1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/code/vtableStubs.hpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,137 @@
1.4 +/*
1.5 + * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#ifndef SHARE_VM_CODE_VTABLESTUBS_HPP
1.29 +#define SHARE_VM_CODE_VTABLESTUBS_HPP
1.30 +
1.31 +#include "code/vmreg.hpp"
1.32 +#include "memory/allocation.hpp"
1.33 +
1.34 +// A VtableStub holds an individual code stub for a pair (vtable index, #args) for either itables or vtables
1.35 +// There's a one-to-one relationship between a VtableStub and such a pair.
1.36 +
1.37 +class VtableStub {
1.38 + private:
1.39 + friend class VtableStubs;
1.40 +
1.41 + static address _chunk; // For allocation
1.42 + static address _chunk_end; // For allocation
1.43 + static VMReg _receiver_location; // Where to find receiver
1.44 +
1.45 + VtableStub* _next; // Pointer to next entry in hash table
1.46 + const short _index; // vtable index
1.47 + short _ame_offset; // Where an AbstractMethodError might occur
1.48 + short _npe_offset; // Where a NullPointerException might occur
1.49 + bool _is_vtable_stub; // True if vtable stub, false, is itable stub
1.50 + /* code follows here */ // The vtableStub code
1.51 +
1.52 + void* operator new(size_t size, int code_size) throw();
1.53 +
1.54 + VtableStub(bool is_vtable_stub, int index)
1.55 + : _next(NULL), _is_vtable_stub(is_vtable_stub),
1.56 + _index(index), _ame_offset(-1), _npe_offset(-1) {}
1.57 + VtableStub* next() const { return _next; }
1.58 + int index() const { return _index; }
1.59 + static VMReg receiver_location() { return _receiver_location; }
1.60 + void set_next(VtableStub* n) { _next = n; }
1.61 +
1.62 + public:
1.63 + address code_begin() const { return (address)(this + 1); }
1.64 + address code_end() const { return code_begin() + pd_code_size_limit(_is_vtable_stub); }
1.65 + address entry_point() const { return code_begin(); }
1.66 + static int entry_offset() { return sizeof(class VtableStub); }
1.67 +
1.68 + bool matches(bool is_vtable_stub, int index) const {
1.69 + return _index == index && _is_vtable_stub == is_vtable_stub;
1.70 + }
1.71 + bool contains(address pc) const { return code_begin() <= pc && pc < code_end(); }
1.72 +
1.73 + private:
1.74 + void set_exception_points(address npe_addr, address ame_addr) {
1.75 + _npe_offset = npe_addr - code_begin();
1.76 + _ame_offset = ame_addr - code_begin();
1.77 + assert(is_abstract_method_error(ame_addr), "offset must be correct");
1.78 + assert(is_null_pointer_exception(npe_addr), "offset must be correct");
1.79 + assert(!is_abstract_method_error(npe_addr), "offset must be correct");
1.80 + assert(!is_null_pointer_exception(ame_addr), "offset must be correct");
1.81 + }
1.82 +
1.83 + // platform-dependent routines
1.84 + static int pd_code_size_limit(bool is_vtable_stub);
1.85 + static int pd_code_alignment();
1.86 + // CNC: Removed because vtable stubs are now made with an ideal graph
1.87 + // static bool pd_disregard_arg_size();
1.88 +
1.89 + static void align_chunk() {
1.90 + uintptr_t off = (uintptr_t)( _chunk + sizeof(VtableStub) ) % pd_code_alignment();
1.91 + if (off != 0) _chunk += pd_code_alignment() - off;
1.92 + }
1.93 +
1.94 + public:
1.95 + // Query
1.96 + bool is_itable_stub() { return !_is_vtable_stub; }
1.97 + bool is_vtable_stub() { return _is_vtable_stub; }
1.98 + bool is_abstract_method_error(address epc) { return epc == code_begin()+_ame_offset; }
1.99 + bool is_null_pointer_exception(address epc) { return epc == code_begin()+_npe_offset; }
1.100 +
1.101 + void print_on(outputStream* st) const;
1.102 + void print() const { print_on(tty); }
1.103 +
1.104 +};
1.105 +
1.106 +
1.107 +// VtableStubs creates the code stubs for compiled calls through vtables.
1.108 +// There is one stub per (vtable index, args_size) pair, and the stubs are
1.109 +// never deallocated. They don't need to be GCed because they contain no oops.
1.110 +
1.111 +class VtableStubs : AllStatic {
1.112 + public: // N must be public (some compilers need this for _table)
1.113 + enum {
1.114 + N = 256, // size of stub table; must be power of two
1.115 + mask = N - 1
1.116 + };
1.117 +
1.118 + private:
1.119 + static VtableStub* _table[N]; // table of existing stubs
1.120 + static int _number_of_vtable_stubs; // number of stubs created so far (for statistics)
1.121 +
1.122 + static VtableStub* create_vtable_stub(int vtable_index);
1.123 + static VtableStub* create_itable_stub(int vtable_index);
1.124 + static VtableStub* lookup (bool is_vtable_stub, int vtable_index);
1.125 + static void enter (bool is_vtable_stub, int vtable_index, VtableStub* s);
1.126 + static inline uint hash (bool is_vtable_stub, int vtable_index);
1.127 + static address find_stub (bool is_vtable_stub, int vtable_index);
1.128 +
1.129 + public:
1.130 + static address find_vtable_stub(int vtable_index) { return find_stub(true, vtable_index); }
1.131 + static address find_itable_stub(int itable_index) { return find_stub(false, itable_index); }
1.132 + static bool is_entry_point(address pc); // is pc a vtable stub entry point?
1.133 + static bool contains(address pc); // is pc within any stub?
1.134 + static VtableStub* stub_containing(address pc); // stub containing pc or NULL
1.135 + static int number_of_vtable_stubs() { return _number_of_vtable_stubs; }
1.136 + static void initialize();
1.137 + static void vtable_stub_do(void f(VtableStub*)); // iterates over all vtable stubs
1.138 +};
1.139 +
1.140 +#endif // SHARE_VM_CODE_VTABLESTUBS_HPP
