add ADB server/client + tests

9 files changed, 686 insertions, 12 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8a35d95..9fa4d10 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -15,6 +15,9 @@ set (SERVICE_EXEC "${PACKAGE}-service")
 option (enable_tests "Build the package's automatic tests." ON)
 option (enable_lcov "Generate lcov code coverage reports." ON)
 
+set(THREADS_PREFER_PTHREAD_FLAG ON)
+find_package(Threads REQUIRED)
+
 ##
 ##  GNU standard paths
 ## 
@@ -47,7 +50,7 @@ include_directories (${CMAKE_CURRENT_SOURCE_DIR})
 
 # set the compiler warnings
 if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
-  set (CXX_WARNING_ARGS "${CXX_WARNING_ARGS} -Weverything -Wno-c++98-compat")
+  set (CXX_WARNING_ARGS "${CXX_WARNING_ARGS} -Weverything -Wno-c++98-compat -Wno-padded")
 else()
   set (CXX_WARNING_ARGS "${CXX_WARNING_ARGS} -Wall -Wextra -Wpedantic")
 endif()
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 982aa49..414a750 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -5,6 +5,7 @@ add_definitions (-DG_LOG_DOMAIN="${CMAKE_PROJECT_NAME}")
 
 # handwritten source code...
 set (SERVICE_LIB_HANDWRITTEN_SOURCES
+     adbd-client.cpp
      exporter.cpp
      rotation-lock.cpp)
 
@@ -19,7 +20,7 @@ link_directories (${SERVICE_DEPS_LIBRARY_DIRS})
 
 set (SERVICE_EXEC_HANDWRITTEN_SOURCES main.cpp)
 add_executable (${SERVICE_EXEC} ${SERVICE_EXEC_HANDWRITTEN_SOURCES})
-target_link_libraries (${SERVICE_EXEC} ${SERVICE_LIB} ${SERVICE_DEPS_LIBRARIES} ${GCOV_LIBS})
+target_link_libraries (${SERVICE_EXEC} ${SERVICE_LIB} ${SERVICE_DEPS_LIBRARIES} Threads::Threads ${GCOV_LIBS})
 install (TARGETS ${SERVICE_EXEC} RUNTIME DESTINATION ${CMAKE_INSTALL_FULL_PKGLIBEXECDIR})
 
