Shutdown operations queue

app/src/main/java/eu/faircode/email/Helper.java

@@ -163,12 +163,14 @@ public class Helper {
 
         if (threads == 0)
             return new ThreadPoolExecutorEx(
+                    name,
                     0, Integer.MAX_VALUE,
                     60L, TimeUnit.SECONDS,
                     new SynchronousQueue<Runnable>(),
                     factory);
         else if (threads == 1)
             return new ThreadPoolExecutorEx(
+                    name,
                     threads, threads,
                     0L, TimeUnit.MILLISECONDS,
                     new PriorityBlockingQueue<Runnable>(10, new PriorityComparator()),
@@ -184,6 +186,7 @@ public class Helper {
             };
         else
             return new ThreadPoolExecutorEx(
+                    name,
                     threads, threads,
                     0L, TimeUnit.MILLISECONDS,
                     new LinkedBlockingQueue<Runnable>(),
@@ -191,14 +194,29 @@ public class Helper {
     }
 
     private static class ThreadPoolExecutorEx extends ThreadPoolExecutor {
-        public ThreadPoolExecutorEx(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit, BlockingQueue<Runnable> workQueue, ThreadFactory threadFactory) {
+        String name;
+
+        public ThreadPoolExecutorEx(
+                String name,
+                int corePoolSize, int maximumPoolSize,
+                long keepAliveTime, TimeUnit unit,
+                BlockingQueue<Runnable> workQueue,
+                ThreadFactory threadFactory) {
             super(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue, threadFactory);
+            this.name = name;
         }
 
         @Override
         protected void beforeExecute(Thread t, Runnable r) {
             Log.d("Executing " + t.getName());
         }
+
+        @Override
+        public void shutdown() {
+            Log.i("Shutdown " + name);
+            super.getQueue().clear();
+            super.shutdown();
+        }
     }
 
     private static class PriorityFuture<T> implements RunnableFuture<T> {

app/src/main/java/eu/faircode/email/ServiceSynchronize.java

@@ -825,6 +825,9 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
                     }
                 });
 
+                final ExecutorService executor =
+                        Helper.getBackgroundExecutor(1, "account_" + account.id);
+
                 final Map<EntityFolder, IMAPFolder> mapFolders = new HashMap<>();
                 List<Thread> idlers = new ArrayList<>();
                 try {
@@ -944,9 +947,6 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
                         Core.onSynchronizeFolders(this, account, iservice.getStore(), state);
 
                     // Open synchronizing folders
-                    final ExecutorService executor =
-                            Helper.getBackgroundExecutor(1, "account_" + account.id);
-
                     List<EntityFolder> folders = db.folder().getFolders(account.id, false, true);
                     Collections.sort(folders, new Comparator<EntityFolder>() {
                         @Override
@@ -1416,6 +1416,8 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
                         }
                     });
 
+                    executor.shutdown();
+
                     // Close folders
                     for (EntityFolder folder : mapFolders.keySet())
                         if (folder.synchronize && !folder.poll && mapFolders.get(folder) != null) {