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Commit 8948c01e authored by Jeff Sharkey's avatar Jeff Sharkey
Browse files

Yell when calling installd with PM lock held. 

As a matter of policy, we should never be holding the mPackages lock
while calling down into installd.  This little bit of logic helps us
catch accidental cases where this happens.

Change-Id: I676c81df43ef936ffd36290d45a79429630c1b4b
parent fafb81b7

core/java/com/android/internal/os/InstallerConnection.java

+18 −0
Original line number Diff line number Diff line
@@ -21,6 +21,8 @@ import android.net.LocalSocketAddress; 
import android.os.SystemClock;

import android.util.Slog;



import com.android.internal.util.Preconditions;



import libcore.io.IoUtils;

import libcore.io.Streams;
@@ -42,11 +44,22 @@ public class InstallerConnection { 
    private OutputStream mOut;

    private LocalSocket mSocket;



    private volatile Object mWarnIfHeld;



    private final byte buf[] = new byte[1024];



    public InstallerConnection() {

    }



    /**

     * Yell loudly if someone tries making future calls while holding a lock on

     * the given object.

     */

    public void setWarnIfHeld(Object warnIfHeld) {

        Preconditions.checkState(mWarnIfHeld == null);

        mWarnIfHeld = Preconditions.checkNotNull(warnIfHeld);

    }



    public synchronized String transact(String cmd) {

        if (!connect()) {

            Slog.e(TAG, "connection failed");
@@ -84,6 +97,11 @@ public class InstallerConnection { 
    }



    public int execute(String cmd) {

        if (mWarnIfHeld != null && Thread.holdsLock(mWarnIfHeld)) {

            Slog.wtf(TAG, "Calling thread " + Thread.currentThread().getName() + " is holding 0x"

                    + Integer.toHexString(System.identityHashCode(mWarnIfHeld)), new Throwable());

        }



        String res = transact(cmd);

        try {

            return Integer.parseInt(res);

services/core/java/com/android/server/MountService.java

+1 −1
Original line number Diff line number Diff line
@@ -1440,7 +1440,7 @@ class MountService extends IMountService.Stub 
        mConnector = new NativeDaemonConnector(this, "vold", MAX_CONTAINERS * 2, VOLD_TAG, 25,

                null);

        mConnector.setDebug(true);

        mConnector.setLockWarning(mLock);

        mConnector.setWarnIfHeld(mLock);



        Thread thread = new Thread(mConnector, VOLD_TAG);

        thread.start();

services/core/java/com/android/server/NativeDaemonConnector.java

+10 −8
Original line number Diff line number Diff line
@@ -25,10 +25,10 @@ import android.os.Message; 
import android.os.PowerManager;

import android.os.SystemClock;

import android.util.LocalLog;

import android.util.Log;

import android.util.Slog;



import com.android.internal.annotations.VisibleForTesting;

import com.android.internal.util.Preconditions;

import com.google.android.collect.Lists;



import java.io.FileDescriptor;
@@ -58,7 +58,7 @@ final class NativeDaemonConnector implements Runnable, Handler.Callback, Watchdo 
    private LocalLog mLocalLog;



    private volatile boolean mDebug = false;

    private volatile Object mLockWarning;

    private volatile Object mWarnIfHeld;



    private final ResponseQueue mResponseQueue;
@@ -110,11 +110,12 @@ final class NativeDaemonConnector implements Runnable, Handler.Callback, Watchdo 
    }



    /**

     * Yell loudly if someone tries making future {@link #execute(Command)} calls while holding a

     * lock on the given object.

     * Yell loudly if someone tries making future {@link #execute(Command)}

     * calls while holding a lock on the given object.

     */

    public void setLockWarning(Object lockWarning) {

        mLockWarning = lockWarning;

    public void setWarnIfHeld(Object warnIfHeld) {

        Preconditions.checkState(mWarnIfHeld == null);

        mWarnIfHeld = Preconditions.checkNotNull(warnIfHeld);

    }



    @Override
@@ -404,8 +405,9 @@ final class NativeDaemonConnector implements Runnable, Handler.Callback, Watchdo 
     */

    public NativeDaemonEvent[] executeForList(long timeoutMs, String cmd, Object... args)

            throws NativeDaemonConnectorException {

        if (mLockWarning != null && Thread.holdsLock(mLockWarning)) {

            Log.wtf(TAG, "Calling thread is holding lock " + mLockWarning, new Throwable());

        if (mWarnIfHeld != null && Thread.holdsLock(mWarnIfHeld)) {

            Slog.wtf(TAG, "Calling thread " + Thread.currentThread().getName() + " is holding 0x"

                    + Integer.toHexString(System.identityHashCode(mWarnIfHeld)), new Throwable());

        }



        final long startTime = SystemClock.elapsedRealtime();

services/core/java/com/android/server/pm/Installer.java

+8 −0
Original line number Diff line number Diff line
@@ -53,6 +53,14 @@ public final class Installer extends SystemService { 
        mInstaller = new InstallerConnection();

    }



    /**

     * Yell loudly if someone tries making future calls while holding a lock on

     * the given object.

     */

    public void setWarnIfHeld(Object warnIfHeld) {

        mInstaller.setWarnIfHeld(warnIfHeld);

    }



    @Override

    public void onStart() {

        Slog.i(TAG, "Waiting for installd to be ready.");

services/core/java/com/android/server/pm/PackageManagerService.java

+5 −0
Original line number Diff line number Diff line
@@ -2391,6 +2391,11 @@ public class PackageManagerService extends IPackageManager.Stub { 
        // tidy.

        Runtime.getRuntime().gc();













        // The initial scanning above does many calls into installd while













        // holding the mPackages lock, but we're mostly interested in yelling













        // once we have a booted system.













        mInstaller.setWarnIfHeld(mPackages);



























        // Expose private service for system components to use.















        LocalServices.addService(PackageManagerInternal.class, new PackageManagerInternalImpl());















    }