Merge lp:~michihenning/unity-scopes-api/scope-exceptions into lp:unity-scopes-api

[Michi Henning]

Fixed core dump in the run time when a scope threw an exception from PreviewQueryBase::run().

Added tests for the various scope methods to make sure that they are exception-safe.

Improved logging and error reporting for throwing scopes.

This MR fixes a core dump in the run time when a scope threw an exception from PreviewQueryBase::run().

Added tests for the various scope methods to make sure that they are exception-safe.

Improved logging and error reporting for throwing scopes.

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FAILED: Continuous integration, rev:279
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FAILED: Continuous integration, rev:281
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FAILED: Continuous integration, rev:281
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FAILED: Continuous integration, rev:281
http://jenkins.qa.ubuntu.com/job/unity-scopes-api-ci/540/
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FAILED: Continuous integration, rev:281
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PASSED: Continuous integration, rev:282
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[Paweł Stołowski (stolowski)]

Looks good, thanks!

review: Approve

[Paweł Stołowski (stolowski)]

After resolving conflicts and attempting to build it with some other big branches (such as loop-prevention) we were seeing new kind of test failures in the silo, so I had to pull that branch off for the moment.

Here is the log:
https://launchpadlibrarian.net/195924595/buildlog_ubuntu-vivid-ppc64el.unity-scopes-api_0.6.12%2B15.04.20150127.1-0ubuntu1_FAILEDTOBUILD.txt.gz

In case the full log disappears, here is an excerpt of failures:

      Start 68: ThrowingScope

68: Test command: /build/buildd/unity-scopes-api-0.6.12+15.04.20150127.1/obj-powerpc64le-linux-gnu/test/gtest/scopes/ThrowingScope/ThrowingScope_test
68: Test timeout computed to be: 1500
68: [==========] Running 11 tests from 1 test case.
68: [----------] Global test environment set-up.
68: [----------] 11 tests from ThrowingScopeTest
68: [ RUN ] ThrowingScopeTest.no_error
68: scoperegistry [ThrowingScope_test]: unity::FileException: cannot open scope installation directory "/unused": No such file or directory (errno = 2)
68: scoperegistry [ThrowingScope_test]: could not open OEM installation directory, ignoring OEM scopes
68: scoperegistry [ThrowingScope_test]: unity::FileException: cannot open scope installation directory "/build/buildd/unity-scopes-api-0.6.12+15.04.20150127.1/obj-powerpc64le-linux-gnu/test/gtest/scopes/ThrowingScope/click": No such file or directory (errno = 2)
68: scoperegistry [ThrowingScope_test]: could not open Click installation directory, ignoring Click scopes
68: scoperegistry [ThrowingScope_test]: no remote registry configured, only local scopes will be available
68: [2015-01-27 09:06:51.739966] INFO: TestRegistry: ScopesWatcher: scope: "ThrowingScope" installed to: "/build/buildd/unity-scopes-api-0.6.12+15.04.20150127.1/obj-powerpc64le-linux-gnu/test/gtest/scopes/ThrowingScope/scopes/ThrowingScope"
68: [2015-01-27 09:06:51.772695] INFO: TestRegistry: RegistryObject::ScopeProcess::exec(): Process for scope: "ThrowingScope" started
68: [ OK ] ThrowingScopeTest.no_error (60 ms)
68: [ RUN ] ThrowingScopeTest.throw_from_search
68: [2015-01-27 09:06:51.781175] ERROR: ThrowingScope: Scope "ThrowingScope" threw an exception from search()
68: [ OK ] ThrowingScopeTest.throw_from_search (5 ms)
68: [ RUN ] ThrowingScopeTest.throw_from_run
68: [2015-01-27 09:06:51.786344] ERROR: ThrowingScope: QueryBase::run(): unity::ResourceException: exception from run
68: [2015-01-27 09:06:51.787049] WARNING: c-4e02aa2d00000000: ObjectAdapter: no servant for oneway request (id: f1dd504500000000, adapter: c-4e02aa2d00000000-r, op: finished)
68: [ OK ] ThrowingScopeTest.throw_from_run (5 ms)
68: [ RUN ] ThrowingScopeTest.throw_from_cancelled
68: [2015-01-27 09:06:52.791321] ERROR: ThrowingScope: QueryBase::cancelled(): unity::ResourceException: exception from cancelled
68: [2015-01-27 09:06:52.791663] WARNING: ThrowingScope: ObjectAdapter: no servant for oneway request (id: f82c2eee00000004, adapter: ThrowingScope-c, op: destroy)
68: [2015-01-27 09:06:52.791880] WARNING: c-4ce6aad900000000: ObjectAdapter: no servant for oneway request (id: 7e69520600000000, adapter: c-4ce6aad900000000-r, op: finished)
68: [2015-01-27 09:06:52.792170] WARNIN...

review: Needs Fixing

[lp:~michihenning/unity-scopes-api/scope-exceptions]

283. By Michi Henning on 2015-02-03

Merged trunk and resolved conflicts.

284. By Michi Henning on 2015-02-03

Removed trailing whitespace.

285. By Michi Henning on 2015-02-04

Fixed race in test that caused bogus test failure if exception
from cancelled wasn't processed by the time run() returned. Fixed
race in ReplyObject. (info_list_ was accessed whithout holding a lock.)

[Michi Henning (michihenning)]

The failure that Pawel saw was caused by the merge having omitted a change from my branch. While testing, I found a race in the test that caused a bogus failure, and also fixed a real race in ReplyObject. Should be good now.

[PS Jenkins bot (ps-jenkins)]

PASSED: Continuous integration, rev:285
http://jenkins.qa.ubuntu.com/job/unity-scopes-api-ci/561/
Executed test runs:
    SUCCESS: http://jenkins.qa.ubuntu.com/job/unity-scopes-api-vivid-amd64-ci/88
    SUCCESS: http://jenkins.qa.ubuntu.com/job/unity-scopes-api-vivid-armhf-ci/86
        deb: http://jenkins.qa.ubuntu.com/job/unity-scopes-api-vivid-armhf-ci/86/artifact/work/output/*zip*/output.zip
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review: Approve (continuous-integration)

[Paweł Stołowski (stolowski)]

Thanks!

review: Approve

=== modified file 'debian/libunity-scopes3.symbols'
--- debian/libunity-scopes3.symbols	2015-01-30 12:34:39 +0000
+++ debian/libunity-scopes3.symbols	2015-02-04 05:47:34 +0000
@@ -546,7 +546,7 @@
  (c++)"unity::scopes::internal::ScopeObject::debug_mode() const@Base" 0.6.2+rtm+rtm+rtm+14.09.20140818
  (c++)"unity::scopes::internal::ScopeObject::perform_action(unity::scopes::Result const&, unity::scopes::ActionMetadata const&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::shared_ptr<unity::scopes::internal::MWReply> const&, unity::scopes::internal::InvokeInfo const&)@Base" 0.4.0+14.04.20140312.1
  (c++)"unity::scopes::internal::ScopeObject::preview(unity::scopes::Result const&, unity::scopes::ActionMetadata const&, std::shared_ptr<unity::scopes::internal::MWReply> const&, unity::scopes::internal::InvokeInfo const&)@Base" 0.4.0+14.04.20140312.1
- (c++)"unity::scopes::internal::ScopeObject::query(std::shared_ptr<unity::scopes::internal::MWReply> const&, unity::scopes::internal::MiddlewareBase*, std::function<std::shared_ptr<unity::scopes::QueryBase> ()> const&, std::function<std::shared_ptr<unity::scopes::internal::QueryObjectBase> (std::shared_ptr<unity::scopes::QueryBase>, std::shared_ptr<unity::scopes::internal::MWQueryCtrl>)> const&)@Base" 0.4.0+14.04.20140312.1
+ (c++)"unity::scopes::internal::ScopeObject::query(std::shared_ptr<unity::scopes::internal::MWReply> const&, unity::scopes::internal::MiddlewareBase*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::function<std::shared_ptr<unity::scopes::QueryBase> ()> const&, std::function<std::shared_ptr<unity::scopes::internal::QueryObjectBase> (std::shared_ptr<unity::scopes::QueryBase>, std::shared_ptr<unity::scopes::internal::MWQueryCtrl>)> const&)@Base" 0replaceme
  (c++)"unity::scopes::internal::ScopeObject::~ScopeObject()@Base" 0.4.0+14.04.20140312.1
  (c++)"unity::scopes::internal::ScopeObject::ScopeObject(unity::scopes::ScopeBase*, bool)@Base" 0.6.12+15.04.20150127.2
  (c++)"unity::scopes::internal::ScopeObject::search(unity::scopes::CannedQuery const&, unity::scopes::SearchMetadata const&, std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, unity::scopes::Variant, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::basic_string<char, std::char_traits<char>, std::allocator<char> > const, unity::scopes::Variant> > > const&, std::shared_ptr<unity::scopes::internal::MWReply> const&, unity::scopes::internal::InvokeInfo const&)@Base" 0.6.12+15.04.20150127.2

