Merge \"Fix unsafe concurrent access in LegacyTypeTracker\" (e82b43f7) · Commits · e / os / android_frameworks_base

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

+30 −17

Original line number	Original line	Diff line number	Diff line
	@@ -487,8 +487,16 @@ public class ConnectivityService extends IConnectivityManager.Stub
	*		*
	* The actual lists are populated when we scan the network types that		* The actual lists are populated when we scan the network types that
	* are supported on this device.		* are supported on this device.
			*
			* Threading model:
			* - addSupportedType() is only called in the constructor
			* - add(), update(), remove() are only called from the ConnectivityService handler thread.
			* They are therefore not thread-safe with respect to each other.
			* - getNetworkForType() can be called at any time on binder threads. It is synchronized
			* on mTypeLists to be thread-safe with respect to a concurrent remove call.
			* - dump is thread-safe with respect to concurrent add and remove calls.
	*/		*/
	private ArrayList<NetworkAgentInfo> mTypeLists[];		private final ArrayList<NetworkAgentInfo> mTypeLists[];

	public LegacyTypeTracker() {		public LegacyTypeTracker() {
	mTypeLists = (ArrayList<NetworkAgentInfo>[])		mTypeLists = (ArrayList<NetworkAgentInfo>[])
	@@ -508,12 +516,13 @@ public class ConnectivityService extends IConnectivityManager.Stub
	}		}

	public NetworkAgentInfo getNetworkForType(int type) {		public NetworkAgentInfo getNetworkForType(int type) {
			synchronized (mTypeLists) {
	if (isTypeSupported(type) && !mTypeLists[type].isEmpty()) {		if (isTypeSupported(type) && !mTypeLists[type].isEmpty()) {
	return mTypeLists[type].get(0);		return mTypeLists[type].get(0);
	} else {
	return null;
	}		}
	}		}
			return null;
			}

	private void maybeLogBroadcast(NetworkAgentInfo nai, DetailedState state, int type,		private void maybeLogBroadcast(NetworkAgentInfo nai, DetailedState state, int type,
	boolean isDefaultNetwork) {		boolean isDefaultNetwork) {
	@@ -535,12 +544,13 @@ public class ConnectivityService extends IConnectivityManager.Stub
	if (list.contains(nai)) {		if (list.contains(nai)) {
	return;		return;
	}		}
			synchronized (mTypeLists) {
	list.add(nai);		list.add(nai);
			}

	// Send a broadcast if this is the first network of its type or if it's the default.		// Send a broadcast if this is the first network of its type or if it's the default.
	final boolean isDefaultNetwork = isDefaultNetwork(nai);		final boolean isDefaultNetwork = isDefaultNetwork(nai);
	if (list.size() == 1 \|\| isDefaultNetwork) {		if ((list.size() == 1) \|\| isDefaultNetwork) {
	maybeLogBroadcast(nai, DetailedState.CONNECTED, type, isDefaultNetwork);		maybeLogBroadcast(nai, DetailedState.CONNECTED, type, isDefaultNetwork);
	sendLegacyNetworkBroadcast(nai, DetailedState.CONNECTED, type);		sendLegacyNetworkBroadcast(nai, DetailedState.CONNECTED, type);
	}		}
	@@ -552,12 +562,13 @@ public class ConnectivityService extends IConnectivityManager.Stub
	if (list == null \|\| list.isEmpty()) {		if (list == null \|\| list.isEmpty()) {
	return;		return;
	}		}

	final boolean wasFirstNetwork = list.get(0).equals(nai);		final boolean wasFirstNetwork = list.get(0).equals(nai);

			synchronized (mTypeLists) {
	if (!list.remove(nai)) {		if (!list.remove(nai)) {
	return;		return;
	}		}
			}

	final DetailedState state = DetailedState.DISCONNECTED;		final DetailedState state = DetailedState.DISCONNECTED;

	@@ -591,8 +602,8 @@ public class ConnectivityService extends IConnectivityManager.Stub
	for (int type = 0; type < mTypeLists.length; type++) {		for (int type = 0; type < mTypeLists.length; type++) {
	final ArrayList<NetworkAgentInfo> list = mTypeLists[type];		final ArrayList<NetworkAgentInfo> list = mTypeLists[type];
	final boolean contains = (list != null && list.contains(nai));		final boolean contains = (list != null && list.contains(nai));
	final boolean isFirst = (list != null && list.size() > 0 && nai == list.get(0));		final boolean isFirst = contains && (nai == list.get(0));
	if (isFirst \|\| (contains && isDefault)) {		if (isFirst \|\| contains && isDefault) {
	maybeLogBroadcast(nai, state, type, isDefault);		maybeLogBroadcast(nai, state, type, isDefault);
	sendLegacyNetworkBroadcast(nai, state, type);		sendLegacyNetworkBroadcast(nai, state, type);
	}		}
	@@ -617,12 +628,14 @@ public class ConnectivityService extends IConnectivityManager.Stub
	pw.println();		pw.println();
	pw.println("Current state:");		pw.println("Current state:");
	pw.increaseIndent();		pw.increaseIndent();
			synchronized (mTypeLists) {
	for (int type = 0; type < mTypeLists.length; type++) {		for (int type = 0; type < mTypeLists.length; type++) {
	if (mTypeLists[type] == null\|\| mTypeLists[type].size() == 0) continue;		if (mTypeLists[type] == null \|\| mTypeLists[type].isEmpty()) continue;
	for (NetworkAgentInfo nai : mTypeLists[type]) {		for (NetworkAgentInfo nai : mTypeLists[type]) {
	pw.println(type + " " + naiToString(nai));		pw.println(type + " " + naiToString(nai));
	}		}
	}		}
			}
	pw.decreaseIndent();		pw.decreaseIndent();
	pw.decreaseIndent();		pw.decreaseIndent();
	pw.println();		pw.println();