[#3315] use internal IOService for hooks

src/bin/agent/ca_process.cc

@@ -89,6 +89,7 @@ CtrlAgentProcess::run() {
 
 size_t
 CtrlAgentProcess::runIO() {
+    getIOService()->pollExternalIOServices();
     size_t cnt = getIOService()->poll();
     if (!cnt) {
         cnt = getIOService()->runOne();
@@ -192,6 +193,17 @@ CtrlAgentProcess::configure(isc::data::ConstElementPtr config_set,
 
     int rcode = 0;
     config::parseAnswer(rcode, answer);
+
+    /// Let postponed hook initializations to run.
+    try {
+        getIOService()->pollExternalIOServices();
+    } catch (const std::exception& ex) {
+        std::ostringstream err;
+        err << "Error initializing hooks: "
+            << ex.what();
+        return (isc::config::createAnswer(CONTROL_RESULT_ERROR, err.str()));
+    }
+
     return (answer);
 }
 

src/bin/d2/d2_hooks.dox

@@ -55,12 +55,15 @@ to the end of this list.
 
  - @b Description: this callout is executed when the server has completed
    its (re)configuration. The server provides received and parsed configuration
-   structures to the hook library. It also provides a pointer to the IOService
+   structures to the hook library.
-   object which is used by the server to run asynchronous operations. The hooks
+   If the library uses any IO operations, it should create a local IOService
-   libraries can use this IOService object to schedule asynchronous tasks which
+   object and register it to the main IOService which is also provided. This way
-   are triggered by the Kea DHCP DDNS's main loop. The hook library should hold
+   the local IOService is used by the server to run asynchronous operations. The
-   the provided pointer until the library is unloaded. The D2CfgContext
+   hooks library can use the local IOService object to schedule asynchronous
-   object provides access to the D2 running configuration.
+   tasks which are triggered by the D2 server's main loop. The hook library
+   should hold the provided pointer until the library is unloaded at which stage
+   it must unregister the local IOService.
+   The D2CfgContext object provides access to the D2 running configuration.
 
  - <b>Next step status</b>: If any callout sets the status to DROP, the server
    considers the configuration is incorrect and rejects it using the error

src/bin/d2/d2_process.cc

@@ -129,6 +129,7 @@ D2Process::run() {
 
 size_t
 D2Process::runIO() {
+    getIOService()->pollExternalIOServices();
     // We want to block until at least one handler is called.  We'll use
     // boost::asio::io_service directly for two reasons. First off
     // asiolink::IOService::runOne is a void and boost::asio::io_service::stopped
@@ -148,7 +149,6 @@ D2Process::runIO() {
         // service is stopped it will return immediately with a cnt of zero.
         cnt = getIOService()->runOne();
     }
-
     return (cnt);
 }
 
@@ -301,6 +301,16 @@ D2Process::configure(isc::data::ConstElementPtr config_set, bool check_only) {
         }
     }
 
+    /// Let postponed hook initializations to run.
+    try {
+        getIOService()->pollExternalIOServices();
+    } catch (const std::exception& ex) {
+        std::ostringstream err;
+        err << "Error initializing hooks: "
+            << ex.what();
+        return (isc::config::createAnswer(CONTROL_RESULT_ERROR, err.str()));
+    }
+
     // If we are here, configuration was valid, at least it parsed correctly
     // and therefore contained no invalid values.
     // Return the success answer from above.

src/bin/d2/tests/d2_simple_parser_unittest.cc

@@ -579,8 +579,7 @@ public:
         // We don't use SimpleParser::setListDefaults() as this does
         // not handle sub-lists or sub-maps
         for (auto const& domain : config->listValue()) {
-            cnt += D2SimpleParser::
+            cnt += D2SimpleParser::setDdnsDomainDefaults(domain, D2SimpleParser::
-                   setDdnsDomainDefaults(domain, D2SimpleParser::
                                                          DDNS_DOMAIN_DEFAULTS);
         }
 

src/bin/dhcp4/ctrl_dhcp4_srv.cc

@@ -241,6 +241,7 @@ ControlledDhcpv4Srv::commandLibReloadHandler(const string&, ConstElementPtr) {
         HookLibsCollection loaded = HooksManager::getLibraryInfo();
         HooksManager::prepareUnloadLibraries();
         static_cast<void>(HooksManager::unloadLibraries());
+        getIOService()->clearExternalIOServices();
         bool multi_threading_enabled = true;
         uint32_t thread_count = 0;
         uint32_t queue_size = 0;
@@ -452,7 +453,7 @@ ControlledDhcpv4Srv::commandConfigSetHandler(const string&,
 
     /// Let postponed hook initializations to run.
     try {
-        getIOService()->poll();
+        getIOService()->pollExternalIOServices();
     } catch (const std::exception& ex) {
         std::ostringstream err;
         err << "Error initializing hooks: "

src/bin/dhcp4/dhcp4_hooks.dox

@@ -55,13 +55,17 @@ to the end of this list.
 
  - @b Description: this callout is executed when the server has completed
    its (re)configuration. The server provides received and parsed configuration
-   structures to the hook library. It also provides a pointer to the IOService
+   structures to the hook library.
-   object which is used by the server to run asynchronous operations. The hooks
+   If the library uses any IO operations, it should create a local IOService
-   libraries can use this IOService object to schedule asynchronous tasks which
+   object and register it to the main IOService which is also provided. This way
-   are triggered by the DHCP server's main loop. The hook library should hold the
+   the local IOService is used by the server to run asynchronous operations. The
-   provided pointer until the library is unloaded. The NetworkState object
+   hooks library can use the local IOService object to schedule asynchronous
-   provides access to the DHCP service state of the server and allows for
+   tasks which are triggered by the DHCP server's main loop. The hook library
-   enabling and disabling the DHCP service from the hooks libraries.
+   should hold the provided pointer until the library is unloaded at which stage
+   it must unregister the local IOService.
+   The NetworkState object provides access to the DHCP service state of the
+   server and allows for enabling and disabling the DHCP service from the hooks
+   libraries.
 
  - <b>Next step status</b>: If any callout sets the status to DROP, the server
    will interrupt the reconfiguration process. The hook callout is expected to

src/bin/dhcp4/dhcp4_srv.cc

@@ -706,6 +706,7 @@ Dhcpv4Srv::~Dhcpv4Srv() {
         }
         LOG_ERROR(dhcp4_logger, DHCP4_SRV_UNLOAD_LIBRARIES_ERROR).arg(msg);
     }
+    getIOService()->clearExternalIOServices();
     io_service_->stop();
     io_service_->restart();
     try {
@@ -1132,6 +1133,7 @@ Dhcpv4Srv::run() {
 #endif // ENABLE_AFL
         try {
             runOne();
+            getIOService()->pollExternalIOServices();
             getIOService()->poll();
         } catch (const std::exception& e) {
             // General catch-all exception that are not caught by more specific

src/bin/dhcp4/tests/callout_library_4.cc

@@ -31,6 +31,9 @@ void start_service(void) {
     isc_throw(isc::Unexpected, "start service failed");
 };
 
+IOServicePtr io_service;
+IOServicePtr main_io_service;
+
 } // end anonymous
 
 // Functions accessed by the hooks framework use C linkage to avoid the name
@@ -40,6 +43,7 @@ extern "C" {
 
 int
 do_load_impl(LibraryHandle& handle) {
+    io_service.reset(new IOService());
     // Determine if this callout is configured to fail.
     isc::dhcp::SrvConfigPtr config;
     isc::data::ConstElementPtr const& parameters(handle.getParameters());
@@ -51,9 +55,17 @@ do_load_impl(LibraryHandle& handle) {
     return (0);
 }
 
+int
+do_unload_impl() {
+    if (main_io_service) {
+        main_io_service->unregisterExternalIOService(io_service);
+    }
+    return (0);
+}
+
 int (*do_load)(LibraryHandle& handle) = do_load_impl;
 
-int (*do_unload)();
+int (*do_unload)() = do_unload_impl;
 
 /// @brief Callout which appends library number and provided arguments to
 /// the marker file for dhcp4_srv_configured callout.
@@ -79,13 +91,13 @@ dhcp4_srv_configured(CalloutHandle& handle) {
 
     // Get the IO context to post start_service on it.
     std::string error("");
-    IOServicePtr io_context;
     try {
-        handle.getArgument("io_context", io_context);
+        handle.getArgument("io_context", main_io_service);
-        if (!io_context) {
+        if (!main_io_service) {
             error = "null io_context";
         }
-        io_context->post(start_service);
+        main_io_service->registerExternalIOService(io_service);
+        io_service->post(start_service);
     } catch (const std::exception& ex) {
         error = "no io_context in arguments";
     }

src/bin/dhcp6/ctrl_dhcp6_srv.cc

@@ -244,6 +244,7 @@ ControlledDhcpv6Srv::commandLibReloadHandler(const string&, ConstElementPtr) {
         HookLibsCollection loaded = HooksManager::getLibraryInfo();
         HooksManager::prepareUnloadLibraries();
         static_cast<void>(HooksManager::unloadLibraries());
+        getIOService()->clearExternalIOServices();
         bool multi_threading_enabled = true;
         uint32_t thread_count = 0;
         uint32_t queue_size = 0;
@@ -454,7 +455,7 @@ ControlledDhcpv6Srv::commandConfigSetHandler(const string&,
 
     /// Let postponed hook initializations to run.
     try {
-        getIOService()->poll();
+        getIOService()->pollExternalIOServices();
     } catch (const std::exception& ex) {
         std::ostringstream err;
         err << "Error initializing hooks: "

src/bin/dhcp6/dhcp6_hooks.dox

@@ -55,14 +55,17 @@ to the end of this list.
 
  - @b Description: this callout is executed when the server has completed
    its (re)configuration. The server provides received and parsed configuration
-   structures to the hook library. It also provides a pointer to the IOService
+   structures to the hook library.
-   object which is used by the server to run asynchronous operations. The hooks
+   If the library uses any IO operations, it should create a local IOService
-   libraries can use this IOService object to schedule asynchronous tasks which
+   object and register it to the main IOService which is also provided. This way
-   are triggered by the DHCP server's main loop. The hook library should hold the
+   the local IOService is used by the server to run asynchronous operations. The
-   provided pointer until the library is unloaded. The NetworkState object
+   hooks library can use the local IOService object to schedule asynchronous
-   provides access to the DHCP service state of the server and allows for
+   tasks which are triggered by the DHCP server's main loop. The hook library
-   enabling and disabling the DHCP service from the hooks libraries.
+   should hold the provided pointer until the library is unloaded at which stage
-
+   it must unregister the local IOService.
+   The NetworkState object provides access to the DHCP service state of the
+   server and allows for enabling and disabling the DHCP service from the hooks
+   libraries.
 