=== modified file 'include/unity/scopes/internal/QueryObject.h'
--- include/unity/scopes/internal/QueryObject.h	2015-01-09 00:14:14 +0000
+++ include/unity/scopes/internal/QueryObject.h	2015-02-04 05:47:34 +0000
@@ -67,7 +67,7 @@
 
 protected:
     std::shared_ptr<QueryBase> query_base_;
-    MWReplyProxy reply_;
+    MWReplyProxy const reply_;
     std::weak_ptr<unity::scopes::Reply> reply_proxy_;
     MWQueryCtrlProxy const ctrl_;
     bool pushable_;

=== modified file 'include/unity/scopes/internal/ReplyObject.h'
--- include/unity/scopes/internal/ReplyObject.h	2015-01-22 03:54:58 +0000
+++ include/unity/scopes/internal/ReplyObject.h	2015-02-04 05:47:34 +0000
@@ -69,7 +69,6 @@
     std::condition_variable idle_;
     std::string origin_proxy_;
     int num_push_;
-    std::atomic_bool info_occurred_;
     std::vector<OperationInfo> info_list_;
 };
 

=== modified file 'include/unity/scopes/internal/ScopeObject.h'
--- include/unity/scopes/internal/ScopeObject.h	2015-01-26 08:20:45 +0000
+++ include/unity/scopes/internal/ScopeObject.h	2015-02-04 05:47:34 +0000
@@ -84,6 +84,7 @@
 
 private:
     MWQueryCtrlProxy query(MWReplyProxy const& reply, MiddlewareBase* mw_base,
+        std::string const& method,
         std::function<QueryBase::SPtr(void)> const& query_factory_fun,
         std::function<QueryObjectBase::SPtr(QueryBase::SPtr, MWQueryCtrlProxy)> const& query_object_factory_fun);
     ScopeBase* const scope_base_;

=== modified file 'src/scopes/QueryBase.cpp'
--- src/scopes/QueryBase.cpp	2014-08-05 06:42:04 +0000
+++ src/scopes/QueryBase.cpp	2015-02-04 05:47:34 +0000
@@ -43,20 +43,7 @@
 void QueryBase::cancel()
 {
     p->cancel();    // Forward cancel to subqueries
-    try
-    {
-        cancelled();    // Inform this query that it was cancelled
-    }
-    catch (std::exception const& e)
-    {
-        cerr << "QueryBase::cancel(): exception from cancelled(): " << e.what() << endl;
-        // TODO: log error
-    }
-    catch (...)
-    {
-        cerr << "QueryBase::cancel(): unknown exception from cancelled()" << endl;
-        // TODO: log error
-    }
+    cancelled();
 }
 /// @endcond
 

=== modified file 'src/scopes/internal/ActivationQueryObject.cpp'
--- src/scopes/internal/ActivationQueryObject.cpp	2015-01-09 00:14:14 +0000
+++ src/scopes/internal/ActivationQueryObject.cpp	2015-02-04 05:47:34 +0000
@@ -55,8 +55,8 @@
 {
     assert(self_);
 
-    // The reply proxy now holds our reference count high, so
-    // we can drop our own smart pointer and disconnect from the middleware.
+    // Disconnect from middleware. While this request is in progress,
+    // this instance will not be deallocated.
     self_ = nullptr;
     disconnect();
 
@@ -71,13 +71,15 @@
     }
     catch (std::exception const& e)
     {
-        BOOST_LOG(info.mw->runtime()->logger()) << "ActivationQueryObject::run(): " << e.what();
-        reply_->finished(CompletionDetails(CompletionDetails::Error, e.what()));  // Oneway, can't block
+        BOOST_LOG(info.mw->runtime()->logger()) << "ActivationQueryBase::activate(): " << e.what();
+        reply_->finished(CompletionDetails(CompletionDetails::Error,
+                                           string("ActivationQueryBase::activate(): ") + e.what()));
     }
     catch (...)
     {
-        BOOST_LOG(info.mw->runtime()->logger()) << "ActivationQueryObject::run(): unknown exception";
-        reply_->finished(CompletionDetails(CompletionDetails::Error, "unknown exception"));  // Oneway, can't block
+        BOOST_LOG(info.mw->runtime()->logger()) << "ActivationQueryBase::activate(): unknown exception";
+        reply_->finished(CompletionDetails(CompletionDetails::Error,
+                                           "ActivationQueryBase::activate(): unknown exception"));
     }
 }
 

=== modified file 'src/scopes/internal/PreviewQueryObject.cpp'
--- src/scopes/internal/PreviewQueryObject.cpp	2015-01-09 03:16:51 +0000
+++ src/scopes/internal/PreviewQueryObject.cpp	2015-02-04 05:47:34 +0000
@@ -57,6 +57,16 @@
 
 void PreviewQueryObject::run(MWReplyProxy const& reply, InvokeInfo const& info) noexcept
 {
+    unique_lock<mutex> lock(mutex_);
+
+    // See comment in QueryObject::run()
+    if (!pushable_)
+    {
+        self_ = nullptr;
+        disconnect();
+        return;
+    }
+
     assert(self_);
 
     auto reply_proxy = make_shared<PreviewReplyImpl>(reply, self_);
@@ -68,24 +78,33 @@
     self_ = nullptr;
     disconnect();
 
-    // Synchronous call into scope implementation.
-    // On return, replies for the query may still be outstanding.
     try
     {
+        lock.unlock();
+
+        // Synchronous call into scope implementation.
+        // On return, replies for the preview may still be outstanding.
         auto preview_query = dynamic_pointer_cast<PreviewQueryBase>(query_base_);
         assert(preview_query);
         preview_query->run(reply_proxy);
     }
     catch (std::exception const& e)
     {
-        pushable_ = false;
-        BOOST_LOG(info.mw->runtime()->logger()) << "PreviewQueryObject::run(): " << e.what();
-        reply_->finished(CompletionDetails(CompletionDetails::Error, e.what()));  // Oneway, can't block
+        {
+            lock_guard<mutex> lock(mutex_);
+            pushable_ = false;
+        }
+        BOOST_LOG(info.mw->runtime()->logger()) << "PreviewQueryBase::run(): " << e.what();
+        reply_->finished(CompletionDetails(CompletionDetails::Error, string("PreviewQueryBase::run(): ") + e.what()));
     }
     catch (...)
     {
-        BOOST_LOG(info.mw->runtime()->logger()) << "PreviewQueryObject::run(): unknown exception";
-        reply_->finished(CompletionDetails(CompletionDetails::Error, "unknown exception"));  // Oneway, can't block
+        {
+            lock_guard<mutex> lock(mutex_);
+            pushable_ = false;
+        }
+        BOOST_LOG(info.mw->runtime()->logger()) << "PreviewQueryBase::run(): unknown exception";
+        reply_->finished(CompletionDetails(CompletionDetails::Error, "PreviewQueryBase::run(): unknown exception"));
     }
 }
 

