Dont use timer if closed (#312)

* dont use timer if null

* dont use timer if null

* UserPromptTokenProvider public

* synchronized PublicAppTokenProviderBase

* synchronized PublicAppTokenProviderBase

* format

* add comment

* add comment

---------

Co-authored-by: Ohad Bitton <ohbitton@microsoft.com>

CHANGELOG.md

@@ -8,6 +8,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 * Automatic retries for queued ingestion
 * `executeQuery`, `executeMgmt` to call with a specific type.
+### Fixed 
+* Timer was used if authentication throws after client was closed 
+* Public client credentials (user prompt,device auth) are synchronized - so that users are prompt once
 
 ## [5.0.0]
 ### Fixed

data/src/main/java/com/microsoft/azure/kusto/data/auth/PublicAppTokenProviderBase.java

@@ -28,6 +28,13 @@ public abstract class PublicAppTokenProviderBase extends MsalTokenProviderBase {
         super(clusterUrl, authorityId, httpClient);
     }
 
+    // This is synchronized as we don't want users to be prompt many times on async operations.
+    // This way the first thread gets here, finishes and token can be retrieved silently by other threads.
+    @Override
+    protected synchronized String acquireAccessTokenImpl() throws DataServiceException, DataClientException {
+        return super.acquireAccessTokenImpl();
+    }
+
     @Override
     protected void initializeWithCloudInfo(CloudInfo cloudInfo) throws DataClientException, DataServiceException {
         super.initializeWithCloudInfo(cloudInfo);

ingest/src/main/java/com/microsoft/azure/kusto/ingest/ResourceManager.java

@@ -54,7 +54,7 @@ public class ResourceManager implements Closeable, IngestionResourceManager {
     public static int UPLOAD_TIMEOUT_MINUTES = 10;
     private final Client client;
     private final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
-    private final Timer timer;
+    private Timer timer;
     private final ReadWriteLock ingestionResourcesLock = new ReentrantReadWriteLock();
     private final ReadWriteLock authTokenLock = new ReentrantReadWriteLock();
     private final Long defaultRefreshTime;
@@ -90,8 +90,10 @@ public class ResourceManager implements Closeable, IngestionResourceManager {
 
     @Override
     public void close() {
-        timer.cancel();
-        timer.purge();
+        Timer closeTimer = timer;
+        timer = null;
+        closeTimer.cancel();
+        closeTimer.purge();
     }
 
     private RetryConfig buildRetryConfig() {
@@ -115,7 +117,9 @@ public class ResourceManager implements Closeable, IngestionResourceManager {
                     timer.schedule(new RefreshIngestionResourcesTask(), defaultRefreshTime);
                 } catch (Exception e) {
                     log.error("Error in refreshIngestionResources. " + e.getMessage(), e);
-                    timer.schedule(new RefreshIngestionResourcesTask(), refreshTimeOnFailure);
+                    if (timer != null) {
+                        timer.schedule(new RefreshIngestionResourcesTask(), refreshTimeOnFailure);
+                    }
                 }
             }
         }
@@ -128,7 +132,9 @@ public class ResourceManager implements Closeable, IngestionResourceManager {
                     timer.schedule(new RefreshIngestionAuthTokenTask(), defaultRefreshTime);
                 } catch (Exception e) {
                     log.error("Error in refreshIngestionAuthToken. " + e.getMessage(), e);
-                    timer.schedule(new RefreshIngestionAuthTokenTask(), refreshTimeOnFailure);
+                    if (timer != null) {
+                        timer.schedule(new RefreshIngestionAuthTokenTask(), refreshTimeOnFailure);
+                    }
                 }
             }
         }