Merge #2861

Synchronize the workthread and main thread in the authoritative server,
by providing callbacks executed in the main thread after a work in the
workthread is completed.

src/bin/auth/auth_messages.mes

@@ -151,6 +151,10 @@ A separate thread for maintaining data source clients has been started.
 % AUTH_DATASRC_CLIENTS_BUILDER_STOPPED data source builder thread stopped
 The separate thread for maintaining data source clients has been stopped.
 
+% AUTH_DATASRC_CLIENTS_BUILDER_WAKE_ERR failed to wake up main thread: %1
+A low-level error happened when trying to send data to the main thread to wake
+it up. Terminating to prevent inconsistent state and possiblu hang ups.
+
 % AUTH_DATASRC_CLIENTS_SHUTDOWN_ERROR error on waiting for data source builder thread: %1
 This indicates that the separate thread for maintaining data source
 clients had been terminated due to an uncaught exception, and the

src/bin/auth/auth_srv.cc

@@ -319,6 +319,7 @@ AuthSrvImpl::AuthSrvImpl(AbstractXfroutClient& xfrout_client,
     xfrin_session_(NULL),
     counters_(),
     keyring_(NULL),
+    datasrc_clients_mgr_(io_service_),
     ddns_base_forwarder_(ddns_forwarder),
     ddns_forwarder_(NULL),
     xfrout_connected_(false),

src/bin/auth/datasrc_clients_mgr.h

@@ -29,6 +29,9 @@
 #include <datasrc/client_list.h>
 #include <datasrc/memory/zone_writer.h>
 
+#include <asiolink/io_service.h>
+#include <asiolink/local_socket.h>
+
 #include <auth/auth_log.h>
 #include <auth/datasrc_config.h>
 
@@ -36,11 +39,16 @@
 #include <boost/bind.hpp>
 #include <boost/shared_ptr.hpp>
 #include <boost/noncopyable.hpp>
+#include <boost/function.hpp>
+#include <boost/foreach.hpp>
 
 #include <exception>
 #include <cassert>
+#include <cerrno>
 #include <list>
 #include <utility>
+#include <sys/types.h>
+#include <sys/socket.h>
 
 namespace isc {
 namespace auth {
@@ -77,13 +85,40 @@ enum CommandID {
     NUM_COMMANDS
 };
 
+/// \brief Callback to be called when the command is completed.
+typedef boost::function<void ()> FinishedCallback;
+
 /// \brief The data type passed from DataSrcClientsMgr to
-/// DataSrcClientsBuilder.
+///     DataSrcClientsBuilder.
 ///
-/// The first element of the pair is the command ID, and the second element
-/// is its argument.  If the command doesn't take an argument it should be
-/// a null pointer.
-typedef std::pair<CommandID, data::ConstElementPtr> Command;
+/// This just holds the data items together, no logic or protection
+/// is present here.
+struct Command {
+    /// \brief Constructor
+    ///
+    /// It just initializes the member variables of the same names
+    /// as the parameters.
+    Command(CommandID id, const data::ConstElementPtr& params,
+            const FinishedCallback& callback) :
+        id(id),
+        params(params),
+        callback(callback)
+    {}
+    /// \brief The command to execute
+    CommandID id;
+    /// \brief Argument of the command.
+    ///
+    /// If the command takes no argument, it should be null pointer.
+    ///
+    /// This may be a null pointer if the command takes no parameters.
+    data::ConstElementPtr params;
+    /// \brief A callback to be called once the command finishes.
+    ///
+    /// This may be an empty boost::function. In such case, no callback
+    /// will be called after completion.
+    FinishedCallback callback;
+};
+
 } // namespace datasrc_clientmgr_internal
 
 /// \brief Frontend to the manager object for data source clients.
@@ -113,6 +148,24 @@ private:
                      boost::shared_ptr<datasrc::ConfigurableClientList> >
     ClientListsMap;
 
+    class FDGuard : boost::noncopyable {
+    public:
+        FDGuard(DataSrcClientsMgrBase *mgr) :
+            mgr_(mgr)
+        {}
+        ~FDGuard() {
+            if (mgr_->read_fd_ != -1) {
+                close(mgr_->read_fd_);
+            }
+            if (mgr_->write_fd_ != -1) {
+                close(mgr_->write_fd_);
+            }
+        }
+    private:
+        DataSrcClientsMgrBase* mgr_;
+    };
+    friend class FDGuard;
+
 public:
     /// \brief Thread-safe accessor to the data source client lists.
     ///
@@ -176,12 +229,20 @@ public:
     ///
     /// \throw std::bad_alloc internal memory allocation failure.
     /// \throw isc::Unexpected general unexpected system errors.
-    DataSrcClientsMgrBase() :
+    DataSrcClientsMgrBase(asiolink::IOService& service) :
         clients_map_(new ClientListsMap),
-        builder_(&command_queue_, &cond_, &queue_mutex_, &clients_map_,
-                 &map_mutex_),
-        builder_thread_(boost::bind(&BuilderType::run, &builder_))
-    {}
+        fd_guard_(new FDGuard(this)),
+        read_fd_(-1), write_fd_(-1),
+        builder_(&command_queue_, &callback_queue_, &cond_, &queue_mutex_,
+                 &clients_map_, &map_mutex_, createFds()),
+        builder_thread_(boost::bind(&BuilderType::run, &builder_)),
+        wakeup_socket_(service, read_fd_)
+    {
+        // Schedule wakeups when callbacks are pushed.
+        wakeup_socket_.asyncRead(
+            boost::bind(&DataSrcClientsMgrBase::processCallbacks, this, _1),
+            buffer, 1);
+    }
 
