# HG changeset patch
# User johnc
# Date 1326909016 28800
# Node ID d903bf750e9f0c9a029c5d6ae33e7e8bb4e40668
# Parent  caa4652b441496c750379fe9a202e2afe05d1457
7129514: time warp warnings after 7117303
Summary: Replace calls to os::javaTimeMillis() that are used to update the milliseconds since the last GC to an equivalent that uses a monotonically non-decreasing time source.
Reviewed-by: ysr, jmasa

diff -r caa4652b4414 -r d903bf750e9f src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp
--- a/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	Tue Feb 14 08:21:08 2012 -0500
+++ b/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	Wed Jan 18 09:50:16 2012 -0800
@@ -6092,7 +6092,11 @@
   _inter_sweep_timer.reset();
   _inter_sweep_timer.start();
 
-  update_time_of_last_gc(os::javaTimeMillis());
+  // We need to use a monotonically non-deccreasing time in ms
+  // or we will see time-warp warnings and os::javaTimeMillis()
+  // does not guarantee monotonicity.
+  jlong now = os::javaTimeNanos() / NANOSECS_PER_MILLISEC;
+  update_time_of_last_gc(now);
 
   // NOTE on abstract state transitions:
   // Mutators allocate-live and/or mark the mod-union table dirty
diff -r caa4652b4414 -r d903bf750e9f src/share/vm/gc_implementation/parNew/parNewGeneration.cpp
--- a/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp	Tue Feb 14 08:21:08 2012 -0500
+++ b/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp	Wed Jan 18 09:50:16 2012 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2012, 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
@@ -1042,7 +1042,11 @@
     size_policy->avg_survived()->sample(from()->used());
   }
 
-  update_time_of_last_gc(os::javaTimeMillis());
+  // We need to use a monotonically non-deccreasing time in ms
+  // or we will see time-warp warnings and os::javaTimeMillis()
+  // does not guarantee monotonicity.
+  jlong now = os::javaTimeNanos() / NANOSECS_PER_MILLISEC;
+  update_time_of_last_gc(now);
 
   SpecializationStats::print();
 
diff -r caa4652b4414 -r d903bf750e9f src/share/vm/memory/defNewGeneration.cpp
--- a/src/share/vm/memory/defNewGeneration.cpp	Tue Feb 14 08:21:08 2012 -0500
+++ b/src/share/vm/memory/defNewGeneration.cpp	Wed Jan 18 09:50:16 2012 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2012, 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
@@ -655,7 +655,12 @@
   from()->set_concurrent_iteration_safe_limit(from()->top());
   to()->set_concurrent_iteration_safe_limit(to()->top());
   SpecializationStats::print();
-  update_time_of_last_gc(os::javaTimeMillis());
+
+  // We need to use a monotonically non-deccreasing time in ms
+  // or we will see time-warp warnings and os::javaTimeMillis()
+  // does not guarantee monotonicity.
+  jlong now = os::javaTimeNanos() / NANOSECS_PER_MILLISEC;
+  update_time_of_last_gc(now);
 }
 
 class RemoveForwardPointerClosure: public ObjectClosure {
diff -r caa4652b4414 -r d903bf750e9f src/share/vm/memory/genMarkSweep.cpp
--- a/src/share/vm/memory/genMarkSweep.cpp	Tue Feb 14 08:21:08 2012 -0500
+++ b/src/share/vm/memory/genMarkSweep.cpp	Wed Jan 18 09:50:16 2012 -0800
@@ -176,7 +176,11 @@
 
   // Update time of last gc for all generations we collected
   // (which curently is all the generations in the heap).
-  gch->update_time_of_last_gc(os::javaTimeMillis());
+  // We need to use a monotonically non-deccreasing time in ms
+  // or we will see time-warp warnings and os::javaTimeMillis()
+  // does not guarantee monotonicity.
+  jlong now = os::javaTimeNanos() / NANOSECS_PER_MILLISEC;
+  gch->update_time_of_last_gc(now);
 }
 
 void GenMarkSweep::allocate_stacks() {