  - <b>Next step status</b>: If any callout sets the status to DROP, the server
    will interrupt the reconfiguration process. The hook callout is expected to

src/bin/dhcp6/dhcp6_srv.cc

@@ -302,6 +302,7 @@ Dhcpv6Srv::~Dhcpv6Srv() {
         }
         LOG_ERROR(dhcp6_logger, DHCP6_SRV_UNLOAD_LIBRARIES_ERROR).arg(msg);
     }
+    getIOService()->clearExternalIOServices();
     io_service_->stop();
     io_service_->restart();
     try {
@@ -613,6 +614,7 @@ Dhcpv6Srv::run() {
 #endif // ENABLE_AFL
         try {
             runOne();
+            getIOService()->pollExternalIOServices();
             getIOService()->poll();
         } catch (const std::exception& e) {
             // General catch-all standard exceptions that are not caught by more

src/bin/dhcp6/tests/callout_library_4.cc

@@ -31,6 +31,9 @@ void start_service(void) {
     isc_throw(isc::Unexpected, "start service failed");
 };
 
+IOServicePtr io_service;
+IOServicePtr main_io_service;
+
 } // end anonymous
 
 // Functions accessed by the hooks framework use C linkage to avoid the name
@@ -40,6 +43,7 @@ extern "C" {
 
 int
 do_load_impl(LibraryHandle& handle) {
+    io_service.reset(new IOService());
     // Determine if this callout is configured to fail.
     isc::dhcp::SrvConfigPtr config;
     isc::data::ConstElementPtr const& parameters(handle.getParameters());
@@ -51,9 +55,17 @@ do_load_impl(LibraryHandle& handle) {
     return (0);
 }
 
+int
+do_unload_impl() {
+    if (main_io_service) {
+        main_io_service->unregisterExternalIOService(io_service);
+    }
+    return (0);
+}
+
 int (*do_load)(LibraryHandle& handle) = do_load_impl;
 
-int (*do_unload)();
+int (*do_unload)() = do_unload_impl;
 
 /// @brief Callout which appends library number and provided arguments to
 /// the marker file for dhcp6_srv_configured callout.
@@ -79,13 +91,13 @@ dhcp6_srv_configured(CalloutHandle& handle) {
 
     // Get the IO context to post start_service on it.
     std::string error("");
-    IOServicePtr io_context;
     try {
-        handle.getArgument("io_context", io_context);
+        handle.getArgument("io_context", main_io_service);
-        if (!io_context) {
+        if (!main_io_service) {
             error = "null io_context";
         }
-        io_context->post(start_service);
+        main_io_service->registerExternalIOService(io_service);
+        io_service->post(start_service);
     } catch (const std::exception& ex) {
         error = "no io_context in arguments";
     }

src/bin/netconf/netconf_process.cc

@@ -65,6 +65,7 @@ NetconfProcess::run() {
 
 size_t
 NetconfProcess::runIO() {
+    getIOService()->pollExternalIOServices();
     size_t cnt = getIOService()->poll();
     if (!cnt) {
         cnt = getIOService()->runOne();
@@ -85,6 +86,17 @@ NetconfProcess::configure(isc::data::ConstElementPtr config_set,
         getCfgMgr()->simpleParseConfig(config_set, check_only);
     int rcode = 0;
     config::parseAnswer(rcode, answer);
+
+    /// Let postponed hook initializations to run.
+    try {
+        getIOService()->pollExternalIOServices();
+    } catch (const std::exception& ex) {
+        std::ostringstream err;
+        err << "Error initializing hooks: "
+            << ex.what();
+        return (isc::config::createAnswer(CONTROL_RESULT_ERROR, err.str()));
+    }
+
     return (answer);
 }
 

src/hooks/dhcp/bootp/libloadtests/load_unload_unittests.cc

@@ -12,12 +12,8 @@
 
 #include <config.h>
 
-#include <cc/data.h>
+#include <dhcpsrv/testutils/lib_load_test_fixture.h>
-#include <dhcpsrv/cfgmgr.h>
-#include <hooks/hooks_manager.h>
-#include <process/daemon.h>
 #include <testutils/gtest_utils.h>
-#include <testutils/lib_load_test_fixture.h>
 
 #include <gtest/gtest.h>
 #include <errno.h>

src/hooks/dhcp/flex_option/libloadtests/load_unload_unittests.cc

@@ -12,11 +12,8 @@
 
 #include <config.h>
 
-#include <flex_option.h>
+#include <dhcpsrv/testutils/lib_load_test_fixture.h>
-#include <dhcpsrv/cfgmgr.h>
+#include <testutils/gtest_utils.h>
-#include <hooks/hooks_manager.h>
-#include <process/daemon.h>
-#include <testutils/lib_load_test_fixture.h>
 
 #include <gtest/gtest.h>
 #include <errno.h>

src/hooks/dhcp/high_availability/ha.dox

@@ -142,6 +142,9 @@ have been introduced. These hook points are used by the DHCPv4 and the
 DHCPv6 servers respectively, to pass the instance of the IOService
 (via "io_context" argument) to the hooks libraries which require to
 schedule asynchronous tasks.
+The hook's IOService object must be registered on the server's main IOService by
+calling registerExternalIOService and must unregister it on "unload" hook point
+by calling unregisterExternalIOService.
 
 It is also worth to note that the blocking reception of the DHCP packets
 may cause up to 1 second delays in the asynchronous operations. This is

src/hooks/dhcp/high_availability/ha_callouts.cc

@@ -46,9 +46,8 @@ extern "C" {
 /// @param handle callout handle.
 int dhcp4_srv_configured(CalloutHandle& handle) {
     try {
-        isc::asiolink::IOServicePtr io_service;
+        handle.getArgument("io_context", impl->getMainIOService());
-        handle.getArgument("io_context", io_service);
+        if (!impl->getMainIOService()) {
-        if (!io_service) {
             // Should not happen!
             handle.setStatus(isc::hooks::CalloutHandle::NEXT_STEP_DROP);
             const string error("Error: io_context is null");
@@ -57,7 +56,8 @@ int dhcp4_srv_configured(CalloutHandle& handle) {
         }
         isc::dhcp::NetworkStatePtr network_state;
         handle.getArgument("network_state", network_state);
-        impl->startServices(io_service, network_state, HAServerType::DHCPv4);
+        impl->startServices(network_state, HAServerType::DHCPv4);
+        impl->getMainIOService()->registerExternalIOService(impl->getIOService());
 
     } catch (const std::exception& ex) {
         LOG_ERROR(ha_logger, HA_DHCP4_START_SERVICE_FAILED)
@@ -164,9 +164,8 @@ int lease4_server_decline(CalloutHandle& handle) {
 /// @param handle callout handle.
 int dhcp6_srv_configured(CalloutHandle& handle) {
     try {
-        isc::asiolink::IOServicePtr io_service;
+        handle.getArgument("io_context", impl->getMainIOService());
-        handle.getArgument("io_context", io_service);
+        if (!impl->getMainIOService()) {
-        if (!io_service) {
             // Should not happen!
             handle.setStatus(isc::hooks::CalloutHandle::NEXT_STEP_DROP);
             const string error("Error: io_context is null");
@@ -175,7 +174,8 @@ int dhcp6_srv_configured(CalloutHandle& handle) {
         }
         isc::dhcp::NetworkStatePtr network_state;
         handle.getArgument("network_state", network_state);
-        impl->startServices(io_service, network_state, HAServerType::DHCPv6);
+        impl->startServices(network_state, HAServerType::DHCPv6);
+        impl->getMainIOService()->registerExternalIOService(impl->getIOService());
 
     } catch (const std::exception& ex) {
         LOG_ERROR(ha_logger, HA_DHCP6_START_SERVICE_FAILED)
@@ -442,6 +442,17 @@ int load(LibraryHandle& handle) {
 ///
 /// @return 0 if deregistration was successful, 1 otherwise
 int unload() {
+    if (impl) {
+        if (impl->getMainIOService()) {
+            impl->getMainIOService()->unregisterExternalIOService(impl->getIOService());
+        }
+        impl->getIOService()->stop();
+        impl->getIOService()->restart();
+        try {
+            impl->getIOService()->poll();
+        } catch (...) {
+        }
+    }
     impl.reset();
     LOG_INFO(ha_logger, HA_DEINIT_OK);
     return (0);

src/hooks/dhcp/high_availability/ha_impl.cc

@@ -31,7 +31,7 @@ namespace isc {
 namespace ha {
 
 HAImpl::HAImpl()
-    : config_(), services_(new HAServiceMapper()) {
+    : io_service_(new IOService()), config_(), services_(new HAServiceMapper()) {
 }
 
 void
@@ -40,13 +40,12 @@ HAImpl::configure(const ConstElementPtr& input_config) {
 }
 
 void
-HAImpl::startServices(const IOServicePtr& io_service,
+HAImpl::startServices(const NetworkStatePtr& network_state,
-                      const NetworkStatePtr& network_state,
                       const HAServerType& server_type) {
     auto configs = config_->getAll();
     for (auto id = 0; id < configs.size(); ++id) {
         // Create the HA service and crank up the state machine.
-        auto service = boost::make_shared<HAService>(id, io_service, network_state,
+        auto service = boost::make_shared<HAService>(id, io_service_, network_state,
                                                      configs[id], server_type);
         for (auto const& peer_config : configs[id]->getAllServersConfig()) {
             services_->map(peer_config.first, service);
@@ -54,7 +53,7 @@ HAImpl::startServices(const IOServicePtr& io_service,
     }
     // Schedule a start of the services. This ensures we begin after
     // the dust has settled and Kea MT mode has been firmly established.
-    io_service->post([&]() {
+    io_service_->post([&]() {
         for (auto const& service : services_->getAll()) {
             service->startClientAndListener();
         }

src/hooks/dhcp/high_availability/ha_impl.h

@@ -45,13 +45,11 @@ public:
     /// The caller must ensure that the HA configuration is valid before
     /// calling this function.
     ///
-    /// @param io_service IO service object provided by the DHCP server.
     /// @param network_state pointer to the object holding a state of the
     /// DHCP service (enabled/disabled).
     /// @param server_type DHCP server type for which the HA service should
     /// be created.
-    void startServices(const asiolink::IOServicePtr& io_service,
+    void startServices(const dhcp::NetworkStatePtr& network_state,
-                       const dhcp::NetworkStatePtr& network_state,
                        const HAServerType& server_type);
 
     /// @brief Destructor.
@@ -223,8 +221,42 @@ public:
     HAServicePtr getHAServiceByServerName(const std::string& command_name,
                                           data::ConstElementPtr args) const;
 
+    /// @brief Get the hook I/O service.
+    ///
+    /// @return the hook I/O service.
+    isc::asiolink::IOServicePtr& getIOService() {
+        return (io_service_);
+    }
+
+    /// @brief Set the hook I/O service.
+    ///
+    /// @param io_service the hook I/O service.
+    void setIOService(isc::asiolink::IOServicePtr io_service) {
+        io_service_ = io_service;
+    }
+
+    /// @brief Get the main I/O service.
+    ///
+    /// @return the main I/O service.
+    isc::asiolink::IOServicePtr& getMainIOService() {
+        return (main_io_service_);
+    }
+
+    /// @brief Set the main I/O service.
+    ///
+    /// @param io_service the main I/O service.
+    void setMainIOService(isc::asiolink::IOServicePtr io_service) {
+        main_io_service_ = io_service;
+    }
+
 protected:
 
+    /// @brief The hook I/O service.
+    isc::asiolink::IOServicePtr io_service_;
+
+    /// @brief The main I/O service.
+    isc::asiolink::IOServicePtr main_io_service_;
+
     /// @brief Holds parsed configuration.
     HAConfigMapperPtr config_;
 

src/hooks/dhcp/high_availability/libloadtests/load_unload_unittests.cc

@@ -12,11 +12,8 @@
 
 #include <config.h>
 
-#include <cc/data.h>
+#include <dhcpsrv/testutils/lib_load_test_fixture.h>
-#include <dhcpsrv/cfgmgr.h>
+#include <testutils/gtest_utils.h>
-#include <hooks/hooks_manager.h>
-#include <process/daemon.h>
-#include <testutils/lib_load_test_fixture.h>
 
 #include <gtest/gtest.h>
 #include <errno.h>

src/hooks/dhcp/high_availability/tests/ha_impl_unittest.cc

@@ -127,11 +127,12 @@ public:
                                 const std::string& expected_response) {
         io_service_.reset(new IOService());
         ha_impl_.reset(new HAImpl());
+        ha_impl_->setIOService(io_service_);
         ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
         // Starting the service is required prior to running any callouts.
         NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-        ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+        ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                                 HAServerType::DHCPv4));
 
         ConstElementPtr command = Element::fromJSON(ha_sync_command);
@@ -174,13 +175,14 @@ public:
 TEST_F(HAImplTest, startServices) {
     // Valid configuration must be provided prior to starting the service.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(createValidJsonConfiguration()));
 
     // Network state is also required.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
 
     // Start the service for DHCPv4 server.
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv4));
 
     // Make sure that the HA service has been created for the requested
@@ -193,13 +195,14 @@ TEST_F(HAImplTest, startServices) {
 TEST_F(HAImplTest, startServices6) {
     // Valid configuration must be provided prior to starting the service.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(createValidJsonConfiguration()));
 
