src/java/com/android/internal/telephony/RetryManager.java - platform/frameworks/opt/telephony - Git at Google

 /**
  * Copyright (C) 2009 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.android.internal.telephony;

 import android.annotation.Nullable;
 import android.compat.annotation.UnsupportedAppUsage;
 import android.content.Context;
 import android.os.PersistableBundle;
 import android.os.SystemProperties;
 import android.telephony.CarrierConfigManager;
 import android.telephony.data.ApnSetting;
 import android.text.TextUtils;
 import android.util.Pair;

 import com.android.internal.telephony.util.TelephonyUtils;
 import com.android.telephony.Rlog;

 import java.util.ArrayList;
 import java.util.Random;

 /**
  * Retry manager allows a simple way to declare a series of
  * retry timeouts. After creating a RetryManager the configure
  * method is used to define the sequence. A simple linear series
  * may be initialized using configure with three integer parameters
  * The other configure method allows a series to be declared using
  * a string.
  *<p>
  * The format of the configuration string is the apn type followed by a series of parameters
  * separated by a comma. There are two name value pair parameters plus a series
  * of delay times. The units of of these delay times is unspecified.
  * The name value pairs which may be specified are:
  *<ul>
  *<li>max_retries=<value>
  *<li>default_randomizationTime=<value>
  *</ul>
  *<p>
  * apn type specifies the APN type that the retry pattern will apply for. "others" is for all other
  * APN types not specified in the config.
  *
  * max_retries is the number of times that incrementRetryCount
  * maybe called before isRetryNeeded will return false. if value
  * is infinite then isRetryNeeded will always return true.
  *
  * default_randomizationTime will be used as the randomizationTime
  * for delay times which have no supplied randomizationTime. If
  * default_randomizationTime is not defined it defaults to 0.
  *<p>
  * The other parameters define The series of delay times and each
  * may have an optional randomization value separated from the
  * delay time by a colon.
  *<p>
  * Examples:
  * <ul>
  * <li>3 retries for mms with no randomization value which means its 0:
  * <ul><li><code>"mms:1000, 2000, 3000"</code></ul>
  *
  * <li>10 retries for default APN with a 500 default randomization value for each and
  * the 4..10 retries all using 3000 as the delay:
  * <ul><li><code>"default:max_retries=10, default_randomization=500, 1000, 2000, 3000"</code></ul>
  *
  * <li>4 retries for supl APN with a 100 as the default randomization value for the first 2 values
  * and the other two having specified values of 500:
  * <ul><li><code>"supl:default_randomization=100, 1000, 2000, 4000:500, 5000:500"</code></ul>
  *
  * <li>Infinite number of retries for all other APNs with the first one at 1000, the second at 2000
  * all others will be at 3000.
  * <ul><li><code>"others:max_retries=infinite,1000,2000,3000</code></ul>
  * </ul>
  *
  * {@hide}
  */
 public class RetryManager {
     public static final String LOG_TAG = "RetryManager";
     public static final boolean DBG = true;
     public static final boolean VDBG = false; // STOPSHIP if true

     /**
      * The default retry configuration for APNs. See above for the syntax.
      */
     private static final String DEFAULT_DATA_RETRY_CONFIG = "max_retries=3, 5000, 5000, 5000";

     /**
      * The APN type used for all other APNs retry configuration.
      */
     private static final String OTHERS_APN_TYPE = "others";

     /**
      * The default value (in milliseconds) for delay between APN trying (mInterApnDelay)
      * within the same round
      */
     private static final long DEFAULT_INTER_APN_DELAY = 20000;

     /**
      * The default value (in milliseconds) for delay between APN trying (mFailFastInterApnDelay)
      * within the same round when we are in fail fast mode
      */
     private static final long DEFAULT_INTER_APN_DELAY_FOR_PROVISIONING = 3000;

     /**
      * The default value (in milliseconds) for retrying APN after disconnect
      */
     private static final long DEFAULT_APN_RETRY_AFTER_DISCONNECT_DELAY = 10000;

     /**
      * The value indicating no retry is needed
      */
     public static final long NO_RETRY = -1;

     /**
      * The value indicating modem did not suggest any retry delay
      */
     public static final long NO_SUGGESTED_RETRY_DELAY = -2;

     /**
      * If the modem suggests a retry delay in the data call setup response, we will retry
      * the current APN setting again. However, if the modem keeps suggesting retrying the same
      * APN setting, we'll fall into an infinite loop. Therefore adding a counter to retry up to
      * MAX_SAME_APN_RETRY times can avoid it.
      */
     private static final int MAX_SAME_APN_RETRY = 3;

     /**
      * The delay (in milliseconds) between APN trying within the same round
      */
     @UnsupportedAppUsage
     private long mInterApnDelay;

     /**
      * The delay (in milliseconds) between APN trying within the same round when we are in
      * fail fast mode
      */
     @UnsupportedAppUsage
     private long mFailFastInterApnDelay;

     /**
      * The delay (in milliseconds) for APN retrying after disconnect (e.g. Modem suddenly reports
      * data call lost)
      */
     private long mApnRetryAfterDisconnectDelay;

     /**
      * Modem suggested delay for retrying the current APN
      */
     private long mModemSuggestedDelay = NO_SUGGESTED_RETRY_DELAY;

     /**
      * The counter for same APN retrying. See MAX_SAME_APN_RETRY for the details.
      */
     private int mSameApnRetryCount = 0;

     /**
      * Retry record with times in milli-seconds
      */
     private static class RetryRec {
         RetryRec(int delayTime, int randomizationTime) {
             mDelayTime = delayTime;
             mRandomizationTime = randomizationTime;
         }

         int mDelayTime;
         int mRandomizationTime;
     }

     /**
      * The array of retry records
      */
     private ArrayList<RetryRec> mRetryArray = new ArrayList<RetryRec>();

