Fix problem when cancelled tasks did not receive interrupt

Author: ahornace

suggester/src/main/java/org/opengrok/suggest/Suggester.java

@@ -84,7 +84,9 @@ public final class Suggester implements Closeable {
 
     private final int timeThreshold;
 
-    private final ExecutorService executorService = Executors.newWorkStealingPool();
+    // do NOT use fork join thread pool (work stealing thread pool) because it does not send interrupts upon cancellation
+    private final ExecutorService executorService = Executors.newFixedThreadPool(
+            Runtime.getRuntime().availableProcessors());
 
     /**
      * @param suggesterDir directory under which the suggester data should be created

suggester/src/main/java/org/opengrok/suggest/SuggesterSearcher.java

@@ -131,7 +131,7 @@ private List<LookupResultItem> suggest(
             final SuggesterQuery suggesterQuery,
             final PopularityCounter searchCounts
     ) throws IOException {
-        if (Thread.interrupted()) {
+        if (Thread.currentThread().isInterrupted()) {
             interrupted = true;
             return Collections.emptyList();
         }
@@ -150,6 +150,9 @@ private List<LookupResultItem> suggest(
         ComplexQueryData complexQueryData = null;
         if (needsDocumentIds) {
             complexQueryData = getComplexQueryData(query, leafReaderContext);
+            if (interrupted) {
+                return Collections.emptyList();
+            }
         }
 
         Terms terms = leafReaderContext.reader().terms(suggesterQuery.getField());
@@ -164,7 +167,7 @@ private List<LookupResultItem> suggest(
 
         BytesRef term = termsEnum.next();
         while (term != null) {
-            if (Thread.interrupted()) {
+            if (Thread.currentThread().isInterrupted()) {
                 interrupted = true;
                 break;
             }
@@ -261,6 +264,13 @@ public boolean needsScores() {
                     return false;
                 }
             });
+        } catch (IOException e) {
+            if (Thread.currentThread().isInterrupted()) {
+                interrupted = true;
+                return null;
+            } else {
+                logger.log(Level.WARNING, "Could not get document ids for " + query, e);
+            }
         } catch (Exception e) {
             logger.log(Level.WARNING, "Could not get document ids for " + query, e);
         }

suggester/src/main/java/org/opengrok/suggest/query/customized/CustomExactPhraseScorer.java

@@ -96,6 +96,10 @@ public TwoPhaseIterator twoPhaseIterator() {
         return new TwoPhaseIterator(conjunction) {
             @Override
             public boolean matches() throws IOException {
+                // custom – interrupt handler
+                if (Thread.currentThread().isInterrupted()) {
+                    throw new IOException("Interrupted while scoring documents");
+                }
                 return phraseFreq() > 0; // custom – only necessary part left
             }
 

suggester/src/main/java/org/opengrok/suggest/query/customized/CustomSloppyPhraseScorer.java

@@ -633,6 +633,10 @@ public TwoPhaseIterator twoPhaseIterator() {
         return new TwoPhaseIterator(conjunction) {
             @Override
             public boolean matches() throws IOException {
+                // custom – interrupt handler
+                if (Thread.currentThread().isInterrupted()) {
+                    throw new IOException("Interrupted while scoring documents");
+                }
                 sloppyFreq = phraseFreq(); // check for phrase
                 return sloppyFreq != 0F;
             }