use ref_counted in fnet

also get rid of some cleanup functions on reference counted classes

enable specifying low-level parameters to addref/subref (cnt/reserve)

34 files changed, 159 insertions, 365 deletions

diff --git a/fnet/src/examples/frt/rpc/echo_client.cpp b/fnet/src/examples/frt/rpc/echo_client.cpp
index 0176337c466..869a010bfda 100644
--- a/fnet/src/examples/frt/rpc/echo_client.cpp
+++ b/fnet/src/examples/frt/rpc/echo_client.cpp
@@ -85,8 +85,8 @@ EchoClient::main(int argc, char **argv)
     } else {
         printf("Return values != parameters.\n");
     }
-    req->SubRef();
-    target->SubRef();
+    req->internal_subref();
+    target->internal_subref();
     return 0;
 }
 
diff --git a/fnet/src/examples/frt/rpc/rpc_callback_client.cpp b/fnet/src/examples/frt/rpc/rpc_callback_client.cpp
index b41c40ba29d..c52d48f24eb 100644
--- a/fnet/src/examples/frt/rpc/rpc_callback_client.cpp
+++ b/fnet/src/examples/frt/rpc/rpc_callback_client.cpp
@@ -102,8 +102,8 @@ MyApp::main(int argc, char **argv)
         ok = false;
     }
 
-    req->SubRef();
-    target->SubRef();
+    req->internal_subref();
+    target->internal_subref();
     return ok ? 0 : 1;
 }
 
diff --git a/fnet/src/examples/frt/rpc/rpc_callback_server.cpp b/fnet/src/examples/frt/rpc/rpc_callback_server.cpp
index 37a819c6ee7..5c21f73da7f 100644
--- a/fnet/src/examples/frt/rpc/rpc_callback_server.cpp
+++ b/fnet/src/examples/frt/rpc/rpc_callback_server.cpp
@@ -27,7 +27,7 @@ void do_callback(FRT_RPCRequest *req) {
                cb->GetErrorCode(),
                cb->GetErrorMessage());
     }
-    cb->SubRef();
+    cb->internal_subref();
     req->Return();
 }
 
diff --git a/fnet/src/examples/frt/rpc/rpc_client.cpp b/fnet/src/examples/frt/rpc/rpc_client.cpp
index acb20a880c9..55168a2acba 100644
--- a/fnet/src/examples/frt/rpc/rpc_client.cpp
+++ b/fnet/src/examples/frt/rpc/rpc_client.cpp
@@ -49,7 +49,7 @@ RPCClient::main(int argc, char **argv)
     }
 
     fprintf(stdout, "\nTesting addFloat method\n");
-    req->SubRef();
+    req->internal_subref();
     req = supervisor.AllocRPCRequest();
     req->SetMethodName("addFloat");
     req->GetParams()->AddFloat(float1);
@@ -65,7 +65,7 @@ RPCClient::main(int argc, char **argv)
     }
 
     fprintf(stdout, "\nTesting addDouble method\n");
-    req->SubRef();
+    req->internal_subref();
     req = supervisor.AllocRPCRequest();
     req->SetMethodName("addDouble");
     req->GetParams()->AddDouble(double1);
@@ -80,8 +80,8 @@ RPCClient::main(int argc, char **argv)
                 req->GetErrorMessage());
     }
 
-    req->SubRef();
-    target->SubRef();
+    req->internal_subref();
+    target->internal_subref();
     return 0;
 }
 
diff --git a/fnet/src/examples/frt/rpc/rpc_info.cpp b/fnet/src/examples/frt/rpc/rpc_info.cpp
index 9734342a24e..ab534a254c2 100644
--- a/fnet/src/examples/frt/rpc/rpc_info.cpp
+++ b/fnet/src/examples/frt/rpc/rpc_info.cpp
@@ -15,16 +15,16 @@ public:
     void GetReq(FRT_RPCRequest **req, FRT_Supervisor *supervisor)
     {
         if ((*req) != nullptr)
-            (*req)->SubRef();
+            (*req)->internal_subref();
         (*req) = supervisor->AllocRPCRequest();
     }
 
     void FreeReqs(FRT_RPCRequest *r1, FRT_RPCRequest *r2)
     {
         if (r1 != nullptr)
-            r1->SubRef();
+            r1->internal_subref();
         if (r2 != nullptr)
-            r2->SubRef();
+            r2->internal_subref();
     }
 
     void DumpMethodInfo(const char *indent, FRT_RPCRequest *info,
@@ -130,7 +130,7 @@ RPCInfo::main(int argc, char **argv)
                 m_list->GetErrorMessage());
     }
     FreeReqs(m_list, info);
-    target->SubRef();
+    target->internal_subref();
     return 0;
 }
 
diff --git a/fnet/src/examples/frt/rpc/rpc_invoke.cpp b/fnet/src/examples/frt/rpc/rpc_invoke.cpp
index 9f3e90f469a..d56847098d8 100644
--- a/fnet/src/examples/frt/rpc/rpc_invoke.cpp
+++ b/fnet/src/examples/frt/rpc/rpc_invoke.cpp
@@ -113,8 +113,8 @@ RPCClient::run(int argc, char **argv)
             retCode = 3;
         }
     }
-    req->SubRef();
-    target->SubRef();
+    req->internal_subref();
+    target->internal_subref();
     return retCode;
 }
 
diff --git a/fnet/src/examples/ping/pingclient.cpp b/fnet/src/examples/ping/pingclient.cpp
index 43296df7e57..b59df31607a 100644
--- a/fnet/src/examples/ping/pingclient.cpp
+++ b/fnet/src/examples/ping/pingclient.cpp
@@ -86,7 +86,7 @@ PingClient::main(int argc, char **argv)
         packet->Free();
     }
     if (conn != nullptr)
-        conn->SubRef();
+        conn->internal_subref();
     transport.ShutDown(true);
     return 0;
 }
diff --git a/fnet/src/examples/ping/pingserver.cpp b/fnet/src/examples/ping/pingserver.cpp
index fb5b12b66c0..79a67cd18a7 100644
--- a/fnet/src/examples/ping/pingserver.cpp
+++ b/fnet/src/examples/ping/pingserver.cpp
@@ -51,7 +51,7 @@ PingServer::main(int argc, char **argv)
     FNET_Connector *listener =
         transport.Listen(argv[1], &streamer, this);
     if (listener != nullptr)
-        listener->SubRef();
+        listener->internal_subref();
 
     FNET_SignalShutDown ssd(transport);
     transport.Main();
diff --git a/fnet/src/tests/connect/connect_test.cpp b/fnet/src/tests/connect/connect_test.cpp
index 9d566cf37a7..d635fea6f94 100644
--- a/fnet/src/tests/connect/connect_test.cpp
+++ b/fnet/src/tests/connect/connect_test.cpp
@@ -86,25 +86,22 @@ struct BlockingCryptoEngine : public CryptoEngine {
 