     /// \brief The destructor.
     ///
@@ -220,6 +281,7 @@ public:
                       AUTH_DATASRC_CLIENTS_SHUTDOWN_UNEXPECTED_ERROR);
         }
 
+        processCallbacks(); // Any leftover callbacks
         cleanup();              // see below
     }
 
@@ -234,11 +296,18 @@ public:
     /// \brief std::bad_alloc
     ///
     /// \param config_arg The new data source configuration.  Must not be NULL.
-    void reconfigure(data::ConstElementPtr config_arg) {
+    /// \param callback Called once the reconfigure command completes. It is
+    ///     called in the main thread (not in the work one). It should be
+    ///     exceptionless.
+    void reconfigure(const data::ConstElementPtr& config_arg,
+                     const datasrc_clientmgr_internal::FinishedCallback&
+                     callback = datasrc_clientmgr_internal::FinishedCallback())
+    {
         if (!config_arg) {
             isc_throw(InvalidParameter, "Invalid null config argument");
         }
-        sendCommand(datasrc_clientmgr_internal::RECONFIGURE, config_arg);
+        sendCommand(datasrc_clientmgr_internal::RECONFIGURE, config_arg,
+                    callback);
         reconfigureHook();      // for test's customization
     }
 
@@ -257,12 +326,18 @@ public:
     /// \param args Element argument that should be a map of the form
     /// { "class": "IN", "origin": "example.com" }
     /// (but class is optional and will default to IN)
+    /// \param callback Called once the loadZone command completes. It
+    ///     is called in the main thread, not in the work thread. It should
+    ///     be exceptionless.
     ///
     /// \exception CommandError if the args value is null, or not in
     ///                                 the expected format, or contains
     ///                                 a bad origin or class string
     void
-    loadZone(data::ConstElementPtr args) {
+    loadZone(const data::ConstElementPtr& args,
+             const datasrc_clientmgr_internal::FinishedCallback& callback =
+             datasrc_clientmgr_internal::FinishedCallback())
+    {
         if (!args) {
             isc_throw(CommandError, "loadZone argument empty");
         }
@@ -303,7 +378,7 @@ public:
         // implement it would be to factor out the code from
         // the start of doLoadZone(), and call it here too
 
-        sendCommand(datasrc_clientmgr_internal::LOADZONE, args);
+        sendCommand(datasrc_clientmgr_internal::LOADZONE, args, callback);
     }
 
 private:
@@ -317,30 +392,79 @@ private:
     void reconfigureHook() {}
 
     void sendCommand(datasrc_clientmgr_internal::CommandID command,
-                     data::ConstElementPtr arg)
+                     const data::ConstElementPtr& arg,
+                     const datasrc_clientmgr_internal::FinishedCallback&
+                     callback = datasrc_clientmgr_internal::FinishedCallback())
     {
         // The lock will be held until the end of this method.  Only
         // push_back has to be protected, but we can avoid having an extra
         // block this way.
         typename MutexType::Locker locker(queue_mutex_);
         command_queue_.push_back(
-            datasrc_clientmgr_internal::Command(command, arg));
+            datasrc_clientmgr_internal::Command(command, arg, callback));
         cond_.signal();
     }
 
+    int createFds() {
+        int fds[2];
+        int result = socketpair(AF_LOCAL, SOCK_STREAM, 0, fds);
+        if (result != 0) {
+            isc_throw(Unexpected, "Can't create socket pair: " <<
+                      strerror(errno));
+        }
+        read_fd_ = fds[0];
+        write_fd_ = fds[1];
+        return write_fd_;
+    }
+
+    void processCallbacks(const std::string& error = std::string()) {
+        // Schedule the next read.
+        wakeup_socket_.asyncRead(
+            boost::bind(&DataSrcClientsMgrBase::processCallbacks, this, _1),
+            buffer, 1);
+        if (!error.empty()) {
+            // Generally, there should be no errors (as we are the other end
+            // as well), but check just in case.
+            isc_throw(Unexpected, error);
+        }
+
+        // Steal the callbacks into local copy.
+        std::list<datasrc_clientmgr_internal::FinishedCallback> queue;
+        {
+            typename MutexType::Locker locker(queue_mutex_);
+            queue.swap(callback_queue_);
+        }
+
+        // Execute the callbacks
+        BOOST_FOREACH(const datasrc_clientmgr_internal::FinishedCallback&
+                      callback, queue) {
+            callback();
+        }
+    }
+
     //
     // The following are shared with the builder.
     //
     // The list is used as a one-way queue: back-in, front-out
     std::list<datasrc_clientmgr_internal::Command> command_queue_;
+    // Similar to above, for the callbacks that are ready to be called.
+    // While the command queue is for sending commands from the main thread
+    // to the work thread, this one is for the other direction. Protected
+    // by the same mutex (queue_mutex_).
+    std::list<datasrc_clientmgr_internal::FinishedCallback> callback_queue_;
     CondVarType cond_;          // condition variable for queue operations
     MutexType queue_mutex_;     // mutex to protect the queue
     datasrc::ClientListMapPtr clients_map_;
                                 // map of actual data source client objects
+    boost::scoped_ptr<FDGuard> fd_guard_; // A guard to close the fds.
+    int read_fd_, write_fd_;    // Descriptors for wakeup
     MutexType map_mutex_;       // mutex to protect the clients map
 
