Make signum and compareTo check for interruptsandroid-o-mr1-iot-preview-6o-mr1-iot-preview-6

Bug: 68670525

Unless we check for interrupts some comparisons will run forever
uninterruptibly.

If the client, for example, compares sqrt(11) - sqrt(11) to zero,
and then interrupts, it may still take quite a while for the interrupt
to be recognized, since each iteration of the compare loop can take
seconds. For the Android Calculator, this is usually not directly
visible, except that the compute thread will continue to use cpu
for several seconds.

Test: Ran Android calculator tests, manually exercised this case.
Change-Id: I0fe0922a8ee68bf0e08ce59c0d8c372ad10ef419

1 files changed, 7 insertions, 0 deletions

diff --git a/src/com/hp/creals/CR.java b/src/com/hp/creals/CR.java
index de89faf..d051050 100644
--- a/src/com/hp/creals/CR.java
+++ b/src/com/hp/creals/CR.java
@@ -109,6 +109,7 @@
 // Don't negate argument and compute inverse for exp(). That causes severe
 // performance problems for (-huge).exp()
 // hboehm@google.com 8/21/2017
+// Have comparison check for interruption. hboehm@google.com 10/31/2017
 
 package com.hp.creals;
 
@@ -513,6 +514,9 @@ public volatile static boolean please_stop = false;
             check_prec(a);
             int result = compareTo(x, a);
             if (0 != result) return result;
+            if (Thread.interrupted() || please_stop) {
+                throw new AbortedException();
+            }
         }
       }
 
@@ -542,6 +546,9 @@ public volatile static boolean please_stop = false;
             check_prec(a);
             int result = signum(a);
             if (0 != result) return result;
+            if (Thread.interrupted() || please_stop) {
+                throw new AbortedException();
+            }
         }
       }