=== modified file 'src/scopes/internal/QueryObject.cpp'
--- src/scopes/internal/QueryObject.cpp	2015-01-09 03:16:51 +0000
+++ src/scopes/internal/QueryObject.cpp	2015-02-04 05:47:34 +0000
@@ -123,19 +123,25 @@
     }
     catch (std::exception const& e)
     {
-        pushable_ = false;
-        BOOST_LOG(info.mw->runtime()->logger()) << "ScopeBase::run(): " << e.what();
-        reply_->finished(CompletionDetails(CompletionDetails::Error, e.what()));  // Oneway, can't block
+        {
+            lock_guard<mutex> lock(mutex_);
+            pushable_ = false;
+        }
+        BOOST_LOG(info.mw->runtime()->logger()) << "QueryBase::run(): " << e.what();
+        reply_->finished(CompletionDetails(CompletionDetails::Error, string("QueryBase::run(): ") + e.what()));
     }
     catch (...)
     {
-        pushable_ = false;
-        BOOST_LOG(info.mw->runtime()->logger()) << "ScopeBase::run(): unknown exception";
-        reply_->finished(CompletionDetails(CompletionDetails::Error, "unknown exception"));  // Oneway, can't block
+        {
+            lock_guard<mutex> lock(mutex_);
+            pushable_ = false;
+        }
+        BOOST_LOG(info.mw->runtime()->logger()) << "QueryBase::run(): unknown exception";
+        reply_->finished(CompletionDetails(CompletionDetails::Error, "QueryBase::run(): unknown exception"));
     }
 }
 
-void QueryObject::cancel(InvokeInfo const& /* info */)
+void QueryObject::cancel(InvokeInfo const& info)
 {
     {
         lock_guard<mutex> lock(mutex_);
@@ -145,6 +151,13 @@
             return;
         }
         pushable_ = false;
+    }  // Release lock
+
+    try
+    {
+        // Forward the cancellation to the query base (which in turn will forward it to any subqueries).
+        // The query base also calls the cancelled() callback to inform the application code.
+        query_base_->cancel();
 
         auto rp = reply_proxy_.lock();
         if (rp)
@@ -154,11 +167,24 @@
             // a CompletionDetails::CompletionStatus (whereas the public ReplyProxy does not).
             reply_->finished(CompletionDetails(CompletionDetails::Cancelled));  // Oneway, can't block
         }
-    }  // Release lock
-
-    // Forward the cancellation to the query base (which in turn will forward it to any subqueries).
-    // The query base also calls the cancelled() callback to inform the application code.
-    query_base_->cancel();
+    }
+    catch (std::exception const& e)
+    {
+        BOOST_LOG(info.mw->runtime()->logger()) << "QueryBase::cancelled(): " << e.what();
+        // Deliberately no error completion here. On the client side, we short-cut the cancelled()
+        // callback locally, which unregisters the servant for the cancel message and assumes that
+        // cancellation will work, passing a Cancelled status, even if cancellation throws in the scope.
+        // But, removing the servant may be slow, allowing the finished message below to occasionally
+        // reach the client. If it does, we want the same completion status that we get if the
+        // local short-cut call hasn't done the job yet.
+        reply_->finished(CompletionDetails(CompletionDetails::Cancelled, ""));
+    }
+    catch (...)
+    {
+        BOOST_LOG(info.mw->runtime()->logger()) << "QueryBase::cancelled(): unknown exception";
+        // Same caveat as for std::exception here.
+        reply_->finished(CompletionDetails(CompletionDetails::Cancelled, ""));
+    }
 }
 
 bool QueryObject::pushable(InvokeInfo const& /* info */) const noexcept

=== modified file 'src/scopes/internal/ReplyObject.cpp'
--- src/scopes/internal/ReplyObject.cpp	2014-12-10 02:05:26 +0000
+++ src/scopes/internal/ReplyObject.cpp	2015-02-04 05:47:34 +0000
@@ -40,19 +40,20 @@
 namespace internal
 {
 
-ReplyObject::ReplyObject(ListenerBase::SPtr const& receiver_base, RuntimeImpl const* runtime,
-                         std::string const& scope_proxy, bool dont_reap) :
-    runtime_(runtime),
-    listener_base_(receiver_base),
-    finished_(false),
-    origin_proxy_(scope_proxy),
-    num_push_(0),
-    info_occurred_(false)
+ReplyObject::ReplyObject(ListenerBase::SPtr const& receiver_base,
+                         RuntimeImpl const* runtime,
+                         std::string const& scope_proxy,
+                         bool dont_reap)
+    : runtime_(runtime)
+    , listener_base_(receiver_base)
+    , finished_(false)
+    , origin_proxy_(scope_proxy)
+    , num_push_(0)
 {
     assert(receiver_base);
     assert(runtime);
 
-    if (dont_reap == false)
+    if (!dont_reap)
     {
         unique_lock<mutex> lock(mutex_);  // Make sure that when lambda fires, it sees current values.
         reap_item_ = runtime->reply_reaper()->add([this] {
@@ -134,12 +135,11 @@
     // Safe to call finished now if something went wrong or cardinality was exceeded.
     if (!error.empty())
     {
-        // TODO: log error
+        BOOST_LOG(runtime_->logger()) << "ReplyObject::push(): " << error;
         finished(CompletionDetails(CompletionDetails::Error, error));
     }
     else if (stop)
     {
-        // TODO: log error
         finished(CompletionDetails(CompletionDetails::OK));
     }
 }
@@ -171,7 +171,6 @@
     unique_lock<mutex> lock(mutex_);
     assert(num_push_ >= 0);
     idle_.wait(lock, [this] { return num_push_ == 0; });
-    lock.unlock(); // Inform the application code that the query is complete outside synchronization.
     try
     {
         CompletionDetails details_with_info(details);
@@ -179,6 +178,7 @@
         {
             details_with_info.add_info(info);
         }
+        lock.unlock(); // Inform the application code that the query is complete outside synchronization.
         listener_base_->finished(details_with_info);
     }
     catch (std::exception const& e)
@@ -208,11 +208,13 @@
     {
         reap_item_->refresh();
     }
-    info_occurred_.exchange(true);
 
     try
     {
-        info_list_.push_back(op_info);
+        {
+            unique_lock<mutex> lock(mutex_);
+            info_list_.push_back(op_info);
+        }
         listener_base_->info(op_info);
     }
     catch (std::exception const& e)

=== modified file 'src/scopes/internal/ScopeObject.cpp'
--- src/scopes/internal/ScopeObject.cpp	2015-01-26 08:20:45 +0000
+++ src/scopes/internal/ScopeObject.cpp	2015-02-04 05:47:34 +0000
@@ -59,7 +59,9 @@
 {
 }
 
-MWQueryCtrlProxy ScopeObject::query(MWReplyProxy const& reply, MiddlewareBase* mw_base,
+MWQueryCtrlProxy ScopeObject::query(MWReplyProxy const& reply,
+        MiddlewareBase* mw_base,
+        std::string const& method,
         std::function<QueryBase::SPtr()> const& query_factory_fun,
         std::function<QueryObjectBase::SPtr(QueryBase::SPtr, MWQueryCtrlProxy)> const& query_object_factory_fun)
 {
@@ -70,7 +72,8 @@
         // to be safe, we don't assert, in case someone is running a broken client.
 