     BuilderType builder_;
     ThreadType builder_thread_; // for safety this should be placed last
+    isc::asiolink::LocalSocket wakeup_socket_; // For integration of read_fd_
+                                               // to the asio loop
+    char buffer[1];   // Buffer for the wakeup socket.
 };
 
 namespace datasrc_clientmgr_internal {
@@ -385,12 +509,15 @@ public:
     ///
     /// \throw None
     DataSrcClientsBuilderBase(std::list<Command>* command_queue,
+                              std::list<FinishedCallback>* callback_queue,
                               CondVarType* cond, MutexType* queue_mutex,
                               datasrc::ClientListMapPtr* clients_map,
-                              MutexType* map_mutex
+                              MutexType* map_mutex,
+                              int wake_fd
         ) :
-        command_queue_(command_queue), cond_(cond), queue_mutex_(queue_mutex),
-        clients_map_(clients_map), map_mutex_(map_mutex)
+        command_queue_(command_queue), callback_queue_(callback_queue),
+        cond_(cond), queue_mutex_(queue_mutex),
+        clients_map_(clients_map), map_mutex_(map_mutex), wake_fd_(wake_fd)
     {}
 
     /// \brief The main loop.
@@ -457,10 +584,12 @@ private:
 
     // The following are shared with the manager
     std::list<Command>* command_queue_;
+    std::list<FinishedCallback> *callback_queue_;
     CondVarType* cond_;
     MutexType* queue_mutex_;
     datasrc::ClientListMapPtr* clients_map_;
     MutexType* map_mutex_;
+    int wake_fd_;
 };
 
 // Shortcut typedef for normal use
@@ -494,6 +623,31 @@ DataSrcClientsBuilderBase<MutexType, CondVarType>::run() {
                               AUTH_DATASRC_CLIENTS_BUILDER_COMMAND_ERROR).
                         arg(e.what());
                 }
+                if (current_commands.front().callback) {
+                    // Lock the queue
+                    typename MutexType::Locker locker(*queue_mutex_);
+                    callback_queue_->
+                        push_back(current_commands.front().callback);
+                    // Wake up the other end. If it would block, there are data
+                    // and it'll wake anyway.
+                    int result = send(wake_fd_, "w", 1, MSG_DONTWAIT);
+                    if (result == -1 &&
+                        (errno != EWOULDBLOCK && errno != EAGAIN)) {
+                        // Note: the strerror might not be thread safe, as
+                        // subsequent call to it might change the returned
+                        // string. But that is unlikely and strerror_r is
+                        // not portable and we are going to terminate anyway,
+                        // so that's better than nothing.
+                        //
+                        // Also, this error handler is not tested. It should
+                        // be generally impossible to happen, so it is hard
+                        // to trigger in controlled way.
+                        LOG_FATAL(auth_logger,
+                                  AUTH_DATASRC_CLIENTS_BUILDER_WAKE_ERR).
+                            arg(strerror(errno));
+                        std::terminate();
+                    }
+                }
                 current_commands.pop_front();
             }
         }
@@ -515,7 +669,7 @@ bool
 DataSrcClientsBuilderBase<MutexType, CondVarType>::handleCommand(
     const Command& command)
 {
-    const CommandID cid = command.first;
+    const CommandID cid = command.id;
     if (cid >= NUM_COMMANDS) {
         // This shouldn't happen except for a bug within this file.
         isc_throw(Unexpected, "internal bug: invalid command, ID: " << cid);
@@ -526,12 +680,12 @@ DataSrcClientsBuilderBase<MutexType, CondVarType>::handleCommand(
     };
     LOG_DEBUG(auth_logger, DBGLVL_TRACE_BASIC,
               AUTH_DATASRC_CLIENTS_BUILDER_COMMAND).arg(command_desc.at(cid));
-    switch (command.first) {
+    switch (command.id) {
     case RECONFIGURE:
-        doReconfigure(command.second);
+        doReconfigure(command.params);
         break;
     case LOADZONE:
-        doLoadZone(command.second);
+        doLoadZone(command.params);
         break;
     case SHUTDOWN:
         return (false);

src/bin/auth/tests/datasrc_clients_builder_unittest.cc

@@ -36,9 +36,13 @@
 
 #include <boost/function.hpp>
 
+#include <sys/types.h>
+#include <sys/socket.h>
+
 #include <cstdlib>
 #include <string>
 #include <sstream>
+#include <cerrno>
 
 using isc::data::ConstElementPtr;
 using namespace isc::dns;
@@ -54,17 +58,24 @@ protected:
     DataSrcClientsBuilderTest() :
         clients_map(new std::map<RRClass,
                     boost::shared_ptr<ConfigurableClientList> >),
-        builder(&command_queue, &cond, &queue_mutex, &clients_map, &map_mutex),
+        write_end(-1), read_end(-1),
+        builder(&command_queue, &callback_queue, &cond, &queue_mutex,
+                &clients_map, &map_mutex, generateSockets()),
         cond(command_queue, delayed_command_queue), rrclass(RRClass::IN()),
-        shutdown_cmd(SHUTDOWN, ConstElementPtr()),
-        noop_cmd(NOOP, ConstElementPtr())
+        shutdown_cmd(SHUTDOWN, ConstElementPtr(), FinishedCallback()),
+        noop_cmd(NOOP, ConstElementPtr(), FinishedCallback())
     {}
+    ~ DataSrcClientsBuilderTest() {
+
+    }
 
