Limit broadcast rate for low priority DropBox entries (fd6523ec) · Commits · e / os / android_frameworks_base

core/java/android/os/DropBoxManager.java

+2 −1

Original line number	Diff line number	Diff line
		@@ -69,7 +69,8 @@ public class DropBoxManager {
		/**
		* Broadcast Action: This is broadcast when a new entry is added in the dropbox.
		* You must hold the {@link android.Manifest.permission#READ_LOGS} permission
		* in order to receive this broadcast.
		* in order to receive this broadcast. This broadcast can be rate limited for low priority
		* entries
		*
		* <p class="note">This is a protected intent that can only be sent
		* by the system.

core/res/res/values/config.xml

+15 −0

Original line number	Diff line number	Diff line
		@@ -3978,4 +3978,19 @@

		<!-- Whether or not to enable automatic heap dumps for the system server on debuggable builds. -->
		<bool name="config_debugEnableAutomaticSystemServerHeapDumps">false</bool>

		<!-- See DropBoxManagerService.
		The minimum period in milliseconds between broadcasts for entries with low priority
		dropbox tags. -->
		<integer name="config_dropboxLowPriorityBroadcastRateLimitPeriod">2000</integer>

		<!-- See DropBoxManagerService.
		An array of dropbox entry tags to marked as low priority. Low priority broadcasts will be
		rated limited to a period defined by config_dropboxLowPriorityBroadcastRateLimitPeriod
		(high frequency broadcasts for the tag will be dropped) -->
		<string-array name="config_dropboxLowPriorityTags" translatable="false">
		<item>keymaster</item>
		<item>system_server_strictmode</item>
		</string-array>

		</resources>

core/res/res/values/symbols.xml

+3 −0

Original line number	Diff line number	Diff line
		@@ -3730,4 +3730,7 @@
		<java-symbol type="dimen" name="resolver_icon_size"/>
		<java-symbol type="dimen" name="resolver_badge_size"/>

		<!-- For DropBox -->
		<java-symbol type="integer" name="config_dropboxLowPriorityBroadcastRateLimitPeriod" />
		<java-symbol type="array" name="config_dropboxLowPriorityTags" />
		</resources>

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

+191 −20

Original line number	Diff line number	Diff line
		@@ -23,6 +23,7 @@ import android.content.ContentResolver;
		import android.content.Context;
		import android.content.Intent;
		import android.content.IntentFilter;
		import android.content.res.Resources;
		import android.database.ContentObserver;
		import android.net.Uri;
		import android.os.Binder;
		@@ -32,6 +33,9 @@ import android.os.FileUtils;
		import android.os.Handler;
		import android.os.Looper;
		import android.os.Message;
		import android.os.ResultReceiver;
		import android.os.ShellCallback;
		import android.os.ShellCommand;
		import android.os.StatFs;
		import android.os.SystemClock;
		import android.os.UserHandle;
		@@ -39,8 +43,11 @@ import android.provider.Settings;
		import android.text.TextUtils;
		import android.text.format.Time;
		import android.util.ArrayMap;
		import android.util.ArraySet;
		import android.util.Slog;

		import com.android.internal.R;
		import com.android.internal.annotations.GuardedBy;
		import com.android.internal.annotations.VisibleForTesting;
		import com.android.internal.os.IDropBoxManagerService;
		import com.android.internal.util.DumpUtils;
		@@ -76,9 +83,6 @@ public final class DropBoxManagerService extends SystemService {
		private static final int DEFAULT_RESERVE_PERCENT = 10;
		private static final int QUOTA_RESCAN_MILLIS = 5000;

		// mHandler 'what' value.
		private static final int MSG_SEND_BROADCAST = 1;

		private static final boolean PROFILE_DUMP = false;

		// TODO: This implementation currently uses one file per entry, which is
		@@ -95,6 +99,9 @@ public final class DropBoxManagerService extends SystemService {
		private FileList mAllFiles = null;
		private ArrayMap<String, FileList> mFilesByTag = null;

		private long mLowPriorityRateLimitPeriod = 0;
		private ArraySet<String> mLowPriorityTags = null;

		// Various bits of disk information

		private StatFs mStatFs = null;
		@@ -105,7 +112,7 @@ public final class DropBoxManagerService extends SystemService {
		private volatile boolean mBooted = false;

		// Provide a way to perform sendBroadcast asynchronously to avoid deadlocks.
		private final Handler mHandler;
		private final DropBoxManagerBroadcastHandler mHandler;

		private int mMaxFiles = -1; // -1 means uninitialized.

