ActiveModeWarden: made EcmState into an abstract base state

ECM state is now a sub-state of every other state (Scan, Disabled, Client).
Other states are tied to the life time of the corresponding ActiveModeManager.
When the state is exited, the ActiveModeManager is shut down.
However, entering ECM state doesn't necessarily mean that Client state has to
be shut down. Thus, ECM state needs to be a sub-state of Client state.
Same logic applies to scanning state.

Bug: 139157226
Test: Unit tests in a following commit
Test: Will submit for integration testing
Change-Id: I2e708a6efd82a0527d129130e8ca357e8214a7c2

1 files changed, 100 insertions, 82 deletions

diff --git a/service/java/com/android/server/wifi/ActiveModeWarden.java b/service/java/com/android/server/wifi/ActiveModeWarden.java
index e1929fc58..6b4681a9c 100644
--- a/service/java/com/android/server/wifi/ActiveModeWarden.java
+++ b/service/java/com/android/server/wifi/ActiveModeWarden.java
@@ -385,21 +385,19 @@ public class ActiveModeWarden {
         static final int CMD_DEFERRED_RECOVERY_RESTART_WIFI         = BASE + 22;
         static final int CMD_SCANNING_START_FAILURE                 = BASE + 23;
 
-        private final DefaultState mDefaultState = new DefaultState();
         private final StaEnabledState mStaEnabledState = new StaEnabledState();
         private final StaDisabledState mStaDisabledState = new StaDisabledState();
         private final StaDisabledWithScanState mStaDisabledWithScanState =
                 new StaDisabledWithScanState();
-        private final EcmState mEcmState = new EcmState();
 
         WifiController() {
             super(TAG, mLooper);
 
-            addState(mDefaultState); {
-                addState(mStaDisabledState, mDefaultState);
-                addState(mStaEnabledState, mDefaultState);
-                addState(mStaDisabledWithScanState, mDefaultState);
-                addState(mEcmState, mDefaultState);
+            DefaultState defaultState = new DefaultState();
+            addState(defaultState); {
+                addState(mStaDisabledState, defaultState);
+                addState(mStaEnabledState, defaultState);
+                addState(mStaDisabledWithScanState, defaultState);
             }
 
             setLogRecSize(100);
@@ -456,6 +454,91 @@ public class ActiveModeWarden {
             return recoveryDelayMillis;
         }
 
+        abstract class BaseState extends State {
+            private boolean mIsInEmergencyCall;
+            private boolean mIsInEmergencyCallbackMode;
+
+            private boolean mWasWifiDisabled;
+
+            @Override
+            public void enter() {
+                super.enter();
+                // Not allowed to change state when ECM is enabled!
+                // Thus reset to false when changing states just to be safe.
+                mIsInEmergencyCall = false;
+                mIsInEmergencyCallbackMode = false;
+                mWasWifiDisabled = false;
+            }
+
+            private boolean isInEmergencyMode() {
+                return mIsInEmergencyCall || mIsInEmergencyCallbackMode;
+            }
+
+            private void updateEmergencyMode(Message msg) {
+                if (msg.what == CMD_EMERGENCY_CALL_STATE_CHANGED) {
+                    mIsInEmergencyCall = msg.arg1 == 1;
+                } else if (msg.what == CMD_EMERGENCY_MODE_CHANGED) {
+                    mIsInEmergencyCallbackMode = msg.arg1 == 1;
+                }
+            }
+
+            private void enterEmergencyMode() {
+                stopSoftAPMode(WifiManager.IFACE_IP_MODE_UNSPECIFIED);
+                boolean configWiFiDisableInECBM = mFacade.getConfigWiFiDisableInECBM(mContext);
+                log("WifiController msg getConfigWiFiDisableInECBM " + configWiFiDisableInECBM);
+                if (configWiFiDisableInECBM) {
+                    shutdownWifi();
+                    mWasWifiDisabled = true;
+                }
+            }
+
+            private void exitEmergencyMode() {
+                State stateToTransitionTo;
+                if (mSettingsStore.isWifiToggleEnabled()) {
+                    stateToTransitionTo = mStaEnabledState;
+                } else if (checkScanOnlyModeAvailable()) {
+                    stateToTransitionTo = mStaDisabledWithScanState;
+                } else {
+                    stateToTransitionTo = mStaDisabledState;
+                }
+
+                if (stateToTransitionTo == this) {
+                    // stay in same state
+                    if (mWasWifiDisabled) {
+                        // if Wifi was shutdown, restart the current state
+                        this.enter();
+                    }
+                } else {
+                    transitionTo(stateToTransitionTo);
+                }
+            }
+
+            @Override
+            public final boolean processMessage(Message msg) {
+                // potentially enter emergency mode
+                if (msg.what == CMD_EMERGENCY_CALL_STATE_CHANGED
+                        || msg.what == CMD_EMERGENCY_MODE_CHANGED) {
+                    boolean wasInEmergencyMode = isInEmergencyMode();
+                    updateEmergencyMode(msg);
+                    boolean isInEmergencyMode = isInEmergencyMode();
+                    if (!wasInEmergencyMode && isInEmergencyMode) {
+                        enterEmergencyMode();
+                    } else if (wasInEmergencyMode && !isInEmergencyMode) {
+                        exitEmergencyMode();
+                    }
+                    return HANDLED;
+                }
+                // already in emergency mode, drop all messages
+                if (isInEmergencyMode()) {
+                    return HANDLED;
+                }
+                // not in emergency mode, process messages normally
+                return processMessageFiltered(msg);
+            }
+
+            protected abstract boolean processMessageFiltered(Message msg);
+        }
+
         class DefaultState extends State {
             @Override
             public boolean processMessage(Message msg) {
@@ -501,12 +584,6 @@ public class ActiveModeWarden {
                             // wifi should remain disabled, do not need to transition
                         }
                         break;
-                    case CMD_EMERGENCY_CALL_STATE_CHANGED:
-                    case CMD_EMERGENCY_MODE_CHANGED:
-                        if (msg.arg1 == 1) {
-                            transitionTo(mEcmState);
-                        }
-                        break;
                     case CMD_AP_STOPPED:
                         log("SoftAp mode disabled, determine next state");
                         if (mSettingsStore.isWifiToggleEnabled()) {
@@ -523,7 +600,7 @@ public class ActiveModeWarden {
             }
         }
 
