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Commit f9b74cc7 authored by Michal Karpinski's avatar Michal Karpinski
Browse files

[RefactoredBMS] Ensure backup doesn't reuse ack tokens nearby in time 

This CL replicates both ag/2551800 and ag/2613950 in RefactoredBMS.

Test: runtest -p com.android.server.backup frameworks-services
Bug: 37973765
Change-Id: I5e42dee67d587adabbfb81de03f3205d92a46add
parent 78ec67a2

services/backup/java/com/android/server/backup/RefactoredBackupManagerService.java

+9 −7
Original line number Diff line number Diff line
@@ -150,6 +150,7 @@ import java.util.Queue; 
import java.util.Random;

import java.util.Set;

import java.util.concurrent.CountDownLatch;

import java.util.concurrent.atomic.AtomicInteger;



public class RefactoredBackupManagerService implements BackupManagerServiceInterface {
@@ -626,6 +627,7 @@ public class RefactoredBackupManagerService implements BackupManagerServiceInter 
    private final SparseArray<Operation> mCurrentOperations = new SparseArray<>();

    private final Object mCurrentOpLock = new Object();

    private final Random mTokenGenerator = new Random();

    final AtomicInteger mNextToken = new AtomicInteger();



    private final SparseArray<AdbParams> mAdbBackupRestoreConfirmations = new SparseArray<>();
@@ -665,15 +667,15 @@ public class RefactoredBackupManagerService implements BackupManagerServiceInter 
    @GuardedBy("mQueueLock")

    private ArrayList<FullBackupEntry> mFullBackupQueue;



    // Utility: build a new random integer token

    // Utility: build a new random integer token. The low bits are the ordinal of the

    // operation for near-time uniqueness, and the upper bits are random for app-

    // side unpredictability.

    @Override

    public int generateRandomIntegerToken() {

        int token;

        do {

            synchronized (mTokenGenerator) {

                token = mTokenGenerator.nextInt();

            }

        } while (token < 0);

        int token = mTokenGenerator.nextInt();

        if (token < 0) token = -token;

        token &= ~0xFF;

        token |= (mNextToken.incrementAndGet() & 0xFF);

        return token;

    }