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src/cpu/x86/vm/metaspaceShared_x86_64.cpp@f90c822e73f8 (annotated)

src/cpu/x86/vm/metaspaceShared_x86_64.cpp

Wed, 27 Apr 2016 01:25:04 +0800

author

aoqi

date

Wed, 27 Apr 2016 01:25:04 +0800

changeset 0

f90c822e73f8

child 6876

710a3c8b516e

permissions

-rw-r--r--

Initial load
http://hg.openjdk.java.net/jdk8u/jdk8u/hotspot/
changeset: 6782:28b50d07f6f8
tag: jdk8u25-b17

aoqi@0	1	/*
aoqi@0	2	* Copyright (c) 2004, 2012, Oracle and/or its affiliates. All rights reserved.
aoqi@0	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0	4	*
aoqi@0	5	* This code is free software; you can redistribute it and/or modify it
aoqi@0	6	* under the terms of the GNU General Public License version 2 only, as
aoqi@0	7	* published by the Free Software Foundation.
aoqi@0	8	*
aoqi@0	9	* This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
aoqi@0	12	* version 2 for more details (a copy is included in the LICENSE file that
aoqi@0	13	* accompanied this code).
aoqi@0	14	*
aoqi@0	15	* You should have received a copy of the GNU General Public License version
aoqi@0	16	* 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0	18	*
aoqi@0	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0	20	* or visit www.oracle.com if you need additional information or have any
aoqi@0	21	* questions.
aoqi@0	22	*
aoqi@0	23	*/
aoqi@0	24
aoqi@0	25	#include "precompiled.hpp"
aoqi@0	26	#include "asm/macroAssembler.hpp"
aoqi@0	27	#include "asm/codeBuffer.hpp"
aoqi@0	28	#include "memory/metaspaceShared.hpp"
aoqi@0	29
aoqi@0	30	// Generate the self-patching vtable method:
aoqi@0	31	//
aoqi@0	32	// This method will be called (as any other Klass virtual method) with
aoqi@0	33	// the Klass itself as the first argument. Example:
aoqi@0	34	//
aoqi@0	35	// oop obj;
aoqi@0	36	// int size = obj->klass()->oop_size(this);
aoqi@0	37	//
aoqi@0	38	// for which the virtual method call is Klass::oop_size();
aoqi@0	39	//
aoqi@0	40	// The dummy method is called with the Klass object as the first
aoqi@0	41	// operand, and an object as the second argument.
aoqi@0	42	//
aoqi@0	43
aoqi@0	44	//=====================================================================
aoqi@0	45
aoqi@0	46	// All of the dummy methods in the vtable are essentially identical,
aoqi@0	47	// differing only by an ordinal constant, and they bear no relationship
aoqi@0	48	// to the original method which the caller intended. Also, there needs
aoqi@0	49	// to be 'vtbl_list_size' instances of the vtable in order to
aoqi@0	50	// differentiate between the 'vtable_list_size' original Klass objects.
aoqi@0	51
aoqi@0	52	#define __ masm->
aoqi@0	53
aoqi@0	54	void MetaspaceShared::generate_vtable_methods(void** vtbl_list,
aoqi@0	55	void** vtable,
aoqi@0	56	char** md_top,
aoqi@0	57	char* md_end,
aoqi@0	58	char** mc_top,
aoqi@0	59	char* mc_end) {
aoqi@0	60
aoqi@0	61	intptr_t vtable_bytes = (num_virtuals * vtbl_list_size) * sizeof(void*);
aoqi@0	62	*(intptr_t *)(*md_top) = vtable_bytes;
aoqi@0	63	*md_top += sizeof(intptr_t);
aoqi@0	64	void** dummy_vtable = (void**)*md_top;
aoqi@0	65	*vtable = dummy_vtable;
aoqi@0	66	*md_top += vtable_bytes;
aoqi@0	67
aoqi@0	68	// Get ready to generate dummy methods.
aoqi@0	69
aoqi@0	70	CodeBuffer cb((unsigned char*)*mc_top, mc_end - *mc_top);
aoqi@0	71	MacroAssembler* masm = new MacroAssembler(&cb);
aoqi@0	72
aoqi@0	73	Label common_code;
aoqi@0	74	for (int i = 0; i < vtbl_list_size; ++i) {
aoqi@0	75	for (int j = 0; j < num_virtuals; ++j) {
aoqi@0	76	dummy_vtable[num_virtuals * i + j] = (void*)masm->pc();
aoqi@0	77
aoqi@0	78	// Load eax with a value indicating vtable/offset pair.
aoqi@0	79	// -- bits[ 7..0] (8 bits) which virtual method in table?
aoqi@0	80	// -- bits[12..8] (5 bits) which virtual method table?
aoqi@0	81	// -- must fit in 13-bit instruction immediate field.
aoqi@0	82	__ movl(rax, (i << 8) + j);
aoqi@0	83	__ jmp(common_code);
aoqi@0	84	}
aoqi@0	85	}
aoqi@0	86
aoqi@0	87	__ bind(common_code);
aoqi@0	88
aoqi@0	89	// Expecting to be called with "thiscall" convections -- the arguments
aoqi@0	90	// are on the stack and the "this" pointer is in c_rarg0. In addition, rax
aoqi@0	91	// was set (above) to the offset of the method in the table.
aoqi@0	92
aoqi@0	93	__ push(c_rarg1); // save & free register
aoqi@0	94	__ push(c_rarg0); // save "this"
aoqi@0	95	__ mov(c_rarg0, rax);
aoqi@0	96	__ shrptr(c_rarg0, 8); // isolate vtable identifier.
aoqi@0	97	__ shlptr(c_rarg0, LogBytesPerWord);
aoqi@0	98	__ lea(c_rarg1, ExternalAddress((address)vtbl_list)); // ptr to correct vtable list.
aoqi@0	99	__ addptr(c_rarg1, c_rarg0); // ptr to list entry.
aoqi@0	100	__ movptr(c_rarg1, Address(c_rarg1, 0)); // get correct vtable address.
aoqi@0	101	__ pop(c_rarg0); // restore "this"
aoqi@0	102	__ movptr(Address(c_rarg0, 0), c_rarg1); // update vtable pointer.
aoqi@0	103
aoqi@0	104	__ andptr(rax, 0x00ff); // isolate vtable method index
aoqi@0	105	__ shlptr(rax, LogBytesPerWord);
aoqi@0	106	__ addptr(rax, c_rarg1); // address of real method pointer.
aoqi@0	107	__ pop(c_rarg1); // restore register.
aoqi@0	108	__ movptr(rax, Address(rax, 0)); // get real method pointer.
aoqi@0	109	__ jmp(rax); // jump to the real method.
aoqi@0	110
aoqi@0	111	__ flush();
aoqi@0	112
aoqi@0	113	*mc_top = (char*)__ pc();
aoqi@0	114	}