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src/share/vm/runtime/jfieldIDWorkaround.hpp@b985cbb00e68 (annotated)

src/share/vm/runtime/jfieldIDWorkaround.hpp

Mon, 12 Aug 2019 18:30:40 +0300

author

apetushkov

date

Mon, 12 Aug 2019 18:30:40 +0300

changeset 9858

b985cbb00e68

parent 4037

da91efe96a93

child 6876

710a3c8b516e

permissions

-rw-r--r--

8223147: JFR Backport
8199712: Flight Recorder
8203346: JFR: Inconsistent signature of jfr_add_string_constant
8195817: JFR.stop should require name of recording
8195818: JFR.start should increase autogenerated name by one
8195819: Remove recording=x from jcmd JFR.check output
8203921: JFR thread sampling is missing fixes from JDK-8194552
8203929: Limit amount of data for JFR.dump
8203664: JFR start failure after AppCDS archive created with JFR StartFlightRecording
8003209: JFR events for network utilization
8207392: [PPC64] Implement JFR profiling
8202835: jfr/event/os/TestSystemProcess.java fails on missing events
Summary: Backport JFR from JDK11. Initial integration
Reviewed-by: neugens

duke@435	1	/*
coleenp@4037	2	* Copyright (c) 2003, 2012, 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	#ifndef SHARE_VM_RUNTIME_JFIELDIDWORKAROUND_HPP
stefank@2314	26	#define SHARE_VM_RUNTIME_JFIELDIDWORKAROUND_HPP
stefank@2314	27
duke@435	28	class jfieldIDWorkaround: AllStatic {
duke@435	29	// This workaround is because JVMTI doesn't have distinct entry points
duke@435	30	// for methods that use static jfieldIDs and instance jfieldIDs.
duke@435	31	// The workaround is to steal a low-order bit:
duke@435	32	// a 1 means the jfieldID is an instance jfieldID,
duke@435	33	// and the rest of the word is the offset of the field.
duke@435	34	// a 0 means the jfieldID is a static jfieldID,
duke@435	35	// and the rest of the word is the JNIid*.
duke@435	36	//
duke@435	37	// Another low-order bit is used to mark if an instance field
duke@435	38	// is accompanied by an indication of which class it applies to.
duke@435	39	//
duke@435	40	// Bit-format of a jfieldID (most significant first):
duke@435	41	// address:30 instance=0:1 checked=0:1
duke@435	42	// offset:30 instance=1:1 checked=0:1
duke@435	43	// klass:23 offset:7 instance=1:1 checked=1:1
duke@435	44	//
duke@435	45	// If the offset does not fit in 7 bits, or if the fieldID is
duke@435	46	// not checked, then the checked bit is zero and the rest of
duke@435	47	// the word (30 bits) contains only the offset.
duke@435	48	//
duke@435	49	private:
duke@435	50	enum {
duke@435	51	checked_bits = 1,
duke@435	52	instance_bits = 1,
duke@435	53	address_bits = BitsPerWord - checked_bits - instance_bits,
duke@435	54
duke@435	55	large_offset_bits = address_bits, // unioned with address
duke@435	56	small_offset_bits = 7,
duke@435	57	klass_bits = address_bits - small_offset_bits,
duke@435	58
duke@435	59	checked_shift = 0,
duke@435	60	instance_shift = checked_shift + checked_bits,
duke@435	61	address_shift = instance_shift + instance_bits,
duke@435	62
duke@435	63	offset_shift = address_shift, // unioned with address
duke@435	64	klass_shift = offset_shift + small_offset_bits,
duke@435	65
duke@435	66	checked_mask_in_place = right_n_bits(checked_bits) << checked_shift,
duke@435	67	instance_mask_in_place = right_n_bits(instance_bits) << instance_shift,
duke@435	68	#ifndef _WIN64
duke@435	69	large_offset_mask = right_n_bits(large_offset_bits),
duke@435	70	small_offset_mask = right_n_bits(small_offset_bits),
duke@435	71	klass_mask = right_n_bits(klass_bits)
duke@435	72	#endif
duke@435	73	};
duke@435	74
duke@435	75	#ifdef _WIN64
duke@435	76	// These values are too big for Win64
duke@435	77	const static uintptr_t large_offset_mask = right_n_bits(large_offset_bits);
duke@435	78	const static uintptr_t small_offset_mask = right_n_bits(small_offset_bits);