 # add warnings/coverage info on handwritten files
diff --git a/src/adbd-client.cpp b/src/adbd-client.cpp
new file mode 100644
index 0000000..38f202f
--- /dev/null
+++ b/src/adbd-client.cpp
@@ -0,0 +1,258 @@
+/*
+ * Copyright 2016 Canonical Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 3, as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranties of
+ * MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors:
+ *   Charles Kerr <charles.kerr@canonical.com>
+ */
+
+#include <src/adbd-client.h>
+
+#include <gio/gio.h>
+#include <gio/gunixsocketaddress.h>
+
+#include <chrono>
+#include <condition_variable>
+#include <mutex>
+#include <thread>
+
+class GAdbdClient::Impl
+{
+public:
+
+    explicit Impl(const std::string& socket_path):
+        m_socket_path{socket_path},
+        m_cancellable{g_cancellable_new()},
+        m_worker_thread{&Impl::worker_func, this}
+    {
+    }
+
+    ~Impl()
+    {
+        // tell the worker thread to stop whatever it's doing and exit.
+        g_cancellable_cancel(m_cancellable);
+        m_sleep_cv.notify_one();
+        m_worker_thread.join();
+        g_clear_object(&m_cancellable);
+    }
+
+    core::Signal<const PKRequest&>& on_pk_request()
+    {
+        return m_on_pk_request;
+    }
+
+private:
+
+    // struct to carry request info from the worker thread to the GMainContext thread
+    struct PKIdleData
+    {
+        Impl* self = nullptr;
+        GCancellable* cancellable = nullptr;
+        const std::string public_key;
+
+        PKIdleData(Impl* self_, GCancellable* cancellable_, std::string public_key_):
+            self(self_),
+            cancellable(G_CANCELLABLE(g_object_ref(cancellable_))),
+            public_key(public_key_) {}
+
+        ~PKIdleData() {g_clear_object(&cancellable);}
+        
+    };
+
+    void pass_public_key_to_main_thread(const std::string& public_key)
+    {
+        g_idle_add_full(G_PRIORITY_DEFAULT_IDLE,
+                        on_public_key_request_static,
+                        new PKIdleData{this, m_cancellable, public_key},
+                        [](gpointer id){delete static_cast<PKIdleData*>(id);});
+    }
+
+    static gboolean on_public_key_request_static (gpointer gdata) // runs in main thread
+    {
+        /* NB: It's possible (though unlikely) that data.self was destroyed
+           while this callback was pending, so we must check is-cancelled FIRST */
+        auto data = static_cast<PKIdleData*>(gdata);
+        if (!g_cancellable_is_cancelled(data->cancellable))
+        {
+            // notify our listeners of the request
+            auto self = data->self;
+            struct PKRequest req;
+            req.public_key = data->public_key;
+            req.respond = [self](PKResponse response){self->on_public_key_response(response);};
+            self->m_on_pk_request(req);
+        }
+
+        return G_SOURCE_REMOVE;
+    }
+
+    void on_public_key_response(PKResponse response)
+    {
+        // set m_pkresponse and wake up the waiting worker thread
+        std::unique_lock<std::mutex> lk(m_pkresponse_mutex);
+        m_pkresponse = response;
+        m_pkresponse_ready = true;
+        m_pkresponse_cv.notify_one();
+    }
+
+    /***
+    ****
+    ***/
+
+    void worker_func() // runs in worker thread
+    {
+        const auto socket_path {m_socket_path};
+
+        while (!g_cancellable_is_cancelled(m_cancellable))
+        {
+            g_debug("%s creating a client socket", G_STRLOC);
+            auto socket = create_client_socket(socket_path);
+            bool got_valid_req = false;
+
+            g_debug("%s calling read_request", G_STRLOC);
+            std::string reqstr;
+            if (socket != nullptr)
+                reqstr = read_request(socket);
+            if (!reqstr.empty())
+                g_debug("%s got request [%s]", G_STRLOC, reqstr.c_str());
+
+            if (reqstr.substr(0,2) == "PK") {
+                PKResponse response = PKResponse::DENY;
+                const auto public_key = reqstr.substr(2);
+                g_debug("%s got pk [%s]", G_STRLOC, public_key.c_str());
+                if (!public_key.empty()) {
+                    got_valid_req = true;
+                    std::unique_lock<std::mutex> lk(m_pkresponse_mutex);
+                    m_pkresponse_ready = false;
+                    pass_public_key_to_main_thread(public_key);
+                    m_pkresponse_cv.wait(lk, [this](){
+                        return m_pkresponse_ready || g_cancellable_is_cancelled(m_cancellable);
+                    });
+                    response = m_pkresponse;
+                    g_debug("%s got response '%d'", G_STRLOC, int(response));
+                }
+                if (!g_cancellable_is_cancelled(m_cancellable))
+                    send_pk_response(socket, response);
+            } else if (!reqstr.empty()) {
+                g_warning("Invalid ADB request: [%s]", reqstr.c_str());
+            }
+
+            g_clear_object(&socket);
+
+            // If nothing interesting's happening, sleep a bit.
+            // (Interval copied from UsbDebuggingManager.java)
+            static constexpr auto sleep_interval {std::chrono::seconds(1)};