         // TODO: log error about incoming request containing an invalid reply proxy.
-        throw LogicException("Scope \"" + mw_base->runtime()->scope_id() + "\": query() called with null reply proxy");
+        throw LogicException("Scope \"" + mw_base->runtime()->scope_id() + "\": "
+                             + method + " called with null reply proxy");
     }
 
     // Ask scope to instantiate a new query.
@@ -80,7 +83,7 @@
         query_base = query_factory_fun();
         if (!query_base)
         {
-            string msg = "Scope \"" + mw_base->runtime()->scope_id() + "\" returned nullptr from query_factory_fun()";
+            string msg = "Scope \"" + mw_base->runtime()->scope_id() + "\" returned nullptr from " + method + "()";
             BOOST_LOG(mw_base->runtime()->logger()) << msg;
             throw ResourceException(msg);
         }
@@ -88,7 +91,7 @@
     }
     catch (...)
     {
-        string msg = "Scope \"" + mw_base->runtime()->scope_id() + "\" threw an exception from query_factory_fun()";
+        string msg = "Scope \"" + mw_base->runtime()->scope_id() + "\" threw an exception from " + method + "()";
         BOOST_LOG(mw_base->runtime()->logger()) << msg;
         throw ResourceException(msg);
     }
@@ -151,45 +154,47 @@
                                      MWReplyProxy const& reply,
                                      InvokeInfo const& info)
 {
-    return query(reply, info.mw,
-            [&q, &hints, &context, this]() -> SearchQueryBase::UPtr {
-                 auto search_query = this->scope_base_->search(q, hints);
-                 search_query->set_department_id(q.department_id());
-
-                 auto sqb = dynamic_cast<SearchQueryBaseImpl*>(search_query->fwd());
-                 assert(sqb);
-
-                 // Set client ID and history that we received in the SearchQueryBase
-                 // for loop detection.
-                 auto const c_it = context.find("client_id");
-                 if (c_it != context.end())
-                 {
-                     string client_id;
-                     client_id = c_it->second.get_string();
-                     sqb->set_client_id(client_id);
-                 }
-
-                 auto const h_it = context.find("history");
-                 if (h_it != context.end())
-                 {
-                    auto const hlist = h_it->second.get_array();
-                    SearchQueryBaseImpl::History history;
-                    for (auto const& t : hlist)
-                    {
-                        string client_id = t.get_dict()["c"].get_string();
-                        string agg = t.get_dict()["a"].get_string();
-                        string recv = t.get_dict()["r"].get_string();
-                        SearchQueryBaseImpl::HistoryData hd = make_tuple(client_id, agg, recv);
-                        history.push_back(hd);
-                    }
-                    sqb->set_history(history);
-                 }
-
-                 return search_query;
-            },
-            [&reply, &hints, this](QueryBase::SPtr query_base, MWQueryCtrlProxy ctrl_proxy) -> QueryObjectBase::SPtr {
-                return make_shared<QueryObject>(query_base, hints.cardinality(), reply, ctrl_proxy);
-            }
+    return query(reply,
+                 info.mw,
+                 "search",
+                 [&q, &hints, &context, this]() -> SearchQueryBase::UPtr {
+                      auto search_query = this->scope_base_->search(q, hints);
+                      search_query->set_department_id(q.department_id());
+
+                      auto sqb = dynamic_cast<SearchQueryBaseImpl*>(search_query->fwd());
+                      assert(sqb);
+
+                      // Set client ID and history that we received in the SearchQueryBase
+                      // for loop detection.
+                      auto const c_it = context.find("client_id");
+                      if (c_it != context.end())
+                      {
+                          string client_id;
+                          client_id = c_it->second.get_string();
+                          sqb->set_client_id(client_id);
+                      }
+
+                      auto const h_it = context.find("history");
+                      if (h_it != context.end())
+                      {
+                         auto const hlist = h_it->second.get_array();
+                         SearchQueryBaseImpl::History history;
+                         for (auto const& t : hlist)
+                         {
+                             string client_id = t.get_dict()["c"].get_string();
+                             string agg = t.get_dict()["a"].get_string();
+                             string recv = t.get_dict()["r"].get_string();
+                             SearchQueryBaseImpl::HistoryData hd = make_tuple(client_id, agg, recv);
+                             history.push_back(hd);
+                         }
+                         sqb->set_history(history);
+                      }
+
+                      return search_query;
+                 },
+                 [&reply, &hints, this](QueryBase::SPtr query_base, MWQueryCtrlProxy ctrl_proxy) -> QueryObjectBase::SPtr {
+                     return make_shared<QueryObject>(query_base, hints.cardinality(), reply, ctrl_proxy);
+                 }
     );
 }
 
@@ -198,15 +203,17 @@
                                            MWReplyProxy const& reply,
                                            InvokeInfo const& info)
 {
-    return query(reply, info.mw,
-            [&result, &hints, this]() -> QueryBase::SPtr {
-                return this->scope_base_->activate(result, hints);
-            },
-            [&reply, this](QueryBase::SPtr query_base, MWQueryCtrlProxy ctrl_proxy) -> QueryObjectBase::SPtr {
-                auto activation_base = dynamic_pointer_cast<ActivationQueryBase>(query_base);
-                assert(activation_base);
-                return make_shared<ActivationQueryObject>(activation_base, reply, ctrl_proxy);
-            }
+    return query(reply,
+                 info.mw,
+                 "activate",
+                 [&result, &hints, this]() -> QueryBase::SPtr {
+                     return this->scope_base_->activate(result, hints);
+                 },
+                 [&reply, this](QueryBase::SPtr query_base, MWQueryCtrlProxy ctrl_proxy) -> QueryObjectBase::SPtr {
+                     auto activation_base = dynamic_pointer_cast<ActivationQueryBase>(query_base);
+                     assert(activation_base);
+                     return make_shared<ActivationQueryObject>(activation_base, reply, ctrl_proxy);
+                 }
     );
 }
 
@@ -217,15 +224,17 @@
                                              MWReplyProxy const &reply,
                                              InvokeInfo const& info)
 {
-    return query(reply, info.mw,
-            [&result, &hints, &widget_id, &action_id, this]() -> QueryBase::SPtr {
-                return this->scope_base_->perform_action(result, hints, widget_id, action_id);
-            },
-            [&reply, this](QueryBase::SPtr query_base, MWQueryCtrlProxy ctrl_proxy) -> QueryObjectBase::SPtr {
-                auto activation_base = dynamic_pointer_cast<ActivationQueryBase>(query_base);
-                assert(activation_base);
-                return make_shared<ActivationQueryObject>(activation_base, reply, ctrl_proxy);
-            }
+    return query(reply,
+                 info.mw,
+                 "perform_action",
+                 [&result, &hints, &widget_id, &action_id, this]() -> QueryBase::SPtr {
+                     return this->scope_base_->perform_action(result, hints, widget_id, action_id);
+                 },
+                 [&reply, this](QueryBase::SPtr query_base, MWQueryCtrlProxy ctrl_proxy) -> QueryObjectBase::SPtr {
+                     auto activation_base = dynamic_pointer_cast<ActivationQueryBase>(query_base);
+                     assert(activation_base);
+                     return make_shared<ActivationQueryObject>(activation_base, reply, ctrl_proxy);
+                 }
     );
 }
 
@@ -234,15 +243,17 @@
                                       MWReplyProxy const& reply,
                                       InvokeInfo const& info)
 {
-    return query(reply, info.mw,
-            [&result, &hints, this]() -> QueryBase::SPtr {
-                return this->scope_base_->preview(result, hints);
-            },
-            [&reply, this](QueryBase::SPtr query_base, MWQueryCtrlProxy ctrl_proxy) -> QueryObjectBase::SPtr {
-                auto preview_query = dynamic_pointer_cast<PreviewQueryBase>(query_base);
-                assert(preview_query);
-                return make_shared<PreviewQueryObject>(preview_query, reply, ctrl_proxy);
-            }
+    return query(reply,
+                 info.mw,
+                 "preview",
+                 [&result, &hints, this]() -> QueryBase::SPtr {
+                     return this->scope_base_->preview(result, hints);
+                 },
+                 [&reply, this](QueryBase::SPtr query_base, MWQueryCtrlProxy ctrl_proxy) -> QueryObjectBase::SPtr {
+                     auto preview_query = dynamic_pointer_cast<PreviewQueryBase>(query_base);
+                     assert(preview_query);
+                     return make_shared<PreviewQueryObject>(preview_query, reply, ctrl_proxy);
+                 }
     );
 }
 

