diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 2492982..a4e93b8 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,62 +1,64 @@
 set(kasync_SRCS
     async.cpp
     future.cpp
     debug.cpp
 )
 
 set(kasync_priv_HEADERS
     continuations_p.h
+    execution_p.h
+    executor_p.h
     async_impl.h
     job_impl.h
     debug.h
 )
 
 ecm_generate_headers(kasync_HEADERS
     HEADER_NAMES
     Async
     Future
     REQUIRED_HEADERS kasync_HEADERS
 )
 
 
 add_library(KAsync ${kasync_SRCS})
 
 generate_export_header(KAsync BASE_NAME kasync)
 
 target_include_directories(KAsync INTERFACE "$<INSTALL_INTERFACE:${KDE_INSTALL_INCLUDEDIR}/KAsync>")
 target_include_directories(KAsync PUBLIC "$<BUILD_INTERFACE:${KAsync_SOURCE_DIR}/src>")
 
 target_link_libraries(KAsync
     PUBLIC
         Qt5::Core
 )
 
 
 set_target_properties(KAsync PROPERTIES
     VERSION ${KASYNC_VERSION_STRING}
     SOVERSION ${KASYNC_SOVERSION}
     EXPORT_NAME KAsync
 )
 
 ecm_generate_pri_file(BASE_NAME KAsync
     LIB_NAME KAsync
     FILENAME_VAR PRI_FILENAME
 )
 
 install(TARGETS
     KAsync
     EXPORT KAsyncTargets ${KDE_INSTALL_TARGETS_DEFAULT_ARGS}
 )
 
 install(FILES
     ${CMAKE_CURRENT_BINARY_DIR}/kasync_export.h
     ${kasync_HEADERS}
     ${kasync_priv_HEADERS}
     DESTINATION ${KDE_INSTALL_INCLUDEDIR}/KAsync
     COMPONENT Devel
 )
 
 install(FILES
     ${PRI_FILENAME}
     DESTINATION ${ECM_MKSPECS_INSTALL_DIR}
 )
diff --git a/src/async.cpp b/src/async.cpp
index c762e2b..9cbf174 100644
--- a/src/async.cpp
+++ b/src/async.cpp
@@ -1,88 +1,63 @@
 /*
  * Copyright 2014  Daniel Vrátil <dvratil@redhat.com>
  * Copyright 2016  Christian Mollekopf <mollekopf@kolabsystems.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public License as
  * published by the Free Software Foundation; either version 2 of
  * the License, or (at your option) any later version.
  *
  * This library 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 Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library. If not, see <http://www.gnu.org/licenses/>.
  */
 
 #include "async.h"
 
 #include <QCoreApplication>
 #include <QDebug>
 #include <QEventLoop>
 #include <QTimer>
 
 using namespace KAsync;
 
-Private::Execution::Execution(const Private::ExecutorBasePtr &executor)
-    : executor(executor)
-{
-}
-
-Private::Execution::~Execution()
-{
-    if (resultBase) {
-        resultBase->releaseExecution();
-        delete resultBase;
-    }
-    prevExecution.reset();
-}
-
-void Private::Execution::setFinished()
-{
-    tracer.reset();
-}
-
-void Private::Execution::releaseFuture()
-{
-    resultBase = nullptr;
-}
-
-
 Job<void> KAsync::doWhile(const Job<ControlFlowFlag> &body)
 {
     return KAsync::start<void>([body] (KAsync::Future<void> &future) {
         auto job = body.then<void, ControlFlowFlag>([&future, body](const KAsync::Error &error, ControlFlowFlag flag) {
             if (error) {
                 future.setError(error);
                 future.setFinished();
             } else if (flag == ControlFlowFlag::Continue) {
                 doWhile(body).then<void>([&future](const KAsync::Error &error) {
                     if (error) {
                         future.setError(error);
                     }
                     future.setFinished();
                 }).exec();
             } else {
                 future.setFinished();
             }
         }).exec();
     });
 }
 
 Job<void> KAsync::doWhile(const JobContinuation<ControlFlowFlag> &body)
 {
     return doWhile(KAsync::start<ControlFlowFlag>([body] {
         return body();
     }));
 }
 
 Job<void> KAsync::wait(int delay)
 {
     return KAsync::start<void>([delay](KAsync::Future<void> &future) {
         QTimer::singleShot(delay, [&future]() {
             future.setFinished();
         });
     });
 }
diff --git a/src/async.h b/src/async.h
index 2cb5ae0..105f538 100644
--- a/src/async.h
+++ b/src/async.h
@@ -1,701 +1,583 @@
 /*
  * Copyright 2014 - 2015 Daniel Vrátil <dvratil@redhat.com>
  * Copyright 2016  Daniel Vrátil <dvratil@kde.org>
  * Copyright 2016  Christian Mollekopf <mollekopf@kolabsystems.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public License as
  * published by the Free Software Foundation; either version 2 of
  * the License, or (at your option) any later version.
  *
  * This library 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 Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library. If not, see <http://www.gnu.org/licenses/>.
  */
 