     void configureZones();      // used for loadzone related tests
 
     ClientListMapPtr clients_map; // configured clients
     std::list<Command> command_queue; // test command queue
     std::list<Command> delayed_command_queue; // commands available after wait
+    std::list<FinishedCallback> callback_queue; // Callbacks from commands
+    int write_end, read_end;
     TestDataSrcClientsBuilder builder;
     TestCondVar cond;
     TestMutex queue_mutex;
@@ -72,6 +83,15 @@ protected:
     const RRClass rrclass;
     const Command shutdown_cmd;
     const Command noop_cmd;
+private:
+    int generateSockets() {
+        int pair[2];
+        int result = socketpair(AF_LOCAL, SOCK_STREAM, 0, pair);
+        assert(result == 0);
+        write_end = pair[0];
+        read_end = pair[1];
+        return write_end;
+    }
 };
 
 TEST_F(DataSrcClientsBuilderTest, runSingleCommand) {
@@ -82,6 +102,44 @@ TEST_F(DataSrcClientsBuilderTest, runSingleCommand) {
     EXPECT_EQ(0, cond.wait_count); // no wait because command queue is not empty
     EXPECT_EQ(1, queue_mutex.lock_count);
     EXPECT_EQ(1, queue_mutex.unlock_count);
+    // No callback scheduled, none called.
+    EXPECT_TRUE(callback_queue.empty());
+    // Not woken up.
+    char c;
+    int result = recv(read_end, &c, 1, MSG_DONTWAIT);
+    EXPECT_EQ(-1, result);
+    EXPECT_TRUE(errno == EAGAIN || errno == EWOULDBLOCK);
+}
+
+// Just to have a valid function callback to pass
+void emptyCallsback() {}
+
+// Check a command finished callback is passed
+TEST_F(DataSrcClientsBuilderTest, commandFinished) {
+    command_queue.push_back(Command(SHUTDOWN, ConstElementPtr(),
+                                    emptyCallsback));
+    builder.run();
+    EXPECT_EQ(0, cond.wait_count); // no wait because command queue is not empty
+    // Once for picking up data, once for putting the callback there
+    EXPECT_EQ(2, queue_mutex.lock_count);
+    EXPECT_EQ(2, queue_mutex.unlock_count);
+    // There's one callback in the queue
+    ASSERT_EQ(1, callback_queue.size());
+    EXPECT_EQ(emptyCallsback, callback_queue.front());
+    // And we are woken up.
+    char c;
+    int result = recv(read_end, &c, 1, MSG_DONTWAIT);
+    EXPECT_EQ(1, result);
+}
+
+// Test that low-level errors with the synchronization socket
+// (an unexpected condition) is detected and program aborted.
+TEST_F(DataSrcClientsBuilderTest, finishedCrash) {
+    command_queue.push_back(Command(SHUTDOWN, ConstElementPtr(),
+                                    emptyCallsback));
+    // Break the socket
+    close(write_end);
+    EXPECT_DEATH_IF_SUPPORTED({builder.run();}, "");
 }
 
 TEST_F(DataSrcClientsBuilderTest, runMultiCommands) {
@@ -138,7 +196,7 @@ TEST_F(DataSrcClientsBuilderTest, reconfigure) {
     // the error handling
 
     // A command structure we'll modify to send different commands
-    Command reconfig_cmd(RECONFIGURE, ConstElementPtr());
+    Command reconfig_cmd(RECONFIGURE, ConstElementPtr(), FinishedCallback());
 
     // Initially, no clients should be there
     EXPECT_TRUE(clients_map->empty());
@@ -166,7 +224,7 @@ TEST_F(DataSrcClientsBuilderTest, reconfigure) {
         "}"
     );
 
-    reconfig_cmd.second = good_config;
+    reconfig_cmd.params = good_config;
     EXPECT_TRUE(builder.handleCommand(reconfig_cmd));
     EXPECT_EQ(1, clients_map->size());
     EXPECT_EQ(1, map_mutex.lock_count);
@@ -177,7 +235,7 @@ TEST_F(DataSrcClientsBuilderTest, reconfigure) {
     // If a 'bad' command argument got here, the config validation should
     // have failed already, but still, the handler should return true,
     // and the clients_map should not be updated.
-    reconfig_cmd.second = Element::create("{ \"foo\": \"bar\" }");
+    reconfig_cmd.params = Element::create("{ \"foo\": \"bar\" }");
     EXPECT_TRUE(builder.handleCommand(reconfig_cmd));
     EXPECT_EQ(working_config_clients, clients_map);
     // Building failed, so map mutex should not have been locked again
@@ -185,7 +243,7 @@ TEST_F(DataSrcClientsBuilderTest, reconfigure) {
 