-        class ModeActiveState extends State {
+        abstract class ModeActiveState extends BaseState {
             protected ActiveModeManager mManager;
 
             @Override
@@ -537,6 +614,7 @@ public class ActiveModeWarden {
                     updateScanMode();
                 }
                 updateBatteryStatsWifiState(false);
+                super.exit();
             }
 
             // Hook to be used by sub-classes of ModeActiveState to indicate the completion of
@@ -569,9 +647,9 @@ public class ActiveModeWarden {
             }
         }
 
-        class StaDisabledState extends State {
+        class StaDisabledState extends BaseState {
             @Override
-            public boolean processMessage(Message msg) {
+            public boolean processMessageFiltered(Message msg) {
                 switch (msg.what) {
                     case CMD_WIFI_TOGGLED:
                         if (mSettingsStore.isWifiToggleEnabled()) {
@@ -649,6 +727,7 @@ public class ActiveModeWarden {
 
             @Override
             public void enter() {
+                super.enter();
                 log("StaEnabledState.enter()");
 
                 mListener = new ClientListener();
@@ -661,12 +740,12 @@ public class ActiveModeWarden {
 
             @Override
             public void exit() {
-                super.exit();
                 mListener = null;
+                super.exit();
             }
 
             @Override
-            public boolean processMessage(Message msg) {
+            public boolean processMessageFiltered(Message msg) {
                 switch (msg.what) {
                     case CMD_WIFI_TOGGLED:
                         if (! mSettingsStore.isWifiToggleEnabled()) {
@@ -775,6 +854,7 @@ public class ActiveModeWarden {
 
             @Override
             public void enter() {
+                super.enter();
                 log("StaDisabledWithScanState.enter()");
 
                 mListener = new ScanOnlyListener();
@@ -788,12 +868,12 @@ public class ActiveModeWarden {
 
             @Override
             public void exit() {
-                super.exit();
                 mListener = null;
+                super.exit();
             }
 
             @Override
-            public boolean processMessage(Message msg) {
+            public boolean processMessageFiltered(Message msg) {
                 switch (msg.what) {
                     case CMD_WIFI_TOGGLED:
                         if (mSettingsStore.isWifiToggleEnabled()) {
@@ -835,67 +915,5 @@ public class ActiveModeWarden {
                 return HANDLED;
             }
         }
-
-        class EcmState extends ModeActiveState {
-            /**
-             * we can enter EcmState either because an emergency call started or because
-             * emergency callback mode started. This count keeps track of how many such
-             * events happened; so we can exit after all are undone
-             */
-            private int mEcmEntryCount;
-
-            @Override
-            public void enter() {
-                stopSoftAPMode(WifiManager.IFACE_IP_MODE_UNSPECIFIED);
-                boolean configWiFiDisableInECBM =
-                        mFacade.getConfigWiFiDisableInECBM(mContext);
-                log("WifiController msg getConfigWiFiDisableInECBM "
-                        + configWiFiDisableInECBM);
-                if (configWiFiDisableInECBM) {
-                    shutdownWifi();
-                }
-                mEcmEntryCount = 1;
-            }
-
-            /**
-             * Handles messages received while in EcmMode.
-             */
-            @Override
-            public boolean processMessage(Message msg) {
-                switch (msg.what) {
-                    case CMD_EMERGENCY_CALL_STATE_CHANGED:
-                    case CMD_EMERGENCY_MODE_CHANGED:
-                        if (msg.arg1 == 1) {
-                            mEcmEntryCount++;
-                        } else {
-                            mEcmEntryCount--;
-                        }
-                        if (mEcmEntryCount <= 0) {
-                            if (mSettingsStore.isWifiToggleEnabled()) {
-                                transitionTo(mStaEnabledState);
-                            } else if (checkScanOnlyModeAvailable()) {
-                                transitionTo(mStaDisabledWithScanState);
-                            } else {
-                                transitionTo(mStaDisabledState);
-                            }
-                        }
-                        return HANDLED;
-                    case CMD_RECOVERY_RESTART_WIFI:
-                    case CMD_RECOVERY_DISABLE_WIFI:
-                        // do not want to restart wifi if we are in emergency mode
-                        return HANDLED;
-                    case CMD_AP_STOPPED:
-                    case CMD_SCANNING_STOPPED:
-                    case CMD_STA_STOPPED:
-                        // do not want to trigger a mode switch if we are in emergency mode
-                        return HANDLED;
-                    case CMD_SET_AP:
-                        // do not want to start softap if we are in emergency mode
-                        return HANDLED;
-                    default:
-                        return NOT_HANDLED;
-                }
-            }
-        }
     }
 }