Add support for anonymous in-process servers.

core/src/main/java/io/grpc/inprocess/InProcessChannelBuilder.java

@@ -55,15 +55,28 @@ public final class InProcessChannelBuilder extends
    * @return a new builder
    */
   public static InProcessChannelBuilder forName(String name) {
-    return new InProcessChannelBuilder(name);
+    return forAddress(new InProcessSocketAddress(checkNotNull(name, "name")));
   }
 
   /**
-   * Always fails.  Call {@link #forName} instead.
+   * Create a channel builder that will connect to the server referenced by the given target URI.
+   * Only intended for use with a custom name resolver.
+   *
+   * @param target the identity of the server to connect to
+   * @return a new builder
    */
-  @DoNotCall("Unsupported. Use forName() instead")
   public static InProcessChannelBuilder forTarget(String target) {
-    throw new UnsupportedOperationException("call forName() instead");
+    return new InProcessChannelBuilder(null, checkNotNull(target, "target"));
+  }
+
+  /**
+   * Create a channel builder that will connect to the server referenced by the given address.
+   *
+   * @param address the address of the server to connect to
+   * @return a new builder
+   */
+  public static InProcessChannelBuilder forAddress(InProcessSocketAddress address) {
+    return new InProcessChannelBuilder(checkNotNull(address, "address"), null);
   }
 
   /**
@@ -75,13 +88,12 @@ public static InProcessChannelBuilder forAddress(String name, int port) {
   }
 
   private final ManagedChannelImplBuilder managedChannelImplBuilder;
-  private final String name;
   private ScheduledExecutorService scheduledExecutorService;
   private int maxInboundMetadataSize = Integer.MAX_VALUE;
   private boolean transportIncludeStatusCause = false;
 
-  private InProcessChannelBuilder(String name) {
-    this.name = checkNotNull(name, "name");
+  private InProcessChannelBuilder(
+      @Nullable InProcessSocketAddress directAddress, @Nullable String target) {
 
     final class InProcessChannelTransportFactoryBuilder implements ClientTransportFactoryBuilder {
       @Override
@@ -90,8 +102,13 @@ public ClientTransportFactory buildClientTransportFactory() {
       }
     }
 
-    managedChannelImplBuilder = new ManagedChannelImplBuilder(new InProcessSocketAddress(name),
-        "localhost", new InProcessChannelTransportFactoryBuilder(), null);
+    if (directAddress != null) {
+      managedChannelImplBuilder = new ManagedChannelImplBuilder(directAddress, "localhost",
+          new InProcessChannelTransportFactoryBuilder(), null);
+    } else {
+      managedChannelImplBuilder = new ManagedChannelImplBuilder(target,
+          new InProcessChannelTransportFactoryBuilder(), null);
+    }
 
     // In-process transport should not record its traffic to the stats module.
     // https://github.com/grpc/grpc-java/issues/2284
@@ -204,7 +221,7 @@ public InProcessChannelBuilder propagateCauseWithStatus(boolean enable) {
 
   ClientTransportFactory buildTransportFactory() {
     return new InProcessClientTransportFactory(
-        name, scheduledExecutorService, maxInboundMetadataSize, transportIncludeStatusCause);
+        scheduledExecutorService, maxInboundMetadataSize, transportIncludeStatusCause);
   }
 
   void setStatsEnabled(boolean value) {
@@ -215,18 +232,15 @@ void setStatsEnabled(boolean value) {
    * Creates InProcess transports. Exposed for internal use, as it should be private.
    */
   static final class InProcessClientTransportFactory implements ClientTransportFactory {
-    private final String name;
     private final ScheduledExecutorService timerService;
     private final boolean useSharedTimer;
     private final int maxInboundMetadataSize;
     private boolean closed;
     private final boolean includeCauseWithStatus;
 
     private InProcessClientTransportFactory(
-        String name,
         @Nullable ScheduledExecutorService scheduledExecutorService,
         int maxInboundMetadataSize, boolean includeCauseWithStatus) {
-      this.name = name;
       useSharedTimer = scheduledExecutorService == null;
       timerService = useSharedTimer
           ? SharedResourceHolder.get(GrpcUtil.TIMER_SERVICE) : scheduledExecutorService;
@@ -242,7 +256,7 @@ public ConnectionClientTransport newClientTransport(
       }
       // TODO(carl-mastrangelo): Pass channelLogger in.
       return new InProcessTransport(
-          name, maxInboundMetadataSize, options.getAuthority(), options.getUserAgent(),
+          addr, maxInboundMetadataSize, options.getAuthority(), options.getUserAgent(),
           options.getEagAttributes(), includeCauseWithStatus);
     }
 

core/src/main/java/io/grpc/inprocess/InProcessServer.java

@@ -40,13 +40,23 @@ final class InProcessServer implements InternalServer {
   private static final ConcurrentMap<String, InProcessServer> registry
       = new ConcurrentHashMap<>();
 