     // Network state is also required.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv6));
 
     // Start the service for DHCPv4 server.
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv6));
 
     // Make sure that the HA service has been created for the requested
@@ -216,11 +219,12 @@ TEST_F(HAImplTest, buffer4Receive) {
 
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(ha_config));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv4));
 
     // Initially the HA service is in the waiting state and serves no scopes.
@@ -329,11 +333,12 @@ TEST_F(HAImplTest, subnet4Select) {
 
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(ha_config));
 
     // Starting the service is required before any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv4));
 
     // The hub is a standby server and by default serves no scopes. Explicitly
@@ -386,11 +391,12 @@ TEST_F(HAImplTest, subnet4SelectSharedNetwork) {
 
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(ha_config));
 
     // Starting the service is required before any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv4));
 
     // The hub is a standby server and by default serves no scopes. Explicitly
@@ -446,11 +452,12 @@ TEST_F(HAImplTest, subnet4SelectSingleRelationship) {
 
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(ha_config));
 
     // Starting the service is required before any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv4));
 
     // Create callout handle to be used for passing arguments to the
@@ -487,11 +494,12 @@ TEST_F(HAImplTest, subnet4SelectDropNoServerName) {
 
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(ha_config));
 
     // Starting the service is required before any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv4));
 
     // The hub is a standby server and by default serves no scopes. Explicitly
@@ -532,11 +540,12 @@ TEST_F(HAImplTest, subnet4SelectDropInvalidServerNameType) {
 
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(ha_config));
 
     // Starting the service is required before any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv4));
 
     // The hub is a standby server and by default serves no scopes. Explicitly
@@ -581,11 +590,12 @@ TEST_F(HAImplTest, subnet4SelectDropNotInScope) {
 
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(ha_config));
 
     // Starting the service is required before any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv4));
 
     // This server serves server1/server2 scopes but not server3/server4 scopes.
@@ -633,11 +643,12 @@ TEST_F(HAImplTest, subnet4SelectNoSubnet) {
 
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(ha_config));
 
     // Starting the service is required before any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv4));
 
     test_ha_impl_->services_->get("server2")->serveFailoverScopes();
@@ -679,11 +690,12 @@ TEST_F(HAImplTest, buffer6Receive) {
 
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(ha_config));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv6));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv6));
 
     // Initially the HA service is in the waiting state and serves no scopes.
@@ -769,11 +781,12 @@ TEST_F(HAImplTest, subnet6Select) {
 
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(ha_config));
 
     // Starting the service is required before any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv6));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv6));
 
     // The hub is a standby server and by default serves no scopes. Explicitly
@@ -823,11 +836,12 @@ TEST_F(HAImplTest, subnet6SelectSharedNetwork) {
 
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(ha_config));
 
     // Starting the service is required before any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv6));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv6));
 
     // The hub is a standby server and by default serves no scopes. Explicitly
@@ -883,11 +897,12 @@ TEST_F(HAImplTest, subnet6SelectSingleRelationship) {
 
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(ha_config));
 
     // Starting the service is required before any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv6));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv6));
 
     // Create callout handle to be used for passing arguments to the
@@ -924,11 +939,12 @@ TEST_F(HAImplTest, subnet6SelectDropNoServerName) {
 
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(ha_config));
 
     // Starting the service is required before any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv6));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv6));
 
     // The hub is a standby server and by default serves no scopes. Explicitly
@@ -969,11 +985,12 @@ TEST_F(HAImplTest, subnet6SelectDropInvalidServerNameType) {
 
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(ha_config));
 
     // Starting the service is required before any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv6));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv6));
 
     // The hub is a standby server and by default serves no scopes. Explicitly
@@ -1018,11 +1035,12 @@ TEST_F(HAImplTest, subnet6SelectDropNotInScope) {
 
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(ha_config));
 
     // Starting the service is required before any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv6));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv6));
 
     // This server serves server1/server2 scopes but not server3/server4 scopes.
@@ -1070,11 +1088,12 @@ TEST_F(HAImplTest, subnet6SelectNoSubnet) {
 
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(ha_config));
 
     // Starting the service is required before any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv6));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv6));
 
     test_ha_impl_->services_->get("server2")->serveFailoverScopes();
@@ -1112,11 +1131,12 @@ TEST_F(HAImplTest, subnet6SelectNoSubnet) {
 TEST_F(HAImplTest, leases4Committed) {
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv4));
 
     // Make sure we wait for the acks from the backup server to be able to
@@ -1198,11 +1218,12 @@ TEST_F(HAImplTest, leases4Committed) {
 TEST_F(HAImplTest, leases4CommittedMultipleRelationships) {
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(createValidHubJsonConfiguration()));
 
     // Starting the service is required before running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv4));
 
     // By enabling this setting we ensure that the lease updates are always
@@ -1254,11 +1275,12 @@ TEST_F(HAImplTest, leases4CommittedMultipleRelationships) {
 TEST_F(HAImplTest, leases4CommittedMultipleRelationshipsNoServerName) {
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(createValidHubJsonConfiguration()));
 
     // Starting the service is required before running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv4));
 
     // By enabling this setting we ensure that the lease updates are always
@@ -1306,11 +1328,12 @@ TEST_F(HAImplTest, leases4CommittedMultipleRelationshipsNoServerName) {
 TEST_F(HAImplTest, leases4CommittedMultipleRelationshipsInvalidServerName) {
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(createValidHubJsonConfiguration()));
 
     // Starting the service is required before running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv4));
 
     // By enabling this setting we ensure that the lease updates are always
@@ -1360,11 +1383,12 @@ TEST_F(HAImplTest, leases4CommittedMultipleRelationshipsInvalidServerName) {
 TEST_F(HAImplTest, leases6Committed) {
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv6));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv6));
 
     // Make sure we wait for the acks from the backup server to be able to
@@ -1445,11 +1469,12 @@ TEST_F(HAImplTest, leases6Committed) {
 TEST_F(HAImplTest, leases6CommittedMultipleRelationships) {
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(createValidHubJsonConfiguration()));
 
     // Starting the service is required before running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv6));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv6));
 
     // By enabling this setting we ensure that the lease updates are always
@@ -1500,11 +1525,12 @@ TEST_F(HAImplTest, leases6CommittedMultipleRelationships) {
 TEST_F(HAImplTest, leases6CommittedMultipleRelationshipsNoServerName) {
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(createValidHubJsonConfiguration()));
 
     // Starting the service is required before running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv6));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv6));
 
     // By enabling this setting we ensure that the lease updates are always
@@ -1551,11 +1577,12 @@ TEST_F(HAImplTest, leases6CommittedMultipleRelationshipsNoServerName) {
 TEST_F(HAImplTest, leases6CommittedMultipleRelationshipsInvalidServerName) {
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(createValidHubJsonConfiguration()));
 
     // Starting the service is required before running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv6));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv6));
 
     // By enabling this setting we ensure that the lease updates are always
@@ -1682,11 +1709,12 @@ TEST_F(HAImplTest, synchronizeHandler) {
 // Tests ha-continue command handler with a specified server name.
 TEST_F(HAImplTest, continueHandler) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON("{"
@@ -1711,11 +1739,12 @@ TEST_F(HAImplTest, continueHandler) {
 // Tests ha-continue command handler without a server name.
 TEST_F(HAImplTest, continueHandlerWithNoServerName) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON("{ \"command\": \"ha-continue\" }");
@@ -1735,11 +1764,12 @@ TEST_F(HAImplTest, continueHandlerWithNoServerName) {
 // Tests ha-continue command handler with wrong server name.
 TEST_F(HAImplTest, continueHandlerWithWrongServerName) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON("{"
@@ -1764,11 +1794,12 @@ TEST_F(HAImplTest, continueHandlerWithWrongServerName) {
 // Tests status-get command processed handler.
 TEST_F(HAImplTest, statusGet) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     std::string name = "status-get";
@@ -1825,12 +1856,13 @@ TEST_F(HAImplTest, statusGet) {
 // Tests status-get command processed handler for backup server.
 TEST_F(HAImplTest, statusGetBackupServer) {
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(createValidJsonConfiguration()));
     test_ha_impl_->config_->get()->setThisServerName("server3");
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv4));
 
     std::string name = "status-get";
@@ -1875,11 +1907,12 @@ TEST_F(HAImplTest, statusGetBackupServer) {
 // passive-backup state.
 TEST_F(HAImplTest, statusGetPassiveBackup) {
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(createValidPassiveBackupJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv4));
 
     std::string name = "status-get";
@@ -1924,11 +1957,12 @@ TEST_F(HAImplTest, statusGetPassiveBackup) {
 // hub-and-spoke mode.
 TEST_F(HAImplTest, statusGetHubAndSpoke) {
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(createValidHubJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv4));
 
     std::string name = "status-get";
@@ -2009,11 +2043,12 @@ TEST_F(HAImplTest, statusGetHubAndSpoke) {
 // Test ha-maintenance-notify command handler with server name.
 TEST_F(HAImplTest, maintenanceNotify) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON(
@@ -2041,11 +2076,12 @@ TEST_F(HAImplTest, maintenanceNotify) {
 // Test ha-maintenance-notify command handler without server name.
 TEST_F(HAImplTest, maintenanceNotifyNoServerName) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON(
@@ -2072,11 +2108,12 @@ TEST_F(HAImplTest, maintenanceNotifyNoServerName) {
 // Test ha-maintenance-notify command handler without server name.
 TEST_F(HAImplTest, maintenanceNotifyBadServerName) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON(
@@ -2104,11 +2141,12 @@ TEST_F(HAImplTest, maintenanceNotifyBadServerName) {
 // Test ha-reset command handler with a specified server name.
 TEST_F(HAImplTest, haReset) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON(
@@ -2135,11 +2173,12 @@ TEST_F(HAImplTest, haReset) {
 // Test ha-reset command handler without a specified server name.
 TEST_F(HAImplTest, haResetNoServerName) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON(
@@ -2163,11 +2202,12 @@ TEST_F(HAImplTest, haResetNoServerName) {
 // Test ha-reset command handler with a wrong server name.
 TEST_F(HAImplTest, haResetBadServerName) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON(
@@ -2194,11 +2234,12 @@ TEST_F(HAImplTest, haResetBadServerName) {
 // Test ha-heartbeat command handler with a specified server name.
 TEST_F(HAImplTest, haHeartbeat) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON(
@@ -2225,11 +2266,12 @@ TEST_F(HAImplTest, haHeartbeat) {
 // Test ha-heartbeat command handler without a specified server name.
 TEST_F(HAImplTest, haHeartbeatNoServerName) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON(
@@ -2253,11 +2295,12 @@ TEST_F(HAImplTest, haHeartbeatNoServerName) {
 // Test ha-heartbeat command handler with a wrong server name.
 TEST_F(HAImplTest, haHeartbeatBadServerName) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON(
@@ -2284,11 +2327,12 @@ TEST_F(HAImplTest, haHeartbeatBadServerName) {
 // Test ha-sync-complete-notify command handler with a specified server name.
 TEST_F(HAImplTest, haSyncCompleteNotify) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON(
@@ -2316,11 +2360,12 @@ TEST_F(HAImplTest, haSyncCompleteNotify) {
 // Test ha-sync-complete-notify command handler without a specified server name.
 TEST_F(HAImplTest, haSyncCompleteNotifyNoServerName) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON(
@@ -2345,11 +2390,12 @@ TEST_F(HAImplTest, haSyncCompleteNotifyNoServerName) {
 // Test ha-sync-complete-notify command handler with a wrong server name.
 TEST_F(HAImplTest, haSyncCompleteNotifyBadServerName) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON(
@@ -2376,11 +2422,12 @@ TEST_F(HAImplTest, haSyncCompleteNotifyBadServerName) {
 // Test ha-scopes command handler with a specified server name.
 TEST_F(HAImplTest, haScopes) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON(
@@ -2408,11 +2455,12 @@ TEST_F(HAImplTest, haScopes) {
 // Test ha-scopes command handler without a specified server name.
 TEST_F(HAImplTest, haScopesNoServerName) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON(
@@ -2439,11 +2487,12 @@ TEST_F(HAImplTest, haScopesNoServerName) {
 // Test ha-scopes command handler with a wrong server name.
 TEST_F(HAImplTest, haScopesBadServerName) {
     ha_impl_.reset(new HAImpl());
+    ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(ha_impl_->startServices(network_state,
                                             HAServerType::DHCPv4));
 
