Broadcast ACTION_NETWORK_STATS_UPDATED in NetworkStatsHandler
There is a corner case which may cause the deadlock:
When NetworkStatsService tried to broadcast the intent,
NetworkStatsService was waiting for a lock which was hold by
ActivityManagerService. In the same time, ActivityManagerService
was waiting for ActiveService#startServiceInnerLocked() to get a
lock which was hold by ConnectivityService. ConnectivityService
was waiting for a lock which was hold by BatteryStatsImpl.
BatteryStatsImpl was waiting for a lock which was hold by
NetworkStatsService, and the lock was locked by
NetworkStatsService when NetworkStatsService tried to broadcast
the intent.
To prevent deadlock when broadcasting the intent in
performPollLocked(), move the intent broadcasting from
performPollLocked() to NetworkStatsHandler.
Bug: 150418178
Bug: 155155473
Test: 1. Create the second user and see if the device will
do factory reset or not.
2. Factory reset manually and see if there is a deadlock.
Change-Id: I80569cb4388beb3fd6cbf64a7885bccee8b1c53c
Merged-In: Icf88d3e7a38562ab15187f6c71bc8fb0486d37c0
(cherry picked from commit 3f8ab0350450202910ea702799570c538e96d5cd)
diff --git a/services/core/java/com/android/server/net/NetworkStatsService.java b/services/core/java/com/android/server/net/NetworkStatsService.java
index 1951fc0..adf0176 100644
--- a/services/core/java/com/android/server/net/NetworkStatsService.java
+++ b/services/core/java/com/android/server/net/NetworkStatsService.java
@@ -178,6 +178,9 @@
// Perform polling, persist network, and register the global alert again.
private static final int MSG_PERFORM_POLL_REGISTER_ALERT = 2;
private static final int MSG_UPDATE_IFACES = 3;
+ // A message for broadcasting ACTION_NETWORK_STATS_UPDATED in handler thread to prevent
+ // deadlock.
+ private static final int MSG_BROADCAST_NETWORK_STATS_UPDATED = 4;
/** Flags to control detail level of poll event. */
private static final int FLAG_PERSIST_NETWORK = 0x1;
@@ -386,6 +389,13 @@
registerGlobalAlert();
break;
}
+ case MSG_BROADCAST_NETWORK_STATS_UPDATED: {
+ final Intent updatedIntent = new Intent(ACTION_NETWORK_STATS_UPDATED);
+ updatedIntent.setFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
+ mContext.sendBroadcastAsUser(updatedIntent, UserHandle.ALL,
+ READ_NETWORK_USAGE_HISTORY);
+ break;
+ }
}
}
}
@@ -1513,10 +1523,7 @@
}
// finally, dispatch updated event to any listeners
- final Intent updatedIntent = new Intent(ACTION_NETWORK_STATS_UPDATED);
- updatedIntent.setFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
- mContext.sendBroadcastAsUser(updatedIntent, UserHandle.ALL,
- READ_NETWORK_USAGE_HISTORY);
+ mHandler.sendMessage(mHandler.obtainMessage(MSG_BROADCAST_NETWORK_STATS_UPDATED));
Trace.traceEnd(TRACE_TAG_NETWORK);
}