Close netlink socket when shutting down IpReachabilityMonitor

This forces the NetlinkSocketObserver thread to exit quickly, rather
than lingering until the next random netlink neighbor multicast message
arrives.

Additionally, add a small unittest to verify that multiple calls to
NetlinkSocket#close() are safe.

Change-Id: I101730fad7eee72f9c6e8a7e7bd10c634f2ceab4

1 files changed, 23 insertions, 0 deletions

diff --git a/core/tests/coretests/src/android/net/netlink/NetlinkSocketTest.java b/core/tests/coretests/src/android/net/netlink/NetlinkSocketTest.java
index b32de78..c599fe3 100644
--- a/core/tests/coretests/src/android/net/netlink/NetlinkSocketTest.java
+++ b/core/tests/coretests/src/android/net/netlink/NetlinkSocketTest.java
@@ -90,4 +90,27 @@ public class NetlinkSocketTest extends TestCase {
 
         s.close();
     }
+
+    public void testRepeatedCloseCallsAreQuiet() throws Exception {
+        // Create a working NetlinkSocket.
+        NetlinkSocket s = new NetlinkSocket(OsConstants.NETLINK_ROUTE);
+        assertNotNull(s);
+        s.connectToKernel();
+        NetlinkSocketAddress localAddr = s.getLocalAddress();
+        assertNotNull(localAddr);
+        assertEquals(0, localAddr.getGroupsMask());
+        assertTrue(0 != localAddr.getPortId());
+        // Close once.
+        s.close();
+        // Test that it is closed.
+        boolean expectedErrorSeen = false;
+        try {
+            localAddr = s.getLocalAddress();
+        } catch (ErrnoException e) {
+            expectedErrorSeen = true;
+        }
+        assertTrue(expectedErrorSeen);
+        // Close once more.
+        s.close();
+    }
 }