--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/code/vtableStubs.hpp Tue Sep 12 19:03:39 2017 +0200
@@ -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