     // The same for a configuration that has bad data for the type it
     // specifies
-    reconfig_cmd.second = bad_config;
+    reconfig_cmd.params = bad_config;
     builder.handleCommand(reconfig_cmd);
     EXPECT_TRUE(builder.handleCommand(reconfig_cmd));
     EXPECT_EQ(working_config_clients, clients_map);
@@ -194,21 +252,21 @@ TEST_F(DataSrcClientsBuilderTest, reconfigure) {
 
     // The same goes for an empty parameter (it should at least be
     // an empty map)
-    reconfig_cmd.second = ConstElementPtr();
+    reconfig_cmd.params = ConstElementPtr();
     EXPECT_TRUE(builder.handleCommand(reconfig_cmd));
     EXPECT_EQ(working_config_clients, clients_map);
     EXPECT_EQ(1, map_mutex.lock_count);
 
     // Reconfigure again with the same good clients, the result should
     // be a different map than the original, but not an empty one.
-    reconfig_cmd.second = good_config;
+    reconfig_cmd.params = good_config;
     EXPECT_TRUE(builder.handleCommand(reconfig_cmd));
     EXPECT_NE(working_config_clients, clients_map);
     EXPECT_EQ(1, clients_map->size());
     EXPECT_EQ(2, map_mutex.lock_count);
 
     // And finally, try an empty config to disable all datasource clients
-    reconfig_cmd.second = Element::createMap();
+    reconfig_cmd.params = Element::createMap();
     EXPECT_TRUE(builder.handleCommand(reconfig_cmd));
     EXPECT_EQ(0, clients_map->size());
     EXPECT_EQ(3, map_mutex.lock_count);
@@ -224,7 +282,8 @@ TEST_F(DataSrcClientsBuilderTest, shutdown) {
 TEST_F(DataSrcClientsBuilderTest, badCommand) {
     // out-of-range command ID
     EXPECT_THROW(builder.handleCommand(Command(NUM_COMMANDS,
-                                               ConstElementPtr())),
+                                               ConstElementPtr(),
+                                               FinishedCallback())),
                  isc::Unexpected);
 }
 
@@ -308,7 +367,8 @@ TEST_F(DataSrcClientsBuilderTest, loadZone) {
 
     const Command loadzone_cmd(LOADZONE, Element::fromJSON(
                                    "{\"class\": \"IN\","
-                                   " \"origin\": \"test1.example\"}"));
+                                   " \"origin\": \"test1.example\"}"),
+                               FinishedCallback());
     EXPECT_TRUE(builder.handleCommand(loadzone_cmd));
 
     // loadZone involves two critical sections: one for getting the zone
@@ -369,7 +429,8 @@ TEST_F(DataSrcClientsBuilderTest,
     // Now send the command to reload it
     const Command loadzone_cmd(LOADZONE, Element::fromJSON(
                                    "{\"class\": \"IN\","
-                                   " \"origin\": \"example.org\"}"));
+                                   " \"origin\": \"example.org\"}"),
+                               FinishedCallback());
     EXPECT_TRUE(builder.handleCommand(loadzone_cmd));
     // And now it should be present too.
     EXPECT_EQ(ZoneFinder::SUCCESS,
@@ -380,7 +441,8 @@ TEST_F(DataSrcClientsBuilderTest,
     // An error case: the zone has no configuration. (note .com here)
     const Command nozone_cmd(LOADZONE, Element::fromJSON(
                                  "{\"class\": \"IN\","
-                                 " \"origin\": \"example.com\"}"));
+                                 " \"origin\": \"example.com\"}"),
+                             FinishedCallback());
     EXPECT_THROW(builder.handleCommand(nozone_cmd),
                  TestDataSrcClientsBuilder::InternalCommandError);
     // The previous zone is not hurt in any way
@@ -403,7 +465,8 @@ TEST_F(DataSrcClientsBuilderTest,
     builder.handleCommand(
                      Command(LOADZONE, Element::fromJSON(
                                  "{\"class\": \"IN\","
-                                 " \"origin\": \"example.org\"}")));
+                                 " \"origin\": \"example.org\"}"),
+                             FinishedCallback()));
     // Only one mutex was needed because there was no actual reload.
     EXPECT_EQ(orig_lock_count + 1, map_mutex.lock_count);
     EXPECT_EQ(orig_unlock_count + 1, map_mutex.unlock_count);
@@ -421,7 +484,8 @@ TEST_F(DataSrcClientsBuilderTest,
         builder.handleCommand(
             Command(LOADZONE, Element::fromJSON(
                         "{\"class\": \"IN\","
-                        " \"origin\": \"nosuchzone.example\"}"))),
+                        " \"origin\": \"nosuchzone.example\"}"),
+                    FinishedCallback())),
         TestDataSrcClientsBuilder::InternalCommandError);
 
     // basically impossible case: in-memory cache is completely disabled.
@@ -441,7 +505,8 @@ TEST_F(DataSrcClientsBuilderTest,
     EXPECT_THROW(builder.handleCommand(
                      Command(LOADZONE, Element::fromJSON(
                                  "{\"class\": \"IN\","
-                                 " \"origin\": \"example.org\"}"))),
+                                 " \"origin\": \"example.org\"}"),
+                             FinishedCallback())),
                  TestDataSrcClientsBuilder::InternalCommandError);
 }
 
