Tethering offload stats updates are eventually consistent
This patch removes the call to runWithScissors() in
OffloadController#getTetherStats() that was causing a deadlock when
NetworkStatsService would be polled for stats in certain threading
contexts.
Instead of trying to query the tethering offload HAL synchronously all
the time, this patch:
- changes getTetherStats() to only call into the offload HAL when it
detects that it is called on the same thread as the Tethering handler
thread.
- changes the map of interface to accumulated tethering forwarded stats
to be concurrent.
This makes stats reading from getTetherStats() eventually consistent.
From the point of view of getTetherStats(), it preserves the guarantees
that tethering stats are monotonically increasing, and also guarantees
no tearing between rx bytes and tx bytes.
Bug: 29337859
Bug: 32163131
Bug: 64771555
Test: runtest frameworks-net
Merged-In: Ibcd351ad0225ef146b00a807833f76d2a886f6c1
Merged-In: I61786d61fe1422e429c0dd9eadaff6f02eb850e7
Merged-In: I999d1d1bf72e7ab02c5d17f37aad00bc711d3fc5
(cherry pick from commit eb5e465edd78bea26289f779b635c7e94d934854)
Change-Id: I28646b962cee8c8a6efd66059f84873c02ac5810
diff --git a/tests/net/java/com/android/server/connectivity/tethering/OffloadControllerTest.java b/tests/net/java/com/android/server/connectivity/tethering/OffloadControllerTest.java
index 360e5f6..3f17b9eb 100644
--- a/tests/net/java/com/android/server/connectivity/tethering/OffloadControllerTest.java
+++ b/tests/net/java/com/android/server/connectivity/tethering/OffloadControllerTest.java
@@ -404,23 +404,39 @@
when(mHardware.getForwardedStats(eq(ethernetIface))).thenReturn(ethernetStats);
when(mHardware.getForwardedStats(eq(mobileIface))).thenReturn(mobileStats);
+ InOrder inOrder = inOrder(mHardware);
+
final LinkProperties lp = new LinkProperties();
lp.setInterfaceName(ethernetIface);
offload.setUpstreamLinkProperties(lp);
+ // Previous upstream was null, so no stats are fetched.
+ inOrder.verify(mHardware, never()).getForwardedStats(any());
lp.setInterfaceName(mobileIface);
offload.setUpstreamLinkProperties(lp);
+ // Expect that we fetch stats from the previous upstream.
+ inOrder.verify(mHardware, times(1)).getForwardedStats(eq(ethernetIface));
lp.setInterfaceName(ethernetIface);
offload.setUpstreamLinkProperties(lp);
+ // Expect that we fetch stats from the previous upstream.
+ inOrder.verify(mHardware, times(1)).getForwardedStats(eq(mobileIface));
+ ethernetStats = new ForwardedStats();
ethernetStats.rxBytes = 100000;
ethernetStats.txBytes = 100000;
+ when(mHardware.getForwardedStats(eq(ethernetIface))).thenReturn(ethernetStats);
offload.setUpstreamLinkProperties(null);
+ // Expect that we fetch stats from the previous upstream.
+ inOrder.verify(mHardware, times(1)).getForwardedStats(eq(ethernetIface));
ITetheringStatsProvider provider = mTetherStatsProviderCaptor.getValue();
NetworkStats stats = provider.getTetherStats(STATS_PER_IFACE);
NetworkStats perUidStats = provider.getTetherStats(STATS_PER_UID);
+ waitForIdle();
+ // There is no current upstream, so no stats are fetched.
+ inOrder.verify(mHardware, never()).getForwardedStats(eq(ethernetIface));
+ inOrder.verifyNoMoreInteractions();
assertEquals(2, stats.size());
assertEquals(2, perUidStats.size());