 //-----------------------------------------------------------------------------
 
-struct TransportFixture : FNET_IPacketHandler, FNET_IConnectionCleanupHandler {
+struct TransportFixture : FNET_IPacketHandler {
     FNET_SimplePacketStreamer streamer;
     FNET_Transport transport;
     Gate conn_lost;
-    Gate conn_deleted;
-    TransportFixture() : streamer(nullptr), transport(),
-                         conn_lost(), conn_deleted()
-    {
+    TransportFixture() : streamer(nullptr), transport(), conn_lost() {
         transport.Start();
     }
     TransportFixture(AsyncResolver::HostResolver::SP host_resolver)
         : streamer(nullptr), transport(fnet::TransportConfig().resolver(make_resolver(std::move(host_resolver)))),
-          conn_lost(), conn_deleted()
+          conn_lost()
     {
         transport.Start();
     }
     TransportFixture(CryptoEngine::SP crypto)
         : streamer(nullptr), transport(fnet::TransportConfig().crypto(std::move(crypto))),
-          conn_lost(), conn_deleted()
+          conn_lost()
     {
         transport.Start();
     }
@@ -114,14 +111,12 @@ struct TransportFixture : FNET_IPacketHandler, FNET_IConnectionCleanupHandler {
         packet->Free();
         return FNET_FREE_CHANNEL;
     }
-    void Cleanup(FNET_Connection *) override { conn_deleted.countDown(); }
     FNET_Connection *connect(const vespalib::string &spec) {
         FNET_Connection *conn = transport.Connect(spec.c_str(), &streamer);
         ASSERT_TRUE(conn != nullptr);
         if (conn->OpenChannel(this, FNET_Context()) == nullptr) {
             conn_lost.countDown();
         }
-        conn->SetCleanupHandler(this);
         return conn;
     }
     ~TransportFixture() override {
@@ -131,8 +126,26 @@ struct TransportFixture : FNET_IPacketHandler, FNET_IConnectionCleanupHandler {
 
 //-----------------------------------------------------------------------------
 
-TEST_MT_FFF("require that normal connect works", 2,
-            ServerSocket("tcp/0"), TransportFixture(), TimeBomb(60))
+struct ConnCheck {
+    uint64_t target;
+    ConnCheck() : target(FNET_Connection::get_num_connections()) {
+        EXPECT_EQUAL(target, uint64_t(0));
+    }
+    bool at_target() const { return (FNET_Connection::get_num_connections() == target); };
+    bool await(duration max_wait) const {
+        auto until = saturated_add(steady_clock::now(), max_wait);
+        while (!at_target() && steady_clock::now() < until) {
+            std::this_thread::sleep_for(1ms);
+        }
+        return at_target();
+    }
+    void await() const {
+        ASSERT_TRUE(await(3600s));
+    }
+};
+
+TEST_MT_FFFF("require that normal connect works", 2,
+             ServerSocket("tcp/0"), TransportFixture(), ConnCheck(), TimeBomb(60))
 {
     if (thread_id == 0) {
         SocketHandle socket = f1.accept();
@@ -144,23 +157,23 @@ TEST_MT_FFF("require that normal connect works", 2,
         TEST_BARRIER();
         conn->Owner()->Close(conn);
         f2.conn_lost.await();
-        EXPECT_TRUE(!f2.conn_deleted.await(short_time));
-        conn->SubRef();
-        f2.conn_deleted.await();
+        EXPECT_TRUE(!f3.await(short_time));
+        conn->internal_subref();
+        f3.await();
     }
 }
 
-TEST_FF("require that bogus connect fail asynchronously", TransportFixture(), TimeBomb(60)) {
+TEST_FFF("require that bogus connect fail asynchronously", TransportFixture(), ConnCheck(), TimeBomb(60)) {
     FNET_Connection *conn = f1.connect("invalid");
     f1.conn_lost.await();
-    EXPECT_TRUE(!f1.conn_deleted.await(short_time));
-    conn->SubRef();
-    f1.conn_deleted.await();
+    EXPECT_TRUE(!f2.await(short_time));
+    conn->internal_subref();
+    f2.await();
 }
 
-TEST_MT_FFFF("require that async close can be called before async resolve completes", 2,
-             ServerSocket("tcp/0"), std::shared_ptr<BlockingHostResolver>(new BlockingHostResolver()),
-             TransportFixture(f2), TimeBomb(60))
+TEST_MT_FFFFF("require that async close can be called before async resolve completes", 2,
+              ServerSocket("tcp/0"), std::shared_ptr<BlockingHostResolver>(new BlockingHostResolver()),
+              TransportFixture(f2), ConnCheck(), TimeBomb(60))
 {
     if (thread_id == 0) {
         SocketHandle socket = f1.accept();
@@ -172,16 +185,16 @@ TEST_MT_FFFF("require that async close can be called before async resolve comple
         conn->Owner()->Close(conn);
         f3.conn_lost.await();
         f2->release_caller();
-        EXPECT_TRUE(!f3.conn_deleted.await(short_time));
-        conn->SubRef();
-        f3.conn_deleted.await();
+        EXPECT_TRUE(!f4.await(short_time));
+        conn->internal_subref();
+        f4.await();
         f1.shutdown();
     }
 }
 
-TEST_MT_FFFF("require that async close during async do_handshake_work works", 2,
-             ServerSocket("tcp/0"), std::shared_ptr<BlockingCryptoEngine>(new BlockingCryptoEngine()),
-             TransportFixture(f2), TimeBomb(60))
+TEST_MT_FFFFF("require that async close during async do_handshake_work works", 2,
+              ServerSocket("tcp/0"), std::shared_ptr<BlockingCryptoEngine>(new BlockingCryptoEngine()),
+              TransportFixture(f2), ConnCheck(), TimeBomb(60))
 {
     if (thread_id == 0) {
         SocketHandle socket = f1.accept();
@@ -196,10 +209,10 @@ TEST_MT_FFFF("require that async close during async do_handshake_work works", 2,
         f3.conn_lost.await();
         TEST_BARRIER(); // #1
         // verify that pending work keeps relevant objects alive
-        EXPECT_TRUE(!f3.conn_deleted.await(short_time));
+        EXPECT_TRUE(!f4.await(short_time));
         EXPECT_TRUE(!f2->handshake_socket_deleted.await(short_time));
         f2->handshake_work_exit.countDown();
-        f3.conn_deleted.await();
+        f4.await();
         f2->handshake_socket_deleted.await();
     }
 }
diff --git a/fnet/src/tests/connection_spread/connection_spread_test.cpp b/fnet/src/tests/connection_spread/connection_spread_test.cpp
index 6286ce65657..5908e6a4982 100644
--- a/fnet/src/tests/connection_spread/connection_spread_test.cpp
+++ b/fnet/src/tests/connection_spread/connection_spread_test.cpp
@@ -84,9 +84,9 @@ TEST_F("require that connections are spread among transport threads", Fixture)
     f1.wait_for_components(256, 257);    
     check_threads(f1.client, 8, "client");
     check_threads(f1.server, 8, "server");
-    listener->SubRef();
+    listener->internal_subref();
     for (FNET_Connection *conn: connections) {
-        conn->SubRef();
+        conn->internal_subref();
     }
 }
 
