IP connectivity metrics: ConnectStats additions

This patch:
  - adds a counter to ConnectStats for counting the number of successful
    connect() calls done in blocking mode. This allows to compute error
    rates for connect() in blocking mode.
  - add printing of ConnectStats when dumping NetdEventListenerService
    and/or IpConnectivityMetrics service.

Test: $ runtest frameworks-net, + manual tests verifying logged events.
Bug: 34901696
Change-Id: I889e8ccd12681b0511be487e9d2ee44290a2d7d7

core/java/android/net/metrics/ConnectStats.java

@@ -43,6 +43,8 @@ public class ConnectStats {
     private final int mMaxLatencyRecords;
     /** Total count of successful connects. */
     private int mConnectCount = 0;
+    /** Total count of successful connects done in blocking mode. */
+    private int mConnectBlockingCount = 0;
     /** Total count of successful connects with IPv6 socket address. */
     private int mIpv6ConnectCount = 0;
 
@@ -54,6 +56,7 @@ public class ConnectStats {
     public ConnectStatistics toProto() {
         ConnectStatistics stats = new ConnectStatistics();
         stats.connectCount = mConnectCount;
+        stats.connectBlockingCount = mConnectBlockingCount;
         stats.ipv6AddrCount = mIpv6ConnectCount;
         stats.latenciesMs = mLatencies.toArray();
         stats.errnosCounters = toPairArrays(mErrnos);
@@ -62,16 +65,21 @@ public class ConnectStats {
 
     public void addEvent(int errno, int latencyMs, String ipAddr) {
         if (isSuccess(errno)) {
-            countConnect(ipAddr);
+            countConnect(errno, ipAddr);
             countLatency(errno, latencyMs);
         } else {
             countError(errno);
         }
     }
 
-    private void countConnect(String ipAddr) {
+    private void countConnect(int errno, String ipAddr) {
         mConnectCount++;
-        if (isIPv6(ipAddr)) mIpv6ConnectCount++;
+        if (!isNonBlocking(errno)) {
+            mConnectBlockingCount++;
+        }
+        if (isIPv6(ipAddr)) {
+            mIpv6ConnectCount++;
+        }
     }
 
     private void countLatency(int errno, int ms) {
@@ -120,4 +128,18 @@ public class ConnectStats {
         }
         return pairs;
     }
+
+    @Override
+    public String toString() {
+        StringBuilder builder = new StringBuilder("ConnectStats(")
+                .append(String.format("%d success, ", mConnectCount))
+                .append(String.format("%d blocking, ", mConnectBlockingCount))
+                .append(String.format("%d IPv6 dst", mIpv6ConnectCount));
+        for (int i = 0; i < mErrnos.size(); i++) {
+            String errno = OsConstants.errnoName(mErrnos.keyAt(i));
+            int count = mErrnos.valueAt(i);
+            builder.append(String.format(", %s: %d", errno, count));
+        }
+        return builder.append(")").toString();
+    }
 }

services/core/java/com/android/server/connectivity/IpConnectivityMetrics.java

@@ -201,12 +201,18 @@ final public class IpConnectivityMetrics extends SystemService {
             for (IpConnectivityEvent ev : IpConnectivityEventBuilder.toProto(events)) {
                 pw.print(ev.toString());
             }
+            if (mNetdListener != null) {
+                mNetdListener.listAsProtos(pw);
+            }
             return;
         }
 
         for (ConnectivityMetricsEvent ev : events) {
             pw.println(ev.toString());
         }
+        if (mNetdListener != null) {
+            mNetdListener.list(pw);
+        }
     }
 
     private void cmdStats(FileDescriptor fd, PrintWriter pw, String[] args) {

services/core/java/com/android/server/connectivity/NetdEventListenerService.java

@@ -204,10 +204,15 @@ public class NetdEventListenerService extends INetdEventListener.Stub {
         // TODO: migrate DnsEventBatch to IpConnectivityLogClass.DNSLatencies
     }
 
-    private IpConnectivityEvent flushConnectStats() {
+    private IpConnectivityEvent connectStatsProto() {
+        // TODO: add transport information
         IpConnectivityEvent ev = new IpConnectivityEvent();
         ev.setConnectStatistics(mConnectStats.toProto());
-        // TODO: add transport information
+        return ev;
+    }
+
+    private IpConnectivityEvent flushConnectStats() {
+        IpConnectivityEvent ev = connectStatsProto();
         mConnectStats = makeConnectStats();
         return ev;
     }
@@ -216,11 +221,19 @@ public class NetdEventListenerService extends INetdEventListener.Stub {
         IndentingPrintWriter pw = new IndentingPrintWriter(writer, "  ");
         pw.println(TAG + ":");
         pw.increaseIndent();
+        list(pw);
+        pw.decreaseIndent();
+    }
+
+    public synchronized void list(PrintWriter pw) {
         for (DnsEventBatch batch : mEventBatches.values()) {
             pw.println(batch.toString());
         }
-        // TODO: also dump ConnectStats
-        pw.decreaseIndent();
+        pw.println(mConnectStats.toString());
+    }
+
+    public synchronized void listAsProtos(PrintWriter pw) {
+        pw.println(connectStatsProto().toString());
     }
 
     private ConnectStats makeConnectStats() {

tests/net/java/com/android/server/connectivity/NetdEventListenerServiceTest.java

@@ -219,7 +219,7 @@ public class NetdEventListenerServiceTest extends TestCase {
                 "time_ms: 0",
                 "transports: 0",
                 "connect_statistics <",
-                "  connect_blocking_count: 0",
+                "  connect_blocking_count: 7",
                 "  connect_count: 12",
                 "  errnos_counters <",
                 "    key: 1",