+            if (!got_valid_req && !g_cancellable_is_cancelled(m_cancellable)) {
+                std::unique_lock<std::mutex> lk(m_sleep_mutex);
+                m_sleep_cv.wait_for(lk, sleep_interval);
+            }
+        }
+    }
+
+    // connect to a local domain socket
+    GSocket* create_client_socket(const std::string& socket_path)
+    {
+        GError* error {};
+        auto socket = g_socket_new(G_SOCKET_FAMILY_UNIX,
+                                   G_SOCKET_TYPE_STREAM,
+                                   G_SOCKET_PROTOCOL_DEFAULT,
+                                   &error);
+        if (error != nullptr) {
+            g_warning("Error creating adbd client socket: %s", error->message);
+            g_clear_error(&error);
+            g_clear_object(&socket);
+            return nullptr;
+        }
+
+        auto address = g_unix_socket_address_new(socket_path.c_str());
+        const auto connected = g_socket_connect(socket, address, m_cancellable, nullptr);
+        g_clear_object(&address);
+        if (!connected) {
+            g_clear_object(&socket);
+            return nullptr;
+        }
+
+        return socket;
+    }
+
+    std::string read_request(GSocket* socket)
+    {
+        char buf[4096] = {};
+        g_debug("%s calling g_socket_receive()", G_STRLOC);
+        const auto n_bytes = g_socket_receive (socket, buf, sizeof(buf), m_cancellable, nullptr);
+        std::string ret;
+        if (n_bytes > 0)
+            ret.append(buf, std::string::size_type(n_bytes));
+        g_debug("%s g_socket_receive got %d bytes: [%s]", G_STRLOC, int(n_bytes), ret.c_str());
+        return ret;
+    }
+
+    void send_pk_response(GSocket* socket, PKResponse response)
+    {
+        std::string response_str;
+        switch(response) {
+            case PKResponse::ALLOW: response_str = "OK"; break;
+            case PKResponse::DENY:  response_str = "NO"; break;
+        }
+        g_debug("%s sending reply: [%s]", G_STRLOC, response_str.c_str());
+
+        GError* error {};
+        g_socket_send(socket,
+                      response_str.c_str(),
+                      response_str.size(),
+                      m_cancellable,
+                      &error);
+        if (error != nullptr) {
+            if (!g_error_matches(error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+                g_warning("GAdbdServer: Error accepting socket connection: %s", error->message);
+            g_clear_error(&error);
+        }
+    }
+
+    const std::string m_socket_path;
+    GCancellable* m_cancellable = nullptr;
+    std::thread m_worker_thread;
+    core::Signal<const PKRequest&> m_on_pk_request;
+
+    std::mutex m_sleep_mutex;
+    std::condition_variable m_sleep_cv;
+
+    std::mutex m_pkresponse_mutex;
+    std::condition_variable m_pkresponse_cv;
+    bool m_pkresponse_ready = false;
+    PKResponse m_pkresponse = PKResponse::DENY;
+};
+
+/***
+****
+***/
+
+AdbdClient::~AdbdClient()
+{
+}
+
+GAdbdClient::GAdbdClient(const std::string& socket_path):
+    impl{new Impl{socket_path}}
+{
+}
+
+GAdbdClient::~GAdbdClient()
+{
+}
+
+core::Signal<const AdbdClient::PKRequest&>&
+GAdbdClient::on_pk_request()
+{
+    return impl->on_pk_request();
+}
+
diff --git a/src/adbd-client.h b/src/adbd-client.h
new file mode 100644
index 0000000..aef7674
--- /dev/null
+++ b/src/adbd-client.h
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2016 Canonical Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 3, as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranties of
+ * MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors:
+ *   Charles Kerr <charles.kerr@canonical.com>
+ */
+
+#pragma once
+
+#include <functional>
+#include <memory>
+#include <string>
+
+#include <core/signal.h>
+
+/**
+ * Receives public key requests from ADBD and sends a response back.
+ *
+ * AdbClient only provides a receive/respond mechanism. The decision
+ * of what response gets sent is delegated out to a listener via
+ * the on_pk_request signal.
+ *
+ * The decider should connect to on_pk_request, listen for PKRequests,
+ * and call the request's `respond' method with the desired response.
+ */
+class AdbdClient
+{
+public:
+    virtual ~AdbdClient();
+
+    enum class PKResponse { DENY, ALLOW };
+
+    struct PKRequest {
+        std::string public_key;
+        std::function<void(PKResponse)> respond;
+    };
+
+    virtual core::Signal<const PKRequest&>& on_pk_request() =0;
+
+protected:
+    AdbdClient() =default;
+};
+
+/**
+ * An AdbdClient designed to work with GLib's event loop.
+ *
+ * The on_pk_request() signal will be called in global GMainContext's thread;
+ * ie, just like a function passed to g_idle_add() or g_timeout_add().
+ */
+class GAdbdClient: public AdbdClient
+{
+public:
+    explicit GAdbdClient(const std::string& socket_path);
+    ~GAdbdClient();
+    core::Signal<const PKRequest&>& on_pk_request() override;
+
+private:
+    class Impl;
+    std::unique_ptr<Impl> impl;
+};
+
diff --git a/src/main.cpp b/src/main.cpp
index 86bdeb3..0c56bd6 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -17,6 +17,7 @@
  *   Charles Kerr <charles.kerr@canonical.com>
  */
 
