Continue aborting if polling while aborting

If a thread is killed and then quickly interrupted in another way,
it may end up polling for that other event and stop aborting from
the kill. This ensures that once aborted a thread can never stop
aborting by picking up a new interrupt event.

This broke the new test server in test/mri/net/http/utils.rb when
it killed the server and then closed the socket; while aborting
the closed socket could trigger additional exceptions, stopping
the abort. This ensures it will be seen at the next poll and
resumed.

Author: headius

core/src/main/java/org/jruby/RubyThread.java

@@ -794,13 +794,17 @@ public void pollThreadEvents(ThreadContext context, boolean blocking) {
 
     // CHECK_INTS
     public void pollThreadEvents(ThreadContext context) {
+        killIfAborting();
+
         if (anyInterrupted()) {
             executeInterrupts(context, false);
         }
     }
 
     // RUBY_VM_CHECK_INTS_BLOCKING
     public void blockingThreadPoll(ThreadContext context) {
+        killIfAborting();
+
         if (pendingInterruptQueue.isEmpty() && !anyInterrupted()) {
             return;
         }
@@ -810,6 +814,13 @@ public void blockingThreadPoll(ThreadContext context) {
         executeInterrupts(context, true);
     }
 
+    private void killIfAborting() {
+        if (status == Status.ABORTING) {
+            // currently aborting, resume abort
+            throwThreadKill();
+        }
+    }
+
     // RUBY_VM_INTERRUPTED_ANY
     private boolean anyInterrupted() {
         return Thread.interrupted() || (interruptFlag & ~interruptMask) != 0;