-  static InProcessServer findServer(String name) {
-    return registry.get(name);
+  static InProcessServer findServer(SocketAddress addr) {
+    if (addr instanceof InProcessSocketAddress) {
+      InProcessSocketAddress inProcessAddress = (InProcessSocketAddress) addr;
+      if (inProcessAddress.getServer() != null) {
+        return inProcessAddress.getServer();
+      } else {
+        return registry.get(inProcessAddress.getName());
+      }
+    }
+    return null;
   }
 
   private final String name;
+  private final boolean anonymous;
   private final int maxInboundMetadataSize;
   private final List<ServerStreamTracer.Factory> streamTracerFactories;
+  private final InProcessSocketAddress listenAddress;
   private ServerListener listener;
   private boolean shutdown;
   /** Defaults to be a SharedResourcePool. */
@@ -61,25 +71,29 @@ static InProcessServer findServer(String name) {
       InProcessServerBuilder builder,
       List<? extends ServerStreamTracer.Factory> streamTracerFactories) {
     this.name = builder.name;
+    this.anonymous = builder.anonymous;
     this.schedulerPool = builder.schedulerPool;
     this.maxInboundMetadataSize = builder.maxInboundMetadataSize;
     this.streamTracerFactories =
         Collections.unmodifiableList(checkNotNull(streamTracerFactories, "streamTracerFactories"));
+    this.listenAddress = new InProcessSocketAddress(name, anonymous ? this : null);
   }
 
   @Override
   public void start(ServerListener serverListener) throws IOException {
     this.listener = serverListener;
     this.scheduler = schedulerPool.getObject();
-    // Must be last, as channels can start connecting after this point.
-    if (registry.putIfAbsent(name, this) != null) {
-      throw new IOException("name already registered: " + name);
+    if (!anonymous) {
+      // Must be last, as channels can start connecting after this point.
+      if (registry.putIfAbsent(name, this) != null) {
+        throw new IOException("name already registered: " + name);
+      }
     }
   }
 
   @Override
   public SocketAddress getListenSocketAddress() {
-    return new InProcessSocketAddress(name);
+    return listenAddress;
   }
 
   @Override
@@ -99,8 +113,10 @@ public List<InternalInstrumented<SocketStats>> getListenSocketStatsList() {
 
   @Override
   public void shutdown() {
-    if (!registry.remove(name, this)) {
-      throw new AssertionError();
+    if (!anonymous) {
+      if (!registry.remove(name, this)) {
+        throw new AssertionError();
+      }
     }
     scheduler = schedulerPool.returnObject(scheduler);
     synchronized (this) {

core/src/main/java/io/grpc/inprocess/InProcessServerBuilder.java

@@ -81,7 +81,17 @@ public final class InProcessServerBuilder extends
    * @return a new builder
    */
   public static InProcessServerBuilder forName(String name) {
-    return new InProcessServerBuilder(name);
+    return new InProcessServerBuilder(name, false);
+  }
+
+  /**
+   * Create a server builder for an anonymous in-process server.
+   * Anonymous servers can only be connected to via their listen address,
+   * and can't be referenced by name.
+   * @return a new builder
+   */
+  public static InProcessServerBuilder anonymous() {
+    return new InProcessServerBuilder("anonymous", true);
   }
 
   /**
@@ -101,12 +111,14 @@ public static String generateName() {
 
   private final ServerImplBuilder serverImplBuilder;
   final String name;
+  final boolean anonymous;
   int maxInboundMetadataSize = Integer.MAX_VALUE;
   ObjectPool<ScheduledExecutorService> schedulerPool =
       SharedResourcePool.forResource(GrpcUtil.TIMER_SERVICE);
 
-  private InProcessServerBuilder(String name) {
+  private InProcessServerBuilder(String name, boolean anonymous) {
     this.name = Preconditions.checkNotNull(name, "name");
+    this.anonymous = anonymous;
 
     final class InProcessClientTransportServersBuilder implements ClientTransportServersBuilder {
       @Override

core/src/main/java/io/grpc/inprocess/InProcessSocketAddress.java

@@ -19,6 +19,7 @@
 import static com.google.common.base.Preconditions.checkNotNull;
 
 import java.net.SocketAddress;
+import javax.annotation.Nullable;
 
 /**
  * Custom SocketAddress class for {@link InProcessTransport}.
@@ -27,13 +28,25 @@ public final class InProcessSocketAddress extends SocketAddress {
   private static final long serialVersionUID = -2803441206326023474L;
 
   private final String name;
+  @Nullable
+  private final InProcessServer server;
 
   /**
    * @param name - The name of the inprocess channel or server.
    * @since 1.0.0
    */
   public InProcessSocketAddress(String name) {
+    this(name, null);
+  }
+
+  /**
+   * @param name - The name of the inprocess channel or server.
+   * @param server - The concrete {@link InProcessServer} instance, Will be present on the listen
+   *     address of an anonymous server.
+   */
+  InProcessSocketAddress(String name, @Nullable InProcessServer server) {
     this.name = checkNotNull(name, "name");
+    this.server = server;
   }
 
   /**
@@ -45,6 +58,11 @@ public String getName() {
     return name;
   }
 
+  @Nullable
+  InProcessServer getServer() {
+    return server;
+  }
+
   /**
    * @since 1.14.0
    */
@@ -58,7 +76,13 @@ public String toString() {
    */
   @Override
   public int hashCode() {
-    return name.hashCode();
+    if (server != null) {
+      // Since there's a single canonical InProcessSocketAddress instance for
+      // an anonymous inprocess server, we can just use identity equality.
+      return super.hashCode();
+    } else {
+      return name.hashCode();
+    }
   }
 
   /**
@@ -69,6 +93,13 @@ public boolean equals(Object obj) {
     if (!(obj instanceof InProcessSocketAddress)) {
       return false;
     }
-    return name.equals(((InProcessSocketAddress) obj).name);
+    InProcessSocketAddress addr = (InProcessSocketAddress) obj;
+    if (server == null && addr.server == null) {
+      return name.equals(addr.name);
+    } else {
+      // Since there's a single canonical InProcessSocketAddress instance for
+      // an anonymous inprocess server, we can just use identity equality.
+      return addr == this;
+    }
   }
 }