diff --git a/fnet/src/tests/frt/detach_supervisor/detach_supervisor_test.cpp b/fnet/src/tests/frt/detach_supervisor/detach_supervisor_test.cpp
index 6325c60413a..c5ca6dc6ce9 100644
--- a/fnet/src/tests/frt/detach_supervisor/detach_supervisor_test.cpp
+++ b/fnet/src/tests/frt/detach_supervisor/detach_supervisor_test.cpp
@@ -36,7 +36,7 @@ struct RpcFixture : FRT_Invokable {
     }
     ~RpcFixture() {
         if (back_conn.load() != nullptr) {
-            back_conn.load()->SubRef();
+            back_conn.load()->internal_subref();
         }
     }
     uint32_t port() const { return orb.GetListenPort(); }
@@ -61,7 +61,7 @@ struct RpcFixture : FRT_Invokable {
         ASSERT_TRUE(back_conn.load() == nullptr);
         back_conn.store(req->GetConnection());
         ASSERT_TRUE(back_conn.load() != nullptr);
-        back_conn.load()->AddRef();
+        back_conn.load()->internal_addref();
     }
     FRT_Target *meta_connect(uint32_t port) {
         auto *target = orb.Get2WayTarget(fmt("tcp/localhost:%u", port).c_str());
@@ -69,7 +69,7 @@ struct RpcFixture : FRT_Invokable {
         req->SetMethodName("connect");
         target->InvokeSync(req, 300.0);
         ASSERT_TRUE(req->CheckReturnTypes(""));
-        req->SubRef();
+        req->internal_subref();
         return target;
     };
     static int check_result(FRT_RPCRequest *req, uint64_t expect) {
@@ -81,7 +81,7 @@ struct RpcFixture : FRT_Invokable {
             ASSERT_EQUAL(ret, expect);
             ++num_ok;
         }
-        req->SubRef();
+        req->internal_subref();
         return num_ok;
     }
     static int verify_rpc(FNET_Connection *conn) {
@@ -101,7 +101,7 @@ struct RpcFixture : FRT_Invokable {
     int verify_rpc(FRT_Target *target, uint32_t port) {
         auto *my_target = connect(port);
         int num_ok = verify_rpc(target) + verify_rpc(my_target) + verify_rpc(back_conn.load());
-        my_target->SubRef();
+        my_target->internal_subref();
         return num_ok;
     }
 };
@@ -135,8 +135,8 @@ TEST_MT_FFFFF("require that supervisor can be detached from transport", 4, Basic
         EXPECT_EQUAL(RpcFixture::verify_rpc(target), 0); // outgoing 2way target should be closed
         EXPECT_EQUAL(RpcFixture::verify_rpc(client_target), 1); // pure client target should not be closed
         TEST_BARRIER(); // #5
-        target->SubRef();
-        client_target->SubRef();
+        target->internal_subref();
+        client_target->internal_subref();
     } else if (thread_id == 1) { // server 2 (talks to client 2)
         auto self = std::make_unique<RpcFixture>(f1);
         f3 = self->port();
@@ -146,7 +146,7 @@ TEST_MT_FFFFF("require that supervisor can be detached from transport", 4, Basic
         TEST_BARRIER(); // #3
         TEST_BARRIER(); // #4
         TEST_BARRIER(); // #5
-        target->SubRef();
+        target->internal_subref();
     } else if (thread_id == 2) { // client 1 (talks to server 1)
         auto self = std::make_unique<RpcFixture>(f1);
         f4 = self->port();
@@ -165,7 +165,7 @@ TEST_MT_FFFFF("require that supervisor can be detached from transport", 4, Basic
         TEST_BARRIER(); // #4
         EXPECT_EQUAL(self->verify_rpc(target, f2), 0);
         TEST_BARRIER(); // #5
-        target->SubRef();
+        target->internal_subref();
     } else {                     // client 2 (talks to server 2)
         ASSERT_EQUAL(thread_id, 3u);
         auto self = std::make_unique<RpcFixture>(f1);
@@ -179,7 +179,7 @@ TEST_MT_FFFFF("require that supervisor can be detached from transport", 4, Basic
         TEST_BARRIER(); // #4
         EXPECT_EQUAL(self->verify_rpc(target, f3), 3);
         TEST_BARRIER(); // #5
-        target->SubRef();
+        target->internal_subref();
     }
 }
 
diff --git a/fnet/src/tests/frt/method_pt/method_pt.cpp b/fnet/src/tests/frt/method_pt/method_pt.cpp
index 2ac706369ae..d6c42ef7790 100644
--- a/fnet/src/tests/frt/method_pt/method_pt.cpp
+++ b/fnet/src/tests/frt/method_pt/method_pt.cpp
@@ -174,7 +174,7 @@ void finiTest() {
   delete _complexHandler;
   delete _mediumHandler;
   delete _simpleHandler;
-  _target->SubRef();
+  _target->internal_subref();
   _server.reset();
 }
 
@@ -187,7 +187,7 @@ TEST("method pt") {
 
   //-------------------------------- MEDIUM
 
-  req->SubRef();
+  req->internal_subref();
   req = FRT_Supervisor::AllocRPCRequest();
   req->SetMethodName("mediumMethod");
   _target->InvokeSync(req, 60.0);
@@ -195,7 +195,7 @@ TEST("method pt") {
 
   //-------------------------------- COMPLEX
 
-  req->SubRef();
+  req->internal_subref();
   req = FRT_Supervisor::AllocRPCRequest();
   req->SetMethodName("complexMethod");
   _target->InvokeSync(req, 60.0);
@@ -213,7 +213,7 @@ TEST("method pt") {
       fprintf(stderr, "Object inheritance NOT ok for method handlers\n");
   }
 
-  req->SubRef();
+  req->internal_subref();
 }
 
 //-------------------------------------------------------------
diff --git a/fnet/src/tests/frt/parallel_rpc/parallel_rpc_test.cpp b/fnet/src/tests/frt/parallel_rpc/parallel_rpc_test.cpp
index 41bfb7d06a6..74f69541d8b 100644
--- a/fnet/src/tests/frt/parallel_rpc/parallel_rpc_test.cpp
+++ b/fnet/src/tests/frt/parallel_rpc/parallel_rpc_test.cpp
@@ -125,8 +125,8 @@ void perform_test(size_t thread_id, Client &client, Result &result, bool vital =
     BenchmarkTimer::benchmark(invoke, invoke, 0.5);
     EXPECT_GREATER_EQUAL(seq, loop_cnt);
     result.req_per_sec[thread_id] = double(loop_cnt) / t;
-    req->SubRef();
-    target->SubRef();
+    req->internal_subref();
+    target->internal_subref();
     TEST_BARRIER();
     if (thread_id == 0) {
         result.print();
diff --git a/fnet/src/tests/frt/parallel_rpc/tls_rpc_bench.cpp b/fnet/src/tests/frt/parallel_rpc/tls_rpc_bench.cpp
index d15fca93c0b..812f0a57c5e 100644
--- a/fnet/src/tests/frt/parallel_rpc/tls_rpc_bench.cpp
+++ b/fnet/src/tests/frt/parallel_rpc/tls_rpc_bench.cpp
@@ -86,7 +86,7 @@ void benchmark_rpc(Fixture &fixture, bool reconnect) {
     auto invoke = [&seq, &target, &req, &fixture, reconnect](){
         TT_Sample sample(req_tag);
         if (reconnect) {
-            target->SubRef();
+            target->internal_subref();
             target = fixture.connect();
         }
         req = fixture.orb.AllocRPCRequest(req);
@@ -101,8 +101,8 @@ void benchmark_rpc(Fixture &fixture, bool reconnect) {
     auto before = TimeTracer::now();
     double t = BenchmarkTimer::benchmark(invoke, 5.0);
     auto after = TimeTracer::now();
-    target->SubRef();
-    req->SubRef();
+    target->internal_subref();
+    req->internal_subref();
     auto stats = TimeTracer::extract().by_time(before, after).by_tag(req_tag.id()).get();
     ASSERT_TRUE(stats.size() > 0);
     std::sort(stats.begin(), stats.end(), DurationCmp());
diff --git a/fnet/src/tests/frt/rpc/detach_return_invoke.cpp b/fnet/src/tests/frt/rpc/detach_return_invoke.cpp
index 17c38ab6e3a..9a0f1778cb6 100644
--- a/fnet/src/tests/frt/rpc/detach_return_invoke.cpp
+++ b/fnet/src/tests/frt/rpc/detach_return_invoke.cpp
@@ -31,14 +31,14 @@ struct Server : public FRT_Invokable
 
     void rpc_hook(FRT_RPCRequest *req) {
         FNET_Connection *conn = req->GetConnection();
-        conn->AddRef(); // need to keep it alive
+        conn->internal_addref(); // need to keep it alive
         req->Detach();
         req->Return();  // will free request channel
         FRT_RPCRequest *r = orb.AllocRPCRequest();
         r->SetMethodName("frt.rpc.ping");
         // might re-use request channel before it is unlinked from hashmap
         orb.InvokeAsync(orb.GetTransport(), conn, r, 5.0, &receptor);
-        conn->SubRef(); // invocation will now keep the connection alive as needed
+        conn->internal_subref(); // invocation will now keep the connection alive as needed
     }
 };
 
