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src/share/vm/runtime/fieldType.cpp@72053ed6f8d4 (annotated)

src/share/vm/runtime/fieldType.cpp

Thu, 24 Nov 2016 11:27:57 +0100

author

tschatzl

date

Thu, 24 Nov 2016 11:27:57 +0100

changeset 9982

72053ed6f8d4

parent 2708

1d1603768966

child 6876

710a3c8b516e

permissions

-rw-r--r--

8057003: Large reference arrays cause extremely long synchronization times
Summary: Slice large object arrays into parts so that the synchronization of marking threads with an STW pause request does not take long.
Reviewed-by: ehelin, pliden
Contributed-by: maoliang.ml@alibaba-inc.com

duke@435	1	/*
trims@2708	2	* Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
duke@435	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435	4	*
duke@435	5	* This code is free software; you can redistribute it and/or modify it
duke@435	6	* under the terms of the GNU General Public License version 2 only, as
duke@435	7	* published by the Free Software Foundation.
duke@435	8	*
duke@435	9	* This code is distributed in the hope that it will be useful, but WITHOUT
duke@435	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435	12	* version 2 for more details (a copy is included in the LICENSE file that
duke@435	13	* accompanied this code).
duke@435	14	*
duke@435	15	* You should have received a copy of the GNU General Public License version
duke@435	16	* 2 along with this work; if not, write to the Free Software Foundation,
duke@435	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435	18	*
trims@1907	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907	20	* or visit www.oracle.com if you need additional information or have any
trims@1907	21	* questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
stefank@2314	25	#include "precompiled.hpp"
stefank@2314	26	#include "classfile/systemDictionary.hpp"
stefank@2314	27	#include "memory/oopFactory.hpp"
stefank@2314	28	#include "oops/oop.inline.hpp"
stefank@2314	29	#include "oops/typeArrayKlass.hpp"
stefank@2314	30	#include "runtime/fieldType.hpp"
stefank@2314	31	#include "runtime/signature.hpp"
duke@435	32
coleenp@2497	33	void FieldType::skip_optional_size(Symbol* signature, int* index) {
duke@435	34	jchar c = signature->byte_at(*index);
duke@435	35	while (c >= '0' && c <= '9') {
duke@435	36	*index = *index + 1;
duke@435	37	c = signature->byte_at(*index);
duke@435	38	}
duke@435	39	}
duke@435	40
coleenp@2497	41	BasicType FieldType::basic_type(Symbol* signature) {
duke@435	42	return char2type(signature->byte_at(0));
duke@435	43	}
duke@435	44
duke@435	45	// Check if it is a valid array signature
coleenp@2497	46	bool FieldType::is_valid_array_signature(Symbol* sig) {
duke@435	47	assert(sig->utf8_length() > 1, "this should already have been checked");
duke@435	48	assert(sig->byte_at(0) == '[', "this should already have been checked");
duke@435	49	// The first character is already checked
duke@435	50	int i = 1;
duke@435	51	int len = sig->utf8_length();
duke@435	52	// First skip all '['s
duke@435	53	while(i < len - 1 && sig->byte_at(i) == '[') i++;
duke@435	54
duke@435	55	// Check type
duke@435	56	switch(sig->byte_at(i)) {
duke@435	57	case 'B': // T_BYTE
duke@435	58	case 'C': // T_CHAR
duke@435	59	case 'D': // T_DOUBLE
duke@435	60	case 'F': // T_FLOAT
duke@435	61	case 'I': // T_INT
duke@435	62	case 'J': // T_LONG
duke@435	63	case 'S': // T_SHORT
duke@435	64	case 'Z': // T_BOOLEAN
duke@435	65	// If it is an array, the type is the last character
duke@435	66	return (i + 1 == len);
duke@435	67	case 'L':
duke@435	68	// If it is an object, the last character must be a ';'
duke@435	69	return sig->byte_at(len - 1) == ';';
duke@435	70	}
duke@435	71
duke@435	72	return false;
duke@435	73	}
duke@435	74
duke@435	75
coleenp@2497	76	BasicType FieldType::get_array_info(Symbol* signature, FieldArrayInfo& fd, TRAPS) {
duke@435	77	assert(basic_type(signature) == T_ARRAY, "must be array");
duke@435	78	int index = 1;
duke@435	79	int dim = 1;
duke@435	80	skip_optional_size(signature, &index);
duke@435	81	while (signature->byte_at(index) == '[') {
duke@435	82	index++;
duke@435	83	dim++;
duke@435	84	skip_optional_size(signature, &index);
duke@435	85	}
duke@435	86	ResourceMark rm;
coleenp@2497	87	char *element = signature->as_C_string() + index;
coleenp@2497	88	BasicType element_type = char2type(element[0]);
duke@435	89	if (element_type == T_OBJECT) {
coleenp@2497	90	int len = (int)strlen(element);
coleenp@2497	91	assert(element[len-1] == ';', "last char should be a semicolon");
coleenp@2497	92	element[len-1] = '\0'; // chop off semicolon
coleenp@2497	93	fd._object_key = SymbolTable::new_symbol(element + 1, CHECK_(T_BYTE));
duke@435	94	}
duke@435	95	// Pass dimension back to caller
coleenp@2497	96	fd._dimension = dim;
duke@435	97	return element_type;
duke@435	98	}