 #ifndef KASYNC_H
 #define KASYNC_H
 
 #include "kasync_export.h"
 
 #include <functional>
-#include <list>
 #include <type_traits>
 #include <cassert>
-#include <iterator>
-#include <memory>
 
 #include "future.h"
 #include "debug.h"
+
 #include "async_impl.h"
 #include "continuations_p.h"
+#include "executor_p.h"
 
-#include <QVector>
-#include <QObject>
-#include <QSharedPointer>
-#include <QPointer>
-
-#include <QDebug>
-
+class QObject;
 
 /**
  * @mainpage KAsync
  *
  * @brief API to help write async code.
  *
  * This API is based around jobs that take lambdas to execute asynchronous tasks.
  * Each async operation can take a continuation that can then be used to execute
  * further async operations. That way it is possible to build async chains of
  * operations that can be stored and executed later on. Jobs can be composed,
  * similarly to functions.
  *
  * Relations between the components:
  * * Job: API wrapper around Executors chain. Can be destroyed while still running,
  *        because the actual execution happens in the background
  * * Executor: Describes task to execute. Executors form a linked list matching the
  *        order in which they will be executed. The Executor chain is destroyed when
  *        the parent Job is destroyed. However if the Job is still running it is
  *        guaranteed that the Executor chain will not be destroyed until the execution
  *        is finished.
  * * Execution: The running execution of the task stored in Executor. Each call to
  *        Job::exec() instantiates new Execution chain, which makes it possible for
  *        the Job to be executed multiple times (even in parallel).
  * * Future: Representation of the result that is being calculated
  *
  *
  * TODO: Possibility to abort a job through future (perhaps optional?)
  * TODO: Support for timeout, specified during exec call, after which the error
  *       handler gets called with a defined errorCode.
  */
 
 
 namespace KAsync {
 
 template<typename PrevOut, typename Out, typename ... In>
 class Executor;
 
 class JobBase;
 
 template<typename Out, typename ... In>
 class Job;
 
-
-//@cond PRIVATE
-namespace Private
-{
-
-class ExecutorBase;
-typedef QSharedPointer<ExecutorBase> ExecutorBasePtr;
-
-class ExecutionContext;
-
-struct KASYNC_EXPORT Execution {
-    explicit Execution(const ExecutorBasePtr &executor);
-    virtual ~Execution();
-    void setFinished();
-
-    template<typename T>
-    KAsync::Future<T>* result() const
-    {
-        return static_cast<KAsync::Future<T>*>(resultBase);
-    }
-
-    void releaseFuture();
-
-    ExecutorBasePtr executor;
-    ExecutionPtr prevExecution;
-    std::unique_ptr<Tracer> tracer;
-    FutureBase *resultBase = nullptr;
-};
-
-typedef QSharedPointer<Execution> ExecutionPtr;
-
-class KASYNC_EXPORT ExecutorBase
-{
-    template<typename PrevOut, typename Out, typename ... In>
-    friend class Executor;
-
-    template<typename Out, typename ... In>
-    friend class KAsync::Job;
-
-    friend struct Execution;
-    friend class KAsync::Tracer;
-
-public:
-    virtual ~ExecutorBase() = default;
-    virtual ExecutionPtr exec(const ExecutorBasePtr &self, QSharedPointer<Private::ExecutionContext> context) = 0;
-
-protected:
-    ExecutorBase(const ExecutorBasePtr &parent)
-        : mPrev(parent)
-    {}
-
-    template<typename T>
-    KAsync::Future<T>* createFuture(const ExecutionPtr &execution) const;
-
-    ExecutorBasePtr mPrev;
-
-    void prepend(const ExecutorBasePtr &e)
-    {
-        if (mPrev) {
-            mPrev->prepend(e);
-        } else {
-            mPrev = e;
-        }
-    }
-
-    void addToContext(const QVariant &entry)
-    {
-        mContext << entry;
-    }
-
-    void guard(const QObject *o)
-    {
-        mGuards.append(QPointer<const QObject>{o});
-    }
-
-    QString mExecutorName;
-    QVector<QVariant> mContext;
-    QVector<QPointer<const QObject>> mGuards;
-};
-
-enum ExecutionFlag {
-    Always,
-    ErrorCase,
-    GoodCase
-};
-
-template<typename PrevOut, typename Out, typename ... In>
-class Executor : public ExecutorBase
-{
-protected:
-
-    Executor(const Private::ExecutorBasePtr &parent, ExecutionFlag executionFlag)
-        : ExecutorBase(parent)
-        , executionFlag(executionFlag)
-    {}
-
-    virtual ~Executor() {}
-    virtual void run(const ExecutionPtr &execution) = 0;
-
-    ExecutionPtr exec(const ExecutorBasePtr &self, QSharedPointer<Private::ExecutionContext> context) override;
-
-    const ExecutionFlag executionFlag;
-
-private:
-    void runExecution(const KAsync::Future<PrevOut> *prevFuture, const ExecutionPtr &execution, bool guardIsBroken);
-};
-
-} // namespace Private
-//@endcond
-
-
 template<typename Out, typename ... In>
 Job<Out, In ...> startImpl(Private::ContinuationHolder<Out, In ...> &&);
 
 template<typename Out, typename ... In>
 Job<Out, In ...> syncStartImpl(SyncContinuation<Out, In ...> &&);
 