@@ -61,11 +61,11 @@ TEST("detach return invoke") {
         }
         std::this_thread::sleep_for(10ms);
     }
-    req->SubRef();
-    target->SubRef();
+    req->internal_subref();
+    target->internal_subref();
     if (receptor.req.load() != nullptr) {
         EXPECT_TRUE(!receptor.req.load()->IsError());
-        receptor.req.load()->SubRef();
+        receptor.req.load()->internal_subref();
     }
     EXPECT_TRUE(receptor.req.load() != nullptr);
 };
diff --git a/fnet/src/tests/frt/rpc/invoke.cpp b/fnet/src/tests/frt/rpc/invoke.cpp
index e930c1252bf..f06c7428c22 100644
--- a/fnet/src/tests/frt/rpc/invoke.cpp
+++ b/fnet/src/tests/frt/rpc/invoke.cpp
@@ -65,7 +65,7 @@ public:
     }
     ~MyReq() {
         if (_req != nullptr) {
-            _req->SubRef();
+            _req->internal_subref();
         }
     }
     MyReq(const MyReq &rhs) = delete;
@@ -331,7 +331,7 @@ public:
     }
 
     ~Fixture() {
-        _target->SubRef();
+        _target->internal_subref();
     }
 };
 
@@ -410,7 +410,7 @@ TEST_F("require that a bad target gives connection error", Fixture()) {
     {
         FRT_Target *bad_target = f1.make_bad_target();
         bad_target->InvokeSync(req.borrow(), timeout);
-        bad_target->SubRef();
+        bad_target->internal_subref();
     }
     EXPECT_EQUAL(req.get().GetErrorCode(), FRTE_RPC_CONNECTION);
 }
diff --git a/fnet/src/tests/frt/rpc/sharedblob.cpp b/fnet/src/tests/frt/rpc/sharedblob.cpp
index 2ccb44d03cb..94f57a136a4 100644
--- a/fnet/src/tests/frt/rpc/sharedblob.cpp
+++ b/fnet/src/tests/frt/rpc/sharedblob.cpp
@@ -122,7 +122,7 @@ struct ServerSampler : public FRT_Invokable
         dataSet.sample(*req->GetReturn()); // server return before drop
 
         // keep request to sample return after drop
-        req->AddRef();
+        req->internal_addref();
         serverReq = req;
     }
 };
@@ -176,7 +176,7 @@ TEST("testExplicitShared") {
     req->GetParams()->AddSharedData(&blob);
 
     EXPECT_EQUAL(4, blob.refcnt);
-    req->SubRef();
+    req->internal_subref();
     EXPECT_EQUAL(1, blob.refcnt);
 }
 
@@ -262,10 +262,10 @@ TEST("testImplicitShared") {
     }
 
     if (serverSampler.serverReq != 0) {
-        serverSampler.serverReq->SubRef();
+        serverSampler.serverReq->internal_subref();
     }
-    req->SubRef();
-    target->SubRef();
+    req->internal_subref();
+    target->internal_subref();
 }
 
 TEST_MAIN() { TEST_RUN_ALL(); }
diff --git a/fnet/src/tests/info/info.cpp b/fnet/src/tests/info/info.cpp
index 00075cb75dd..92fe6526a10 100644
--- a/fnet/src/tests/info/info.cpp
+++ b/fnet/src/tests/info/info.cpp
@@ -63,9 +63,9 @@ TEST("info") {
     fprintf(stderr, "FD_SETSIZE: %d\n", l[2]._intval32);
     fprintf(stderr, "sizeof(FRT_RPCRequest): %d\n", l[3]._intval32);
 
-    target->SubRef();
-    local_info->SubRef();
-    remote_info->SubRef();
+    target->internal_subref();
+    local_info->internal_subref();
+    remote_info->internal_subref();
 };
 
 TEST("size of important objects")
diff --git a/fnet/src/tests/printstuff/printstuff_test.cpp b/fnet/src/tests/printstuff/printstuff_test.cpp
index a9621728c5a..bd76ad29405 100644
--- a/fnet/src/tests/printstuff/printstuff_test.cpp
+++ b/fnet/src/tests/printstuff/printstuff_test.cpp
@@ -37,7 +37,7 @@ TEST("rpc packets in a queue") {
         q2.QueuePacket(&req->getStash().create<FRT_RPCRequestPacket>(req, 0, false), FNET_Context());
         q2.Print();
     }
-    req->SubRef();
+    req->internal_subref();
 }
 
 TEST("info") {
diff --git a/fnet/src/tests/transport_debugger/transport_debugger_test.cpp b/fnet/src/tests/transport_debugger/transport_debugger_test.cpp
index a363b1df4c2..eaf2fd71bde 100644
--- a/fnet/src/tests/transport_debugger/transport_debugger_test.cpp
+++ b/fnet/src/tests/transport_debugger/transport_debugger_test.cpp
@@ -113,9 +113,9 @@ TEST_FF("transport layers can be run with transport debugger", Fixture(), vespal
     EXPECT_EQUAL(req4->GetErrorCode(), FRTE_RPC_TIMEOUT);
     ASSERT_TRUE(req6->CheckReturnTypes("l"));
     EXPECT_EQUAL(req6->GetReturn()->GetValue(0)._intval64, 8u);
-    target->SubRef();
-    req4->SubRef();
-    req6->SubRef();
+    target->internal_subref();
+    req4->internal_subref();
+    req6->internal_subref();
 }
 
 TEST_MAIN() { TEST_RUN_ALL(); }
diff --git a/fnet/src/vespa/fnet/connection.cpp b/fnet/src/vespa/fnet/connection.cpp
index e344f2a22a6..fef8a6bf01b 100644
--- a/fnet/src/vespa/fnet/connection.cpp
+++ b/fnet/src/vespa/fnet/connection.cpp
@@ -63,7 +63,7 @@ struct DoHandshakeWork : vespalib::Executor::Task {
     DoHandshakeWork(FNET_Connection *conn_in, vespalib::CryptoSocket *socket_in)
         : conn(conn_in), socket(socket_in)
     {
-        conn->AddRef();
+        conn->internal_addref();
     }
     void run() override {
         socket->do_handshake_work();
@@ -82,7 +82,7 @@ FNET_Connection::ResolveHandler::ResolveHandler(FNET_Connection *conn)
     : connection(conn),
       address()
 {
-    connection->AddRef();
+    connection->internal_addref();
 }
 
 void
@@ -94,7 +94,7 @@ FNET_Connection::ResolveHandler::handle_result(vespalib::SocketAddress result)
 
 FNET_Connection::ResolveHandler::~ResolveHandler()
 {
-    connection->SubRef();
+    connection->internal_subref();
 }
 
 
@@ -149,10 +149,9 @@ FNET_Connection::SetState(State state)
     }
 
     if ( ! toDelete.empty() ) {
-        for (const FNET_Channel::UP & ch : toDelete) {
-            (void) ch;
-            SubRef_NoLock();
-        }
+        const uint32_t cnt = toDelete.size();
+        const uint32_t reserve = 1;
+        internal_subref(cnt, reserve);
     }
 }
 