     ConstElementPtr command = Element::fromJSON(
@@ -2472,11 +2521,12 @@ TEST_F(HAImplTest, haScopesBadServerName) {
 TEST_F(HAImplTest, lease4ServerDecline) {
     // Create implementation object and configure it.
     test_ha_impl_.reset(new TestHAImpl());
+    test_ha_impl_->setIOService(io_service_);
     ASSERT_NO_THROW(test_ha_impl_->configure(createValidJsonConfiguration()));
 
     // Starting the service is required prior to running any callouts.
     NetworkStatePtr network_state(new NetworkState(NetworkState::DHCPv4));
-    ASSERT_NO_THROW(test_ha_impl_->startServices(io_service_, network_state,
+    ASSERT_NO_THROW(test_ha_impl_->startServices(network_state,
                                                  HAServerType::DHCPv4));
 
     // Make sure we wait for the acks from the backup server to be able to

src/hooks/dhcp/lease_cmds/libloadtests/load_unload_unittests.cc

@@ -12,12 +12,8 @@
 
 #include <config.h>
 
-#include <cc/data.h>
+#include <dhcpsrv/testutils/lib_load_test_fixture.h>
-#include <dhcpsrv/cfgmgr.h>
-#include <hooks/hooks_manager.h>
-#include <process/daemon.h>
 #include <testutils/gtest_utils.h>
-#include <testutils/lib_load_test_fixture.h>
 
 #include <gtest/gtest.h>
 #include <errno.h>

src/hooks/dhcp/mysql_cb/libloadtests/load_unload_unittests.cc

@@ -12,12 +12,8 @@
 
 #include <config.h>
 
-#include <cc/data.h>
+#include <dhcpsrv/testutils/lib_load_test_fixture.h>
-#include <dhcpsrv/cfgmgr.h>
-#include <hooks/hooks_manager.h>
-#include <process/daemon.h>
 #include <testutils/gtest_utils.h>
-#include <testutils/lib_load_test_fixture.h>
 
 #include <gtest/gtest.h>
 #include <errno.h>

src/hooks/dhcp/mysql_cb/mysql_cb_callouts.cc

@@ -22,6 +22,7 @@
 #include <sstream>
 #include <string>
 
+using namespace isc::asiolink;
 using namespace isc::cb;
 using namespace isc::dhcp;
 using namespace isc::hooks;
@@ -67,15 +68,15 @@ int load(LibraryHandle& /* handle */) {
 /// @param handle callout handle passed to the callout.
 /// @return 0 on success, 1 otherwise.
 int dhcp4_srv_configured(CalloutHandle& handle) {
-    isc::asiolink::IOServicePtr io_service;
+    handle.getArgument("io_context", isc::dhcp::MySqlConfigBackendImpl::getMainIOService());
-    handle.getArgument("io_context", io_service);
+    if (!isc::dhcp::MySqlConfigBackendImpl::getMainIOService()) {
-    if (!io_service) {
         const string error("Error: io_context is null");
         handle.setArgument("error", error);
         handle.setStatus(isc::hooks::CalloutHandle::NEXT_STEP_DROP);
         return (1);
     }
-    isc::dhcp::MySqlConfigBackendImpl::setIOService(io_service);
+    isc::dhcp::MySqlConfigBackendImpl::getIOService().reset(new IOService());
+    isc::dhcp::MySqlConfigBackendImpl::getMainIOService()->registerExternalIOService(isc::dhcp::MySqlConfigBackendImpl::getIOService());
     return (0);
 }
 
@@ -86,15 +87,15 @@ int dhcp4_srv_configured(CalloutHandle& handle) {
 /// @param handle callout handle passed to the callout.
 /// @return 0 on success, 1 otherwise.
 int dhcp6_srv_configured(CalloutHandle& handle) {
-    isc::asiolink::IOServicePtr io_service;
+    handle.getArgument("io_context", isc::dhcp::MySqlConfigBackendImpl::getMainIOService());
-    handle.getArgument("io_context", io_service);
+    if (!isc::dhcp::MySqlConfigBackendImpl::getMainIOService()) {
-    if (!io_service) {
         const string error("Error: io_context is null");
         handle.setArgument("error", error);
         handle.setStatus(isc::hooks::CalloutHandle::NEXT_STEP_DROP);
         return (1);
     }
-    isc::dhcp::MySqlConfigBackendImpl::setIOService(io_service);
+    isc::dhcp::MySqlConfigBackendImpl::getIOService().reset(new IOService());
+    isc::dhcp::MySqlConfigBackendImpl::getMainIOService()->registerExternalIOService(isc::dhcp::MySqlConfigBackendImpl::getIOService());
     return (0);
 }
 
@@ -106,6 +107,17 @@ int unload() {
     // Unregister the factories and remove MySQL backends
     isc::dhcp::MySqlConfigBackendDHCPv4::unregisterBackendType();
     isc::dhcp::MySqlConfigBackendDHCPv6::unregisterBackendType();
+    if (isc::dhcp::MySqlConfigBackendImpl::getMainIOService()) {
+        isc::dhcp::MySqlConfigBackendImpl::getMainIOService()->unregisterExternalIOService(isc::dhcp::MySqlConfigBackendImpl::getIOService());
+    }
+    if (isc::dhcp::MySqlConfigBackendImpl::getIOService()) {
+        isc::dhcp::MySqlConfigBackendImpl::getIOService()->stop();
+        isc::dhcp::MySqlConfigBackendImpl::getIOService()->restart();
+        try {
+            isc::dhcp::MySqlConfigBackendImpl::getIOService()->poll();
+        } catch (...) {
+        }
+    }
     return (0);
 }
 

src/hooks/dhcp/mysql_cb/mysql_cb_impl.cc

@@ -29,7 +29,8 @@ using namespace isc::util;
 namespace isc {
 namespace dhcp {
 
-isc::asiolink::IOServicePtr MySqlConfigBackendImpl::io_service_ = isc::asiolink::IOServicePtr();
+isc::asiolink::IOServicePtr MySqlConfigBackendImpl::io_service_;
+isc::asiolink::IOServicePtr MySqlConfigBackendImpl::main_io_service_;
 
 MySqlConfigBackendImpl::
 ScopedAuditRevision::ScopedAuditRevision(MySqlConfigBackendImpl* impl,
@@ -86,6 +87,11 @@ MySqlConfigBackendImpl(const std::string& space,
     }
 }
 
+MySqlConfigBackendImpl::~MySqlConfigBackendImpl() {
+    /// nothing to do there. The conn_ connection will be deleted and its dtor
+    /// will take care of releasing the compiled statements and similar.
+}
+
 MySqlBindingPtr
 MySqlConfigBackendImpl::createBinding(const Triplet<uint32_t>& triplet) {
     if (triplet.unspecified()) {

src/hooks/dhcp/mysql_cb/mysql_cb_impl.h

@@ -115,7 +115,7 @@ public:
                                     const db::DbCallback db_reconnect_callback);
 
     /// @brief Destructor.
-    virtual ~MySqlConfigBackendImpl() {};
+    virtual ~MySqlConfigBackendImpl();
 
     /// @brief Creates MySQL binding from an @c Optional of integer type.
     ///
@@ -836,16 +836,32 @@ public:
         return (parameters_);
     }
 
-    /// @brief Sets IO service to be used by the MySQL config backend.
+    /// @brief Get the hook I/O service.
     ///
-    /// @param IOService object, used for all ASIO operations.
+    /// @return the hook I/O service.
-    static void setIOService(const isc::asiolink::IOServicePtr& io_service) {
+    static isc::asiolink::IOServicePtr& getIOService() {
+        return (io_service_);
+    }
+
+    /// @brief Set the hook I/O service.
+    ///
+    /// @param io_service the hook I/O service.
+    static void setIOService(isc::asiolink::IOServicePtr io_service) {
         io_service_ = io_service;
     }
 
-    /// @brief Returns pointer to the IO service.
+    /// @brief Get the main I/O service.
-    static isc::asiolink::IOServicePtr& getIOService() {
+    ///
-        return (io_service_);
+    /// @return the main I/O service.
+    static isc::asiolink::IOServicePtr& getMainIOService() {
+        return (main_io_service_);
+    }
+
+    /// @brief Set the main I/O service.
+    ///
+    /// @param io_service the main I/O service.
+    static void setMainIOService(isc::asiolink::IOServicePtr io_service) {
+        main_io_service_ = io_service;
     }
 
     /// @brief Represents connection to the MySQL database.
@@ -864,8 +880,11 @@ private:
     /// @brief Connection parameters
     isc::db::DatabaseConnection::ParameterMap parameters_;
 
-    /// @brief The IOService object, used for all ASIO operations.
+    /// @brief The hook I/O service.
     static isc::asiolink::IOServicePtr io_service_;
+
+    /// @brief The main I/O service.
+    static isc::asiolink::IOServicePtr main_io_service_;
 };
 
 } // end of namespace isc::dhcp

src/hooks/dhcp/perfmon/libloadtests/load_unload_unittests.cc

@@ -12,12 +12,8 @@
 
 #include <config.h>
 
-#include <cc/data.h>
+#include <dhcpsrv/testutils/lib_load_test_fixture.h>
-#include <dhcpsrv/cfgmgr.h>
-#include <hooks/hooks_manager.h>
-#include <process/daemon.h>
 #include <testutils/gtest_utils.h>
-#include <testutils/lib_load_test_fixture.h>
 
 #include <gtest/gtest.h>
 #include <errno.h>

src/hooks/dhcp/pgsql_cb/libloadtests/load_unload_unittests.cc

@@ -12,12 +12,8 @@
 
 #include <config.h>
 
-#include <cc/data.h>
+#include <dhcpsrv/testutils/lib_load_test_fixture.h>
-#include <dhcpsrv/cfgmgr.h>
-#include <hooks/hooks_manager.h>
-#include <process/daemon.h>
 #include <testutils/gtest_utils.h>
-#include <testutils/lib_load_test_fixture.h>
 
 #include <gtest/gtest.h>
 #include <errno.h>

src/hooks/dhcp/pgsql_cb/pgsql_cb_callouts.cc

@@ -22,6 +22,7 @@
 #include <sstream>
 #include <string>
 
+using namespace isc::asiolink;
 using namespace isc::cb;
 using namespace isc::dhcp;
 using namespace isc::hooks;
@@ -67,15 +68,15 @@ int load(LibraryHandle& /* handle */) {
 /// @param handle callout handle passed to the callout.
 /// @return 0 on success, 1 otherwise.
 int dhcp4_srv_configured(CalloutHandle& handle) {
-    isc::asiolink::IOServicePtr io_service;
+    handle.getArgument("io_context", isc::dhcp::PgSqlConfigBackendImpl::getMainIOService());
-    handle.getArgument("io_context", io_service);
+    if (!isc::dhcp::PgSqlConfigBackendImpl::getMainIOService()) {
-    if (!io_service) {
         const string error("Error: io_context is null");
         handle.setArgument("error", error);
         handle.setStatus(isc::hooks::CalloutHandle::NEXT_STEP_DROP);
         return (1);
     }
-    isc::dhcp::PgSqlConfigBackendImpl::setIOService(io_service);
+    isc::dhcp::PgSqlConfigBackendImpl::getIOService().reset(new IOService());
+    isc::dhcp::PgSqlConfigBackendImpl::getMainIOService()->registerExternalIOService(isc::dhcp::PgSqlConfigBackendImpl::getIOService());
     return (0);
 }
 