     @UnsupportedAppUsage
     private Phone mPhone;

     /**
      * Flag indicating whether retrying forever regardless the maximum retry count mMaxRetryCount
      */
     private boolean mRetryForever = false;

     /**
      * The maximum number of retries to attempt
      */
     private int mMaxRetryCount;

     /**
      * The current number of retries
      */
     private int mRetryCount = 0;

     /**
      * Random number generator. The random delay will be added into retry timer to avoid all devices
      * around retrying the APN at the same time.
      */
     private Random mRng = new Random();

     /**
      * Retry manager configuration string. See top of the detailed explanation.
      */
     private String mConfig;

     /**
      * The list to store APN setting candidates for data call setup. Most of the carriers only have
      * one APN, but few carriers have more than one.
      */
     private ArrayList<ApnSetting> mWaitingApns = null;

     /**
      * Index pointing to the current trying APN from mWaitingApns
      */
     private int mCurrentApnIndex = -1;

     /**
      * Apn context type. Could be "default, "mms", "supl", etc...
      */
     @UnsupportedAppUsage
     private String mApnType;

     /**
      * Retry manager constructor
      * @param phone Phone object
      * @param apnType APN type
      */
     public RetryManager(Phone phone, String apnType) {
         mPhone = phone;
         mApnType = apnType;
     }

     /**
      * Configure for using string which allow arbitrary
      * sequences of times. See class comments for the
      * string format.
      *
      * @return true if successful
      */
     @UnsupportedAppUsage
     private boolean configure(String configStr) {
         // Strip quotes if present.
         if ((configStr.startsWith("\"") && configStr.endsWith("\""))) {
             configStr = configStr.substring(1, configStr.length() - 1);
         }

         // Reset the retry manager since delay, max retry count, etc...will be reset.
         reset();

         if (DBG) log("configure: '" + configStr + "'");
         mConfig = configStr;

         if (!TextUtils.isEmpty(configStr)) {
             int defaultRandomization = 0;

             if (VDBG) log("configure: not empty");

             String strArray[] = configStr.split(",");
             for (int i = 0; i < strArray.length; i++) {
                 if (VDBG) log("configure: strArray[" + i + "]='" + strArray[i] + "'");
                 Pair<Boolean, Integer> value;
                 String splitStr[] = strArray[i].split("=", 2);
                 splitStr[0] = splitStr[0].trim();
                 if (VDBG) log("configure: splitStr[0]='" + splitStr[0] + "'");
                 if (splitStr.length > 1) {
                     splitStr[1] = splitStr[1].trim();
                     if (VDBG) log("configure: splitStr[1]='" + splitStr[1] + "'");
                     if (TextUtils.equals(splitStr[0], "default_randomization")) {
                         value = parseNonNegativeInt(splitStr[0], splitStr[1]);
                         if (!value.first) return false;
                         defaultRandomization = value.second;
                     } else if (TextUtils.equals(splitStr[0], "max_retries")) {
                         if (TextUtils.equals("infinite", splitStr[1])) {
                             mRetryForever = true;
                         } else {
                             value = parseNonNegativeInt(splitStr[0], splitStr[1]);
                             if (!value.first) return false;
                             mMaxRetryCount = value.second;
                         }
                     } else {
                         Rlog.e(LOG_TAG, "Unrecognized configuration name value pair: "
                                         + strArray[i]);
                         return false;
                     }
                 } else {
                     /**
                      * Assume a retry time with an optional randomization value
                      * following a ":"
                      */
                     splitStr = strArray[i].split(":", 2);
                     splitStr[0] = splitStr[0].trim();
                     RetryRec rr = new RetryRec(0, 0);
                     value = parseNonNegativeInt("delayTime", splitStr[0]);
                     if (!value.first) return false;
                     rr.mDelayTime = value.second;

                     // Check if optional randomization value present
                     if (splitStr.length > 1) {
                         splitStr[1] = splitStr[1].trim();
                         if (VDBG) log("configure: splitStr[1]='" + splitStr[1] + "'");
                         value = parseNonNegativeInt("randomizationTime", splitStr[1]);
                         if (!value.first) return false;
                         rr.mRandomizationTime = value.second;
                     } else {
                         rr.mRandomizationTime = defaultRandomization;
                     }
                     mRetryArray.add(rr);
                 }
             }
             if (mRetryArray.size() > mMaxRetryCount) {
                 mMaxRetryCount = mRetryArray.size();
                 if (VDBG) log("configure: setting mMaxRetryCount=" + mMaxRetryCount);
             }
         } else {
             log("configure: cleared");
         }

         if (VDBG) log("configure: true");
         return true;
     }

     /**
      * Configure the retry manager
      */
     private void configureRetry() {
         String configString = null;
         String otherConfigString = null;

         try {
             if (TelephonyUtils.IS_DEBUGGABLE) {
                 // Using system properties is easier for testing from command line.
                 String config = SystemProperties.get("test.data_retry_config");
                 if (!TextUtils.isEmpty(config)) {
                     configure(config);
                     return;
                 }
             }

             CarrierConfigManager configManager = (CarrierConfigManager)
                     mPhone.getContext().getSystemService(Context.CARRIER_CONFIG_SERVICE);
             PersistableBundle b = configManager.getConfigForSubId(mPhone.getSubId());

             mInterApnDelay = b.getLong(
                     CarrierConfigManager.KEY_CARRIER_DATA_CALL_APN_DELAY_DEFAULT_LONG,
                     DEFAULT_INTER_APN_DELAY);
             mFailFastInterApnDelay = b.getLong(
                     CarrierConfigManager.KEY_CARRIER_DATA_CALL_APN_DELAY_FASTER_LONG,
                     DEFAULT_INTER_APN_DELAY_FOR_PROVISIONING);
             mApnRetryAfterDisconnectDelay = b.getLong(
                     CarrierConfigManager.KEY_CARRIER_DATA_CALL_APN_RETRY_AFTER_DISCONNECT_LONG,
                     DEFAULT_APN_RETRY_AFTER_DISCONNECT_DELAY);

