Debug: added max back-off slider

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

@@ -351,6 +351,7 @@ public class ApplicationEx extends Application
             EntityLog.log(context, "Upgrading from " + version + " to " + BuildConfig.VERSION_CODE);
 
         SharedPreferences.Editor editor = prefs.edit();
+        editor.remove("max_backoff_power");
 
         if (version < BuildConfig.VERSION_CODE)
             editor.remove("crash_report_count");

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

@@ -213,6 +213,8 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
     private SwitchCompat swEmptyPool;
     private SwitchCompat swIdleDone;
     private SwitchCompat swFastFetch;
+    private TextView tvMaxBackoff;
+    private SeekBar sbMaxBackOff;
     private SwitchCompat swLogarithmicBackoff;
     private SwitchCompat swExactAlarms;
     private SwitchCompat swInfra;
@@ -271,7 +273,8 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
             "show_recent",
             "use_modseq", "preamble", "uid_command", "perform_expunge", "uid_expunge",
             "auth_plain", "auth_login", "auth_ntlm", "auth_sasl", "auth_apop", "use_top",
-            "keep_alive_poll", "empty_pool", "idle_done", "fast_fetch", "logarithmic_backoff",
+            "keep_alive_poll", "empty_pool", "idle_done", "fast_fetch",
+            "max_backoff_power", "logarithmic_backoff",
             "exact_alarms", "infra", "dkim_verify", "dup_msgids", "global_keywords", "test_iab"
     };
 
@@ -433,6 +436,8 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
         swEmptyPool = view.findViewById(R.id.swEmptyPool);
         swIdleDone = view.findViewById(R.id.swIdleDone);
         swFastFetch = view.findViewById(R.id.swFastFetch);
+        tvMaxBackoff = view.findViewById(R.id.tvMaxBackoff);
+        sbMaxBackOff = view.findViewById(R.id.sbMaxBackOff);
         swLogarithmicBackoff = view.findViewById(R.id.swLogarithmicBackoff);
         swExactAlarms = view.findViewById(R.id.swExactAlarms);
         swInfra = view.findViewById(R.id.swInfra);
@@ -1549,6 +1554,23 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
             }
         });
 
+        sbMaxBackOff.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
+            @Override
+            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
+                prefs.edit().putInt("max_backoff_power", progress).apply();
+            }
+
+            @Override
+            public void onStartTrackingTouch(SeekBar seekBar) {
+                // Do nothing
+            }
+
+            @Override
+            public void onStopTrackingTouch(SeekBar seekBar) {
+                // Do nothing
+            }
+        });
+
         swLogarithmicBackoff.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
             @Override
             public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
@@ -2263,6 +2285,12 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
         swEmptyPool.setChecked(prefs.getBoolean("empty_pool", true));
         swIdleDone.setChecked(prefs.getBoolean("idle_done", true));
         swFastFetch.setChecked(prefs.getBoolean("fast_fetch", false));
+
+        int max_backoff_power = prefs.getInt("max_backoff_power", ServiceSynchronize.DEFAULT_BACKOFF_POWER - 3);
+        int max_backoff = (int) Math.pow(2, max_backoff_power + 3);
+        tvMaxBackoff.setText(getString(R.string.title_advanced_max_backoff, max_backoff));
+        sbMaxBackOff.setProgress(max_backoff_power);
+
         swLogarithmicBackoff.setChecked(prefs.getBoolean("logarithmic_backoff", true));
         swExactAlarms.setChecked(prefs.getBoolean("exact_alarms", true));
         swInfra.setChecked(prefs.getBoolean("infra", false));

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

@@ -133,6 +133,8 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
     private static final ExecutorService executorNotify =
             Helper.getBackgroundExecutor(1, "notify");
 
+    static final int DEFAULT_BACKOFF_POWER = 3; // 2^3=8 seconds (totally 8+2x20=48 seconds)
+
     private static final long BACKUP_DELAY = 30 * 1000L; // milliseconds
     private static final long PURGE_DELAY = 30 * 1000L; // milliseconds
     private static final int QUIT_DELAY = 10; // seconds
@@ -141,7 +143,6 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
     private static final int TUNE_KEEP_ALIVE_INTERVAL_STEP = 2; // minutes
     private static final int OPTIMIZE_POLL_INTERVAL = 15; // minutes
     private static final int CONNECT_BACKOFF_START = 8; // seconds
-    private static final int CONNECT_BACKOFF_MAX = 8; // seconds (totally 8+2x20=48 seconds)
     private static final int CONNECT_BACKOFF_INTERMEDIATE = 5; // minutes
     private static final int CONNECT_BACKOFF_ALARM_START = 15; // minutes
     private static final int CONNECT_BACKOFF_ALARM_MAX = 60; // minutes
@@ -2647,6 +2648,8 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
                 if (state.isRunning()) {
                     long now = new Date().getTime();
                     boolean logarithmic_backoff = prefs.getBoolean("logarithmic_backoff", true);
+                    int max_backoff_power = prefs.getInt("max_backoff_power", DEFAULT_BACKOFF_POWER - 3);
+                    int max_backoff = (int) Math.pow(2, max_backoff_power + 3);
 