+#include <src/adbd-client.h>
 #include <src/exporter.h>
 #include <src/rotation-lock.h>
 
@@ -54,6 +55,16 @@ main(int /*argc*/, char** /*argv*/)
       exporters.push_back(exporter);
     }
 
+    // We need the ADBD handler running,
+    // even though it doesn't have an indicator component yet
+    static constexpr char const * ADB_SOCKET_PATH {"/dev/socket/adb"};
+    GAdbdClient adbd_client{ADB_SOCKET_PATH};
+    adbd_client.on_pk_request().connect([](const AdbdClient::PKRequest& req){
+        g_debug("%s got pk_request [%s]", G_STRLOC, req.public_key.c_str());
+        // FIXME: actually decide what response to send back
+        req.respond(AdbdClient::PKResponse::ALLOW);
+    });
+
     g_main_loop_run(loop);
 
     // cleanup
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 59e50bc..706e35b 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -3,19 +3,14 @@ include_directories(${CMAKE_CURRENT_SOURCE_DIR})
 include_directories(${GMOCK_INCLUDE_DIRS})
 include_directories(${GTEST_INCLUDE_DIRS})
 
-# build libgtest
-#add_library (gtest STATIC 
-#             ${GTEST_SOURCE_DIR}/gtest-all.cc 
-#             ${GTEST_SOURCE_DIR}/gtest_main.cc)
-#set_target_properties (gtest PROPERTIES INCLUDE_DIRECTORIES ${INCLUDE_DIRECTORIES} ${GTEST_INCLUDE_DIR})
-#set_target_properties (gtest PROPERTIES COMPILE_FLAGS ${COMPILE_FLAGS} -w)
+set(CTEST_ENVIRONMENT "${CTEST_ENVIRONMENT};G_MESSAGES_DEBUG=all")
 
 if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
   # turn off the warnings that break Google Test
   set (CXX_WARNING_ARGS "${CXX_WARNING_ARGS} -Wno-global-constructors -Wno-weak-vtables -Wno-undef -Wno-c++98-compat-pedantic -Wno-missing-noreturn -Wno-used-but-marked-unused -Wno-padded -Wno-deprecated -Wno-sign-compare -Wno-shift-sign-overflow")
 endif()
 
-SET (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -g ${CXX_WARNING_ARGS}")
+SET (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -g -pthread ${CXX_WARNING_ARGS}")
 
 # look for headers in our src dir, and also in the directories where we autogenerate files...
 include_directories (${CMAKE_SOURCE_DIR}/src)
@@ -26,10 +21,13 @@ function(add_test_by_name name)
   set (TEST_NAME ${name})
   add_executable (${TEST_NAME} ${TEST_NAME}.cpp)
   add_test (${TEST_NAME} ${TEST_NAME})
+ set_property(TEST ${TEST_NAME} PROPERTY ENVIRONMENT "${CTEST_ENVIRONMENT}")
+
   add_dependencies (${TEST_NAME} libindicatordisplayservice)
   target_link_libraries (${TEST_NAME} indicatordisplayservice ${SERVICE_DEPS_LIBRARIES} ${GTEST_LIBRARIES} ${GMOCK_LIBRARIES})
 endfunction()
 add_test_by_name(rotation-lock-test)
+add_test_by_name(adbd-client-test)
 
 add_test (cppcheck cppcheck --enable=all -USCHEMA_DIR --error-exitcode=2 --inline-suppr -I${CMAKE_SOURCE_DIR} ${CMAKE_SOURCE_DIR}/src ${CMAKE_SOURCE_DIR}/tests)
 