             // Load all retry patterns for all different APNs.
             String[] allConfigStrings = b.getStringArray(
                     CarrierConfigManager.KEY_CARRIER_DATA_CALL_RETRY_CONFIG_STRINGS);
             if (allConfigStrings != null) {
                 for (String s : allConfigStrings) {
                     if (!TextUtils.isEmpty(s)) {
                         String splitStr[] = s.split(":", 2);
                         if (splitStr.length == 2) {
                             String apnType = splitStr[0].trim();
                             // Check if this retry pattern is for the APN we want.
                             if (apnType.equals(mApnType)) {
                                 // Extract the config string. Note that an empty string is valid
                                 // here, meaning no retry for the specified APN.
                                 configString = splitStr[1];
                                 break;
                             } else if (apnType.equals(OTHERS_APN_TYPE)) {
                                 // Extract the config string. Note that an empty string is valid
                                 // here, meaning no retry for all other APNs.
                                 otherConfigString = splitStr[1];
                             }
                         }
                     }
                 }
             }

             if (configString == null) {
                 if (otherConfigString != null) {
                     configString = otherConfigString;
                 } else {
                     // We should never reach here. If we reach here, it must be a configuration
                     // error bug.
                     log("Invalid APN retry configuration!. Use the default one now.");
                     configString = DEFAULT_DATA_RETRY_CONFIG;
                 }
             }
         } catch (NullPointerException ex) {
             // We should never reach here unless there is a bug
             log("Failed to read configuration! Use the hardcoded default value.");

             mInterApnDelay = DEFAULT_INTER_APN_DELAY;
             mFailFastInterApnDelay = DEFAULT_INTER_APN_DELAY_FOR_PROVISIONING;
             configString = DEFAULT_DATA_RETRY_CONFIG;
         }

         if (VDBG) {
             log("mInterApnDelay = " + mInterApnDelay + ", mFailFastInterApnDelay = " +
                     mFailFastInterApnDelay);
         }

         configure(configString);
     }

     /**
      * Return the timer that should be used to trigger the data reconnection
      */
     @UnsupportedAppUsage
     private int getRetryTimer() {
         int index;
         if (mRetryCount < mRetryArray.size()) {
             index = mRetryCount;
         } else {
             index = mRetryArray.size() - 1;
         }

         int retVal;
         if ((index >= 0) && (index < mRetryArray.size())) {
             retVal = mRetryArray.get(index).mDelayTime + nextRandomizationTime(index);
         } else {
             retVal = 0;
         }

         if (DBG) log("getRetryTimer: " + retVal);
         return retVal;
     }

     /**
      * Parse an integer validating the value is not negative.
      * @param name Name
      * @param stringValue Value
      * @return Pair.first == true if stringValue an integer >= 0
      */
     private Pair<Boolean, Integer> parseNonNegativeInt(String name, String stringValue) {
         int value;
         Pair<Boolean, Integer> retVal;
         try {
             value = Integer.parseInt(stringValue);
             retVal = new Pair<Boolean, Integer>(validateNonNegativeInt(name, value), value);
         } catch (NumberFormatException e) {
             Rlog.e(LOG_TAG, name + " bad value: " + stringValue, e);
             retVal = new Pair<Boolean, Integer>(false, 0);
         }
         if (VDBG) {
             log("parseNonNetativeInt: " + name + ", " + stringValue + ", "
                     + retVal.first + ", " + retVal.second);
         }
         return retVal;
     }

     /**
      * Validate an integer is >= 0 and logs an error if not
      * @param name Name
      * @param value Value
      * @return Pair.first
      */
     private boolean validateNonNegativeInt(String name, int value) {
         boolean retVal;
         if (value < 0) {
             Rlog.e(LOG_TAG, name + " bad value: is < 0");
             retVal = false;
         } else {
             retVal = true;
         }
         if (VDBG) log("validateNonNegative: " + name + ", " + value + ", " + retVal);
         return retVal;
     }

     /**
      * Return next random number for the index
      * @param index Retry index
      */
     private int nextRandomizationTime(int index) {
         int randomTime = mRetryArray.get(index).mRandomizationTime;
         if (randomTime == 0) {
             return 0;
         } else {
             return mRng.nextInt(randomTime);
         }
     }

     /**
      * Get the next APN setting for data call setup.
      * @return APN setting to try. {@code null} if cannot find any APN,
      */
     public @Nullable ApnSetting getNextApnSetting() {
         if (mWaitingApns == null || mWaitingApns.size() == 0) {
             log("Waiting APN list is null or empty.");
             return null;
         }

         // If the modem had suggested a retry delay, we should retry the current APN again
         // (up to MAX_SAME_APN_RETRY times) instead of getting the next APN setting from
         // our own list. If the APN waiting list has been reset before a setup data responses
         // arrive (i.e. mCurrentApnIndex=-1), then ignore the modem suggested retry.
         if (mCurrentApnIndex != -1 && mModemSuggestedDelay != NO_SUGGESTED_RETRY_DELAY
                 && mSameApnRetryCount < MAX_SAME_APN_RETRY) {
             mSameApnRetryCount++;
             return mWaitingApns.get(mCurrentApnIndex);
         }

         mSameApnRetryCount = 0;

         int index = mCurrentApnIndex;
         // Loop through the APN list to find out the index of next non-permanent failed APN.
         while (true) {
             if (++index == mWaitingApns.size()) index = 0;

             // Stop if we find the non-failed APN.
             if (!mWaitingApns.get(index).getPermanentFailed()) {
                 break;
             }