                     if (logarithmic_backoff) {
                         // Check for fast successive server, connectivity, etc failures
@@ -2679,7 +2682,7 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
                                                     " avg=" + (avg_fail / 1000L) + "/" + (fail_threshold / 1000L) +
                                                     " missing=" + (missing / 1000L) +
                                                     " compensate=" + compensate +
-                                                    " backoff=" + backoff +
+                                                    " backoff=" + backoff + "/" + max_backoff +
                                                     " host=" + account.host +
                                                     " ex=" + Log.formatThrowable(last_fail, false);
                                             if (compensate > 2)
@@ -2700,14 +2703,14 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
                     int backoff = state.getBackoff();
                     int recently = (lastLost + LOST_RECENTLY < now ? 1 : 2);
                     EntityLog.log(this, EntityLog.Type.Account, account,
-                            account.name + " backoff=" + backoff +
+                            account.name + " backoff=" + backoff + "/" + max_backoff +
                                     " recently=" + recently + "x" +
                                     " logarithmic=" + logarithmic_backoff);
 
                     if (logarithmic_backoff) {
-                        if (backoff < CONNECT_BACKOFF_MAX)
+                        if (backoff < max_backoff)
                             state.setBackoff(backoff * 2);
-                        else if (backoff == CONNECT_BACKOFF_MAX)
+                        else if (backoff == max_backoff)
                             if (AlarmManagerCompatEx.hasExactAlarms(this))
                                 state.setBackoff(CONNECT_BACKOFF_INTERMEDIATE * 60);
                             else
@@ -2731,11 +2734,12 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
                     Map<String, String> crumb = new HashMap<>();
                     crumb.put("account", account.name);
                     crumb.put("backoff", Integer.toString(backoff));
+                    crumb.put("max_backoff", Integer.toString(max_backoff));
                     crumb.put("recently", Integer.toString(recently));
                     crumb.put("logarithmic", Boolean.toString(logarithmic_backoff));
                     Log.breadcrumb("Backing off", crumb);
 
-                    if (backoff <= CONNECT_BACKOFF_MAX) {
+                    if (backoff <= max_backoff) {
                         // Short back-off period, keep device awake
                         try {
                             long interval = backoff * 1000L * recently;

app/src/main/res/layout/fragment_options_misc.xml

@@ -1580,6 +1580,28 @@
                     app:layout_constraintTop_toBottomOf="@id/swIdleDone"
                     app:switchPadding="12dp" />
 
+                <TextView
+                    android:id="@+id/tvMaxBackoff"
+                    android:layout_width="0dp"
+                    android:layout_height="wrap_content"
+                    android:layout_marginTop="12dp"
+                    android:layout_marginEnd="48dp"
+                    android:text="@string/title_advanced_max_backoff"
+                    android:textAppearance="@style/TextAppearance.AppCompat.Small"
+                    app:layout_constraintEnd_toEndOf="parent"
+                    app:layout_constraintStart_toStartOf="parent"
+                    app:layout_constraintTop_toBottomOf="@id/swFastFetch" />
+
+                <SeekBar
+                    android:id="@+id/sbMaxBackOff"
+                    android:layout_width="0dp"
+                    android:layout_height="wrap_content"
+                    android:max="4"
+                    android:progress="3"
+                    app:layout_constraintEnd_toEndOf="parent"
+                    app:layout_constraintStart_toStartOf="parent"
+                    app:layout_constraintTop_toBottomOf="@id/tvMaxBackoff" />
+
                 <androidx.appcompat.widget.SwitchCompat
                     android:id="@+id/swLogarithmicBackoff"
                     android:layout_width="0dp"
@@ -1589,7 +1611,7 @@
                     android:text="@string/title_advanced_logarithmic_backoff"
                     app:layout_constraintEnd_toEndOf="parent"
                     app:layout_constraintStart_toStartOf="parent"
-                    app:layout_constraintTop_toBottomOf="@id/swFastFetch"
+                    app:layout_constraintTop_toBottomOf="@id/sbMaxBackOff"
                     app:switchPadding="12dp" />
 
                 <TextView

app/src/main/res/values/strings.xml

@@ -846,6 +846,7 @@
     <string name="title_advanced_use_top" translatable="false">Use TOP</string>
     <string name="title_advanced_idle_done" translatable="false">IDLE/DONE</string>
     <string name="title_advanced_fast_fetch" translatable="false">Fast FETCH</string>
+    <string name="title_advanced_max_backoff" translatable="false">Max. back-off: %1$d s</string>
     <string name="title_advanced_logarithmic_backoff" translatable="false">Logarithmic back-off</string>
     <string name="title_advanced_logarithmic_backoff_hint" translatable="false">Turning this off can result in a significant increase in battery usage!</string>
     <string name="title_advanced_keep_alive_poll" translatable="false">Poll on keep-alive</string>