + // static bool pd_disregard_arg_size(); + + static void align_chunk() { + uintptr_t off = (uintptr_t)( _chunk + sizeof(VtableStub) ) % pd_code_alignment(); + if (off != 0) _chunk += pd_code_alignment() - off; + } + + public: + // Query + bool is_itable_stub() { return !_is_vtable_stub; } + bool is_vtable_stub() { return _is_vtable_stub; } + bool is_abstract_method_error(address epc) { return epc == code_begin()+_ame_offset; } + bool is_null_pointer_exception(address epc) { return epc == code_begin()+_npe_offset; } + + void print_on(outputStream* st) const; + void print() const { print_on(tty); } + +}; + + +// VtableStubs creates the code stubs for compiled calls through vtables. +// There is one stub per (vtable index, args_size) pair, and the stubs are +// never deallocated. They don't need to be GCed because they contain no oops. + +class VtableStubs : AllStatic { + public: // N must be public (some compilers need this for _table) + enum { + N = 256, // size of stub table; must be power of two + mask = N - 1 + }; + + private: + static VtableStub* _table[N]; // table of existing stubs + static int _number_of_vtable_stubs; // number of stubs created so far (for statistics) + + static VtableStub* create_vtable_stub(int vtable_index); + static VtableStub* create_itable_stub(int vtable_index); + static VtableStub* lookup (bool is_vtable_stub, int vtable_index); + static void enter (bool is_vtable_stub, int vtable_index, VtableStub* s); + static inline uint hash (bool is_vtable_stub, int vtable_index); + static address find_stub (bool is_vtable_stub, int vtable_index); + + public: + static address find_vtable_stub(int vtable_index) { return find_stub(true, vtable_index); } + static address find_itable_stub(int itable_index) { return find_stub(false, itable_index); } + static bool is_entry_point(address pc); // is pc a vtable stub entry point? + static bool contains(address pc); // is pc within any stub? + static VtableStub* stub_containing(address pc); // stub containing pc or NULL + static int number_of_vtable_stubs() { return _number_of_vtable_stubs; } + static void initialize(); + static void vtable_stub_do(void f(VtableStub*)); // iterates over all vtable stubs +}; + +#endif // SHARE_VM_CODE_VTABLESTUBS_HPP