             // If all APNs have permanently failed, bail out.
             if (mWaitingApns.stream().allMatch(ApnSetting::getPermanentFailed)) {
                 return null;
             }
         }

         mCurrentApnIndex = index;
         return mWaitingApns.get(mCurrentApnIndex);
     }

     /**
      * Get the delay for trying the next waiting APN from the list.
      * @param failFastEnabled True if fail fast mode enabled. In this case we'll use a shorter
      *                        delay.
      * @return delay in milliseconds
      */
     public long getDelayForNextApn(boolean failFastEnabled) {

         if (mWaitingApns == null || mWaitingApns.size() == 0) {
             log("Waiting APN list is null or empty.");
             return NO_RETRY;
         }

         if (mModemSuggestedDelay == NO_RETRY) {
             log("Modem suggested not retrying.");
             return NO_RETRY;
         }

         if (mModemSuggestedDelay != NO_SUGGESTED_RETRY_DELAY &&
                 mSameApnRetryCount < MAX_SAME_APN_RETRY) {
             // If the modem explicitly suggests a retry delay, we should use it, even in fail fast
             // mode.
             log("Modem suggested retry in " + mModemSuggestedDelay + " ms.");
             return mModemSuggestedDelay;
         }

         // In order to determine the delay to try next APN, we need to peek the next available APN.
         // Case 1 - If we will start the next round of APN trying,
         //    we use the exponential-growth delay. (e.g. 5s, 10s, 30s...etc.)
         // Case 2 - If we are still within the same round of APN trying,
         //    we use the fixed standard delay between APNs. (e.g. 20s)

         int index = mCurrentApnIndex;
         while (true) {
             if (++index >= mWaitingApns.size()) index = 0;

             // Stop if we find the non-failed APN.
             if (!mWaitingApns.get(index).getPermanentFailed()) {
                 break;
             }

             // If all APNs have permanently failed, bail out.
             if (mWaitingApns.stream().allMatch(ApnSetting::getPermanentFailed)) {
                 log("All APNs have permanently failed.");
                 return NO_RETRY;
             }
         }

         long delay;
         if (index <= mCurrentApnIndex) {
             // Case 1, if the next APN is in the next round.
             if (!mRetryForever && mRetryCount + 1 > mMaxRetryCount) {
                 log("Reached maximum retry count " + mMaxRetryCount + ".");
                 return NO_RETRY;
             }
             delay = getRetryTimer();
             ++mRetryCount;
         } else {
             // Case 2, if the next APN is still in the same round.
             delay = mInterApnDelay;
         }

         if (failFastEnabled && delay > mFailFastInterApnDelay) {
             // If we enable fail fast mode, and the delay we got is longer than
             // fail-fast delay (mFailFastInterApnDelay), use the fail-fast delay.
             // If the delay we calculated is already shorter than fail-fast delay,
             // then ignore fail-fast delay.
             delay = mFailFastInterApnDelay;
         }

         return delay;
     }

     /**
      * Mark the APN setting permanently failed.
      * @param apn APN setting to be marked as permanently failed
      * */
     public void markApnPermanentFailed(ApnSetting apn) {
         if (apn != null) {
             apn.setPermanentFailed(true);
         }
     }

     /**
      * Reset the retry manager.
      */
     private void reset() {
         mMaxRetryCount = 0;
         mRetryCount = 0;
         mCurrentApnIndex = -1;
         mSameApnRetryCount = 0;
         mModemSuggestedDelay = NO_SUGGESTED_RETRY_DELAY;
         mRetryArray.clear();
     }

     /**
      * Set waiting APNs for retrying in case needed.
      * @param waitingApns Waiting APN list
      */
     public void setWaitingApns(ArrayList<ApnSetting> waitingApns) {

         if (waitingApns == null) {
             log("No waiting APNs provided");
             return;
         }

         mWaitingApns = waitingApns;

         // Since we replace the entire waiting APN list, we need to re-config this retry manager.
         configureRetry();

         for (ApnSetting apn : mWaitingApns) {
             apn.setPermanentFailed(false);
         }

         log("Setting " + mWaitingApns.size() + " waiting APNs.");

         if (VDBG) {
             for (int i = 0; i < mWaitingApns.size(); i++) {
                 log("  [" + i + "]:" + mWaitingApns.get(i));
             }
         }
     }

     /**
      * Get the list of waiting APNs.
      * @return the list of waiting APNs
      */
     public ArrayList<ApnSetting> getWaitingApns() {
         return mWaitingApns;
     }

     /**
      * Save the modem suggested delay for retrying the current APN.
      * This method is called when we get the suggested delay from RIL.
      * @param delay The delay in milliseconds
      */
     public void setModemSuggestedDelay(long delay) {
         if (mCurrentApnIndex == -1) {
             log("Waiting APN list has been reset. Ignore the value from modem.");
             return;
         }
         mModemSuggestedDelay = delay;
     }

     /**
      * Get the delay in milliseconds for APN retry after disconnect
      * @return The delay in milliseconds
      */
     public long getRetryAfterDisconnectDelay() {
         return mApnRetryAfterDisconnectDelay;
     }

     public String toString() {
         if (mConfig == null) return "";
         return "RetryManager: mApnType=" + mApnType + " mRetryCount=" + mRetryCount
                 + " mMaxRetryCount=" + mMaxRetryCount + " mCurrentApnIndex=" + mCurrentApnIndex
                 + " mSameApnRtryCount=" + mSameApnRetryCount + " mModemSuggestedDelay="
                 + mModemSuggestedDelay + " mRetryForever=" + mRetryForever + " mInterApnDelay="
                 + mInterApnDelay + " mApnRetryAfterDisconnectDelay=" + mApnRetryAfterDisconnectDelay
                 + " mConfig={" + mConfig + "}";
     }