@@ -185,14 +184,14 @@ FNET_Connection::HandlePacket(uint32_t plen, uint32_t pcode,
             _channels.Unregister(channel);
 
             if (hp_rc == FNET_IPacketHandler::FNET_FREE_CHANNEL) {
-                SubRef_NoLock();
+                internal_subref(1, 1);
                 toDelete.reset(channel);
             }
         }
     } else if (CanAcceptChannels() && IsFromPeer(chid)) { // open new channel
         FNET_Channel::UP newChannel(new FNET_Channel(chid, this));
         channel = newChannel.get();
-        AddRef_NoLock();
+        internal_addref();
         BeforeCallback(guard, channel);
 
         if (_serverAdapter->InitChannel(channel, pcode)) {
@@ -203,7 +202,7 @@ FNET_Connection::HandlePacket(uint32_t plen, uint32_t pcode,
             AfterCallback(guard);
 
             if (hp_rc == FNET_IPacketHandler::FNET_FREE_CHANNEL) {
-                SubRef_NoLock();
+                internal_subref(1, 1);
             } else if (hp_rc == FNET_IPacketHandler::FNET_KEEP_CHANNEL) {
                 _channels.Register(newChannel.release());
             } else {
@@ -212,7 +211,7 @@ FNET_Connection::HandlePacket(uint32_t plen, uint32_t pcode,
         } else {
 
             AfterCallback(guard);
-            SubRef_NoLock();
+            internal_subref(1, 1);
             guard.unlock();
 
             LOG(debug, "Connection(%s): channel init failed", GetSpec());
@@ -489,8 +488,7 @@ FNET_Connection::FNET_Connection(FNET_TransportThread *owner,
       _myQueue(256),
       _output(0),
       _channels(),
-      _callbackTarget(nullptr),
-      _cleanup(nullptr)
+      _callbackTarget(nullptr)
 {
     assert(_socket && (_socket->get_fd() >= 0));
     _num_connections.fetch_add(1, std::memory_order_relaxed);
@@ -520,8 +518,7 @@ FNET_Connection::FNET_Connection(FNET_TransportThread *owner,
       _myQueue(256),
       _output(0),
       _channels(),
-      _callbackTarget(nullptr),
-      _cleanup(nullptr)
+      _callbackTarget(nullptr)
 {
     _num_connections.fetch_add(1, std::memory_order_relaxed);
 }
@@ -530,7 +527,6 @@ FNET_Connection::FNET_Connection(FNET_TransportThread *owner,
 FNET_Connection::~FNET_Connection()
 {
     assert(!_resolve_handler);
-    assert(_cleanup == nullptr);
     _num_connections.fetch_sub(1, std::memory_order_relaxed);
 }
 
@@ -576,12 +572,6 @@ FNET_Connection::handle_handshake_act()
     return ((GetState() == FNET_CONNECTING) && handshake());
 }
 
-void
-FNET_Connection::SetCleanupHandler(FNET_IConnectionCleanupHandler *handler)
-{
-    _cleanup = handler;
-}
-
 
 FNET_Channel*
 FNET_Connection::OpenChannel(FNET_IPacketHandler *handler,
@@ -598,7 +588,7 @@ FNET_Connection::OpenChannel(FNET_IPacketHandler *handler,
             *chid = newChannel->GetID();
         }
         WaitCallback(guard, nullptr);
-        AddRef_NoLock();
+        internal_addref();
         ret = newChannel.release();
         _channels.Register(ret);
     }
@@ -614,7 +604,7 @@ FNET_Connection::OpenChannel()
     {
         std::lock_guard<std::mutex> guard(_ioc_lock);
         chid = GetNextID();
-        AddRef_NoLock();
+        internal_addref();
     }
     return new FNET_Channel(chid, this);
 }
@@ -633,18 +623,20 @@ void
 FNET_Connection::FreeChannel(FNET_Channel *channel)
 {
     delete channel;
-    SubRef_HasLock(std::unique_lock<std::mutex>(_ioc_lock));
+    internal_subref();
 }
 
 
 void
 FNET_Connection::CloseAndFreeChannel(FNET_Channel *channel)
 {
-    std::unique_lock<std::mutex> guard(_ioc_lock);
-    WaitCallback(guard, channel);
-    _channels.Unregister(channel);
-    SubRef_HasLock(std::move(guard));
-    delete channel;
+    {
+        std::unique_lock<std::mutex> guard(_ioc_lock);
+        WaitCallback(guard, channel);
+        _channels.Unregister(channel);
+        delete channel;
+    }
+    internal_subref();
 }
 
 
@@ -668,7 +660,7 @@ FNET_Connection::PostPacket(FNET_Packet *packet, uint32_t chid)
     _writeWork++;
     _queue.QueuePacket_NoLock(packet, FNET_Context(chid));
     if ((writeWork == 0) && (GetState() == FNET_CONNECTED)) {
-        AddRef_NoLock();
+        internal_addref();
         guard.unlock();
         Owner()->EnableWrite(this, /* needRef = */ false);
     }
@@ -686,16 +678,6 @@ FNET_Connection::Sync()
 
 
 void
-FNET_Connection::CleanupHook()
-{
-    if (_cleanup != nullptr) {
-        _cleanup->Cleanup(this);
-        _cleanup = nullptr;
-    }
-}
-
-
-void
 FNET_Connection::Close()
 {
     _resolve_handler.reset();
diff --git a/fnet/src/vespa/fnet/connection.h b/fnet/src/vespa/fnet/connection.h
index 10cf74e79de..80927fd375c 100644
--- a/fnet/src/vespa/fnet/connection.h
+++ b/fnet/src/vespa/fnet/connection.h
@@ -21,30 +21,6 @@ class FNET_IPacketHandler;
 namespace vespalib::net { class ConnectionAuthContext; }
 
 /**
- * Interface implemented by objects that want to perform connection
- * cleanup. Use the SetCleanupHandler method to register with a
- * connection. Currently, there can only be one cleanup handler per
- * connection.
- **/
-class FNET_IConnectionCleanupHandler
-{
-public:
-
-    /**
-     * Destructor.  No cleanup needed for base class.
-     */
-    virtual ~FNET_IConnectionCleanupHandler(void) {}
-
-    /**
-     * Perform connection cleanup.
-     *
-     * @param conn the connection
-     **/
-    virtual void Cleanup(FNET_Connection *conn) = 0;
-};
-
-
-/**
  * This class represents a single connection with another
  * computer. The binary format on a connection is defined by the
  * PacketStreamer given to the constructor. Each connection object may
@@ -115,8 +91,6 @@ private:
     FNET_ChannelLookup       _channels;        // channel 'DB'
     FNET_Channel            *_callbackTarget;  // target of current callback
 
-    FNET_IConnectionCleanupHandler *_cleanup;  // cleanup handler
-
     std::unique_ptr<vespalib::net::ConnectionAuthContext> _auth_context;
 
     static std::atomic<uint64_t> _num_connections; // total number of connections
@@ -377,14 +351,6 @@ public:
      **/
     bool handle_handshake_act() override;
 
-    /**
-     * Register a cleanup handler to be invoked when this connection is
-     * about to be destructed.
-     *
-     * @param handler the cleanup handler
-     **/
-    void SetCleanupHandler(FNET_IConnectionCleanupHandler *handler);
-
 
     /**
      * Open a new channel on this connection. This method will return
@@ -468,14 +434,6 @@ public:
 