@@ -86,15 +87,15 @@ int dhcp4_srv_configured(CalloutHandle& handle) {
 /// @param handle callout handle passed to the callout.
 /// @return 0 on success, 1 otherwise.
 int dhcp6_srv_configured(CalloutHandle& handle) {
-    isc::asiolink::IOServicePtr io_service;
+    handle.getArgument("io_context", isc::dhcp::PgSqlConfigBackendImpl::getMainIOService());
-    handle.getArgument("io_context", io_service);
+    if (!isc::dhcp::PgSqlConfigBackendImpl::getMainIOService()) {
-    if (!io_service) {
         const string error("Error: io_context is null");
         handle.setArgument("error", error);
         handle.setStatus(isc::hooks::CalloutHandle::NEXT_STEP_DROP);
         return (1);
     }
-    isc::dhcp::PgSqlConfigBackendImpl::setIOService(io_service);
+    isc::dhcp::PgSqlConfigBackendImpl::getIOService().reset(new IOService());
+    isc::dhcp::PgSqlConfigBackendImpl::getMainIOService()->registerExternalIOService(isc::dhcp::PgSqlConfigBackendImpl::getIOService());
     return (0);
 }
 
@@ -106,6 +107,17 @@ int unload() {
     // Unregister the factories and remove PostgreSQL backends
     isc::dhcp::PgSqlConfigBackendDHCPv4::unregisterBackendType();
     isc::dhcp::PgSqlConfigBackendDHCPv6::unregisterBackendType();
+    if (isc::dhcp::PgSqlConfigBackendImpl::getMainIOService()) {
+        isc::dhcp::PgSqlConfigBackendImpl::getMainIOService()->unregisterExternalIOService(isc::dhcp::PgSqlConfigBackendImpl::getIOService());
+    }
+    if (isc::dhcp::PgSqlConfigBackendImpl::getIOService()) {
+        isc::dhcp::PgSqlConfigBackendImpl::getIOService()->stop();
+        isc::dhcp::PgSqlConfigBackendImpl::getIOService()->restart();
+        try {
+            isc::dhcp::PgSqlConfigBackendImpl::getIOService()->poll();
+        } catch (...) {
+        }
+    }
     return (0);
 }
 

src/hooks/dhcp/pgsql_cb/pgsql_cb_impl.cc

@@ -28,7 +28,8 @@ using namespace isc::util;
 namespace isc {
 namespace dhcp {
 
-isc::asiolink::IOServicePtr PgSqlConfigBackendImpl::io_service_ = isc::asiolink::IOServicePtr();
+isc::asiolink::IOServicePtr PgSqlConfigBackendImpl::io_service_;
+isc::asiolink::IOServicePtr PgSqlConfigBackendImpl::main_io_service_;
 
 PgSqlTaggedStatement&
 PgSqlConfigBackendImpl::getStatement(size_t /* index */) const {

src/hooks/dhcp/pgsql_cb/pgsql_cb_impl.h

@@ -800,18 +800,6 @@ public:
         return (parameters_);
     }
 
-    /// @brief Sets IO service to be used by the PostgreSQL config backend.
-    ///
-    /// @param IOService object, used for all ASIO operations.
-    static void setIOService(const isc::asiolink::IOServicePtr& io_service) {
-        io_service_ = io_service;
-    }
-
-    /// @brief Returns pointer to the IO service.
-    static isc::asiolink::IOServicePtr& getIOService() {
-        return (io_service_);
-    }
-
     /// @brief Fetches the SQL statement for a given statement index.
     ///
     /// Derivations must override the implementation. The reference
@@ -872,6 +860,34 @@ public:
     /// @return Number of affected rows.
     uint64_t updateDeleteQuery(size_t index, const db::PsqlBindArray& in_bindings);
 
+    /// @brief Get the hook I/O service.
+    ///
+    /// @return the hook I/O service.
+    static isc::asiolink::IOServicePtr& getIOService() {
+        return (io_service_);
+    }
+
+    /// @brief Set the hook I/O service.
+    ///
+    /// @param io_service the hook I/O service.
+    static void setIOService(isc::asiolink::IOServicePtr io_service) {
+        io_service_ = io_service;
+    }
+
+    /// @brief Get the main I/O service.
+    ///
+    /// @return the main I/O service.
+    static isc::asiolink::IOServicePtr& getMainIOService() {
+        return (main_io_service_);
+    }
+
+    /// @brief Set the main I/O service.
+    ///
+    /// @param io_service the main I/O service.
+    static void setMainIOService(isc::asiolink::IOServicePtr io_service) {
+        main_io_service_ = io_service;
+    }
+
     /// @brief Represents connection to the PostgreSQL database.
     db::PgSqlConnection conn_;
 
@@ -888,9 +904,12 @@ private:
     /// @brief Connection parameters
     isc::db::DatabaseConnection::ParameterMap parameters_;
 
-    /// @brief The IOService object, used for all ASIO operations.
+    /// @brief The hook I/O service.
     static isc::asiolink::IOServicePtr io_service_;
 
+    /// @brief The main I/O service.
+    static isc::asiolink::IOServicePtr main_io_service_;
+
     /// @brief Statement index of the SQL statement to use for fetching
     /// last inserted id in a given table.
     size_t last_insert_id_index_;

src/hooks/dhcp/run_script/libloadtests/load_unload_unittests.cc

@@ -12,11 +12,8 @@
 
 #include <config.h>
 
-#include <cc/data.h>
+#include <dhcpsrv/testutils/lib_load_test_fixture.h>
-#include <dhcpsrv/cfgmgr.h>
+#include <testutils/gtest_utils.h>
-#include <hooks/hooks_manager.h>
-#include <process/daemon.h>
-#include <testutils/lib_load_test_fixture.h>
 
 #include <gtest/gtest.h>
 #include <errno.h>

src/hooks/dhcp/run_script/run_script.cc

@@ -19,8 +19,9 @@ namespace isc {
 namespace run_script {
 
 IOServicePtr RunScriptImpl::io_service_;
+IOServicePtr RunScriptImpl::main_io_service_;
 
-RunScriptImpl::RunScriptImpl() : name_(), sync_(false) {
+RunScriptImpl::RunScriptImpl() : io_context_(new IOService()), name_(), sync_(false) {
 }
 
 void

src/hooks/dhcp/run_script/run_script.h

@@ -30,20 +30,6 @@ public:
     /// @brief Destructor.
     ~RunScriptImpl() = default;
 
-    /// @brief Sets IO service to be used by the @ref ProcessSpawn instance.
-    ///
-    /// @param io_service The IOService object, used for all ASIO operations.
-    static void setIOService(const isc::asiolink::IOServicePtr& io_service) {
-        io_service_ = io_service;
-    }
-
-    /// @brief Gets IO service to be used by the @ref ProcessSpawn instance.
-    ///
-    /// @return The IOService object, used for all ASIO operations.
-    static isc::asiolink::IOServicePtr getIOService() {
-        return (io_service_);
-    }
-
     /// @brief Extract boolean data and append to environment.
     ///
     /// @param value The value to be exported to target script environment.
@@ -256,7 +242,53 @@ public:
     /// @brief This function parses and applies configuration parameters.
     void configure(isc::hooks::LibraryHandle& handle);
 
+    /// @brief Get the hook I/O service.
+    ///
+    /// @return the hook I/O service.
+    isc::asiolink::IOServicePtr& getIOContext() {
+        return (io_context_);
+    }
+
+    /// @brief Set the hook I/O service.
+    ///
+    /// @param io_service the hook I/O service.
+    void setIOContext(isc::asiolink::IOServicePtr io_service) {
+        io_context_ = io_service;
+    }
+
+    /// @brief Get the hook I/O service.
+    ///
+    /// @return the hook I/O service.
+    static isc::asiolink::IOServicePtr& getIOService() {
+        return (io_service_);
+    }
+
+    /// @brief Set the hook I/O service.
+    ///
+    /// @param io_service the hook I/O service.
+    static void setIOService(isc::asiolink::IOServicePtr io_service) {
+        io_service_ = io_service;
+    }
+
+    /// @brief Get the main I/O service.
+    ///
+    /// @return the main I/O service.
+    static isc::asiolink::IOServicePtr& getMainIOService() {
+        return (main_io_service_);
+    }
+
+    /// @brief Set the main I/O service.
+    ///
+    /// @param io_service the main I/O service.
+    static void setMainIOService(isc::asiolink::IOServicePtr io_service) {
+        main_io_service_ = io_service;
+    }
+
 private:
+
+    /// @brief The IOService object, used for all ASIO operations.
+    isc::asiolink::IOServicePtr io_context_;
+
     /// @brief Script name.
     std::string name_;
 
@@ -267,8 +299,11 @@ private:
     /// started.
     bool sync_;
 
-    /// @brief The IOService object, used for all ASIO operations.
+    /// @brief The hook I/O service.
     static isc::asiolink::IOServicePtr io_service_;
+
+    /// @brief The main I/O service.
+    static isc::asiolink::IOServicePtr main_io_service_;
 };
 
 /// @brief The type of shared pointers to Run Script implementations.

src/hooks/dhcp/run_script/run_script_callouts.cc

@@ -80,7 +80,18 @@ int load(LibraryHandle& handle) {
 ///
 /// @return always 0.
 int unload() {
+    if (RunScriptImpl::getMainIOService()) {
+        RunScriptImpl::getMainIOService()->unregisterExternalIOService(impl->getIOContext());
+    }
     impl.reset();
+    if (RunScriptImpl::getIOService()) {
+        RunScriptImpl::getIOService()->stop();
+        RunScriptImpl::getIOService()->restart();
+        try {
+            RunScriptImpl::getIOService()->poll();
+        } catch (...) {
+        }
+    }
     RunScriptImpl::setIOService(IOServicePtr());
     LOG_INFO(run_script_logger, RUN_SCRIPT_UNLOAD);
     return (0);
@@ -91,16 +102,16 @@ int unload() {
 /// @param handle callout handle.
 int dhcp4_srv_configured(CalloutHandle& handle) {
     try {
-        isc::asiolink::IOServicePtr io_service;
+        handle.getArgument("io_context", RunScriptImpl::getMainIOService());
-        handle.getArgument("io_context", io_service);
+        if (!RunScriptImpl::getMainIOService()) {
-        if (!io_service) {
             // Should not happen!
             handle.setStatus(isc::hooks::CalloutHandle::NEXT_STEP_DROP);
             const string error("Error: io_context is null");
             handle.setArgument("error", error);
             return (1);
         }
-        RunScriptImpl::setIOService(io_service);
+        RunScriptImpl::setIOService(impl->getIOContext());
+        RunScriptImpl::getMainIOService()->registerExternalIOService(impl->getIOContext());
 
     } catch (const exception& ex) {
         LOG_ERROR(run_script_logger, RUN_SCRIPT_LOAD_ERROR)
@@ -116,16 +127,16 @@ int dhcp4_srv_configured(CalloutHandle& handle) {
 /// @param handle callout handle.
 int dhcp6_srv_configured(CalloutHandle& handle) {
     try {
-        isc::asiolink::IOServicePtr io_service;
+        handle.getArgument("io_context", RunScriptImpl::getMainIOService());
-        handle.getArgument("io_context", io_service);
+        if (!RunScriptImpl::getMainIOService()) {
-        if (!io_service) {
             // Should not happen!
             handle.setStatus(isc::hooks::CalloutHandle::NEXT_STEP_DROP);
             const string error("Error: io_context is null");
             handle.setArgument("error", error);
             return (1);
         }
-        RunScriptImpl::setIOService(io_service);
+        RunScriptImpl::setIOService(impl->getIOContext());
+        RunScriptImpl::getMainIOService()->registerExternalIOService(impl->getIOContext());
 
     } catch (const exception& ex) {
         LOG_ERROR(run_script_logger, RUN_SCRIPT_LOAD_ERROR)

src/hooks/dhcp/stat_cmds/libloadtests/load_unload_unittests.cc

@@ -12,12 +12,8 @@
 
 #include <config.h>
 
-#include <cc/data.h>
+#include <dhcpsrv/testutils/lib_load_test_fixture.h>
-#include <dhcpsrv/cfgmgr.h>
-#include <hooks/hooks_manager.h>
-#include <process/daemon.h>
 #include <testutils/gtest_utils.h>
-#include <testutils/lib_load_test_fixture.h>
 
