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src/share/vm/runtime/icache.cpp@63147986a428 (annotated)

src/share/vm/runtime/icache.cpp

Wed, 18 Sep 2013 07:02:10 -0700

author

dcubed

date

Wed, 18 Sep 2013 07:02:10 -0700

changeset 5743

63147986a428

parent 2314

f95d63e2154a

child 6876

710a3c8b516e

permissions

-rw-r--r--

8019835: Strings interned in different threads equal but does not ==
Summary: Add -XX:+VerifyStringTableAtExit option and code to verify StringTable invariants.
Reviewed-by: rdurbin, sspitsyn, coleenp

duke@435	1	/*
twisti@2103	2	* Copyright (c) 1997, 2010, 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 "memory/resourceArea.hpp"
stefank@2314	27	#include "runtime/icache.hpp"
duke@435	28
duke@435	29	// The flush stub function address
duke@435	30	AbstractICache::flush_icache_stub_t AbstractICache::_flush_icache_stub = NULL;
duke@435	31
duke@435	32	void AbstractICache::initialize() {
duke@435	33	// Making this stub must be FIRST use of assembler
duke@435	34	ResourceMark rm;
duke@435	35
duke@435	36	BufferBlob* b = BufferBlob::create("flush_icache_stub", ICache::stub_size);
twisti@2103	37	CodeBuffer c(b);
duke@435	38
duke@435	39	ICacheStubGenerator g(&c);
duke@435	40	g.generate_icache_flush(&_flush_icache_stub);
duke@435	41
duke@435	42	// The first use of flush_icache_stub must apply it to itself.
duke@435	43	// The StubCodeMark destructor in generate_icache_flush will
duke@435	44	// call Assembler::flush, which in turn will call invalidate_range,
duke@435	45	// which will in turn call the flush stub. Thus we don't need an
duke@435	46	// explicit call to invalidate_range here. This assumption is
duke@435	47	// checked in invalidate_range.
duke@435	48	}
duke@435	49
duke@435	50	void AbstractICache::call_flush_stub(address start, int lines) {
duke@435	51	// The business with the magic number is just a little security.
duke@435	52	// We cannot call the flush stub when generating the flush stub
duke@435	53	// because it isn't there yet. So, the stub also returns its third
duke@435	54	// parameter. This is a cheap check that the stub was really executed.
duke@435	55	static int magic = 0xbaadbabe;
duke@435	56
duke@435	57	int auto_magic = magic; // Make a local copy to avoid race condition
duke@435	58	int r = (*_flush_icache_stub)(start, lines, auto_magic);
duke@435	59	guarantee(r == auto_magic, "flush stub routine did not execute");
duke@435	60	++magic;
duke@435	61	}
duke@435	62
duke@435	63	void AbstractICache::invalidate_word(address addr) {
duke@435	64	// Because this is called for instruction patching on the fly, long after
duke@435	65	// bootstrapping, we execute the stub directly. Account for a 4-byte word
duke@435	66	// spanning two cache lines by computing a start line address by rounding
duke@435	67	// addr down to a line_size boundary, and an end line address by adding
duke@435	68	// the word size - 1 and rounding the result down to a line_size boundary.
duke@435	69	// If we just added word size, we'd mistakenly flush the next cache line
duke@435	70	// if the word to be flushed started in the last 4 bytes of the line.
duke@435	71	// Doing that would segv if the next line weren't mapped.
duke@435	72
duke@435	73	const int word_size_in_bytes = 4; // Always, regardless of platform
duke@435	74
duke@435	75	intptr_t start_line = ((intptr_t)addr + 0) & ~(ICache::line_size - 1);
duke@435	76	intptr_t end_line = ((intptr_t)addr + word_size_in_bytes - 1)
duke@435	77	& ~(ICache::line_size - 1);
duke@435	78	(*_flush_icache_stub)((address)start_line, start_line == end_line ? 1 : 2, 0);
duke@435	79	}
duke@435	80
duke@435	81	void AbstractICache::invalidate_range(address start, int nbytes) {
duke@435	82	static bool firstTime = true;
duke@435	83	if (firstTime) {
duke@435	84	guarantee(start == CAST_FROM_FN_PTR(address, _flush_icache_stub),
duke@435	85	"first flush should be for flush stub");
duke@435	86	firstTime = false;
duke@435	87	return;
duke@435	88	}
duke@435	89	if (nbytes == 0) {
duke@435	90	return;
duke@435	91	}
duke@435	92	// Align start address to an icache line boundary and transform
duke@435	93	// nbytes to an icache line count.
duke@435	94	const uint line_offset = mask_address_bits(start, ICache::line_size-1);
duke@435	95	if (line_offset != 0) {
duke@435	96	start -= line_offset;
duke@435	97	nbytes += line_offset;
duke@435	98	}
duke@435	99	call_flush_stub(start, round_to(nbytes, ICache::line_size) >>
duke@435	100	ICache::log2_line_size);
duke@435	101	}
duke@435	102
duke@435	103	// For init.cpp
duke@435	104	void icache_init() {
duke@435	105	ICache::initialize();
duke@435	106	}