		@@ -152,8 +159,142 @@ public final class DropBoxManagerService extends SystemService {
		public void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
		DropBoxManagerService.this.dump(fd, pw, args);
		}

		@Override
		public void onShellCommand(FileDescriptor in, FileDescriptor out,
		FileDescriptor err, String[] args, ShellCallback callback,
		ResultReceiver resultReceiver) {
		(new ShellCmd()).exec(this, in, out, err, args, callback, resultReceiver);
		}
		};

		private class ShellCmd extends ShellCommand {
		@Override
		public int onCommand(String cmd) {
		if (cmd == null) {
		return handleDefaultCommands(cmd);
		}
		final PrintWriter pw = getOutPrintWriter();
		try {
		switch (cmd) {
		case "set-rate-limit":
		final long period = Long.parseLong(getNextArgRequired());
		DropBoxManagerService.this.setLowPriorityRateLimit(period);
		break;
		case "add-low-priority":
		final String addedTag = getNextArgRequired();
		DropBoxManagerService.this.addLowPriorityTag(addedTag);
		break;
		case "remove-low-priority":
		final String removeTag = getNextArgRequired();
		DropBoxManagerService.this.removeLowPriorityTag(removeTag);
		break;
		case "restore-defaults":
		DropBoxManagerService.this.restoreDefaults();
		break;
		default:
		return handleDefaultCommands(cmd);
		}
		} catch (Exception e) {
		pw.println(e);
		}
		return 0;
		}

		@Override
		public void onHelp() {
		PrintWriter pw = getOutPrintWriter();
		pw.println("Dropbox manager service commands:");
		pw.println(" help");
		pw.println(" Print this help text.");
		pw.println(" set-rate-limit PERIOD");
		pw.println(" Sets low priority broadcast rate limit period to PERIOD ms");
		pw.println(" add-low-priority TAG");
		pw.println(" Add TAG to dropbox low priority list");
		pw.println(" remove-low-priority TAG");
		pw.println(" Remove TAG from dropbox low priority list");
		pw.println(" restore-defaults");
		pw.println(" restore dropbox settings to defaults");
		}
		}

		private class DropBoxManagerBroadcastHandler extends Handler {
		private final Object mLock = new Object();

		static final int MSG_SEND_BROADCAST = 1;
		static final int MSG_SEND_DEFERRED_BROADCAST = 2;

		@GuardedBy("mLock")
		private final ArrayMap<String, Intent> mDeferredMap = new ArrayMap();

		DropBoxManagerBroadcastHandler(Looper looper) {
		super(looper);
		}

		@Override
		public void handleMessage(Message msg) {
		switch (msg.what) {
		case MSG_SEND_BROADCAST:
		prepareAndSendBroadcast((Intent) msg.obj);
		break;
		case MSG_SEND_DEFERRED_BROADCAST:
		Intent deferredIntent;
		synchronized (mLock) {
		deferredIntent = mDeferredMap.remove((String) msg.obj);
		}
		if (deferredIntent != null) {
		prepareAndSendBroadcast(deferredIntent);
		}
		break;
		}
		}

		private void prepareAndSendBroadcast(Intent intent) {
		if (!DropBoxManagerService.this.mBooted) {
		intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
		}
		getContext().sendBroadcastAsUser(intent, UserHandle.SYSTEM,
		android.Manifest.permission.READ_LOGS);
		}

		private Intent createIntent(String tag, long time) {
		final Intent dropboxIntent = new Intent(DropBoxManager.ACTION_DROPBOX_ENTRY_ADDED);
		dropboxIntent.putExtra(DropBoxManager.EXTRA_TAG, tag);
		dropboxIntent.putExtra(DropBoxManager.EXTRA_TIME, time);
		return dropboxIntent;
		}

		/**
		* Schedule a dropbox broadcast to be sent asynchronously.
		*/
		public void sendBroadcast(String tag, long time) {
		sendMessage(obtainMessage(MSG_SEND_BROADCAST, createIntent(tag, time)));
		}

		/**
		* Possibly schedule a delayed dropbox broadcast. The broadcast will only be scheduled if
		* no broadcast is currently scheduled. Otherwise updated the scheduled broadcast with the
		* new intent information, effectively dropping the previous broadcast.
		*/
		public void maybeDeferBroadcast(String tag, long time) {
		synchronized (mLock) {
		final Intent intent = mDeferredMap.get(tag);
		if (intent == null) {
		// Schedule new delayed broadcast.
		mDeferredMap.put(tag, createIntent(tag, time));
		sendMessageDelayed(obtainMessage(MSG_SEND_DEFERRED_BROADCAST, tag),
		mLowPriorityRateLimitPeriod);
		} else {
		// Broadcast is already scheduled. Update intent with new data.
		intent.putExtra(DropBoxManager.EXTRA_TIME, time);
		final int dropped = intent.getIntExtra(DropBoxManager.EXTRA_DROPPED_COUNT, 0);
		intent.putExtra(DropBoxManager.EXTRA_DROPPED_COUNT, dropped + 1);
		return;
		}
		}
		}
		}