 
     /**
-     * Invoked by the io component superclass before the object is
-     * destructed. Will invoke the Cleanup method on the cleanup handler
-     * for this connection, if present.
-     **/
-    void CleanupHook() override;
-
-
-    /**
      * Close this connection immidiately. NOTE: this method should only
      * be called by the transport thread.
      **/
diff --git a/fnet/src/vespa/fnet/frt/invoker.cpp b/fnet/src/vespa/fnet/frt/invoker.cpp
index d4b35720a8d..421bd0c4d0b 100644
--- a/fnet/src/vespa/fnet/frt/invoker.cpp
+++ b/fnet/src/vespa/fnet/frt/invoker.cpp
@@ -98,7 +98,7 @@ FRT_RPCInvoker::HandleDone(bool freeChannel)
     }
     // send response to client or get rid of it
     if (_noReply || (_req->GetErrorCode() == FRTE_RPC_BAD_REQUEST))
-        _req->SubRef();
+        _req->internal_subref();
     else
         ch->Send(_req->CreateReplyPacket());
 
@@ -128,7 +128,7 @@ void FRT_HookInvoker::Invoke()
     _req->SetDetachedPT(&detached);
     (_hook->GetHandler()->*_hook->GetMethod())(_req);
     assert(!detached);
-    _req->SubRef();
+    _req->internal_subref();
 }
 
 void
diff --git a/fnet/src/vespa/fnet/frt/packets.cpp b/fnet/src/vespa/fnet/frt/packets.cpp
index 134a869eafb..5e600c8caa3 100644
--- a/fnet/src/vespa/fnet/frt/packets.cpp
+++ b/fnet/src/vespa/fnet/frt/packets.cpp
@@ -14,7 +14,7 @@ FRT_RPCPacket::Free()
 {
     if (_ownsRef) {
         _req->DiscardBlobs();
-        _req->SubRef();
+        _req->internal_subref();
     }
 }
 
diff --git a/fnet/src/vespa/fnet/frt/reflection.cpp b/fnet/src/vespa/fnet/frt/reflection.cpp
index af7fa069eb9..c09057ea675 100644
--- a/fnet/src/vespa/fnet/frt/reflection.cpp
+++ b/fnet/src/vespa/fnet/frt/reflection.cpp
@@ -153,7 +153,7 @@ FRT_ReflectionBuilder::FRT_ReflectionBuilder(FRT_Supervisor *supervisor)
 FRT_ReflectionBuilder::~FRT_ReflectionBuilder()
 {
     Flush();
-    _req->SubRef();
+    _req->internal_subref();
 }
 
 
diff --git a/fnet/src/vespa/fnet/frt/rpcrequest.cpp b/fnet/src/vespa/fnet/frt/rpcrequest.cpp
index ac6dbb26ad6..6870a275ab1 100644
--- a/fnet/src/vespa/fnet/frt/rpcrequest.cpp
+++ b/fnet/src/vespa/fnet/frt/rpcrequest.cpp
@@ -10,7 +10,6 @@ FRT_RPCRequest::FRT_RPCRequest()
       _context(),
       _params(_stash),
       _return(_stash),
-      _refcnt(1),
       _completed(0),
       _errorCode(FRTE_NO_ERROR),
       _errorMessageLen(0),
@@ -19,14 +18,10 @@ FRT_RPCRequest::FRT_RPCRequest()
       _methodName(nullptr),
       _detachedPT(nullptr),
       _abortHandler(nullptr),
-      _returnHandler(nullptr),
-      _cleanupHandler(nullptr)
+      _returnHandler(nullptr)
 { }
 
-FRT_RPCRequest::~FRT_RPCRequest()
-{
-    assert(_refcnt == 0);
-}
+FRT_RPCRequest::~FRT_RPCRequest() = default;
 
 void
 FRT_RPCRequest::SetError(uint32_t errorCode, const char *errorMessage, uint32_t errorMessageLen)
@@ -87,18 +82,9 @@ FRT_RPCRequest::GetConnection() {
     return _returnHandler->GetConnection();
 }
 
-void
-FRT_RPCRequest::Cleanup() {
-    if (_cleanupHandler != nullptr) {
-        _cleanupHandler->HandleCleanup();
-        _cleanupHandler = nullptr;
-    }
-}
 
 void
 FRT_RPCRequest::Reset() {
-    assert(_refcnt <= 1);
-    Cleanup();
     _context = FNET_Context();
     _params.Reset();
     _return.Reset();
@@ -118,7 +104,7 @@ FRT_RPCRequest::Reset() {
 bool
 FRT_RPCRequest::Recycle()
 {
-    if (_refcnt > 1 || _errorCode != FRTE_NO_ERROR)
+    if (count_refs() > 1 || _errorCode != FRTE_NO_ERROR)
         return false;
     Reset();
     return true;
@@ -126,18 +112,6 @@ FRT_RPCRequest::Recycle()
 
 
 void
-FRT_RPCRequest::SubRef()
-{
-    int oldVal = _refcnt.fetch_sub(1);
-    assert(oldVal > 0);
-    if (oldVal == 1) {
-        Reset();
-        delete this;
-    }
-}
-
-
-void
 FRT_RPCRequest::Print(uint32_t indent)
 {
     printf("%*sFRT_RPCRequest {\n", indent, "");
@@ -163,7 +137,7 @@ FRT_RPCRequest::CreateRequestPacket(bool wantReply)
         flags |= FLAG_FRT_RPC_LITTLE_ENDIAN;
 
     if (wantReply)
-        AddRef();
+        internal_addref();
     else
         flags |= FLAG_FRT_RPC_NOREPLY;
 
diff --git a/fnet/src/vespa/fnet/frt/rpcrequest.h b/fnet/src/vespa/fnet/frt/rpcrequest.h
index a095c274687..72dae4a6af1 100644
--- a/fnet/src/vespa/fnet/frt/rpcrequest.h
+++ b/fnet/src/vespa/fnet/frt/rpcrequest.h
@@ -6,6 +6,7 @@
 #include "error.h"
 #include <vespa/fnet/context.h>
 #include <vespa/vespalib/util/stash.h>
+#include <vespa/vespalib/util/ref_counted.h>
 #include <atomic>
 
 class FNET_Packet;
@@ -37,20 +38,7 @@ public:
 };
 
 
-class FRT_ICleanupHandler
-{
-public:
-
-    /**
-     * Destructor.  No cleanup needed for base class.
-     */
-    virtual ~FRT_ICleanupHandler(void) {}
-
-    virtual void HandleCleanup() = 0;
-};
-
-
-class FRT_RPCRequest
+class FRT_RPCRequest : public vespalib::enable_ref_counted
 {
 private:
     using Stash = vespalib::Stash;
@@ -58,7 +46,6 @@ private:
     FNET_Context     _context;
     FRT_Values       _params;
     FRT_Values       _return;
-    std::atomic<int> _refcnt;
     std::atomic<int> _completed;
     uint32_t         _errorCode;
     uint32_t         _errorMessageLen;
@@ -69,7 +56,6 @@ private:
     bool                *_detachedPT;
     FRT_IAbortHandler   *_abortHandler;
     FRT_IReturnHandler  *_returnHandler;
-    FRT_ICleanupHandler *_cleanupHandler;
 
 public:
     FRT_RPCRequest(const FRT_RPCRequest &) = delete;
@@ -86,9 +72,6 @@ public:
         _return.DiscardBlobs();
     }
 
-    void AddRef() { _refcnt.fetch_add(1); }
-    void SubRef();
-
     void SetContext(FNET_Context context) { _context = context; }
     FNET_Context GetContext() { return _context; }
 
@@ -137,10 +120,8 @@ public:
 
     void SetAbortHandler(FRT_IAbortHandler *handler) { _abortHandler = handler; }
     void SetReturnHandler(FRT_IReturnHandler *handler) { _returnHandler = handler; }
-    void SetCleanupHandler(FRT_ICleanupHandler *handler) { _cleanupHandler = handler; }
 
     bool Abort();
     void Return();
     FNET_Connection *GetConnection();
-    void Cleanup();
 };
diff --git a/fnet/src/vespa/fnet/frt/supervisor.cpp b/fnet/src/vespa/fnet/frt/supervisor.cpp
index 966c606bf97..7d6b4d727c7 100644
--- a/fnet/src/vespa/fnet/frt/supervisor.cpp
+++ b/fnet/src/vespa/fnet/frt/supervisor.cpp
@@ -31,7 +31,7 @@ FRT_Supervisor::~FRT_Supervisor()
 {
     _transport->detach(this);
     if (_connector != nullptr) {
-        _connector->SubRef();
+        _connector->internal_subref();
     }
 }
 