duke@435	79	const static uintptr_t klass_mask = right_n_bits(klass_bits);
duke@435	80	#endif
duke@435	81
duke@435	82	// helper routines:
duke@435	83	static bool is_checked_jfieldID(jfieldID id) {
duke@435	84	uintptr_t as_uint = (uintptr_t) id;
duke@435	85	return ((as_uint & checked_mask_in_place) != 0);
duke@435	86	}
duke@435	87	static intptr_t raw_instance_offset(jfieldID id) {
duke@435	88	uintptr_t result = (uintptr_t) id >> address_shift;
duke@435	89	if (VerifyJNIFields && is_checked_jfieldID(id)) {
duke@435	90	result &= small_offset_mask; // cut off the hash bits
duke@435	91	}
duke@435	92	return (intptr_t)result;
duke@435	93	}
coleenp@4037	94	static intptr_t encode_klass_hash(Klass* k, intptr_t offset);
coleenp@4037	95	static bool klass_hash_ok(Klass* k, jfieldID id);
coleenp@4037	96	static void verify_instance_jfieldID(Klass* k, jfieldID id);
duke@435	97
duke@435	98	public:
coleenp@4037	99	static bool is_valid_jfieldID(Klass* k, jfieldID id);
duke@435	100
coleenp@4037	101	static bool is_instance_jfieldID(Klass* k, jfieldID id) {
duke@435	102	uintptr_t as_uint = (uintptr_t) id;
duke@435	103	return ((as_uint & instance_mask_in_place) != 0);
duke@435	104	}
duke@435	105	static bool is_static_jfieldID(jfieldID id) {
duke@435	106	uintptr_t as_uint = (uintptr_t) id;
duke@435	107	return ((as_uint & instance_mask_in_place) == 0);
duke@435	108	}
duke@435	109
coleenp@4037	110	static jfieldID to_instance_jfieldID(Klass* k, int offset) {
duke@435	111	intptr_t as_uint = ((offset & large_offset_mask) << offset_shift) | instance_mask_in_place;
duke@435	112	if (VerifyJNIFields) {
duke@435	113	as_uint |= encode_klass_hash(k, offset);
duke@435	114	}
duke@435	115	jfieldID result = (jfieldID) as_uint;
duke@435	116	#ifndef ASSERT
duke@435	117	// always verify in debug mode; switchable in anything else
duke@435	118	if (VerifyJNIFields)
duke@435	119	#endif // ASSERT
duke@435	120	{
duke@435	121	verify_instance_jfieldID(k, result);
duke@435	122	}
duke@435	123	assert(raw_instance_offset(result) == (offset & large_offset_mask), "extract right offset");
duke@435	124	return result;
duke@435	125	}
duke@435	126
coleenp@4037	127	static intptr_t from_instance_jfieldID(Klass* k, jfieldID id) {
duke@435	128	#ifndef ASSERT
duke@435	129	// always verify in debug mode; switchable in anything else
duke@435	130	if (VerifyJNIFields)
duke@435	131	#endif // ASSERT
duke@435	132	{
duke@435	133	verify_instance_jfieldID(k, id);
duke@435	134	}
duke@435	135	return raw_instance_offset(id);
duke@435	136	}
duke@435	137
duke@435	138	static jfieldID to_static_jfieldID(JNIid* id) {
duke@435	139	assert(id->is_static_field_id(), "from_JNIid, but not static field id");
duke@435	140	jfieldID result = (jfieldID) id;
duke@435	141	assert(from_static_jfieldID(result) == id, "must produce the same static id");
duke@435	142	return result;
duke@435	143	}
duke@435	144
duke@435	145	static JNIid* from_static_jfieldID(jfieldID id) {
duke@435	146	assert(jfieldIDWorkaround::is_static_jfieldID(id),
duke@435	147	"to_JNIid, but not static jfieldID");
duke@435	148	JNIid* result = (JNIid*) id;
duke@435	149	assert(result->is_static_field_id(), "to_JNIid, but not static field id");
duke@435	150	return result;
duke@435	151	}
duke@435	152
duke@435	153	static jfieldID to_jfieldID(instanceKlassHandle k, int offset, bool is_static) {
duke@435	154	if (is_static) {
duke@435	155	JNIid *id = k->jni_id_for(offset);
duke@435	156	debug_only(id->set_is_static_field_id());
duke@435	157	return jfieldIDWorkaround::to_static_jfieldID(id);
duke@435	158	} else {
duke@435	159	return jfieldIDWorkaround::to_instance_jfieldID(k(), offset);
duke@435	160	}
duke@435	161	}
duke@435	162	};
stefank@2314	163
stefank@2314	164	#endif // SHARE_VM_RUNTIME_JFIELDIDWORKAROUND_HPP