diff --git a/tests/adbd-client-test.cpp b/tests/adbd-client-test.cpp
new file mode 100644
index 0000000..4fa16a8
--- /dev/null
+++ b/tests/adbd-client-test.cpp
@@ -0,0 +1,94 @@
+/*
+ * Copyright 2016 Canonical Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 3, as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranties of
+ * MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors:
+ *   Charles Kerr <charles.kerr@canonical.com>
+ */
+
+#include <tests/test-dbus-fixture.h>
+#include <tests/adbd-server.h>
+
+#include <src/adbd-client.h>
+
+#include <stdlib.h> // mkdtemp
+
+class AdbdClientFixture: public TestDBusFixture
+{
+private:
+    typedef TestDBusFixture super;
+
+protected:
+
+    std::string m_tmpdir;
+
+    void SetUp()
+    {
+        super::SetUp();
+
+        char tmpl[] {"adb-client-test-XXXXXX"};
+        m_tmpdir = mkdtemp(tmpl);
+        g_message("using tmpdir '%s'", m_tmpdir.c_str());
+    }
+
+    void TearDown()
+    {
+        g_rmdir(m_tmpdir.c_str());
+
+        super::TearDown();
+    }
+};
+
+
+TEST_F(AdbdClientFixture, SocketPlumbing)
+{
+    const auto socket_path = m_tmpdir + "/test-socket-plumbing";
+    g_message("socket_path is %s", socket_path.c_str());
+
+    struct {
+        const std::string request;
+        const std::string expected_pk;
+        AdbdClient::PKResponse response;
+        const std::string expected_response;
+    } tests[] = {
+        { "PKHelloWorld", "HelloWorld", AdbdClient::PKResponse::ALLOW, "OK" },
+        { "PKHelloWorld", "HelloWorld", AdbdClient::PKResponse::DENY,  "NO" },
+        { "PKFooBar",     "FooBar",     AdbdClient::PKResponse::ALLOW, "OK" },
+        { "PK",           "",           AdbdClient::PKResponse::DENY,  "NO" }
+    };
+
+    for (const auto& test : tests)
+    {
+        // make the AdbdClient and start listening for Requests
+        std::string pk;
+        auto adbd_client = std::make_shared<GAdbdClient>(socket_path);
+        adbd_client->on_pk_request().connect([&pk, test](const AdbdClient::PKRequest& req){
+            g_message("in on_pk_request with %s", req.public_key.c_str());
+            pk = req.public_key;
+            req.respond(test.response);
+        });
+
+        // fire up a mock ADB server with a preloaded request, and wait for a response
+        auto adbd_server = std::make_shared<GAdbdServer>(socket_path, std::vector<std::string>{test.request});
+        wait_for([adbd_server](){return !adbd_server->m_responses.empty();}, 2000);
+        EXPECT_EQ(test.expected_pk, pk);
+        ASSERT_EQ(1, adbd_server->m_responses.size());
+        EXPECT_EQ(test.expected_response, adbd_server->m_responses.front());
+   
+        // cleanup
+        adbd_client.reset();
+        adbd_server.reset();
+        g_unlink(socket_path.c_str());
+    }
+}
diff --git a/tests/adbd-server.h b/tests/adbd-server.h
new file mode 100644
index 0000000..740faaa
--- /dev/null
+++ b/tests/adbd-server.h
@@ -0,0 +1,148 @@
+/*
+ * Copyright 2016 Canonical Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 3, as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranties of
+ * MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors:
+ *   Charles Kerr <charles.kerr@canonical.com>
+ */
+
+#include <gio/gio.h>
+#include <gio/gunixsocketaddress.h>
+
+#include <string>
+#include <thread>
+#include <vector>
+
+
+/**
+ * A Mock ADBD server.
+ *
+ * Binds to a local domain socket, sends public key requests across it,
+ * and reads back the client's responses.
+ */
+class GAdbdServer
+{
+public:
+
+    GAdbdServer(const std::string& socket_path,
+                const std::vector<std::string>& requests):
+        m_requests{requests},
+        m_socket_path{socket_path},
+        m_cancellable{g_cancellable_new()},
+        m_worker_thread{&GAdbdServer::worker_func, this}
+    {
+    }
+
+    ~GAdbdServer()
+    {
+        // tell the worker thread to stop whatever it's doing and exit.
+        g_cancellable_cancel(m_cancellable);