=== modified file 'test/gtest/scopes/CMakeLists.txt'
--- test/gtest/scopes/CMakeLists.txt	2015-01-26 08:20:45 +0000
+++ test/gtest/scopes/CMakeLists.txt	2015-02-04 05:47:34 +0000
@@ -35,6 +35,7 @@
 add_subdirectory(Runtime)
 add_subdirectory(ScopeBase)
 add_subdirectory(ScopeExceptions)
+add_subdirectory(ThrowingScope)
 add_subdirectory(Variant)
 add_subdirectory(VariantBuilder)
 add_subdirectory(Version)

=== added directory 'test/gtest/scopes/ThrowingScope'
=== added file 'test/gtest/scopes/ThrowingScope/CMakeLists.txt'
--- test/gtest/scopes/ThrowingScope/CMakeLists.txt	1970-01-01 00:00:00 +0000
+++ test/gtest/scopes/ThrowingScope/CMakeLists.txt	2015-02-04 05:47:34 +0000
@@ -0,0 +1,26 @@
+configure_file(TestRegistry.ini.in ${CMAKE_CURRENT_BINARY_DIR}/TestRegistry.ini)
+configure_file(Runtime.ini.in ${CMAKE_CURRENT_BINARY_DIR}/Runtime.ini)
+configure_file(Zmq.ini.in ${CMAKE_CURRENT_BINARY_DIR}/Zmq.ini)
+
+add_definitions(-DTEST_RUNTIME_PATH="${CMAKE_CURRENT_BINARY_DIR}")
+add_definitions(-DTEST_RUNTIME_FILE="${CMAKE_CURRENT_BINARY_DIR}/Runtime.ini")
+add_definitions(-DTEST_REGISTRY_PATH="${PROJECT_BINARY_DIR}/scoperegistry")
+
+add_executable(ThrowingScope_test ThrowingScope_test.cpp ThrowingScope.cpp)
+target_link_libraries(ThrowingScope_test ${TESTLIBS})
+
+add_dependencies(ThrowingScope_test scoperegistry scoperunner)
+
+add_test(ThrowingScope ThrowingScope_test)
+
+set(SCOPE_DIR "${CMAKE_CURRENT_BINARY_DIR}/scopes")
+
+foreach (scope ThrowingScope)
+    file(MAKE_DIRECTORY "${SCOPE_DIR}/${scope}")
+    configure_file(ThrowingScope.ini.in ${SCOPE_DIR}/${scope}/${scope}.ini)
+    add_library(${scope} MODULE ThrowingScope.cpp)
+    set_target_properties(${scope}
+      PROPERTIES
+        LIBRARY_OUTPUT_DIRECTORY "${SCOPE_DIR}/${scope}/"
+    )
+endforeach()

=== added file 'test/gtest/scopes/ThrowingScope/Runtime.ini.in'
--- test/gtest/scopes/ThrowingScope/Runtime.ini.in	1970-01-01 00:00:00 +0000
+++ test/gtest/scopes/ThrowingScope/Runtime.ini.in	2015-02-04 05:47:34 +0000
@@ -0,0 +1,7 @@
+[Runtime]
+Registry.Identity = TestRegistry
+Registry.ConfigFile = @CMAKE_CURRENT_BINARY_DIR@/TestRegistry.ini
+Default.Middleware = Zmq
+Zmq.ConfigFile = @CMAKE_CURRENT_BINARY_DIR@/Zmq.ini
+Smartscopes.Registry.Identity =
+LogDir=

=== added file 'test/gtest/scopes/ThrowingScope/TestRegistry.ini.in'
--- test/gtest/scopes/ThrowingScope/TestRegistry.ini.in	1970-01-01 00:00:00 +0000
+++ test/gtest/scopes/ThrowingScope/TestRegistry.ini.in	2015-02-04 05:47:34 +0000
@@ -0,0 +1,7 @@
+[Registry]
+Middleware = Zmq
+Zmq.ConfigFile = @CMAKE_CURRENT_BINARY_DIR@/Zmq.ini
+Scope.InstallDir = @CMAKE_CURRENT_BINARY_DIR@/scopes
+OEM.InstallDir = /unused
+Click.InstallDir = @CMAKE_CURRENT_BINARY_DIR@/click
+Scoperunner.Path = @PROJECT_BINARY_DIR@/scoperunner/scoperunner