@@ -454,7 +519,8 @@ TEST_F(DataSrcClientsBuilderTest, loadBrokenZone) {
     // there's an error in the new zone file.  reload will be rejected.
     const Command loadzone_cmd(LOADZONE, Element::fromJSON(
                                    "{\"class\": \"IN\","
-                                   " \"origin\": \"test1.example\"}"));
+                                   " \"origin\": \"test1.example\"}"),
+                               FinishedCallback());
     EXPECT_THROW(builder.handleCommand(loadzone_cmd),
                  TestDataSrcClientsBuilder::InternalCommandError);
     zoneChecks(clients_map, rrclass);     // zone shouldn't be replaced
@@ -469,7 +535,8 @@ TEST_F(DataSrcClientsBuilderTest, loadUnreadableZone) {
                              TEST_DATA_BUILDDIR "/test1.zone.copied"));
     const Command loadzone_cmd(LOADZONE, Element::fromJSON(
                                    "{\"class\": \"IN\","
-                                   " \"origin\": \"test1.example\"}"));
+                                   " \"origin\": \"test1.example\"}"),
+                               FinishedCallback());
     EXPECT_THROW(builder.handleCommand(loadzone_cmd),
                  TestDataSrcClientsBuilder::InternalCommandError);
     zoneChecks(clients_map, rrclass);     // zone shouldn't be replaced
@@ -482,7 +549,8 @@ TEST_F(DataSrcClientsBuilderTest, loadZoneWithoutDataSrc) {
                      Command(LOADZONE,
                              Element::fromJSON(
                                  "{\"class\": \"IN\", "
-                                 " \"origin\": \"test1.example\"}"))),
+                                 " \"origin\": \"test1.example\"}"),
+                             FinishedCallback())),
                  TestDataSrcClientsBuilder::InternalCommandError);
 }
 
@@ -492,7 +560,8 @@ TEST_F(DataSrcClientsBuilderTest, loadZoneInvalidParams) {
     if (!isc::util::unittests::runningOnValgrind()) {
         // null arg: this causes assertion failure
         EXPECT_DEATH_IF_SUPPORTED({
-                builder.handleCommand(Command(LOADZONE, ElementPtr()));
+                builder.handleCommand(Command(LOADZONE, ElementPtr(),
+                                              FinishedCallback()));
             }, "");
     }
 
@@ -501,7 +570,8 @@ TEST_F(DataSrcClientsBuilderTest, loadZoneInvalidParams) {
                      Command(LOADZONE,
                              Element::fromJSON(
                                  "{\"origin\": \"test1.example\","
-                                 " \"class\": \"no_such_class\"}"))),
+                                 " \"class\": \"no_such_class\"}"),
+                             FinishedCallback())),
                  InvalidRRClass);
 
     // not a string
@@ -509,7 +579,8 @@ TEST_F(DataSrcClientsBuilderTest, loadZoneInvalidParams) {
                      Command(LOADZONE,
                              Element::fromJSON(
                                  "{\"origin\": \"test1.example\","
-                                 " \"class\": 1}"))),
+                                 " \"class\": 1}"),
+                             FinishedCallback())),
                  isc::data::TypeError);
 
     // class or origin is missing: result in assertion failure
@@ -517,7 +588,8 @@ TEST_F(DataSrcClientsBuilderTest, loadZoneInvalidParams) {
         EXPECT_DEATH_IF_SUPPORTED({
                 builder.handleCommand(Command(LOADZONE,
                                               Element::fromJSON(
-                                                  "{\"class\": \"IN\"}")));
+                                                  "{\"class\": \"IN\"}"),
+                                              FinishedCallback()));
             }, "");
     }
 
@@ -525,12 +597,14 @@ TEST_F(DataSrcClientsBuilderTest, loadZoneInvalidParams) {
     EXPECT_THROW(builder.handleCommand(
                      Command(LOADZONE,
                              Element::fromJSON(
-                                 "{\"class\": \"IN\", \"origin\": \"...\"}"))),
+                                 "{\"class\": \"IN\", \"origin\": \"...\"}"),
+                             FinishedCallback())),
                  EmptyLabel);
     EXPECT_THROW(builder.handleCommand(
                      Command(LOADZONE,
                              Element::fromJSON(
-                                 "{\"origin\": 10, \"class\": 1}"))),
+                                 "{\"origin\": 10, \"class\": 1}"),
+                             FinishedCallback())),
                  isc::data::TypeError);
 }
 
@@ -561,7 +635,8 @@ TEST_F(DataSrcClientsBuilderTest,
                      Command(LOADZONE,
                              Element::fromJSON(
                                  "{\"origin\": \"test1.example\","
-                                 " \"class\": \"IN\"}"))),
+                                 " \"class\": \"IN\"}"),
+                             FinishedCallback())),
                  TestDataSrcClientsBuilder::InternalCommandError);
 }
 

src/bin/auth/tests/datasrc_clients_mgr_unittest.cc

@@ -38,13 +38,13 @@ void
 shutdownCheck() {
     // Check for common points on shutdown.  The manager should have acquired
     // the lock, put a SHUTDOWN command to the queue, and should have signaled
-    // the builder.
-    EXPECT_EQ(1, FakeDataSrcClientsBuilder::queue_mutex->lock_count);
+    // the builder. It should check again for the callback queue, with the lock
+    EXPECT_EQ(2, FakeDataSrcClientsBuilder::queue_mutex->lock_count);
     EXPECT_EQ(1, FakeDataSrcClientsBuilder::cond->signal_count);
     EXPECT_EQ(1, FakeDataSrcClientsBuilder::command_queue->size());
     const Command& cmd = FakeDataSrcClientsBuilder::command_queue->front();
-    EXPECT_EQ(SHUTDOWN, cmd.first);
-    EXPECT_FALSE(cmd.second);   // no argument
+    EXPECT_EQ(SHUTDOWN, cmd.id);
+    EXPECT_FALSE(cmd.params);   // no argument
 