@@ -99,7 +99,7 @@ FRT_Supervisor::AllocRPCRequest(FRT_RPCRequest *tradein)
         if (tradein->Recycle()) {
             return tradein;
         }
-        tradein->SubRef();
+        tradein->internal_subref();
     }
     return new FRT_RPCRequest();
 }
@@ -113,7 +113,7 @@ FRT_Supervisor::InvokeVoid(FNET_Connection *conn, FRT_RPCRequest *req)
         ch->Send(req->CreateRequestPacket(false));
         ch->Free();
     } else {
-        req->SubRef();
+        req->internal_subref();
     }
 }
 
diff --git a/fnet/src/vespa/fnet/frt/target.cpp b/fnet/src/vespa/fnet/frt/target.cpp
index 1645fba91ee..47baa95b9e2 100644
--- a/fnet/src/vespa/fnet/frt/target.cpp
+++ b/fnet/src/vespa/fnet/frt/target.cpp
@@ -6,7 +6,6 @@
 
 FRT_Target::~FRT_Target()
 {
-    assert(_refcnt == 0);
     FNET_Connection * conn(_conn);
     _conn = nullptr;
     if (conn != nullptr) {
diff --git a/fnet/src/vespa/fnet/frt/target.h b/fnet/src/vespa/fnet/frt/target.h
index ac6bf377a14..773daaca8b1 100644
--- a/fnet/src/vespa/fnet/frt/target.h
+++ b/fnet/src/vespa/fnet/frt/target.h
@@ -3,16 +3,16 @@
 #pragma once
 
 #include <vespa/fnet/connection.h>
+#include <vespa/vespalib/util/ref_counted.h>
 #include <atomic>
 
 class FNET_Scheduler;
 class FRT_RPCRequest;
 class FRT_IRequestWait;
 
-class FRT_Target
+class FRT_Target : public vespalib::enable_ref_counted
 {
 private:
-    std::atomic<int> _refcnt;
     FNET_Scheduler  *_scheduler;
     FNET_Connection *_conn;
 
@@ -21,23 +21,12 @@ private:
 
 public:
     FRT_Target(FNET_Scheduler *scheduler, FNET_Connection *conn)
-        : _refcnt(1),
-          _scheduler(scheduler),
+        : _scheduler(scheduler),
           _conn(conn) {}
 
     ~FRT_Target();
 
     FNET_Connection *GetConnection() const { return _conn; }
-
-    void AddRef() { _refcnt.fetch_add(1); }
-    void SubRef() {
-        if (_refcnt.fetch_sub(1) == 1) {
-            delete this;
-        }
-    }
-
-    int GetRefCnt() const { return _refcnt; }
-
     bool IsValid() {
         return ((_conn != nullptr) &&
                 (_conn->GetState() <= FNET_Connection::FNET_CONNECTED));
diff --git a/fnet/src/vespa/fnet/iocomponent.cpp b/fnet/src/vespa/fnet/iocomponent.cpp
index f08718c0c5c..c4fc7d859d4 100644
--- a/fnet/src/vespa/fnet/iocomponent.cpp
+++ b/fnet/src/vespa/fnet/iocomponent.cpp
@@ -16,7 +16,6 @@ FNET_IOComponent::FNET_IOComponent(FNET_TransportThread *owner,
       _ioc_spec(spec),
       _flags(shouldTimeOut),
       _ioc_socket_fd(socket_fd),
-      _ioc_refcnt(1),
       _ioc_timestamp(vespalib::steady_clock::now()),
       _ioc_lock(),
       _ioc_cond()
@@ -39,58 +38,6 @@ FNET_IOComponent::UpdateTimeOut() {
     _ioc_owner->UpdateTimeOut(this);
 }
 
-void
-FNET_IOComponent::AddRef()
-{
-    std::lock_guard<std::mutex> guard(_ioc_lock);
-    assert(_ioc_refcnt > 0);
-    _ioc_refcnt++;
-}
-
-
-void
-FNET_IOComponent::AddRef_NoLock()
-{
-    assert(_ioc_refcnt > 0);
-    _ioc_refcnt++;
-}
-
-
-void
-FNET_IOComponent::SubRef()
-{
-    {
-        std::lock_guard<std::mutex> guard(_ioc_lock);
-        assert(_ioc_refcnt > 0);
-        if (--_ioc_refcnt > 0) {
-            return;
-        }
-    }
-    CleanupHook();
-    delete this;
-}
-
-
-void
-FNET_IOComponent::SubRef_HasLock(std::unique_lock<std::mutex> guard)
-{
-    assert(_ioc_refcnt > 0);
-    if (--_ioc_refcnt > 0) {
-        return;
-    }
-    guard.unlock();
-    CleanupHook();
-    delete this;
-}
-
-
-void
-FNET_IOComponent::SubRef_NoLock()
-{
-    assert(_ioc_refcnt > 1);
-    _ioc_refcnt--;
-}
-
 
 void
 FNET_IOComponent::attach_selector(Selector &selector)
@@ -141,8 +88,3 @@ FNET_IOComponent::handle_handshake_act()
 {
     return true;
 }
-
-void
-FNET_IOComponent::CleanupHook()
-{
-}
diff --git a/fnet/src/vespa/fnet/iocomponent.h b/fnet/src/vespa/fnet/iocomponent.h
index 106e31c9236..b88b2700db5 100644
--- a/fnet/src/vespa/fnet/iocomponent.h
+++ b/fnet/src/vespa/fnet/iocomponent.h
@@ -4,6 +4,7 @@
 
 #include "scheduler.h"
 #include <vespa/vespalib/net/selector.h>
+#include <vespa/vespalib/util/ref_counted.h>
 #include <mutex>
 #include <condition_variable>
 #include <chrono>
@@ -18,7 +19,7 @@ class FNET_Config;
  * Components do IO against the network and that they use sockets to
  * perform that IO.
  **/
-class FNET_IOComponent
+class FNET_IOComponent : public vespalib::enable_ref_counted
 {
     friend class FNET_TransportThread;
 
@@ -46,7 +47,6 @@ protected:
     std::string              _ioc_spec;          // connect/listen spec
     Flags                    _flags;             // Compressed representation of boolean flags;
     int                      _ioc_socket_fd;     // source of events.
-    uint32_t                 _ioc_refcnt;        // reference counter
     vespalib::steady_time    _ioc_timestamp;     // last I/O activity
     std::mutex               _ioc_lock;          // synchronization
     std::condition_variable  _ioc_cond;          // synchronization
@@ -88,43 +88,6 @@ public:
     std::unique_lock<std::mutex> getGuard() { return std::unique_lock<std::mutex>(_ioc_lock); }
 