=== added file 'test/gtest/scopes/ThrowingScope/ThrowingScope.cpp'
--- test/gtest/scopes/ThrowingScope/ThrowingScope.cpp	1970-01-01 00:00:00 +0000
+++ test/gtest/scopes/ThrowingScope/ThrowingScope.cpp	2015-02-04 05:47:34 +0000
@@ -0,0 +1,273 @@
+/*
+ * Copyright (C) 2015 Canonical Ltd
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authored by: Michi Henning <[e-mail]>
+ */
+
+#include "ThrowingScope.h"
+
+#include <unity/scopes/ActionMetadata.h>
+#include <unity/scopes/CategorisedResult.h>
+#include <unity/scopes/ScopeBase.h>
+#include <unity/scopes/SearchReply.h>
+
+#include <unity/UnityExceptions.h>
+#include <unity/util/FileIO.h>
+
+#include <condition_variable>
+#include <mutex>
+#include <thread>
+
+using namespace std;
+using namespace unity;
+using namespace unity::scopes;
+
+namespace
+{
+
+class TestQuery : public SearchQueryBase
+{
+public:
+    TestQuery(CannedQuery const& query,
+              SearchMetadata const& metadata,
+              string const& id)
+        : SearchQueryBase(query, metadata)
+        , id_(id)
+        , query_cancelled_(false)
+    {
+    }
+
+    virtual void cancelled() override
+    {
+        if (query().query_string() == "throw from cancelled")
+        {
+            lock_guard<mutex> lock(mutex_);
+            query_cancelled_ = true;
+            cond_.notify_all();
+            throw ResourceException("exception from cancelled");
+        }
+    }
+
+    virtual void run(SearchReplyProxy const& reply) override
+    {
+        string query_string = query().query_string();
+        if (query_string ==  "throw from run")
+        {
+            throw ResourceException("exception from run");
+        }
+        else if (query_string == "throw from cancelled")
+        {
+            unique_lock<mutex> lock(mutex_);
+            cond_.wait(lock, [this] { return this->query_cancelled_; });
+            return;
+        }
+        auto cat = reply->register_category(id_, "", "");
+        CategorisedResult res(cat);
+        res.set_uri("uri");
+        res.set_title(query_string);
+        res.set_intercept_activation();
+        if (valid())
+        {
+            reply->push(res);
+        }
+        // Need to wait a while here, to make sure that the exception thrown from cancelled()
+        // is picked up by the runtime and the cancelled message is sent back to the client.
+        // If we don't do this, a successful completion message will be sent as soon as
+        // we return from here, and that might happen before the runtime has managed to send the
+        // cancelled message, causing the test to fail because then we see successful
+        // completion instead of cancelled completion.
+        this_thread::sleep_for(chrono::milliseconds(200));
+    }
+
+private:
+    string id_;
+    bool query_cancelled_;
+    mutex mutex_;
+    condition_variable cond_;
+};
+
+class TestPreview : public PreviewQueryBase
+{
+public:
+    TestPreview(Result const& result, ActionMetadata const& metadata)
+        : PreviewQueryBase(result, metadata)
+        , result_(result)
+        , preview_cancelled_(false)
+    {
+    }
+
+    virtual void cancelled() override
+    {
+        if (result_.title() == "throw from preview cancelled")
+        {
+            lock_guard<mutex> lock(mutex_);
+            preview_cancelled_ = true;
+            cond_.notify_all();
+            throw ResourceException("exception from preview cancelled");
+        }
+    }
+
+    virtual void run(PreviewReplyProxy const&) override
+    {
+        if (result_.title() == "throw from preview run")
+        {
+            throw ResourceException(result_.title());
+        }
+        else if (result_.title() == "throw from preview cancelled")
+        {
+            unique_lock<mutex> lock(mutex_);
+            cond_.wait(lock, [this] { return this->preview_cancelled_; });
+            // Need to wait a while here, to make sure that the exception thrown from cancelled()
+            // is picked up by the runtime and the cancelled message is sent back to the client.
+            // If we don't do this, a successful completion message will be sent as soon as
+            // we return from here, and that might happen before the runtime has managed to send the
+            // cancelled message, causing the test to fail because then we see successful
+            // completion instead of cancelled completion.
+            this_thread::sleep_for(chrono::milliseconds(200));
+        }
+    }
+
+private:
+    Result result_;
+    bool preview_cancelled_;
+    mutex mutex_;
+    condition_variable cond_;
+};
+
+class TestActivation : public ActivationQueryBase
+{
+public:
+    TestActivation(Result const& result, ActionMetadata const& metadata)
+        : ActivationQueryBase(result, metadata)
+        , result_(result)
+        , activate_cancelled_(false)
+    {
+    }
+
+    virtual void cancelled() override
+    {
+        if (result_.title() == "throw from activation cancelled")
+        {
+            lock_guard<mutex> lock(mutex_);
+            activate_cancelled_ = true;
+            cond_.notify_all();
+            throw ResourceException("exception from activation cancelled");
+        }
+    }
+
+    virtual ActivationResponse activate() override
+    {
+        if (result_.title() == "throw from activation activate")
+        {
+            throw ResourceException(result_.title());
+        }
+        else if (result_.title() == "throw from activation cancelled")
+        {
+            unique_lock<mutex> lock(mutex_);
+            cond_.wait(lock, [this] { return this->activate_cancelled_; });
+            // Need to wait a while here, to make sure that the exception thrown from cancelled()
+            // is picked up by the runtime and the cancelled message is sent back to the client.
+            // If we don't do this, a successful completion message will be sent as soon as
+            // we return from here, and that might happen before the runtime has managed to send the
+            // cancelled message, causing the test to fail because then we see successful
+            // completion instead of cancelled completion.
+            this_thread::sleep_for(chrono::milliseconds(200));
+        }
+        return ActivationResponse(ActivationResponse::NotHandled);
+    }
+
+private:
+    Result result_;
+    bool activate_cancelled_;
+    mutex mutex_;
+    condition_variable cond_;
+};
+
+}  // namespace
+
+void ThrowingScope::start(string const& scope_id)
+{
+    lock_guard<mutex> lock(mutex_);
+    id_ = scope_id;
+}
+
+void ThrowingScope::stop()
+{
+}
+
+void ThrowingScope::run()
+{
+}
+
+SearchQueryBase::UPtr ThrowingScope::search(CannedQuery const& query, SearchMetadata const& metadata)
+{
+    if (query.query_string() == "throw from search")
+    {
+        throw ResourceException("exception from search");
+    }
+    lock_guard<mutex> lock(mutex_);
+    return SearchQueryBase::UPtr(new TestQuery(query, metadata, id_));
+}
+
+PreviewQueryBase::UPtr ThrowingScope::preview(Result const& result, ActionMetadata const& metadata)
+{
+    if (result.title() == "throw from preview")
+    {
+        throw ResourceException("exception from preview");
+    }
+    lock_guard<mutex> lock(mutex_);
+    return PreviewQueryBase::UPtr(new TestPreview(result, metadata));
+}
+
+ActivationQueryBase::UPtr ThrowingScope::activate(Result const& result, ActionMetadata const& metadata)
+{
+    if (result.title() == "throw from activate")
+    {
+        throw ResourceException("exception from activate");
+    }
+    lock_guard<mutex> lock(mutex_);
+    return ActivationQueryBase::UPtr(new TestActivation(result, metadata));
+}
+
+ActivationQueryBase::UPtr ThrowingScope::perform_action(Result const& result,
+                                                        ActionMetadata const& metadata,
+                                                        string const& /* widget_id */,
+                                                        string const& /* action_id */)
+{
+    if (result.title() == "throw from perform_action")
+    {
+        throw ResourceException("exception from perform_action");
+    }
+    lock_guard<mutex> lock(mutex_);
+    return ActivationQueryBase::UPtr(new TestActivation(result, metadata));
+}
+
+extern "C"
+{
+
+    unity::scopes::ScopeBase*
+    // cppcheck-suppress unusedFunction
+    UNITY_SCOPE_CREATE_FUNCTION()
+    {
+        return new ThrowingScope;
+    }
+
+    void
+    // cppcheck-suppress unusedFunction
+    UNITY_SCOPE_DESTROY_FUNCTION(unity::scopes::ScopeBase* scope_base)
+    {
+        delete scope_base;
+    }
+}

=== added file 'test/gtest/scopes/ThrowingScope/ThrowingScope.h'
--- test/gtest/scopes/ThrowingScope/ThrowingScope.h	1970-01-01 00:00:00 +0000
+++ test/gtest/scopes/ThrowingScope/ThrowingScope.h	2015-02-04 05:47:34 +0000
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2015 Canonical Ltd
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authored by: Michi Henning <[e-mail]>
+ */
+
+#pragma once
+
+#include <unity/scopes/ScopeBase.h>
+
+class ThrowingScope : public unity::scopes::ScopeBase
+{
+public:
+    virtual void start(std::string const&) override;
+
+    virtual void stop() override;
+
+    virtual void run() override;
+
+    virtual unity::scopes::SearchQueryBase::UPtr search(unity::scopes::CannedQuery const &,
+                                                        unity::scopes::SearchMetadata const &) override;
+
+    virtual unity::scopes::PreviewQueryBase::UPtr preview(unity::scopes::Result const&,
+                                                          unity::scopes::ActionMetadata const &) override;
+
+    virtual unity::scopes::ActivationQueryBase::UPtr activate(unity::scopes::Result const&,
+                                                              unity::scopes::ActionMetadata const &) override;
+
+    virtual unity::scopes::ActivationQueryBase::UPtr perform_action(unity::scopes::Result const&,
+                                                                    unity::scopes::ActionMetadata const &,
+                                                                    std::string const &,
+                                                                    std::string const&) override;
+
+private:
+    std::string id_;
+    std::mutex mutex_;
+};

=== added file 'test/gtest/scopes/ThrowingScope/ThrowingScope.ini.in'
--- test/gtest/scopes/ThrowingScope/ThrowingScope.ini.in	1970-01-01 00:00:00 +0000
+++ test/gtest/scopes/ThrowingScope/ThrowingScope.ini.in	2015-02-04 05:47:34 +0000
@@ -0,0 +1,4 @@
+[ScopeConfig]
+DisplayName = LoopScope
+Description = Aggregator scope that makes various loops
+Author = Michi