+        m_worker_thread.join();
+        g_clear_object(&m_cancellable);
+    }
+
+    const std::vector<std::string> m_requests;
+    std::vector<std::string> m_responses;
+
+private:
+
+    void worker_func() // runs in worker thread
+    {
+        auto server_socket = create_server_socket(m_socket_path);
+        auto requests = m_requests;
+
+        GError* error {};
+        g_socket_listen (server_socket, &error);
+        g_assert_no_error (error);
+
+        while (!g_cancellable_is_cancelled(m_cancellable) && !requests.empty())
+        {
+            // wait for a client connection
+            g_message("GAdbdServer::Impl::worker_func() calling g_socket_accept()");
+            auto client_socket = g_socket_accept(server_socket, m_cancellable, &error);
+            if (error != nullptr) {
+                if (!g_error_matches(error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+                    g_warning("GAdbdServer: Error accepting socket connection: %s", error->message);
+                g_clear_error(&error);
+                break;
+            }
+
+            // pop the next request off the stack
+            auto request = requests.front();
+            requests.erase(requests.begin());
+
+            // send the request
+            g_message("GAdbdServer::Impl::worker_func() sending req [%s]", request.c_str());
+            g_socket_send(client_socket,
+                          request.c_str(),
+                          request.size(),
+                          m_cancellable,
+                          &error);
+            if (error != nullptr) {
+                if (!g_error_matches(error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+                    g_warning("GAdbdServer: Error sending request: %s", error->message);
+                g_clear_error(&error);
+                g_clear_object(&client_socket);
+                break;
+            }
+
+            // read the response
+            g_message("GAdbdServer::Impl::worker_func() reading response");
+            char buf[4096];
+            const auto n_bytes = g_socket_receive(client_socket,
+                                                  buf,
+                                                  sizeof(buf),
+                                                  m_cancellable,
+                                                  &error);
+            if (error != nullptr) {
+                if (!g_error_matches(error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+                    g_warning("GAdbdServer: Error reading response: %s", error->message);
+                g_clear_error(&error);
+                g_clear_object(&client_socket);
+                break;
+            }
+            const std::string response(buf, std::string::size_type(n_bytes));
+            g_message("server got response: %s", response.c_str()); 
+            m_responses.push_back(response);
+
+            // cleanup
+            g_clear_object(&client_socket);
+        }
+
+        g_clear_object(&server_socket);
+    }
+
+    // bind to a local domain socket
+    static GSocket* create_server_socket(const std::string& socket_path)
+    {
+        GError* error {};
+        auto socket = g_socket_new(G_SOCKET_FAMILY_UNIX,
+                                   G_SOCKET_TYPE_STREAM,
+                                   G_SOCKET_PROTOCOL_DEFAULT,
+                                   &error);
+        g_assert_no_error(error);
+        auto address = g_unix_socket_address_new (socket_path.c_str());
+        g_socket_bind (socket, address, false, &error);
+        g_assert_no_error (error);
+        g_clear_object (&address);
+
+        return socket;
+    }
+
+    const std::string m_socket_path;
+    GCancellable* m_cancellable = nullptr;
+    std::thread m_worker_thread;
+};
+
+
diff --git a/tests/glib-fixture.h b/tests/glib-fixture.h
index 41ac6e8..ccdeccd 100644
--- a/tests/glib-fixture.h
+++ b/tests/glib-fixture.h
@@ -19,7 +19,9 @@
 