     // Finally, the manager should wait for the thread to terminate.
     EXPECT_TRUE(FakeDataSrcClientsBuilder::thread_waited);
@@ -130,8 +130,8 @@ TEST(DataSrcClientsMgrTest, reconfigure) {
     // touch or refer to the map, so it shouldn't acquire the map lock.
     checkSharedMembers(1, 1, 0, 0, 1, 1);
     const Command& cmd1 = FakeDataSrcClientsBuilder::command_queue->front();
-    EXPECT_EQ(RECONFIGURE, cmd1.first);
-    EXPECT_EQ(reconfigure_arg, cmd1.second);
+    EXPECT_EQ(RECONFIGURE, cmd1.id);
+    EXPECT_EQ(reconfigure_arg, cmd1.params);
 
     // Non-null, but semantically invalid argument.  The manager doesn't do
     // this check, so it should result in the same effect.
@@ -140,8 +140,8 @@ TEST(DataSrcClientsMgrTest, reconfigure) {
     mgr.reconfigure(reconfigure_arg);
     checkSharedMembers(2, 2, 0, 0, 2, 1);
     const Command& cmd2 = FakeDataSrcClientsBuilder::command_queue->front();
-    EXPECT_EQ(RECONFIGURE, cmd2.first);
-    EXPECT_EQ(reconfigure_arg, cmd2.second);
+    EXPECT_EQ(RECONFIGURE, cmd2.id);
+    EXPECT_EQ(reconfigure_arg, cmd2.params);
 
     // Passing NULL argument is immediately rejected
     EXPECT_THROW(mgr.reconfigure(ConstElementPtr()), isc::InvalidParameter);
@@ -245,10 +245,52 @@ TEST(DataSrcClientsMgrTest, reload) {
     EXPECT_EQ(3, FakeDataSrcClientsBuilder::command_queue->size());
 }
 
+void
+callback(bool* called, int *tag_target, int tag_value) {
+    *called = true;
+    *tag_target = tag_value;
+}
+
+// Test we can wake up the main thread by writing to the file descriptor and
+// that the callbacks are executed and removed when woken up.
+TEST(DataSrcClientsMgrTest, wakeup) {
+    bool called = false;
+    int tag;
+    {
+        TestDataSrcClientsMgr mgr;
+        // There's some real file descriptor (or something that looks so)
+        ASSERT_GT(FakeDataSrcClientsBuilder::wakeup_fd, 0);
+        // Push a callback in and wake the manager
+        FakeDataSrcClientsBuilder::callback_queue->
+            push_back(boost::bind(callback, &called, &tag, 1));
+        EXPECT_EQ(1, write(FakeDataSrcClientsBuilder::wakeup_fd, "w", 1));
+        mgr.run_one();
+        EXPECT_TRUE(called);
+        EXPECT_EQ(1, tag);
+        EXPECT_TRUE(FakeDataSrcClientsBuilder::callback_queue->empty());
+
+        called = false;
+        // If we wake up and don't push anything, it doesn't break.
+        EXPECT_EQ(1, write(FakeDataSrcClientsBuilder::wakeup_fd, "w", 1));
+        mgr.run_one();
+        EXPECT_FALSE(called);
+
+        // When we terminate, it should process whatever is left
+        // of the callbacks. So push and terminate (and don't directly
+        // wake).
+        FakeDataSrcClientsBuilder::callback_queue->
+            push_back(boost::bind(callback, &called, &tag, 2));
+    }
+    EXPECT_TRUE(called);
+    EXPECT_EQ(2, tag);
+    EXPECT_TRUE(FakeDataSrcClientsBuilder::callback_queue->empty());
+}
+
 TEST(DataSrcClientsMgrTest, realThread) {
     // Using the non-test definition with a real thread.  Just checking
     // no disruption happens.
-    DataSrcClientsMgr mgr;
+    isc::asiolink::IOService service;
+    DataSrcClientsMgr mgr(service);
 }
 
 } // unnamed namespace

src/bin/auth/tests/test_datasrc_clients_mgr.cc

@@ -26,7 +26,9 @@ namespace datasrc_clientmgr_internal {
 // Define static DataSrcClientsBuilder member variables.
 bool FakeDataSrcClientsBuilder::started = false;
 std::list<Command>* FakeDataSrcClientsBuilder::command_queue = NULL;
+std::list<FinishedCallback>* FakeDataSrcClientsBuilder::callback_queue = NULL;
 std::list<Command> FakeDataSrcClientsBuilder::command_queue_copy;
+std::list<FinishedCallback> FakeDataSrcClientsBuilder::callback_queue_copy;
 TestCondVar* FakeDataSrcClientsBuilder::cond = NULL;
 TestCondVar FakeDataSrcClientsBuilder::cond_copy;
 TestMutex* FakeDataSrcClientsBuilder::queue_mutex = NULL;
@@ -38,6 +40,7 @@ bool FakeDataSrcClientsBuilder::thread_waited = false;
 FakeDataSrcClientsBuilder::ExceptionFromWait
 FakeDataSrcClientsBuilder::thread_throw_on_wait =
     FakeDataSrcClientsBuilder::NOTHROW;
+int FakeDataSrcClientsBuilder::wakeup_fd = -1;
 
