RFR: 8185529: JCK api/java_lang/Object/WaitTests failed with jdk10/hs nightly

[David Holmes]

Bug is not public - sorry.

webrev: http://cr.openjdk.java.net/~dholmes/8185529/webrev/

Also patch inline below.

Problem: o.wait(Long.MAX_VALUE) returns immediately

Cause: arithmetic overflow gives a time in the past so the timeout 
expires immediately

This was introduced by the fix for:

https://bugs.openjdk.java.net/browse/JDK-8174231 "Factor out and share 
PlatformEvent and Parker code for POSIX systems."

while we go to great lengths to ensure we avoid overflows inside the 
time calculation functions, I overlooked the fact that we now first 
convert a millisecond value into nanoseconds, which can overflow.

Fix: limit the millis value to the existing hard limit of 
MAX_SECS*MILLIUNITS ms. That can not overflow when converted to nanos.

Thanks,
David
-----

--- old/src/hotspot/os/posix/os_posix.cpp	2017-10-06 00:34:31.595159338 
-0400
+++ new/src/hotspot/os/posix/os_posix.cpp	2017-10-06 00:34:29.443037883 
-0400
@@ -1770,6 +1770,12 @@

    if (v == 0) { // Do this the hard way by blocking ...
      struct timespec abst;
+    // We have to watch for overflow when converting millis to nanos,
+    // but if millis is that large then we will end up limiting to
+    // MAX_SECS anyway, so just do that here.
+    if (millis / MILLIUNITS > MAX_SECS) {
+      millis = jlong(MAX_SECS) * MILLIUNITS;
+    }
      to_abstime(&abst, millis * (NANOUNITS / MILLIUNITS), false);