 #pragma once
 
+#include <functional> // std::function
 #include <map>
+#include <memory> // std::shared_ptr
 
 #include <glib.h>
 #include <glib/gstdio.h>
@@ -74,7 +76,7 @@ class GlibFixture : public ::testing::Test
     static gboolean
     wait_for_signal__timeout(gpointer name)
     {
-      g_error("%s: timed out waiting for signal '%s'", G_STRLOC, (char*)name);
+      g_error("%s: timed out waiting for signal '%s'", G_STRLOC, static_cast<const char*>(name));
       return G_SOURCE_REMOVE;
     }
 
@@ -88,7 +90,7 @@ class GlibFixture : public ::testing::Test
   protected:
 
     /* convenience func to loop while waiting for a GObject's signal */
-    void wait_for_signal(gpointer o, const gchar * signal, const int timeout_seconds=5)
+    void wait_for_signal(gpointer o, const gchar * signal, guint timeout_seconds=5)
     {
       // wait for the signal or for timeout, whichever comes first
       const auto handler_id = g_signal_connect_swapped(o, signal,
@@ -103,13 +105,99 @@ class GlibFixture : public ::testing::Test
     }
 
     /* convenience func to loop for N msec */
-    void wait_msec(int msec=50)
+    void wait_msec(guint msec=50)
     {
       const auto id = g_timeout_add(msec, wait_msec__timeout, loop);
       g_main_loop_run(loop);
       g_source_remove(id);
     }
 
+    bool wait_for(std::function<bool()> test_function, guint timeout_msec=1000)
+    {
+      auto timer = std::shared_ptr<GTimer>(g_timer_new(), [](GTimer* t){g_timer_destroy(t);});
+      const auto timeout_sec = timeout_msec / 1000.0;
+      for (;;) {
+        if (test_function())
+          return true;
+        //g_message("%f ... %f", g_timer_elapsed(timer.get(), nullptr), timeout_sec);
+        if (g_timer_elapsed(timer.get(), nullptr) >= timeout_sec)
+          return false;
+        wait_msec();
+      }
+    }
+
+    bool wait_for_name_owned(GDBusConnection* connection,
+                             const gchar* name,
+                             guint timeout_msec=1000,
+                             GBusNameWatcherFlags flags=G_BUS_NAME_WATCHER_FLAGS_AUTO_START)
+    {
+      struct Data {
+        GMainLoop* loop = nullptr;
+        bool owned = false;
+      };
+      Data data;
+
+      auto on_name_appeared = [](GDBusConnection* /*connection*/,
+                                 const gchar* /*name_*/,
+                                 const gchar* name_owner,
+                                 gpointer gdata)
+      {
+        if (name_owner == nullptr)
+          return;
+        auto tmp = static_cast<Data*>(gdata);
+        tmp->owned = true;
+        g_main_loop_quit(tmp->loop);
+      };
+
+      const auto timeout_id = g_timeout_add(timeout_msec, wait_msec__timeout, loop);
+      data.loop = loop;
+      const auto watch_id = g_bus_watch_name_on_connection(connection,
+                                                           name,
+                                                           flags,
+                                                           on_name_appeared,
+                                                           nullptr, /* name_vanished */
+                                                           &data,
+                                                           nullptr); /* user_data_free_func */
+      g_main_loop_run(loop);
+
+      g_bus_unwatch_name(watch_id);
+      g_source_remove(timeout_id);
+
+      return data.owned;
+    }
+
+    void EXPECT_NAME_OWNED_EVENTUALLY(GDBusConnection* connection,
+                                      const gchar* name,
+                                      guint timeout_msec=1000,
+                                      GBusNameWatcherFlags flags=G_BUS_NAME_WATCHER_FLAGS_AUTO_START)
+    {
+      EXPECT_TRUE(wait_for_name_owned(connection, name, timeout_msec, flags)) << "name: " << name;
+    }
+
+    void EXPECT_NAME_NOT_OWNED_EVENTUALLY(GDBusConnection* connection,
+                                          const gchar* name,
+                                          guint timeout_msec=1000,
+                                          GBusNameWatcherFlags flags=G_BUS_NAME_WATCHER_FLAGS_AUTO_START)
+    {
+      EXPECT_FALSE(wait_for_name_owned(connection, name, timeout_msec, flags)) << "name: " << name;
+    }
+
+    void ASSERT_NAME_OWNED_EVENTUALLY(GDBusConnection* connection,
+                                      const gchar* name,
+                                      guint timeout_msec=1000,
+                                      GBusNameWatcherFlags flags=G_BUS_NAME_WATCHER_FLAGS_AUTO_START)
+    {
+      ASSERT_TRUE(wait_for_name_owned(connection, name, timeout_msec, flags)) << "name: " << name;
+    }
+
+    void ASSERT_NAME_NOT_OWNED_EVENTUALLY(GDBusConnection* connection,
+                                          const gchar* name,
+                                          guint timeout_msec=1000,
+                                          GBusNameWatcherFlags flags=G_BUS_NAME_WATCHER_FLAGS_AUTO_START)
+    {
+      ASSERT_FALSE(wait_for_name_owned(connection, name, timeout_msec, flags)) << "name: " << name;
+    }
+
     GMainLoop * loop;
 };