 #include <gtest/gtest.h>
 #include <errno.h>

src/lib/asiolink/io_service.cc

@@ -18,98 +18,102 @@ namespace isc {
 namespace asiolink {
 
 class IOServiceImpl {
+    /// @brief Constructors and Destructor.
+    ///
+    /// @note The copy constructor and the assignment operator are
+    /// intentionally defined as private, making this class non-copyable.
+    //@{
 private:
     IOServiceImpl(const IOService& source);
     IOServiceImpl& operator=(const IOService& source);
 public:
-    /// \brief The constructor
+    /// @brief The constructor.
     IOServiceImpl() :
         io_service_(),
         work_(new boost::asio::io_service::work(io_service_)) {
     };
 
-    /// \brief The destructor.
+    /// @brief The destructor.
-    ~IOServiceImpl() {
+    ~IOServiceImpl() = default;
-    };
     //@}
 
-    /// \brief Start the underlying event loop.
+    /// @brief Start the underlying event loop.
     ///
     /// This method does not return control to the caller until
-    /// the \c stop() method is called via some handler.
+    /// the @ref stop() method is called via some handler.
     void run() {
         io_service_.run();
     };
 
-    /// \brief Run the underlying event loop for a single event.
+    /// @brief Run the underlying event loop for a single event.
     ///
     /// This method return control to the caller as soon as the
     /// first handler has completed.  (If no handlers are ready when
     /// it is run, it will block until one is.)
     ///
-    /// \return The number of handlers that were executed.
+    /// @return The number of handlers that were executed.
     size_t runOne() {
         return (static_cast<size_t>(io_service_.run_one()));
     };
 
-    /// \brief Run the underlying event loop for a ready events.
+    /// @brief Run the underlying event loop for a ready events.
     ///
     /// This method executes handlers for all ready events and returns.
     /// It will return immediately if there are no ready events.
     ///
-    /// \return The number of handlers that were executed.
+    /// @return The number of handlers that were executed.
     size_t poll() {
         return (static_cast<size_t>(io_service_.poll()));
     };
 
-    /// \brief Run the underlying event loop for a ready events.
+    /// @brief Run the underlying event loop for a ready events.
     ///
     /// This method executes handlers for all ready events and returns.
     /// It will return immediately if there are no ready events.
     ///
-    /// \return The number of handlers that were executed.
+    /// @return The number of handlers that were executed.
     size_t pollOne() {
         return (static_cast<size_t>(io_service_.poll_one()));
     };
 
-    /// \brief Stop the underlying event loop.
+    /// @brief Stop the underlying event loop.
     ///
-    /// This will return the control to the caller of the \c run() method.
+    /// This will return the control to the caller of the @ref run() method.
     void stop() {
         io_service_.stop();
     }
 
-    /// \brief Indicates if the IOService has been stopped.
+    /// @brief Indicates if the IOService has been stopped.
     ///
-    /// \return true if the IOService has been stopped, false otherwise.
+    /// @return true if the IOService has been stopped, false otherwise.
     bool stopped() const {
         return (io_service_.stopped());
     }
 
-    /// \brief Restarts the IOService in preparation for a subsequent \c run() invocation.
+    /// @brief Restarts the IOService in preparation for a subsequent @ref run() invocation.
     void restart() {
         io_service_.reset();
     }
 
-    /// \brief Removes IO service work object to let it finish running
+    /// @brief Removes IO service work object to let it finish running
     /// when all handlers have been invoked.
     void stopWork() {
         work_.reset();
     }
 
-    /// \brief Return the native \c io_service object used in this wrapper.
+    /// @brief Return the native @ref io_service object used in this wrapper.
     ///
     /// This is a short term work around to support other Kea modules
-    /// that share the same \c io_service with the authoritative server.
+    /// that share the same @ref io_service with the authoritative server.
     /// It will eventually be removed once the wrapper interface is
     /// generalized.
     boost::asio::io_service& getInternalIOService() {
         return (io_service_);
     }
 
-    /// \brief Post a callback on the IO service
+    /// @brief Post a callback on the IO service.
     ///
-    /// \param callback The callback to be run on the IO service.
+    /// @param callback The callback to be run on the IO service.
     void post(const std::function<void ()>& callback) {
         io_service_.post(callback);
     }
@@ -175,5 +179,25 @@ IOService::post(const std::function<void ()>& callback) {
     return (io_impl_->post(callback));
 }
 
+void
+IOService::registerExternalIOService(IOServicePtr io_service) {
+    external_io_services_.push_back(io_service);
+}
+
+void
+IOService::unregisterExternalIOService(IOServicePtr io_service) {
+    auto it = std::find(external_io_services_.begin(), external_io_services_.end(), io_service);
+    if (it != external_io_services_.end()) {
+        external_io_services_.erase(it);
+    }
+}
+
+void
+IOService::pollExternalIOServices() {
+    for (auto& io_service : external_io_services_) {
+        io_service->poll();
+    }
+}
+
 }  // namespace asiolink
 }  // namespace isc

src/lib/asiolink/io_service.h

@@ -10,6 +10,7 @@
 #include <boost/version.hpp>
 #include <boost/shared_ptr.hpp>
 #include <functional>
+#include <list>
 
 namespace boost {
 namespace asio {
@@ -26,84 +27,89 @@ namespace isc {
 namespace asiolink {
 
 class IOServiceImpl;
+class IOService;
 
-/// \brief The \c IOService class is a wrapper for the ASIO \c io_service
+/// @brief Defines a smart pointer to an IOService instance.
+typedef boost::shared_ptr<IOService> IOServicePtr;
+
+/// @brief The @ref IOService class is a wrapper for the ASIO @ref io_service
 /// class.
-///
 class IOService {
+    /// @brief Constructors and Destructor.
     ///
-    /// \name Constructors and Destructor
+    /// @note The copy constructor and the assignment operator are
-    ///
-    /// Note: The copy constructor and the assignment operator are
     /// intentionally defined as private, making this class non-copyable.
     //@{
 private:
     IOService(const IOService& source);
     IOService& operator=(const IOService& source);
 public:
-    /// \brief The constructor
+    /// @brief The constructor.
     IOService();
-    /// \brief The destructor.
+
+    /// @brief The destructor.
     ~IOService();
     //@}
 
-    /// \brief Start the underlying event loop.
+    /// @brief Start the underlying event loop.
     ///
     /// This method does not return control to the caller until
-    /// the \c stop() method is called via some handler.
+    /// the @ref stop() method is called via some handler.
     void run();
 
-    /// \brief Run the underlying event loop for a single event.
+    /// @brief Run the underlying event loop for a single event.
     ///
     /// This method return control to the caller as soon as the
     /// first handler has completed.  (If no handlers are ready when
     /// it is run, it will block until one is.)
     ///
-    /// \return The number of handlers that were executed.
+    /// @return The number of handlers that were executed.
     size_t runOne();
 
-    /// \brief Run the underlying event loop for a ready events.
+    /// @brief Run the underlying event loop for a ready events.
     ///
     /// This method executes handlers for all ready events and returns.
     /// It will return immediately if there are no ready events.
     ///
-    /// \return The number of handlers that were executed.
+    /// @return The number of handlers that were executed.
     size_t poll();
 
-    /// \brief Run the underlying event loop for a ready events.
+    /// @brief Run the underlying event loop for a ready events.
     ///
     /// This method executes handlers for all ready events and returns.
     /// It will return immediately if there are no ready events.
     ///
-    /// \return The number of handlers that were executed.
+    /// @return The number of handlers that were executed.
     size_t pollOne();
 
-    /// \brief Stop the underlying event loop.
+    /// @brief Stop the underlying event loop.
     ///
-    /// This will return the control to the caller of the \c run() method.
+    /// This will return the control to the caller of the @ref run() method.
     void stop();
 
-    /// \brief Indicates if the IOService has been stopped.
+    /// @brief Indicates if the IOService has been stopped.
     ///
-    /// \return true if the IOService has been stopped, false otherwise.
+    /// @return true if the IOService has been stopped, false otherwise.
     bool stopped() const;
 
-    /// \brief Restarts the IOService in preparation for a subsequent \c run() invocation.
+    /// @brief Restarts the IOService in preparation for a subsequent @ref run() invocation.
     void restart();
 
-    /// \brief Removes IO service work object to let it finish running
+    /// @brief Removes IO service work object to let it finish running
     /// when all handlers have been invoked.
     void stopWork();
 
-    /// \brief Return the native \c io_service object used in this wrapper.
+    /// @brief Return the native @ref io_service object used in this wrapper.
     ///
     /// This is a short term work around to support other Kea modules
-    /// that share the same \c io_service with the authoritative server.
+    /// that share the same @ref io_service with the authoritative server.
     /// It will eventually be removed once the wrapper interface is
     /// generalized.
+    ///
+    /// @return The internal io_service object.
     boost::asio::io_service& getInternalIOService();
 
-    /// \brief Post a callback to the end of the queue.
+    /// @brief Post a callback to the end of the queue.
     ///
     /// Requests the callback be called sometime later. It is not guaranteed
     /// by the underlying asio, but it can reasonably be expected the callback
@@ -114,12 +120,39 @@ public:
     /// by small bits that are called from time to time).
     void post(const std::function<void ()>& callback);
 
-private:
+    /// @brief Register external IOService.
-    boost::shared_ptr<IOServiceImpl> io_impl_;
+    ///
-};
+    /// @param io_service The external IOService to be registered.
+    void registerExternalIOService(IOServicePtr io_service);
 
-/// @brief Defines a smart pointer to an IOService instance.
+    /// @brief Unregister external IOService.
-typedef boost::shared_ptr<IOService> IOServicePtr;
+    ///
+    /// @param io_service The external IOService to be unregistered.
+    void unregisterExternalIOService(IOServicePtr io_service);
+
+    /// @brief Clear the list of external IOService objects.
+    void clearExternalIOServices() {
+        external_io_services_.clear();
+    }
+
+    /// @brief The count of external IOService objects.
+    ///
+    // @return The count of external IOService objects.
+    size_t externalIOServiceCount() {
+        return (external_io_services_.size());
+    }
+
+    /// @brief Poll external IOService objects.
+    void pollExternalIOServices();
+
+private:
+
+    /// @brief The implementation.
+    boost::shared_ptr<IOServiceImpl> io_impl_;
+
+    /// @brief The list of external IOService objects.
+    std::list<IOServicePtr> external_io_services_;
+};
 