=== added file 'test/gtest/scopes/ThrowingScope/ThrowingScope_test.cpp'
--- test/gtest/scopes/ThrowingScope/ThrowingScope_test.cpp	1970-01-01 00:00:00 +0000
+++ test/gtest/scopes/ThrowingScope/ThrowingScope_test.cpp	2015-02-04 05:47:34 +0000
@@ -0,0 +1,477 @@
+/*
+ * Copyright (C) 2015 Canonical Ltd
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authored by: Michi Henning <[e-mail]>
+ */
+
+#include <unity/scopes/CategorisedResult.h>
+#include <unity/scopes/internal/RegistryObject.h>
+#include <unity/scopes/internal/RuntimeImpl.h>
+#include <unity/scopes/internal/ScopeImpl.h>
+#include <unity/scopes/QueryCtrl.h>
+
+#include <gtest/gtest.h>
+
+#include "ThrowingScope.h"
+
+using namespace std;
+using namespace unity::scopes;
+using namespace unity::scopes::internal;
+
+class Receiver : public SearchListenerBase
+{
+public:
+    Receiver()
+        : query_complete_(false)
+    {
+    }
+
+    virtual void push(CategorisedResult result) override
+    {
+        lock_guard<mutex> lock(mutex_);
+
+        results_.push_back(move(result));
+    }
+
+    virtual void finished(CompletionDetails const& details) override
+    {
+        lock_guard<mutex> lock(mutex_);
+
+        completion_status_ = details.status();
+        completion_msg_ = details.message();
+        query_complete_ = true;
+        cond_.notify_one();
+    }
+
+    void wait_until_finished()
+    {
+        unique_lock<mutex> lock(mutex_);
+
+        cond_.wait(lock, [this] { return this->query_complete_; });
+        query_complete_ = false;
+    }
+
+    CompletionDetails::CompletionStatus completion_status()
+    {
+        lock_guard<mutex> lock(mutex_);
+
+        return completion_status_;
+    }
+
+    string completion_msg()
+    {
+        lock_guard<mutex> lock(mutex_);
+
+        return completion_msg_;
+    }
+
+    vector<CategorisedResult> results()
+    {
+        lock_guard<mutex> lock(mutex_);
+
+        return results_;
+    }
+
+private:
+    vector<CategorisedResult> results_;
+    bool query_complete_;
+    string completion_msg_;
+    CompletionDetails::CompletionStatus completion_status_;
+    mutex mutex_;
+    condition_variable cond_;
+};
+
+class PreviewListener : public PreviewListenerBase
+{
+public:
+    PreviewListener()
+        : preview_complete_(false)
+    {
+    }
+
+    void finished(const unity::scopes::CompletionDetails& details) override
+    {
+        lock_guard<mutex> lock(mutex_);
+
+        completion_status_ = details.status();
+        completion_msg_ = details.message();
+        preview_complete_ = true;
+        cond_.notify_one();
+    }
+
+    void wait_until_finished()
+    {
+        unique_lock<mutex> lock(mutex_);
+
+        cond_.wait(lock, [this] { return this->preview_complete_; });
+        preview_complete_ = false;
+    }
+
+    CompletionDetails::CompletionStatus completion_status()
+    {
+        lock_guard<mutex> lock(mutex_);
+
+        return completion_status_;
+    }
+
+    string completion_msg()
+    {
+        lock_guard<mutex> lock(mutex_);
+
+        return completion_msg_;
+    }
+
+    void push(ColumnLayoutList const&) override
+    {
+    }
+
+    void push(PreviewWidgetList const&) override
+    {
+    }
+
+    void push(std::string const&, Variant const&) override
+    {
+    }
+
+private:
+    bool preview_complete_;
+    string completion_msg_;
+    CompletionDetails::CompletionStatus completion_status_;
+    mutex mutex_;
+    condition_variable cond_;
+};
+
+class ActivationListener : public ActivationListenerBase
+{
+public:
+    ActivationListener()
+        : activate_complete_(false)
+    {
+    }
+
+    void activated(ActivationResponse const& response) override
+    {
+        lock_guard<mutex> lock(mutex_);
+
+        act_status_ = response.status();
+    }
+
+    void finished(const unity::scopes::CompletionDetails& details) override
+    {
+        lock_guard<mutex> lock(mutex_);
+
+        completion_status_ = details.status();
+        completion_msg_ = details.message();
+        activate_complete_ = true;
+        cond_.notify_one();
+    }
+
+    void wait_until_finished()
+    {
+        unique_lock<mutex> lock(mutex_);
+
+        cond_.wait(lock, [this] { return this->activate_complete_; });
+        activate_complete_ = false;
+    }
+
+    CompletionDetails::CompletionStatus completion_status()
+    {
+        lock_guard<mutex> lock(mutex_);
+
+        return completion_status_;
+    }
+
+    string completion_msg()
+    {
+        lock_guard<mutex> lock(mutex_);
+
+        return completion_msg_;
+    }
+
+private:
+    ActivationResponse::Status act_status_;
+    bool activate_complete_;
+    string completion_msg_;
+    CompletionDetails::CompletionStatus completion_status_;
+    mutex mutex_;
+    condition_variable cond_;
+};
+
+class ThrowingScopeTest : public ::testing::Test
+{
+public:
+    ThrowingScopeTest()
+    {
+        runtime_ = Runtime::create(TEST_RUNTIME_FILE);
+        auto reg = runtime_->registry();
+        auto meta = reg->get_metadata("ThrowingScope");
+        scope_ = meta.proxy();
+    }
+
+    ScopeProxy scope() const
+    {
+        return scope_;
+    }
+
+private:
+    Runtime::UPtr runtime_;
+    ScopeProxy scope_;
+};
+
+// The command file for each scope is called A.cmd, B.cmd, etc. It contains scope IDs, one per
+// line. For each scope ID in its command file, the scope sends a subsearch to that scope.
+// Once a scope's subsearch completes, it pushes a single result with the scope's ID as the
+// category ID. This allows us to set up various callgraphs by writing to the various command files.
+
+TEST_F(ThrowingScopeTest, no_error)
+{
+    auto receiver = make_shared<Receiver>();
+    scope()->search("success", SearchMetadata("unused", "unused"), receiver);
+    receiver->wait_until_finished();
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::OK, receiver->completion_status());
+    EXPECT_EQ("", receiver->completion_msg());
+    auto r = receiver->results();
+    EXPECT_EQ(1, r.size());
+}
+
+TEST_F(ThrowingScopeTest, throw_from_search)
+{
+    auto receiver = make_shared<Receiver>();
+    scope()->search("throw from search", SearchMetadata("unused", "unused"), receiver);
+    receiver->wait_until_finished();
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::Error, receiver->completion_status());
+    EXPECT_EQ("unity::scopes::MiddlewareException: unity::ResourceException: Scope \"ThrowingScope\" "
+                  "threw an exception from search():\n"
+                  "    unity::ResourceException: exception from search",
+              receiver->completion_msg());
+    auto r = receiver->results();
+    EXPECT_EQ(0, r.size());
+}
+
+TEST_F(ThrowingScopeTest, throw_from_run)
+{
+    auto receiver = make_shared<Receiver>();
+    scope()->search("throw from run", SearchMetadata("unused", "unused"), receiver);
+    receiver->wait_until_finished();
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::Error, receiver->completion_status());
+    EXPECT_EQ("QueryBase::run(): unity::ResourceException: exception from run", receiver->completion_msg());
+    auto r = receiver->results();
+    EXPECT_EQ(0, r.size());
+}
+
+TEST_F(ThrowingScopeTest, throw_from_cancelled)
+{
+    auto receiver = make_shared<Receiver>();
+    auto ctrl = scope()->search("throw from cancelled", SearchMetadata("unused", "unused"), receiver);
+    // Make sure that the cancel goes to the scope instead of being cached locally.
+    this_thread::sleep_for(chrono::seconds(1));
+    ctrl->cancel();
+    receiver->wait_until_finished();
+
+    auto r = receiver->results();
+    EXPECT_EQ(0, r.size());
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::Cancelled, receiver->completion_status());
+    // No exception string here because we short-cut the cancellation on the client side.
+    // The exception is logged though.