     @UnsupportedAppUsage
     private void log(String s) {
         Rlog.d(LOG_TAG, "[" + mApnType + "] " + s);
     }
 }
	/**
	* Copyright (C) 2009 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.android.internal.telephony;

	import android.annotation.Nullable;
	import android.compat.annotation.UnsupportedAppUsage;
	import android.content.Context;
	import android.os.PersistableBundle;
	import android.os.SystemProperties;
	import android.telephony.CarrierConfigManager;
	import android.telephony.data.ApnSetting;
	import android.text.TextUtils;
	import android.util.Pair;

	import com.android.internal.telephony.util.TelephonyUtils;
	import com.android.telephony.Rlog;

	import java.util.ArrayList;
	import java.util.Random;

	/**
	* Retry manager allows a simple way to declare a series of
	* retry timeouts. After creating a RetryManager the configure
	* method is used to define the sequence. A simple linear series
	* may be initialized using configure with three integer parameters
	* The other configure method allows a series to be declared using
	* a string.
	*<p>
	* The format of the configuration string is the apn type followed by a series of parameters
	* separated by a comma. There are two name value pair parameters plus a series
	* of delay times. The units of of these delay times is unspecified.
	* The name value pairs which may be specified are:
	*<ul>
	*<li>max_retries=<value>
	*<li>default_randomizationTime=<value>
	*</ul>
	*<p>
	* apn type specifies the APN type that the retry pattern will apply for. "others" is for all other
	* APN types not specified in the config.
	*
	* max_retries is the number of times that incrementRetryCount
	* maybe called before isRetryNeeded will return false. if value
	* is infinite then isRetryNeeded will always return true.
	*
	* default_randomizationTime will be used as the randomizationTime
	* for delay times which have no supplied randomizationTime. If
	* default_randomizationTime is not defined it defaults to 0.
	*<p>
	* The other parameters define The series of delay times and each
	* may have an optional randomization value separated from the
	* delay time by a colon.
	*<p>
	* Examples:
	* <ul>
	* <li>3 retries for mms with no randomization value which means its 0:
	* <ul><li><code>"mms:1000, 2000, 3000"</code></ul>
	*
	* <li>10 retries for default APN with a 500 default randomization value for each and
	* the 4..10 retries all using 3000 as the delay:
	* <ul><li><code>"default:max_retries=10, default_randomization=500, 1000, 2000, 3000"</code></ul>
	*
	* <li>4 retries for supl APN with a 100 as the default randomization value for the first 2 values
	* and the other two having specified values of 500:
	* <ul><li><code>"supl:default_randomization=100, 1000, 2000, 4000:500, 5000:500"</code></ul>
	*
	* <li>Infinite number of retries for all other APNs with the first one at 1000, the second at 2000
	* all others will be at 3000.
	* <ul><li><code>"others:max_retries=infinite,1000,2000,3000</code></ul>
	* </ul>
	*
	* {@hide}
	*/
	public class RetryManager {
	public static final String LOG_TAG = "RetryManager";
	public static final boolean DBG = true;
	public static final boolean VDBG = false; // STOPSHIP if true

	/**
	* The default retry configuration for APNs. See above for the syntax.
	*/
	private static final String DEFAULT_DATA_RETRY_CONFIG = "max_retries=3, 5000, 5000, 5000";

	/**
	* The APN type used for all other APNs retry configuration.
	*/
	private static final String OTHERS_APN_TYPE = "others";

	/**
	* The default value (in milliseconds) for delay between APN trying (mInterApnDelay)
	* within the same round
	*/
	private static final long DEFAULT_INTER_APN_DELAY = 20000;

	/**
	* The default value (in milliseconds) for delay between APN trying (mFailFastInterApnDelay)
	* within the same round when we are in fail fast mode
	*/
	private static final long DEFAULT_INTER_APN_DELAY_FOR_PROVISIONING = 3000;

	/**
	* The default value (in milliseconds) for retrying APN after disconnect
	*/
	private static final long DEFAULT_APN_RETRY_AFTER_DISCONNECT_DELAY = 10000;

	/**
	* The value indicating no retry is needed
	*/
	public static final long NO_RETRY = -1;

	/**
	* The value indicating modem did not suggest any retry delay
	*/
	public static final long NO_SUGGESTED_RETRY_DELAY = -2;

	/**
	* If the modem suggests a retry delay in the data call setup response, we will retry
	* the current APN setting again. However, if the modem keeps suggesting retrying the same
	* APN setting, we'll fall into an infinite loop. Therefore adding a counter to retry up to
	* MAX_SAME_APN_RETRY times can avoid it.
	*/
	private static final int MAX_SAME_APN_RETRY = 3;

	/**
	* The delay (in milliseconds) between APN trying within the same round
	*/
	@UnsupportedAppUsage
	private long mInterApnDelay;

	/**
	* The delay (in milliseconds) between APN trying within the same round when we are in
	* fail fast mode
	*/
	@UnsupportedAppUsage
	private long mFailFastInterApnDelay;

	/**
	* The delay (in milliseconds) for APN retrying after disconnect (e.g. Modem suddenly reports
	* data call lost)
	*/
	private long mApnRetryAfterDisconnectDelay;

	/**
	* Modem suggested delay for retrying the current APN
	*/
	private long mModemSuggestedDelay = NO_SUGGESTED_RETRY_DELAY;

	/**
	* The counter for same APN retrying. See MAX_SAME_APN_RETRY for the details.
	*/
	private int mSameApnRetryCount = 0;

	/**
	* Retry record with times in milli-seconds
	*/
	private static class RetryRec {
	RetryRec(int delayTime, int randomizationTime) {
	mDelayTime = delayTime;
	mRandomizationTime = randomizationTime;
	}

	int mDelayTime;
	int mRandomizationTime;
	}

	/**
	* The array of retry records
	*/
	private ArrayList<RetryRec> mRetryArray = new ArrayList<RetryRec>();