 }  // namespace asiolink
 }  // namespace isc

src/lib/asiolink/tests/io_service_unittest.cc

@@ -45,4 +45,105 @@ TEST(IOService, post) {
     EXPECT_EQ(3, called[2]);
 }
 
+TEST(IOService, externalIOService) {
+    IOServicePtr main_io_service(new IOService());
+    EXPECT_EQ(main_io_service->externalIOServiceCount(), 0);
+    int one_io_callback_count = 0;
+    auto one_f = [&one_io_callback_count] () {
+        one_io_callback_count++;
+    };
+    int two_io_callback_count = 0;
+    auto two_f = [&two_io_callback_count] () {
+        two_io_callback_count++;
+    };
+    {
+        IOServicePtr one_io_service(new IOService());
+        one_io_service->post(one_f);
+
+        IOServicePtr two_io_service(new IOService());
+        two_io_service->post(two_f);
+
+        main_io_service->pollExternalIOServices();
+        EXPECT_EQ(one_io_callback_count, 0);
+        EXPECT_EQ(two_io_callback_count, 0);
+
+        main_io_service->registerExternalIOService(one_io_service);
+        EXPECT_EQ(main_io_service->externalIOServiceCount(), 1);
+
+        main_io_service->registerExternalIOService(two_io_service);
+        EXPECT_EQ(main_io_service->externalIOServiceCount(), 2);
+
+        main_io_service->pollExternalIOServices();
+        EXPECT_EQ(one_io_callback_count, 1);
+        EXPECT_EQ(two_io_callback_count, 1);
+        one_io_service->post(one_f);
+        two_io_service->post(two_f);
+    }
+    EXPECT_EQ(main_io_service->externalIOServiceCount(), 2);
+    main_io_service->pollExternalIOServices();
+    EXPECT_EQ(one_io_callback_count, 2);
+    EXPECT_EQ(two_io_callback_count, 2);
+
+    main_io_service->clearExternalIOServices();
+    EXPECT_EQ(main_io_service->externalIOServiceCount(), 0);
+
+    IOServicePtr one_io_service(new IOService());
+    one_io_service->post(one_f);
+
+    IOServicePtr two_io_service(new IOService());
+    two_io_service->post(two_f);
+
+    main_io_service->pollExternalIOServices();
+    EXPECT_EQ(one_io_callback_count, 2);
+    EXPECT_EQ(two_io_callback_count, 2);
+
+    main_io_service->registerExternalIOService(one_io_service);
+    EXPECT_EQ(main_io_service->externalIOServiceCount(), 1);
+
+    main_io_service->pollExternalIOServices();
+    EXPECT_EQ(one_io_callback_count, 3);
+    EXPECT_EQ(two_io_callback_count, 2);
+    one_io_service->post(one_f);
+    two_io_service->post(two_f);
+
+    main_io_service->registerExternalIOService(two_io_service);
+    EXPECT_EQ(main_io_service->externalIOServiceCount(), 2);
+
+    main_io_service->pollExternalIOServices();
+    EXPECT_EQ(one_io_callback_count, 4);
+    EXPECT_EQ(two_io_callback_count, 4);
+    one_io_service->post(one_f);
+    two_io_service->post(two_f);
+
+    main_io_service->unregisterExternalIOService(one_io_service);
+    EXPECT_EQ(main_io_service->externalIOServiceCount(), 1);
+
+    main_io_service->pollExternalIOServices();
+    EXPECT_EQ(one_io_callback_count, 4);
+    EXPECT_EQ(two_io_callback_count, 5);
+    one_io_service->post(one_f);
+    two_io_service->post(two_f);
+
+    main_io_service->unregisterExternalIOService(two_io_service);
+    EXPECT_EQ(main_io_service->externalIOServiceCount(), 0);
+
+    main_io_service->pollExternalIOServices();
+    EXPECT_EQ(one_io_callback_count, 4);
+    EXPECT_EQ(two_io_callback_count, 5);
+
+    EXPECT_NO_THROW(main_io_service->registerExternalIOService(main_io_service));
+    EXPECT_EQ(main_io_service->externalIOServiceCount(), 1);
+    main_io_service->post(one_f);
+
+    main_io_service->pollExternalIOServices();
+    EXPECT_EQ(one_io_callback_count, 5);
+    EXPECT_EQ(two_io_callback_count, 5);
+    EXPECT_NO_THROW(main_io_service->unregisterExternalIOService(main_io_service));
+    EXPECT_EQ(main_io_service->externalIOServiceCount(), 0);
+
+    main_io_service->pollExternalIOServices();
+    EXPECT_EQ(one_io_callback_count, 5);
+    EXPECT_EQ(two_io_callback_count, 5);
+}
+
 }

src/lib/dhcpsrv/testutils/Makefile.am

@@ -16,6 +16,7 @@ libdhcpsrvtest_la_SOURCES  = concrete_lease_mgr.cc concrete_lease_mgr.h
 libdhcpsrvtest_la_SOURCES += config_result_check.cc config_result_check.h
 libdhcpsrvtest_la_SOURCES += dhcp4o6_test_ipc.cc dhcp4o6_test_ipc.h
 libdhcpsrvtest_la_SOURCES += host_data_source_utils.cc host_data_source_utils.h
+libdhcpsrvtest_la_SOURCES += lib_load_test_fixture.h
 libdhcpsrvtest_la_SOURCES += memory_host_data_source.cc memory_host_data_source.h
 libdhcpsrvtest_la_SOURCES += test_utils.cc test_utils.h
 libdhcpsrvtest_la_SOURCES += generic_backend_unittest.cc generic_backend_unittest.h

src/lib/dhcpsrv/testutils/lib_load_test_fixture.h

@@ -9,7 +9,9 @@
 
 #include <cc/data.h>
 #include <dhcpsrv/cfgmgr.h>
+#include <hooks/hooks_manager.h>
 #include <process/daemon.h>
+
 #include <testutils/gtest_utils.h>
 
 namespace isc {

src/lib/process/d_controller.cc

@@ -415,6 +415,8 @@ DControllerBase::configFromFile() {
         // case of problems.
         storage->applyLoggingCfg();
 
+        getIOService()->clearExternalIOServices();
+
         answer = updateConfig(module_config);
         // In all cases the right logging configuration is in the context.
         process_->getCfgMgr()->getContext()->applyLoggingCfg();
@@ -655,6 +657,8 @@ DControllerBase::configSetHandler(const std::string&, ConstElementPtr args) {
         // case of problems.
         storage->applyLoggingCfg();
 
+        getIOService()->clearExternalIOServices();
+
         ConstElementPtr answer = updateConfig(module_config);
         int rcode = 0;
         parseAnswer(rcode, answer);
@@ -844,6 +848,8 @@ DControllerBase::~DControllerBase() {
         LOG_ERROR(dctl_logger, DCTL_UNLOAD_LIBRARIES_ERROR).arg(msg);
     }
 
+    getIOService()->clearExternalIOServices();
+
     io_signal_set_.reset();
     try {
         getIOService()->poll();

src/lib/testutils/Makefile.am

@@ -16,7 +16,6 @@ libkea_testutils_la_SOURCES += unix_control_client.cc unix_control_client.h
 libkea_testutils_la_SOURCES += user_context_utils.cc user_context_utils.h
 libkea_testutils_la_SOURCES += gtest_utils.h
 libkea_testutils_la_SOURCES += multi_threading_utils.h
-libkea_testutils_la_SOURCES += lib_load_test_fixture.h
 libkea_testutils_la_CPPFLAGS = $(AM_CPPFLAGS) $(GTEST_INCLUDES)
 libkea_testutils_la_LIBADD  = $(top_builddir)/src/lib/asiolink/libkea-asiolink.la
 libkea_testutils_la_LIBADD += $(top_builddir)/src/lib/dns/libkea-dns++.la