     /**
-     * Allocate a reference to this component. This method locks the
-     * object to protect the reference counter.
-     **/
-    void AddRef();
-
-
-    /**
-     * Allocate a reference to this component without locking the
-     * object. Caller already has lock on object.
-     **/
-    void AddRef_NoLock();
-
-
-    /**
-     * Free a reference to this component. This method locks the object
-     * to protect the reference counter.
-     **/
-    void SubRef();
-
-
-    /**
-     * Free a reference to this component. This method uses locking to
-     * protect the reference counter, but assumes that the lock has
-     * already been obtained when this method is called.
-     **/
-    void SubRef_HasLock(std::unique_lock<std::mutex> guard);
-
-
-    /**
-     * Free a reference to this component without locking the
-     * object. NOTE: this method may only be called on objects with more
-     * than one reference.
-     **/
-    void SubRef_NoLock();
-
-
-    /**
      * @return the owning TransportThread object.
      **/
     FNET_TransportThread *Owner() { return _ioc_owner; }
@@ -217,13 +180,6 @@ public:
      **/
     virtual bool handle_handshake_act();
 
-    /**
-     * This method is called by the SubRef methods just before the
-     * object is deleted. It may be used to perform cleanup tasks that
-     * must be done before the destructor is invoked.
-     **/
-    virtual void CleanupHook();
-
 
     /**
      * Close this component immediately. NOTE: this method should only
diff --git a/fnet/src/vespa/fnet/transport_thread.cpp b/fnet/src/vespa/fnet/transport_thread.cpp
index 970dc40150f..0b0df02c04c 100644
--- a/fnet/src/vespa/fnet/transport_thread.cpp
+++ b/fnet/src/vespa/fnet/transport_thread.cpp
@@ -107,7 +107,7 @@ FNET_TransportThread::FlushDeleteList()
         FNET_IOComponent *tmp = _deleteList;
         _deleteList = tmp->_ioc_next;
         assert(tmp->_flags._ioc_delete);
-        tmp->SubRef();
+        tmp->internal_subref();
     }
 }
 
@@ -143,12 +143,12 @@ FNET_TransportThread::DiscardEvent(FNET_ControlPacket *cpacket,
     switch (cpacket->GetCommand()) {
     case FNET_ControlPacket::FNET_CMD_IOC_ADD:
         context._value.IOC->Close();
-        context._value.IOC->SubRef();
+        context._value.IOC->internal_subref();
         break;
     case FNET_ControlPacket::FNET_CMD_IOC_ENABLE_WRITE:
     case FNET_ControlPacket::FNET_CMD_IOC_HANDSHAKE_ACT:
     case FNET_ControlPacket::FNET_CMD_IOC_CLOSE:
-        context._value.IOC->SubRef();
+        context._value.IOC->internal_subref();
         break;
     }
 }
@@ -173,7 +173,7 @@ FNET_TransportThread::handle_close_cmd(FNET_IOComponent *ioc)
 {
     if (ioc->_flags._ioc_added) {
         RemoveComponent(ioc);
-        ioc->SubRef();
+        ioc->internal_subref();
     }
     ioc->Close();
     AddDeleteComponent(ioc);
@@ -288,7 +288,7 @@ FNET_TransportThread::Listen(const char *spec, FNET_IPacketStreamer *streamer,
     if (server_socket.valid() && server_socket.set_blocking(false)) {
         FNET_Connector *connector = new FNET_Connector(this, streamer, serverAdapter, spec, std::move(server_socket));
         connector->EnableReadEvent(true);
-        connector->AddRef_NoLock();
+        connector->internal_addref();
         Add(connector, /* needRef = */ false);
         return connector;
     }
@@ -314,7 +314,7 @@ void
 FNET_TransportThread::Add(FNET_IOComponent *comp, bool needRef)
 {
     if (needRef) {
-        comp->AddRef();
+        comp->internal_addref();
     }
     PostEvent(&FNET_ControlPacket::IOCAdd, FNET_Context(comp));
 }
@@ -324,7 +324,7 @@ void
 FNET_TransportThread::EnableWrite(FNET_IOComponent *comp, bool needRef)
 {
     if (needRef) {
-        comp->AddRef();
+        comp->internal_addref();
     }
     PostEvent(&FNET_ControlPacket::IOCEnableWrite, FNET_Context(comp));
 }
@@ -333,7 +333,7 @@ void
 FNET_TransportThread::handshake_act(FNET_IOComponent *comp, bool needRef)
 {
     if (needRef) {
-        comp->AddRef();
+        comp->internal_addref();
     }
     PostEvent(&FNET_ControlPacket::IOCHandshakeACT, FNET_Context(comp));
 }
@@ -342,7 +342,7 @@ void
 FNET_TransportThread::Close(FNET_IOComponent *comp, bool needRef)
 {
     if (needRef) {
-        comp->AddRef();
+        comp->internal_addref();
     }
     PostEvent(&FNET_ControlPacket::IOCClose, FNET_Context(comp));
 }
@@ -449,7 +449,7 @@ FNET_TransportThread::handle_wakeup()
         }
 
         if (context._value.IOC->_flags._ioc_delete) {
-            context._value.IOC->SubRef();
+            context._value.IOC->internal_subref();
             continue;
         }
 
@@ -460,14 +460,14 @@ FNET_TransportThread::handle_wakeup()
         case FNET_ControlPacket::FNET_CMD_IOC_ENABLE_WRITE:
             context._value.IOC->EnableWriteEvent(true);
             if (context._value.IOC->HandleWriteEvent()) {
-                context._value.IOC->SubRef();
+                context._value.IOC->internal_subref();
             } else {
                 handle_close_cmd(context._value.IOC);
             }
             break;
         case FNET_ControlPacket::FNET_CMD_IOC_HANDSHAKE_ACT:
             if (context._value.IOC->handle_handshake_act()) {
-                context._value.IOC->SubRef();
+                context._value.IOC->internal_subref();
             } else {
                 handle_close_cmd(context._value.IOC);
             }
@@ -577,7 +577,7 @@ FNET_TransportThread::endEventLoop() {
         component = component->_ioc_next;
         RemoveComponent(tmp);
         tmp->Close();
-        tmp->SubRef();
+        tmp->internal_subref();
     }
     assert(_componentsHead == nullptr &&
            _componentsTail == nullptr &&
diff --git a/fnet/src/vespa/fnet/transport_thread.h b/fnet/src/vespa/fnet/transport_thread.h
index 1744a3d60e5..6047d4e3482 100644
--- a/fnet/src/vespa/fnet/transport_thread.h
+++ b/fnet/src/vespa/fnet/transport_thread.h
@@ -97,7 +97,7 @@ private:
 
 
     /**
-     * Delete (call SubRef on) all IO Components in the delete list.
+     * Delete (call internal_subref on) all IO Components in the delete list.
      **/
     void FlushDeleteList();
 
@@ -277,7 +277,7 @@ public:
      * @param needRef should be set to false if the caller of this
      *        method already has obtained an extra reference to the
      *        component. If this flag is true, this method will call the
-     *        AddRef method on the component.
+     *        internal_addref method on the component.
      **/
     void Add(FNET_IOComponent *comp, bool needRef = true);
 
@@ -294,7 +294,7 @@ public:
      * @param needRef should be set to false if the caller of this
      *        method already has obtained an extra reference to the
      *        component. If this flag is true, this method will call the
-     *        AddRef method on the component.
+     *        internal_addref method on the component.
      **/
     void EnableWrite(FNET_IOComponent *comp, bool needRef = true);
 
@@ -312,7 +312,7 @@ public:
      * @param needRef should be set to false if the caller of this
      *        method already has obtained an extra reference to the
      *        component. If this flag is true, this method will call the
-     *        AddRef method on the component.
+     *        internal_addref method on the component.
      **/
     void handshake_act(FNET_IOComponent *comp, bool needRef = true);
 
@@ -330,7 +330,7 @@ public:
      * @param needRef should be set to false if the caller of this
      *        method already has obtained an extra reference to the
      *        component. If this flag is true, this method will call the
-     *        AddRef method on the component.
+     *        internal_addref method on the component.
      **/
     void Close(FNET_IOComponent *comp, bool needRef = true);