8184271: Time related C1 intrinsics produce inconsistent results when floating around
authorthartmann
Fri, 14 Jul 2017 11:55:58 +0200
changeset 46663 715d5f268f62
parent 46662 396785d39b69
child 46665 04dbca0ffb10
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
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
--- 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();
+        }
+    }
+}