	@UnsupportedAppUsage
	private Phone mPhone;

	/**
	* Flag indicating whether retrying forever regardless the maximum retry count mMaxRetryCount
	*/
	private boolean mRetryForever = false;

	/**
	* The maximum number of retries to attempt
	*/
	private int mMaxRetryCount;

	/**
	* The current number of retries
	*/
	private int mRetryCount = 0;

	/**
	* Random number generator. The random delay will be added into retry timer to avoid all devices
	* around retrying the APN at the same time.
	*/
	private Random mRng = new Random();

	/**
	* Retry manager configuration string. See top of the detailed explanation.
	*/
	private String mConfig;

	/**
	* The list to store APN setting candidates for data call setup. Most of the carriers only have
	* one APN, but few carriers have more than one.
	*/
	private ArrayList<ApnSetting> mWaitingApns = null;

	/**
	* Index pointing to the current trying APN from mWaitingApns
	*/
	private int mCurrentApnIndex = -1;

	/**
	* Apn context type. Could be "default, "mms", "supl", etc...
	*/
	@UnsupportedAppUsage
	private String mApnType;

	/**
	* Retry manager constructor
	* @param phone Phone object
	* @param apnType APN type
	*/
	public RetryManager(Phone phone, String apnType) {
	mPhone = phone;
	mApnType = apnType;
	}

	/**
	* Configure for using string which allow arbitrary
	* sequences of times. See class comments for the
	* string format.
	*
	* @return true if successful
	*/
	@UnsupportedAppUsage
	private boolean configure(String configStr) {
	// Strip quotes if present.
	if ((configStr.startsWith("\"") && configStr.endsWith("\""))) {
	configStr = configStr.substring(1, configStr.length() - 1);
	}

	// Reset the retry manager since delay, max retry count, etc...will be reset.
	reset();

	if (DBG) log("configure: '" + configStr + "'");
	mConfig = configStr;

	if (!TextUtils.isEmpty(configStr)) {
	int defaultRandomization = 0;

	if (VDBG) log("configure: not empty");

	String strArray[] = configStr.split(",");
	for (int i = 0; i < strArray.length; i++) {
	if (VDBG) log("configure: strArray[" + i + "]='" + strArray[i] + "'");
	Pair<Boolean, Integer> value;
	String splitStr[] = strArray[i].split("=", 2);
	splitStr[0] = splitStr[0].trim();
	if (VDBG) log("configure: splitStr[0]='" + splitStr[0] + "'");
	if (splitStr.length > 1) {
	splitStr[1] = splitStr[1].trim();
	if (VDBG) log("configure: splitStr[1]='" + splitStr[1] + "'");
	if (TextUtils.equals(splitStr[0], "default_randomization")) {
	value = parseNonNegativeInt(splitStr[0], splitStr[1]);
	if (!value.first) return false;
	defaultRandomization = value.second;
	} else if (TextUtils.equals(splitStr[0], "max_retries")) {
	if (TextUtils.equals("infinite", splitStr[1])) {
	mRetryForever = true;
	} else {
	value = parseNonNegativeInt(splitStr[0], splitStr[1]);
	if (!value.first) return false;
	mMaxRetryCount = value.second;
	}
	} else {
	Rlog.e(LOG_TAG, "Unrecognized configuration name value pair: "
	+ strArray[i]);
	return false;
	}
	} else {
	/**
	* Assume a retry time with an optional randomization value
	* following a ":"
	*/
	splitStr = strArray[i].split(":", 2);
	splitStr[0] = splitStr[0].trim();
	RetryRec rr = new RetryRec(0, 0);
	value = parseNonNegativeInt("delayTime", splitStr[0]);
	if (!value.first) return false;
	rr.mDelayTime = value.second;

	// Check if optional randomization value present
	if (splitStr.length > 1) {
	splitStr[1] = splitStr[1].trim();
	if (VDBG) log("configure: splitStr[1]='" + splitStr[1] + "'");
	value = parseNonNegativeInt("randomizationTime", splitStr[1]);
	if (!value.first) return false;
	rr.mRandomizationTime = value.second;
	} else {
	rr.mRandomizationTime = defaultRandomization;
	}
	mRetryArray.add(rr);
	}
	}
	if (mRetryArray.size() > mMaxRetryCount) {
	mMaxRetryCount = mRetryArray.size();
	if (VDBG) log("configure: setting mMaxRetryCount=" + mMaxRetryCount);
	}
	} else {
	log("configure: cleared");
	}

	if (VDBG) log("configure: true");
	return true;
	}

	/**
	* Configure the retry manager
	*/
	private void configureRetry() {
	String configString = null;
	String otherConfigString = null;

	try {
	if (TelephonyUtils.IS_DEBUGGABLE) {
	// Using system properties is easier for testing from command line.
	String config = SystemProperties.get("test.data_retry_config");
	if (!TextUtils.isEmpty(config)) {
	configure(config);
	return;
	}
	}

	CarrierConfigManager configManager = (CarrierConfigManager)
	mPhone.getContext().getSystemService(Context.CARRIER_CONFIG_SERVICE);
	PersistableBundle b = configManager.getConfigForSubId(mPhone.getSubId());

	mInterApnDelay = b.getLong(
	CarrierConfigManager.KEY_CARRIER_DATA_CALL_APN_DELAY_DEFAULT_LONG,
	DEFAULT_INTER_APN_DELAY);
	mFailFastInterApnDelay = b.getLong(
	CarrierConfigManager.KEY_CARRIER_DATA_CALL_APN_DELAY_FASTER_LONG,
	DEFAULT_INTER_APN_DELAY_FOR_PROVISIONING);
	mApnRetryAfterDisconnectDelay = b.getLong(
	CarrierConfigManager.KEY_CARRIER_DATA_CALL_APN_RETRY_AFTER_DISCONNECT_LONG,
	DEFAULT_APN_RETRY_AFTER_DISCONNECT_DELAY);