tools/check-lib-dependencies.sh

@@ -0,0 +1,319 @@
+#!/bin/bash
+
+# extract folder name containing file
+#
+# param ${1} file name
+# return folder name
+extract_folder_name() {
+	# return name of the file until last '/'
+	echo "$(echo "${1}" | rev | cut -d '/' -f 2- | rev)"
+}
+
+# extract all includes found in source files found in the same folder as specified Makefile.am
+#
+# param ${1} path to a Makefile.am
+# return all dependencies libs in the order of compilation
+extract_includes() {
+	# extract folder name from current library Makefile.am
+	CURRENT_FOLDER=$(extract_folder_name "${1}")"/"
+	# select only files in current folder
+	SEARCH_FILES=$(echo "${FILE_LIST}" | grep "${CURRENT_FOLDER}")
+	# select all lines containing '#include ' directive
+	RAW_INCLUDES_LIST=$(echo "${SEARCH_FILES}" | xargs grep "^#include " 2>/dev/null)
+	# filter only included dependencies found in other libraries by using the form 'other_lib_name/header_file.h'
+	# to do this it is required to select the string between '<' and '>', searching for '/' character and returning the name until last '/'
+	RAW_INCLUDES_LIST=$(echo "${RAW_INCLUDES_LIST}" | cut -d "#" -f 2 | tr "\"" " " | cut -d "<" -f 2 | cut -d ">" -f 1 | grep "\/" | rev | cut -d "/" -f 2 | rev | sort | uniq)
+	# filter includes that are not compiled by the project's Makefiles
+	INCLUDES_LIST=
+	for i in ${LIBRARIES_LIST}; do
+		for j in ${RAW_INCLUDES_LIST}; do
+			if test "${j}" = "${i}"; then
+				INCLUDES_LIST="${i} ${INCLUDES_LIST}"
+				break
+			fi
+		done
+	done
+	# remove empty spaces
+	INCLUDES_LIST=$(echo ${INCLUDES_LIST} | tr -s " ")
+	# order dependencies in the order of compilation
+	FILTERED_INCLUDES_LIST=
+	for i in ${LIBRARIES_LIST}; do
+		if test $(echo "${INCLUDES_LIST}" | grep "\b${i}\b" | wc -l) -ne 0; then
+			FILTERED_INCLUDES_LIST="${i} ${FILTERED_INCLUDES_LIST}"
+		fi
+	done
+	echo "${FILTERED_INCLUDES_LIST}"
+}
+
+# extract all header only files and headers and source files found in the external library required by specified library
+# param ${1} name of the current library
+# param ${2} name of the external dependency library required by current library
+# return the list of header only files as 'HEADERS: heaser1.h header2.h' and header and source files as 'HEADERS_AND_SOURCES: source1.h source1.cc source2.h source2.cpp'
+extract_non_include_files() {
+	# extract folder name for current library Makefile.am
+	CURRENT_FOLDER=$(extract_folder_name "src/lib/${1}/Makefile.am")"/"
+	# extract folder name for external dependency library Makefile.am
+	EXTERNAL_FOLDER=$(extract_folder_name "src/lib/${2}/Makefile.am")"/"
+	# select only files in current folder
+	SEARCH_FILES=$(echo "${FILE_LIST}" | grep "${CURRENT_FOLDER}")
+	HEADERS_LIST=
+	NON_HEADERS_LIST=
+	# select all lines containing '#include ' directive
+	RAW_INCLUDES_LIST=$(echo "${SEARCH_FILES}" | xargs grep "^#include " 2>/dev/null)
+	# filter only included headers found in other libraries by using the form 'other_lib_name/header_file.h'
+	# to do this it is required to select the string between '<' and '>', searching for '/' character, search for the extension marker '.' and returning the name after last '/'
+	RAW_INCLUDES_LIST=$(echo "${RAW_INCLUDES_LIST}" | cut -d "#" -f 2 | tr "\"" " " | cut -d "<" -f 2 | cut -d ">" -f 1 | grep "\/" | grep "\b${2}\b" | cut -d "/" -f 2 | grep "\." | sort | uniq)
+	# select only files in dependency library folder and strip full path
+	RELATIVE_SEARCH_FILES=$(echo "${FILE_LIST}" | grep "${EXTERNAL_FOLDER}" | sed -e "s#${REPO_FOLDER}${EXTERNAL_FOLDER}##g")
+	# search for the header file but also for source files
+	for i in ${RAW_INCLUDES_LIST}; do
+		# filter by name only (no extension)
+		FILTER=$(echo "${i}" | cut -d "." -f 1)
+		# filter non header files with exact name of the header file without the extension
+		NON_HEADER=$(echo "${RELATIVE_SEARCH_FILES}" | grep "\b${FILTER}\." | grep -v "${i}")
+		if test $(echo "${NON_HEADER}" | wc -w) -ne 0; then
+			# append header and source file names
+			NON_HEADERS_LIST="${i} ${NON_HEADER} ${NON_HEADERS_LIST}"
+		else
+			# append header only file name
+			HEADERS_LIST="${i} ${HEADERS_LIST}"
+		fi
+	done
+	# sort header only files
+	HEADERS_LIST=$(echo ${HEADERS_LIST} | tr -s " " | sort | uniq)
+	# sort header and source files
+	NON_HEADERS_LIST=$(echo ${NON_HEADERS_LIST} | tr -s " " | sort | uniq)
+	echo "HEADERS_AND_SOURCES:${NON_HEADERS_LIST}"
+	echo "HEADERS:${HEADERS_LIST}"
+}
+
+# extract all valid dependencies of a specified library
+#
+# param ${1} list of all libraries in the reverse compilation order
+# param ${2} library name for which the dependency list is computed
+# return the list of dependencies for specified library in the reverse compilation order 
+extract_dependencies() {
+	echo "${1}" | grep -Eo "\b${2}\b.*$"
+}
+
+# extract computed dependency for specified library
+#
+# param ${1} library name for which the dependency list is retrieved
+# param ${2} library path for which the dependency list is retrieved
+# return stored value of computed dependencies or 'NONE' if dependencies have not been computed yet
+extract_computed_dependencies() {
+	PATH_TO_NAME=$(echo "${2}" | tr -s "/" "_")
+	NAME="COMPUTED_DEPENDENCIES_${PATH_TO_NAME}_${1}"
+	if test -n "${!NAME+x}"; then
+		echo "${!NAME}"
+	else
+		echo "NONE"
+	fi
+}
+
+# extract library directive
+#
+# param ${1} artifact path
+extract_library_directive() {
+	ARTIFACT_PATH="${1}"
+	echo `cat ${ARTIFACT_PATH}/Makefile.am | grep "LIBADD\|LDADD" | sort | tr -s ' ' | cut -d " " -f 1 | sort -u`
+}
+
+# extract library name
+#
+# param ${1} artifact path
+extract_library_name() {
+	ARTIFACT_PATH="${1}"
+	echo `cat ${ARTIFACT_PATH}/Makefile.am | grep "LIBRARIES" | tr -s ' ' | cut -d " " -f 3`
+}
+
+# compute artifact dependencies
+#
+# param ${1} artifact name
+# param ${2} artifact path
+compute_dependencies() {
+	ARTIFACT="${1}"
+	ARTIFACT_PATH="${2}"
+	echo ""
+	echo "########################################"
+	echo "### ${ARTIFACT_PATH}/${ARTIFACT}"
+	echo "########################################"
+	echo ""
+	# all valid dependencies that can be added by each dependency library
+	echo "${ARTIFACT_PATH}/${ARTIFACT} valid dependencies:"
+	echo "${VALID_LIST}"
+	# detect dependencies errors by searching for dependencies that are compiled after the current library and can generate missing symbols
+	NON_RECURSIVE_BASE_DEPENDENCIES=
+	for j in ${BASE_DEPENDENCIES}; do
+		# only add the dependency if it is in the valid dependencies list to prevent infinite recursion and log the error otherwise
+		if test $(echo "${VALID_LIST}" | grep "\b${j}\b" | wc -l) -eq 0; then
+			# search for external header and source files
+			INVALID_EXTERNAL_DEPENDENCIES=$(extract_non_include_files "${ARTIFACT}" "${j}")
+			# filter header only external files
+			EXTERNAL_HEADERS=$(echo "${INVALID_EXTERNAL_DEPENDENCIES}" | grep "HEADERS:" | cut -d ":" -f 2)
+			# filter header and source external files
+			EXTERNAL_ALL=$(echo "${INVALID_EXTERNAL_DEPENDENCIES}" | grep "HEADERS_AND_SOURCES:" | cut -d ":" -f 2)
+			echo "### ERROR ### dependencies ERROR for ${ARTIFACT_PATH}/${ARTIFACT} on ${j} with:"
+			# if there are any header only external files
+			if test $(echo "${EXTERNAL_ALL}" | wc -w) -ne 0; then
+				echo "non header only files: ${EXTERNAL_ALL}"
+			fi
+			# if there are any header and source external files
+			if test $(echo "${EXTERNAL_HEADERS}" | wc -w) -ne 0; then
+				echo "header only files: ${EXTERNAL_HEADERS}"
+			fi
+		else
+			# don't add current library to it's dependencies list
+			if test ${j} != ${ARTIFACT}; then
+				NON_RECURSIVE_BASE_DEPENDENCIES="${NON_RECURSIVE_BASE_DEPENDENCIES} ${j}"
+			fi
+		fi
+	done
+	# all found dependencies in the reverse compilation order
+	BASE_DEPENDENCIES=$(echo "${BASE_DEPENDENCIES}" | xargs)
+	# all found and valid dependencies in the reverse compilation order
+	NON_RECURSIVE_BASE_DEPENDENCIES=$(echo "${NON_RECURSIVE_BASE_DEPENDENCIES}" | xargs)
+	echo "${ARTIFACT_PATH}/${ARTIFACT} base dependencies:"
+	echo "${BASE_DEPENDENCIES}"
+	echo "${ARTIFACT_PATH}/${ARTIFACT} non recursive dependencies:"
+	echo "${NON_RECURSIVE_BASE_DEPENDENCIES}"
+	# minimum set of dependencies for current library
+	DEPENDENCIES=
+	for j in ${NON_RECURSIVE_BASE_DEPENDENCIES}; do
+		NEW_DEPENDENCIES=$(extract_computed_dependencies "${j}" "src/lib")
+		if test "${NEW_DEPENDENCIES}" == "NONE"; then
+			echo "### ERROR ### computed dependency not found for ${j}"
+		else
+			DEPENDENCIES="${NEW_DEPENDENCIES} ${DEPENDENCIES}"
+		fi
+	done
+	DEPENDENCIES=$(echo "${DEPENDENCIES} ${NON_RECURSIVE_BASE_DEPENDENCIES}" | tr -s " " "\n" | sort | uniq | xargs)
+	# order dependencies in the order of compilation
+	SORTED_DEPENDENCIES=
+	for j in ${LIBRARIES_LIST}; do
+		if test $(echo "${DEPENDENCIES}" | grep "\b${j}\b" | wc -l) -ne 0; then
+			SORTED_DEPENDENCIES="${j} ${SORTED_DEPENDENCIES}"
+		fi
+	done
+	echo "${ARTIFACT_PATH}/${ARTIFACT} minimum dependencies:"
+	echo "${SORTED_DEPENDENCIES}"
+	echo ""
+	echo "++++++++++++++++++++++++++++++++++++++++"
+	ARTIFACT_DIRECTIVE=$(extract_library_directive ${ARTIFACT_PATH}/${ARTIFACT})
+	for j in ${SORTED_DEPENDENCIES}; do
+		DEPENDENCY_LIBRARY_NAME=$(extract_library_name "src/lib/${j}")
+		echo "${ARTIFACT_DIRECTIVE} += \$(top_builddir)/src/lib/${j}/${DEPENDENCY_LIBRARY_NAME}"
+	done
+	echo "++++++++++++++++++++++++++++++++++++++++"
+	echo "########################################"
+	echo ""
+}
+
+# if wrong number of parameters print usage
+if test ${#} -ne 1; then
+	echo "Usage: ${0} path/to/kea/repo"
+	exit
+fi
+
+# folder containing full repo
+REPO_FOLDER=${1}
+
+if test $(echo -n ${REPO_FOLDER} | tail -c 1) != "/"; then
+	REPO_FOLDER="${REPO_FOLDER}/"
+fi
+
+# filter all Makefile.am files
+MAKEFILES_LIST=$(find ${REPO_FOLDER} | grep "Makefile\.am" | sed -e "s#${REPO_FOLDER}##g" | grep "src\/" | sort)
+
+# if no Makefile.am found exit
+if test -z "${MAKEFILES_LIST}"; then
+	echo "invalid repo path: no Makefile.am file found"
+	exit
+fi
+
+echo "list of Makefile.am:"
+echo "${MAKEFILES_LIST}"
+
+# base Makefile.am for all sources is in src/lib/Makefile.am
+BASE_MAKEFILE=$(echo "${MAKEFILES_LIST}" | grep "src\/lib\/Makefile.am")
+
+# if no src/lib/Makefile.am found exit
+if test -z ${BASE_MAKEFILE}; then
+	echo "invalid repo path: no src/lib/Makefile.am file found"
+	exit
+fi
+
+echo "base Makefile.am:"
+echo "${BASE_MAKEFILE}"
+
+# generate the list of libraries in the compilation order
+LIBRARIES_LIST=
+RAW_LIBRARIES_LIST=$(cat "${REPO_FOLDER}${BASE_MAKEFILE}" | grep "SUBDIRS")
+for i in ${RAW_LIBRARIES_LIST}; do
+	LIBRARIES_LIST="${LIBRARIES_LIST} $(echo ${i} | grep -v "SUBDIRS" | grep -v '=')"
+done
+
+# remove empty spaces
+LIBRARIES_LIST=$(echo "${LIBRARIES_LIST}" | tr -s ' ' | xargs)
+
+# generate the list of libraries in the reverse compilation order
+REVERSE_LIBRARIES_LIST=
+for i in ${LIBRARIES_LIST}; do
+	REVERSE_LIBRARIES_LIST="${i} ${REVERSE_LIBRARIES_LIST}"
+done
+
+echo "list of libraries:"
+echo "${LIBRARIES_LIST}"
+
+echo "reverse list of libraries:"
+echo "${REVERSE_LIBRARIES_LIST}"
+
+# filter all files of interest ignoring irrelevant ones
+# ignore .git, .libs, .deps doc folders and .o .lo .Plo .Po .gcno .gcda .m4 .dox .json .mes files
+FILE_LIST=$(find "${REPO_FOLDER}" 2>/dev/null | grep -v "\.git" | grep -v "\/\.libs\/" | grep -v "\.o$" | grep -v "\/\.deps\/" | grep -v "\.lo$" | grep -v "\.Plo$" | grep -v "\.Po$" | grep -v "\.gcno$" | grep -v "gcda" | grep -v "\.m4$" | grep -v "\.dox$" | grep -v "\.json$" | grep -v "\/doc\/" | grep -v "\.mes$" | sort)
+
+#echo "files:"
+#echo "${FILE_LIST}"
+
+BASE_LIBRARIES_MAKEFILES=
+
+# generate the list of dependencies for all libraries in src/lib
+for i in ${LIBRARIES_LIST}; do
+	# generate current library Makefile.am path
+	BASE_LIBRARIES_MAKEFILES="${BASE_LIBRARIES_MAKEFILES} src/lib/${i}/Makefile.am"
+	# extract dependencies found in the library folder
+	BASE_DEPENDENCIES=$(extract_includes "src/lib/${i}/Makefile.am")
+	# generate the list of valid dependencies for the current library (take compilation order into account)
+	VALID_LIST=$(extract_dependencies "${REVERSE_LIBRARIES_LIST}" "${i}")
+	compute_dependencies "${i}" "src/lib"
+	PATH_TO_NAME=$(echo "src/lib" | tr -s "/" "_")
+	declare COMPUTED_DEPENDENCIES_${PATH_TO_NAME}_${i}="${SORTED_DEPENDENCIES}"
+done
+
+# remove empty spaces
+BASE_LIBRARIES_MAKEFILES=$(echo "${BASE_LIBRARIES_MAKEFILES}" | xargs | tr -s " " "\n")
+
+echo "base Makefiles.am files:"
+echo "${BASE_LIBRARIES_MAKEFILES}"
+
+OTHER_MAKEFILES=$(echo "${MAKEFILES_LIST}" | tr -s " " "\n" | grep -v "src/lib/" | grep -v "src/share/" | grep -v "src/Makefile.am")
+# remove empty spaces
+OTHER_MAKEFILES=$(echo "${OTHER_MAKEFILES}" | xargs | tr -s " " "\n")
+
+echo "remaining Makefile.am files:"
+echo "${OTHER_MAKEFILES}"
+
+for i in ${OTHER_MAKEFILES}; do
+	# extract dependencies found in the artifact folder
+	BASE_DEPENDENCIES=$(extract_includes "${i}")
+	# generate the list of valid dependencies for the current artifact (take compilation order into account)
+	VALID_LIST="${REVERSE_LIBRARIES_LIST}"
+	ARTIFACT=$(echo "${i}" | rev | cut -d "/" -f 2 | rev)
+	ARTIFACT_PATH=$(echo "${i}" | rev | cut -d "/" -f 3- | rev)
+	compute_dependencies "${ARTIFACT}" "${ARTIFACT_PATH}"
+	PATH_TO_NAME=$(echo "${ARTIFACT_PATH}" | tr -s "/" "_")
+	declare COMPUTED_DEPENDENCIES_${PATH_TO_NAME}_${ARTIFACT}="${SORTED_DEPENDENCIES}"
+done
+
+exit
+