+    EXPECT_EQ("", receiver->completion_msg());
+}
+
+TEST_F(ThrowingScopeTest, throw_from_preview)
+{
+    auto receiver = make_shared<Receiver>();
+    scope()->search("throw from preview", SearchMetadata("unused", "unused"), receiver);
+    receiver->wait_until_finished();
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::OK, receiver->completion_status());
+    EXPECT_EQ("", receiver->completion_msg());
+    auto r = receiver->results();
+    EXPECT_EQ(1, r.size());
+
+    auto plistener = make_shared<PreviewListener>();
+    scope()->preview(r[0], ActionMetadata("unused", "unused"), plistener);
+    plistener->wait_until_finished();
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::Error, plistener->completion_status());
+    EXPECT_EQ("unity::scopes::MiddlewareException: unity::ResourceException: Scope \"ThrowingScope\" "
+                  "threw an exception from preview():\n"
+                  "    unity::ResourceException: exception from preview",
+              plistener->completion_msg());
+}
+
+TEST_F(ThrowingScopeTest, throw_from_preview_run)
+{
+    auto receiver = make_shared<Receiver>();
+    scope()->search("throw from preview run", SearchMetadata("unused", "unused"), receiver);
+    receiver->wait_until_finished();
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::OK, receiver->completion_status());
+    EXPECT_EQ("", receiver->completion_msg());
+    auto r = receiver->results();
+    EXPECT_EQ(1, r.size());
+
+    auto plistener = make_shared<PreviewListener>();
+    scope()->preview(r[0], ActionMetadata("unused", "unused"), plistener);
+    plistener->wait_until_finished();
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::Error, plistener->completion_status());
+    EXPECT_EQ("PreviewQueryBase::run(): unity::ResourceException: throw from preview run", plistener->completion_msg());
+}
+
+TEST_F(ThrowingScopeTest, throw_from_preview_cancelled)
+{
+    auto receiver = make_shared<Receiver>();
+    scope()->search("throw from preview cancelled", SearchMetadata("unused", "unused"), receiver);
+    receiver->wait_until_finished();
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::OK, receiver->completion_status());
+    EXPECT_EQ("", receiver->completion_msg());
+    auto r = receiver->results();
+    EXPECT_EQ(1, r.size());
+
+    auto plistener = make_shared<PreviewListener>();
+    auto ctrl = scope()->preview(r[0], ActionMetadata("unused", "unused"), plistener);
+    this_thread::sleep_for(chrono::seconds(1));
+    ctrl->cancel();
+    plistener->wait_until_finished();
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::Cancelled, plistener->completion_status());
+    // No exception string here because we short-cut the cancellation on the client side.
+    // The exception is logged though.
+    EXPECT_EQ("", plistener->completion_msg());
+}
+
+TEST_F(ThrowingScopeTest, throw_from_activate)
+{
+    auto receiver = make_shared<Receiver>();
+    scope()->search("throw from activate", SearchMetadata("unused", "unused"), receiver);
+    receiver->wait_until_finished();
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::OK, receiver->completion_status());
+    EXPECT_EQ("", receiver->completion_msg());
+    auto r = receiver->results();
+    EXPECT_EQ(1, r.size());
+
+    auto alistener = make_shared<ActivationListener>();
+    scope()->activate(r[0], ActionMetadata("unused", "unused"), alistener);
+    alistener->wait_until_finished();
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::Error, alistener->completion_status());
+    EXPECT_EQ("unity::scopes::MiddlewareException: unity::ResourceException: Scope \"ThrowingScope\" "
+                  "threw an exception from activate():\n"
+                  "    unity::ResourceException: exception from activate",
+              alistener->completion_msg());
+}
+
+TEST_F(ThrowingScopeTest, throw_from_activation_activate)
+{
+    auto receiver = make_shared<Receiver>();
+    scope()->search("throw from activation activate", SearchMetadata("unused", "unused"), receiver);
+    receiver->wait_until_finished();
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::OK, receiver->completion_status());
+    EXPECT_EQ("", receiver->completion_msg());
+    auto r = receiver->results();
+    EXPECT_EQ(1, r.size());
+
+    auto alistener = make_shared<ActivationListener>();
+    scope()->activate(r[0], ActionMetadata("unused", "unused"), alistener);
+    alistener->wait_until_finished();
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::Error, alistener->completion_status());
+    EXPECT_EQ("ActivationQueryBase::activate(): unity::ResourceException: throw from activation activate",
+              alistener->completion_msg());
+}
+
+TEST_F(ThrowingScopeTest, throw_from_activation_cancelled)
+{
+    auto receiver = make_shared<Receiver>();
+    scope()->search("throw from activation cancelled", SearchMetadata("unused", "unused"), receiver);
+    receiver->wait_until_finished();
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::OK, receiver->completion_status());
+    EXPECT_EQ("", receiver->completion_msg());
+    auto r = receiver->results();
+    EXPECT_EQ(1, r.size());
+
+    auto alistener = make_shared<ActivationListener>();
+    auto ctrl = scope()->activate(r[0], ActionMetadata("unused", "unused"), alistener);
+    this_thread::sleep_for(chrono::seconds(1));
+    ctrl->cancel();
+    alistener->wait_until_finished();
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::Cancelled, alistener->completion_status());
+    // No exception string here because we short-cut the cancellation on the client side.
+    // The exception is logged though.
+    EXPECT_EQ("", alistener->completion_msg());
+}
+
+TEST_F(ThrowingScopeTest, throw_from_perform_action)
+{
+    auto receiver = make_shared<Receiver>();
+    scope()->search("throw from perform_action", SearchMetadata("unused", "unused"), receiver);
+    receiver->wait_until_finished();
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::OK, receiver->completion_status());
+    EXPECT_EQ("", receiver->completion_msg());
+    auto r = receiver->results();
+    EXPECT_EQ(1, r.size());
+
+    auto alistener = make_shared<ActivationListener>();
+    scope()->perform_action(r[0], ActionMetadata("unused", "unused"), "", "", alistener);
+    alistener->wait_until_finished();
+
+    EXPECT_EQ(CompletionDetails::CompletionStatus::Error, alistener->completion_status());
+    EXPECT_EQ("unity::scopes::MiddlewareException: unity::ResourceException: Scope \"ThrowingScope\" "
+                  "threw an exception from perform_action():\n"
+                  "    unity::ResourceException: exception from perform_action",
+              alistener->completion_msg());
+}
+
+int main(int argc, char **argv)
+{
+    ::testing::InitGoogleTest(&argc, argv);
+
+    int rc = 0;
+
+    // Set the "TEST_DESKTOP_FILES_DIR" env var before forking as not to create desktop files in ~/.local
+    putenv(const_cast<char*>("TEST_DESKTOP_FILES_DIR=" TEST_RUNTIME_PATH));
+
+    auto rpid = fork();
+    if (rpid == 0)
+    {
+        const char* const args[] = {"scoperegistry [ThrowingScope_test]", TEST_RUNTIME_FILE, nullptr};
+        if (execv(TEST_REGISTRY_PATH "/scoperegistry", const_cast<char* const*>(args)) < 0)
+        {
+            perror("Error starting scoperegistry:");
+        }
+        return 1;
+    }
+    else if (rpid > 0)
+    {
+        rc = RUN_ALL_TESTS();
+        kill(rpid, SIGTERM);
+        waitpid(rpid, nullptr, 0);
+    }
+    else
+    {
+        perror("Failed to fork:");
+    }
+
+    return rc;
+}

=== added file 'test/gtest/scopes/ThrowingScope/Zmq.ini.in'
--- test/gtest/scopes/ThrowingScope/Zmq.ini.in	1970-01-01 00:00:00 +0000
+++ test/gtest/scopes/ThrowingScope/Zmq.ini.in	2015-02-04 05:47:34 +0000
@@ -0,0 +1,2 @@
+[Zmq]
+EndpointDir = /tmp