	// Load all retry patterns for all different APNs.
	String[] allConfigStrings = b.getStringArray(
	CarrierConfigManager.KEY_CARRIER_DATA_CALL_RETRY_CONFIG_STRINGS);
	if (allConfigStrings != null) {
	for (String s : allConfigStrings) {
	if (!TextUtils.isEmpty(s)) {
	String splitStr[] = s.split(":", 2);
	if (splitStr.length == 2) {
	String apnType = splitStr[0].trim();
	// Check if this retry pattern is for the APN we want.
	if (apnType.equals(mApnType)) {
	// Extract the config string. Note that an empty string is valid
	// here, meaning no retry for the specified APN.
	configString = splitStr[1];
	break;
	} else if (apnType.equals(OTHERS_APN_TYPE)) {
	// Extract the config string. Note that an empty string is valid
	// here, meaning no retry for all other APNs.
	otherConfigString = splitStr[1];
	}
	}
	}
	}
	}

	if (configString == null) {
	if (otherConfigString != null) {
	configString = otherConfigString;
	} else {
	// We should never reach here. If we reach here, it must be a configuration
	// error bug.
	log("Invalid APN retry configuration!. Use the default one now.");
	configString = DEFAULT_DATA_RETRY_CONFIG;
	}
	}
	} catch (NullPointerException ex) {
	// We should never reach here unless there is a bug
	log("Failed to read configuration! Use the hardcoded default value.");

	mInterApnDelay = DEFAULT_INTER_APN_DELAY;
	mFailFastInterApnDelay = DEFAULT_INTER_APN_DELAY_FOR_PROVISIONING;
	configString = DEFAULT_DATA_RETRY_CONFIG;
	}

	if (VDBG) {
	log("mInterApnDelay = " + mInterApnDelay + ", mFailFastInterApnDelay = " +
	mFailFastInterApnDelay);
	}

	configure(configString);
	}

	/**
	* Return the timer that should be used to trigger the data reconnection
	*/
	@UnsupportedAppUsage
	private int getRetryTimer() {
	int index;
	if (mRetryCount < mRetryArray.size()) {
	index = mRetryCount;
	} else {
	index = mRetryArray.size() - 1;
	}

	int retVal;
	if ((index >= 0) && (index < mRetryArray.size())) {
	retVal = mRetryArray.get(index).mDelayTime + nextRandomizationTime(index);
	} else {
	retVal = 0;
	}

	if (DBG) log("getRetryTimer: " + retVal);
	return retVal;
	}

	/**
	* Parse an integer validating the value is not negative.
	* @param name Name
	* @param stringValue Value
	* @return Pair.first == true if stringValue an integer >= 0
	*/
	private Pair<Boolean, Integer> parseNonNegativeInt(String name, String stringValue) {
	int value;
	Pair<Boolean, Integer> retVal;
	try {
	value = Integer.parseInt(stringValue);
	retVal = new Pair<Boolean, Integer>(validateNonNegativeInt(name, value), value);
	} catch (NumberFormatException e) {
	Rlog.e(LOG_TAG, name + " bad value: " + stringValue, e);
	retVal = new Pair<Boolean, Integer>(false, 0);
	}
	if (VDBG) {
	log("parseNonNetativeInt: " + name + ", " + stringValue + ", "
	+ retVal.first + ", " + retVal.second);
	}
	return retVal;
	}

	/**
	* Validate an integer is >= 0 and logs an error if not
	* @param name Name
	* @param value Value
	* @return Pair.first
	*/
	private boolean validateNonNegativeInt(String name, int value) {
	boolean retVal;
	if (value < 0) {
	Rlog.e(LOG_TAG, name + " bad value: is < 0");
	retVal = false;
	} else {
	retVal = true;
	}
	if (VDBG) log("validateNonNegative: " + name + ", " + value + ", " + retVal);
	return retVal;
	}

	/**
	* Return next random number for the index
	* @param index Retry index
	*/
	private int nextRandomizationTime(int index) {
	int randomTime = mRetryArray.get(index).mRandomizationTime;
	if (randomTime == 0) {
	return 0;
	} else {
	return mRng.nextInt(randomTime);
	}
	}

	/**
	* Get the next APN setting for data call setup.
	* @return APN setting to try. {@code null} if cannot find any APN,
	*/
	public @Nullable ApnSetting getNextApnSetting() {
	if (mWaitingApns == null \|\| mWaitingApns.size() == 0) {
	log("Waiting APN list is null or empty.");
	return null;
	}

	// If the modem had suggested a retry delay, we should retry the current APN again
	// (up to MAX_SAME_APN_RETRY times) instead of getting the next APN setting from
	// our own list. If the APN waiting list has been reset before a setup data responses
	// arrive (i.e. mCurrentApnIndex=-1), then ignore the modem suggested retry.
	if (mCurrentApnIndex != -1 && mModemSuggestedDelay != NO_SUGGESTED_RETRY_DELAY
	&& mSameApnRetryCount < MAX_SAME_APN_RETRY) {
	mSameApnRetryCount++;
	return mWaitingApns.get(mCurrentApnIndex);
	}

	mSameApnRetryCount = 0;

	int index = mCurrentApnIndex;
	// Loop through the APN list to find out the index of next non-permanent failed APN.
	while (true) {
	if (++index == mWaitingApns.size()) index = 0;

	// Stop if we find the non-failed APN.
	if (!mWaitingApns.get(index).getPermanentFailed()) {
	break;
	}

