Guarantee backoff

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

@@ -4053,6 +4053,7 @@ class Core {
 
     static class State {
         private int backoff;
+        private boolean backingoff = false;
         private ConnectionHelper.NetworkState networkState;
         private Thread thread = new Thread();
         private Semaphore semaphore = new Semaphore(0);
@@ -4097,11 +4098,19 @@ class Core {
             return true;
         }
 
-        boolean acquire(long milliseconds) throws InterruptedException {
-            return semaphore.tryAcquire(milliseconds, TimeUnit.MILLISECONDS);
+        boolean acquire(long milliseconds, boolean backoff) throws InterruptedException {
+            try {
+                backingoff = backoff;
+                return semaphore.tryAcquire(milliseconds, TimeUnit.MILLISECONDS);
+            } finally {
+                backingoff = false;
+            }
         }
 
         void error(Throwable ex) {
+            if (backingoff)
+                return;
+
             if (ex instanceof MessagingException &&
                     ("connection failure".equals(ex.getMessage()) ||
                             "Not connected".equals(ex.getMessage()) || // POP3

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

@@ -899,7 +899,7 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
                 try {
                     long backoff = RECONNECT_BACKOFF - ago;
                     EntityLog.log(ServiceSynchronize.this, account.name + " reconnect backoff=" + (backoff / 1000));
-                    state.acquire(backoff);
+                    state.acquire(backoff, true);
                 } catch (InterruptedException ex) {
                     Log.w(account.name + " backoff " + ex.toString());
                 }
@@ -1523,7 +1523,7 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
 
                             try {
                                 wlAccount.release();
-                                state.acquire(2 * duration);
+                                state.acquire(2 * duration, false);
                                 Log.i("### " + account.name + " keeping alive");
                             } catch (InterruptedException ex) {
                                 EntityLog.log(this, account.name + " waited state=" + state);
@@ -1638,7 +1638,7 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
                     if (cbackoff > backoff) {
                         try {
                             EntityLog.log(this, account.name + " reconnect backoff=" + cbackoff);
-                            state.acquire(cbackoff * 1000L);
+                            state.acquire(cbackoff * 1000L, true);
                         } catch (InterruptedException ex) {
                             Log.w(account.name + " cbackoff " + ex.toString());
                         }
@@ -1648,7 +1648,7 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
                         if (backoff <= CONNECT_BACKOFF_MAX) {
                             // Short back-off period, keep device awake
                             try {
-                                state.acquire(backoff * 1000L);
+                                state.acquire(backoff * 1000L, true);
                             } catch (InterruptedException ex) {
                                 Log.w(account.name + " backoff " + ex.toString());
                             }
@@ -1681,7 +1681,7 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
 
                                 try {
                                     wlAccount.release();
-                                    state.acquire(2 * backoff * 1000L);
+                                    state.acquire(2 * backoff * 1000L, true);
                                     Log.i("### " + account.name + " backoff done");
                                 } catch (InterruptedException ex) {
                                     Log.w(account.name + " backoff " + ex.toString());