		/**
		* Creates an instance of managed drop box storage using the default dropbox
		* directory.
		@@ -176,15 +317,7 @@ public final class DropBoxManagerService extends SystemService {
		super(context);
		mDropBoxDir = path;
		mContentResolver = getContext().getContentResolver();
		mHandler = new Handler(looper) {
		@Override
		public void handleMessage(Message msg) {
		if (msg.what == MSG_SEND_BROADCAST) {
		getContext().sendBroadcastAsUser((Intent)msg.obj, UserHandle.SYSTEM,
		android.Manifest.permission.READ_LOGS);
		}
		}
		};
		mHandler = new DropBoxManagerBroadcastHandler(looper);
		}

		@Override
		@@ -211,6 +344,8 @@ public final class DropBoxManagerService extends SystemService {
		mReceiver.onReceive(getContext(), (Intent) null);
		}
		});

		getLowPriorityResourceConfigs();
		break;

		case PHASE_BOOT_COMPLETED:
		@@ -298,17 +433,16 @@ public final class DropBoxManagerService extends SystemService {
		long time = createEntry(temp, tag, flags);
		temp = null;

		final Intent dropboxIntent = new Intent(DropBoxManager.ACTION_DROPBOX_ENTRY_ADDED);
		dropboxIntent.putExtra(DropBoxManager.EXTRA_TAG, tag);
		dropboxIntent.putExtra(DropBoxManager.EXTRA_TIME, time);
		if (!mBooted) {
		dropboxIntent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
		}
		// Call sendBroadcast after returning from this call to avoid deadlock. In particular
		// the caller may be holding the WindowManagerService lock but sendBroadcast requires a
		// lock in ActivityManagerService. ActivityManagerService has been caught holding that
		// very lock while waiting for the WindowManagerService lock.
		mHandler.sendMessage(mHandler.obtainMessage(MSG_SEND_BROADCAST, dropboxIntent));
		if (mLowPriorityTags != null && mLowPriorityTags.contains(tag)) {
		// Rate limit low priority Dropbox entries
		mHandler.maybeDeferBroadcast(tag, time);
		} else {
		mHandler.sendBroadcast(tag, time);
		}
		} catch (IOException e) {
		Slog.e(TAG, "Can't write: " + tag, e);
		} finally {
		@@ -382,6 +516,22 @@ public final class DropBoxManagerService extends SystemService {
		return null;
		}

		private synchronized void setLowPriorityRateLimit(long period) {
		mLowPriorityRateLimitPeriod = period;
		}

		private synchronized void addLowPriorityTag(String tag) {
		mLowPriorityTags.add(tag);
		}

		private synchronized void removeLowPriorityTag(String tag) {
		mLowPriorityTags.remove(tag);
		}

		private synchronized void restoreDefaults() {
		getLowPriorityResourceConfigs();
		}

		public synchronized void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
		if (!DumpUtils.checkDumpAndUsageStatsPermission(getContext(), TAG, pw)) return;

		@@ -421,6 +571,10 @@ public final class DropBoxManagerService extends SystemService {
		out.append("Drop box contents: ").append(mAllFiles.contents.size()).append(" entries\n");
		out.append("Max entries: ").append(mMaxFiles).append("\n");

		out.append("Low priority rate limit period: ");
		out.append(mLowPriorityRateLimitPeriod).append(" ms\n");
		out.append("Low priority tags: ").append(mLowPriorityTags).append("\n");

		if (!searchArgs.isEmpty()) {
		out.append("Searching for:");
		for (String a : searchArgs) out.append(" ").append(a);
		@@ -936,4 +1090,21 @@ public final class DropBoxManagerService extends SystemService {

		return mCachedQuotaBlocks * mBlockSize;
		}

		private void getLowPriorityResourceConfigs() {
		mLowPriorityRateLimitPeriod = Resources.getSystem().getInteger(
		R.integer.config_dropboxLowPriorityBroadcastRateLimitPeriod);

		final String[] lowPrioritytags = Resources.getSystem().getStringArray(
		R.array.config_dropboxLowPriorityTags);
		final int size = lowPrioritytags.length;
		if (size == 0) {
		mLowPriorityTags = null;
		return;
		}
		mLowPriorityTags = new ArraySet(size);
		for (int i = 0; i < size; i++) {
		mLowPriorityTags.add(lowPrioritytags[i]);
		}
		}
		}