	// If all APNs have permanently failed, bail out.
	if (mWaitingApns.stream().allMatch(ApnSetting::getPermanentFailed)) {
	return null;
	}
	}

	mCurrentApnIndex = index;
	return mWaitingApns.get(mCurrentApnIndex);
	}

	/**
	* Get the delay for trying the next waiting APN from the list.
	* @param failFastEnabled True if fail fast mode enabled. In this case we'll use a shorter
	* delay.
	* @return delay in milliseconds
	*/
	public long getDelayForNextApn(boolean failFastEnabled) {

	if (mWaitingApns == null \|\| mWaitingApns.size() == 0) {
	log("Waiting APN list is null or empty.");
	return NO_RETRY;
	}

	if (mModemSuggestedDelay == NO_RETRY) {
	log("Modem suggested not retrying.");
	return NO_RETRY;
	}

	if (mModemSuggestedDelay != NO_SUGGESTED_RETRY_DELAY &&
	mSameApnRetryCount < MAX_SAME_APN_RETRY) {
	// If the modem explicitly suggests a retry delay, we should use it, even in fail fast
	// mode.
	log("Modem suggested retry in " + mModemSuggestedDelay + " ms.");
	return mModemSuggestedDelay;
	}

	// In order to determine the delay to try next APN, we need to peek the next available APN.
	// Case 1 - If we will start the next round of APN trying,
	// we use the exponential-growth delay. (e.g. 5s, 10s, 30s...etc.)
	// Case 2 - If we are still within the same round of APN trying,
	// we use the fixed standard delay between APNs. (e.g. 20s)

	int index = mCurrentApnIndex;
	while (true) {
	if (++index >= mWaitingApns.size()) index = 0;

	// Stop if we find the non-failed APN.
	if (!mWaitingApns.get(index).getPermanentFailed()) {
	break;
	}

	// If all APNs have permanently failed, bail out.
	if (mWaitingApns.stream().allMatch(ApnSetting::getPermanentFailed)) {
	log("All APNs have permanently failed.");
	return NO_RETRY;
	}
	}

	long delay;
	if (index <= mCurrentApnIndex) {
	// Case 1, if the next APN is in the next round.
	if (!mRetryForever && mRetryCount + 1 > mMaxRetryCount) {
	log("Reached maximum retry count " + mMaxRetryCount + ".");
	return NO_RETRY;
	}
	delay = getRetryTimer();
	++mRetryCount;
	} else {
	// Case 2, if the next APN is still in the same round.
	delay = mInterApnDelay;
	}

	if (failFastEnabled && delay > mFailFastInterApnDelay) {
	// If we enable fail fast mode, and the delay we got is longer than
	// fail-fast delay (mFailFastInterApnDelay), use the fail-fast delay.
	// If the delay we calculated is already shorter than fail-fast delay,
	// then ignore fail-fast delay.
	delay = mFailFastInterApnDelay;
	}

	return delay;
	}

	/**
	* Mark the APN setting permanently failed.
	* @param apn APN setting to be marked as permanently failed
	* */
	public void markApnPermanentFailed(ApnSetting apn) {
	if (apn != null) {
	apn.setPermanentFailed(true);
	}
	}

	/**
	* Reset the retry manager.
	*/
	private void reset() {
	mMaxRetryCount = 0;
	mRetryCount = 0;
	mCurrentApnIndex = -1;
	mSameApnRetryCount = 0;
	mModemSuggestedDelay = NO_SUGGESTED_RETRY_DELAY;
	mRetryArray.clear();
	}

	/**
	* Set waiting APNs for retrying in case needed.
	* @param waitingApns Waiting APN list
	*/
	public void setWaitingApns(ArrayList<ApnSetting> waitingApns) {

	if (waitingApns == null) {
	log("No waiting APNs provided");
	return;
	}

	mWaitingApns = waitingApns;

	// Since we replace the entire waiting APN list, we need to re-config this retry manager.
	configureRetry();

	for (ApnSetting apn : mWaitingApns) {
	apn.setPermanentFailed(false);
	}

	log("Setting " + mWaitingApns.size() + " waiting APNs.");

	if (VDBG) {
	for (int i = 0; i < mWaitingApns.size(); i++) {
	log(" [" + i + "]:" + mWaitingApns.get(i));
	}
	}
	}

	/**
	* Get the list of waiting APNs.
	* @return the list of waiting APNs
	*/
	public ArrayList<ApnSetting> getWaitingApns() {
	return mWaitingApns;
	}

	/**
	* Save the modem suggested delay for retrying the current APN.
	* This method is called when we get the suggested delay from RIL.
	* @param delay The delay in milliseconds
	*/
	public void setModemSuggestedDelay(long delay) {
	if (mCurrentApnIndex == -1) {
	log("Waiting APN list has been reset. Ignore the value from modem.");
	return;
	}
	mModemSuggestedDelay = delay;
	}

	/**
	* Get the delay in milliseconds for APN retry after disconnect
	* @return The delay in milliseconds
	*/
	public long getRetryAfterDisconnectDelay() {
	return mApnRetryAfterDisconnectDelay;
	}

	public String toString() {
	if (mConfig == null) return "";
	return "RetryManager: mApnType=" + mApnType + " mRetryCount=" + mRetryCount
	+ " mMaxRetryCount=" + mMaxRetryCount + " mCurrentApnIndex=" + mCurrentApnIndex
	+ " mSameApnRtryCount=" + mSameApnRetryCount + " mModemSuggestedDelay="
	+ mModemSuggestedDelay + " mRetryForever=" + mRetryForever + " mInterApnDelay="
	+ mInterApnDelay + " mApnRetryAfterDisconnectDelay=" + mApnRetryAfterDisconnectDelay
	+ " mConfig={" + mConfig + "}";
	}

	@UnsupportedAppUsage
	private void log(String s) {
	Rlog.d(LOG_TAG, "[" + mApnType + "] " + s);
	}
	}