 template<>
 void
@@ -58,7 +61,7 @@ TestDataSrcClientsBuilder::doNoop() {
 
 template<>
 void
-TestDataSrcClientsMgr::cleanup() {
+TestDataSrcClientsMgrBase::cleanup() {
     using namespace datasrc_clientmgr_internal;
     // Make copy of some of the manager's member variables and reset the
     // corresponding pointers.  The currently pointed objects are in the
@@ -73,17 +76,21 @@ TestDataSrcClientsMgr::cleanup() {
     FakeDataSrcClientsBuilder::cond_copy = cond_;
     FakeDataSrcClientsBuilder::cond =
         &FakeDataSrcClientsBuilder::cond_copy;
+    FakeDataSrcClientsBuilder::callback_queue_copy =
+        *FakeDataSrcClientsBuilder::callback_queue;
+    FakeDataSrcClientsBuilder::callback_queue =
+        &FakeDataSrcClientsBuilder::callback_queue_copy;
 }
 
 template<>
 void
-TestDataSrcClientsMgr::reconfigureHook() {
+TestDataSrcClientsMgrBase::reconfigureHook() {
     using namespace datasrc_clientmgr_internal;
 
     // Simply replace the local map, ignoring bogus config value.
-    assert(command_queue_.front().first == RECONFIGURE);
+    assert(command_queue_.front().id == RECONFIGURE);
     try {
-        clients_map_ = configureDataSource(command_queue_.front().second);
+        clients_map_ = configureDataSource(command_queue_.front().params);
     } catch (...) {}
 }
 

src/bin/auth/tests/test_datasrc_clients_mgr.h

@@ -20,6 +20,8 @@
 #include <auth/datasrc_clients_mgr.h>
 #include <datasrc/datasrc_config.h>
 
+#include <asiolink/io_service.h>
+
 #include <boost/function.hpp>
 
 #include <list>
@@ -131,15 +133,18 @@ public:
     // true iff a builder has started.
     static bool started;
 
-    // These three correspond to the resource shared with the manager.
+    // These five correspond to the resource shared with the manager.
     // xxx_copy will be set in the manager's destructor to record the
     // final state of the manager.
     static std::list<Command>* command_queue;
+    static std::list<FinishedCallback>* callback_queue;
     static TestCondVar* cond;
     static TestMutex* queue_mutex;
+    static int wakeup_fd;
     static isc::datasrc::ClientListMapPtr* clients_map;
     static TestMutex* map_mutex;
     static std::list<Command> command_queue_copy;
+    static std::list<FinishedCallback> callback_queue_copy;
     static TestCondVar cond_copy;
     static TestMutex queue_mutex_copy;
 
@@ -153,15 +158,18 @@ public:
 
     FakeDataSrcClientsBuilder(
         std::list<Command>* command_queue,
+        std::list<FinishedCallback>* callback_queue,
         TestCondVar* cond,
         TestMutex* queue_mutex,
         isc::datasrc::ClientListMapPtr* clients_map,
-        TestMutex* map_mutex)
+        TestMutex* map_mutex, int wakeup_fd)
     {
         FakeDataSrcClientsBuilder::started = false;
         FakeDataSrcClientsBuilder::command_queue = command_queue;
+        FakeDataSrcClientsBuilder::callback_queue = callback_queue;
         FakeDataSrcClientsBuilder::cond = cond;
         FakeDataSrcClientsBuilder::queue_mutex = queue_mutex;
+        FakeDataSrcClientsBuilder::wakeup_fd = wakeup_fd;
         FakeDataSrcClientsBuilder::clients_map = clients_map;
         FakeDataSrcClientsBuilder::map_mutex = map_mutex;
         FakeDataSrcClientsBuilder::thread_waited = false;
@@ -201,18 +209,30 @@ typedef DataSrcClientsMgrBase<
     datasrc_clientmgr_internal::TestThread,
     datasrc_clientmgr_internal::FakeDataSrcClientsBuilder,
     datasrc_clientmgr_internal::TestMutex,
-    datasrc_clientmgr_internal::TestCondVar> TestDataSrcClientsMgr;
+    datasrc_clientmgr_internal::TestCondVar> TestDataSrcClientsMgrBase;
 
 // A specialization of manager's "cleanup" called at the end of the
 // destructor.  We use this to record the final values of some of the class
 // member variables.
 template<>
 void
-TestDataSrcClientsMgr::cleanup();
+TestDataSrcClientsMgrBase::cleanup();
 
 template<>
 void
-TestDataSrcClientsMgr::reconfigureHook();
+TestDataSrcClientsMgrBase::reconfigureHook();
+
+// A (hackish) trick how to not require the IOService to be passed from the
+// tests. We can't create the io service as a member, because it would
+// get initialized too late.
+class TestDataSrcClientsMgr :
+    public asiolink::IOService,
+    public TestDataSrcClientsMgrBase {
+public:
+    TestDataSrcClientsMgr() :
+        TestDataSrcClientsMgrBase(*static_cast<asiolink::IOService*>(this))
+    {}
+};
 } // namespace auth
 } // namespace isc