OpenJDK / jdk / hs
changeset 46663:715d5f268f62
8184271: Time related C1 intrinsics produce inconsistent results when floating around
Summary: C1 intrinsics for System.nanoTime(), System.currentTimeMillis() and JVM.counterTime() should be pinned.
Reviewed-by: kvn, vlivanov
author | thartmann |
---|---|
date | Fri, 14 Jul 2017 11:55:58 +0200 |
parents | 396785d39b69 |
children | 04dbca0ffb10 |
files | hotspot/src/share/vm/c1/c1_Instruction.hpp hotspot/src/share/vm/classfile/vmSymbols.cpp hotspot/src/share/vm/classfile/vmSymbols.hpp hotspot/test/compiler/c1/TestPinnedIntrinsics.java |
diffstat | 4 files changed, 85 insertions(+), 1 deletions(-) [+] |
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--- a/hotspot/src/share/vm/c1/c1_Instruction.hpp Thu Jul 13 15:11:53 2017 +0000 +++ b/hotspot/src/share/vm/c1/c1_Instruction.hpp Fri Jul 14 11:55:58 2017 +0200 @@ -1566,7 +1566,7 @@ set_needs_null_check(has_receiver); // some intrinsics can't trap, so don't force them to be pinned - if (!can_trap()) { + if (!can_trap() && !vmIntrinsics::should_be_pinned(_id)) { unpin(PinStateSplitConstructor); } }
--- a/hotspot/src/share/vm/classfile/vmSymbols.cpp Thu Jul 13 15:11:53 2017 +0000 +++ b/hotspot/src/share/vm/classfile/vmSymbols.cpp Fri Jul 14 11:55:58 2017 +0200 @@ -399,6 +399,21 @@ } } +// Some intrinsics produce different results if they are not pinned +bool vmIntrinsics::should_be_pinned(vmIntrinsics::ID id) { + assert(id != vmIntrinsics::_none, "must be a VM intrinsic"); + switch(id) { +#ifdef TRACE_HAVE_INTRINSICS + case vmIntrinsics::_counterTime: +#endif + case vmIntrinsics::_currentTimeMillis: + case vmIntrinsics::_nanoTime: + return true; + default: + return false; + } +} + bool vmIntrinsics::does_virtual_dispatch(vmIntrinsics::ID id) { assert(id != vmIntrinsics::_none, "must be a VM intrinsic"); switch(id) {
--- a/hotspot/src/share/vm/classfile/vmSymbols.hpp Thu Jul 13 15:11:53 2017 +0000 +++ b/hotspot/src/share/vm/classfile/vmSymbols.hpp Fri Jul 14 11:55:58 2017 +0200 @@ -1632,6 +1632,7 @@ static bool preserves_state(vmIntrinsics::ID id); static bool can_trap(vmIntrinsics::ID id); + static bool should_be_pinned(vmIntrinsics::ID id); // (2) Information needed by the C2 compiler.
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/hotspot/test/compiler/c1/TestPinnedIntrinsics.java Fri Jul 14 11:55:58 2017 +0200 @@ -0,0 +1,68 @@ +/* + * Copyright (c) 2017, 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. + */ + +/* + * @test + * @bug 8184271 + * @summary Test correct scheduling of System.nanoTime and System.currentTimeMillis C1 intrinsics. + * @run main/othervm -XX:TieredStopAtLevel=1 -Xbatch + * -XX:CompileCommand=dontinline,compiler.c1.TestPinnedIntrinsics::checkNanoTime + * -XX:CompileCommand=dontinline,compiler.c1.TestPinnedIntrinsics::checkCurrentTimeMillis + * compiler.c1.TestPinnedIntrinsics + */ + +package compiler.c1; + +public class TestPinnedIntrinsics { + + private static void testNanoTime() { + long start = System.nanoTime(); + long end = System.nanoTime(); + checkNanoTime(end - start); + } + + private static void checkNanoTime(long diff) { + if (diff < 0) { + throw new RuntimeException("testNanoTime failed with " + diff); + } + } + + private static void testCurrentTimeMillis() { + long start = System.currentTimeMillis(); + long end = System.currentTimeMillis(); + checkCurrentTimeMillis(end - start); + } + + private static void checkCurrentTimeMillis(long diff) { + if (diff < 0) { + throw new RuntimeException("testCurrentTimeMillis failed with " + diff); + } + } + + public static void main(String[] args) { + for (int i = 0; i < 100_000; ++i) { + testNanoTime(); + testCurrentTimeMillis(); + } + } +}