 
 
 /**
  * @relates Job
  *
  * Start an asynchronous job sequence.
  *
  * start() is your starting point to build a chain of jobs to be executed
  * asynchronously.
  *
  * @param func A continuation to be executed.
  */
 
 ///Sync continuation without job: [] () -> T { ... }
 template<typename Out = void, typename ... In, typename F>
 auto start(F &&func) -> std::enable_if_t<!std::is_base_of<JobBase, decltype(func(std::declval<In>() ...))>::value,
                                          Job<decltype(func(std::declval<In>() ...)), In...>>
 {
     static_assert(sizeof...(In) <= 1, "Only one or zero input parameters are allowed.");
     return syncStartImpl<Out, In...>(std::forward<F>(func));
 }
 
 ///continuation with job: [] () -> KAsync::Job<...> { ... }
 template<typename Out = void, typename ... In, typename F>
 auto start(F &&func) -> std::enable_if_t<std::is_base_of<JobBase, decltype(func(std::declval<In>() ...))>::value,
                                          Job<typename decltype(func(std::declval<In>() ...))::OutType, In...>>
 {
     static_assert(sizeof...(In) <= 1, "Only one or zero input parameters are allowed.");
     return startImpl<Out, In...>(Private::ContinuationHolder<Out, In ...>(JobContinuation<Out, In...>(std::forward<F>(func))));
 }
 
 ///Handle continuation: [] (KAsync::Future<T>, ...) { ... }
 template<typename Out = void, typename ... In>
 auto start(AsyncContinuation<Out, In ...> &&func) -> Job<Out, In ...>
 {
     static_assert(sizeof...(In) <= 1, "Only one or zero input parameters are allowed.");
     return startImpl<Out, In...>(Private::ContinuationHolder<Out, In ...>(std::forward<AsyncContinuation<Out, In ...>>(func)));
 }
 
 enum ControlFlowFlag {
     Break,
     Continue
 };
 
 /**
  * @relates Job
  *
  * Async while loop.
  *
  * Loop continues while body returns ControlFlowFlag::Continue.
  */
 KASYNC_EXPORT Job<void> doWhile(const Job<ControlFlowFlag> &body);
 
 /**
  * @relates Job
  *
  * Async while loop.
  *
  * Shorthand that takes a continuation.
  *
  * @see doWhile
  */
 KASYNC_EXPORT Job<void> doWhile(const JobContinuation<ControlFlowFlag> &body);
 
 
 
 /**
  * @relates Job
  *
  * Async delay.
  */
 KASYNC_EXPORT Job<void> wait(int delay);
 
 /**
  * @relates Job
  *
  * A null job.
  *
  * An async noop.
  *
  */
 template<typename Out = void>
 Job<Out> null();
 
 /**
  * @relates Job
  *
  * Async value.
  */
 template<typename Out>
 Job<Out> value(Out);
 
 /**
  * @relates Job
  *
  * Async foreach loop.
  *
  * This will execute a job for every value in the list.
  * Errors while not stop processing of other jobs but set an error on the wrapper job.
  */
 template<typename List, typename ValueType = typename List::value_type>
 Job<void, List> forEach(KAsync::Job<void, ValueType> job);
 
 /**
  * @relates Job
  *
  * Async foreach loop.
  *
  * Shorthand that takes a continuation.
  *
  * @see serialForEach
  */
 template<typename List, typename ValueType = typename List::value_type>
  Job<void, List> forEach(JobContinuation<void, ValueType> &&);
 
 
 /**
  * @relates Job
  *
  * Serial Async foreach loop.
  *
  * This will execute a job for every value in the list sequentially.
  * Errors while not stop processing of other jobs but set an error on the wrapper job.
  */
 template<typename List, typename ValueType = typename List::value_type>
 Job<void, List> serialForEach(KAsync::Job<void, ValueType> job);
 
 /**
  * @relates Job
  *
  * Serial Async foreach loop.
  *
  * Shorthand that takes a continuation.
  *
  * @see serialForEach
  */
 template<typename List, typename ValueType = typename List::value_type>
 Job<void, List> serialForEach(JobContinuation<void, ValueType> &&);
 
 
 /**
  * @relates Job
  *
  * An error job.
  *
  * An async error.
  *
  */
 template<typename Out = void>
 Job<Out> error(int errorCode = 1, const QString &errorMessage = QString());
 
 /**
  * @relates Job
  *
  * An error job.
  *
  * An async error.
  *
  */
 template<typename Out = void>
 Job<Out> error(const char *);
 
 /**
  * @relates Job
  *
  * An error job.
  *
  * An async error.
  *
  */
 template<typename Out = void>
 Job<Out> error(const Error &);
 
 //@cond PRIVATE
 class KASYNC_EXPORT JobBase
 {
     template<typename Out, typename ... In>
     friend class Job;
 
 public:
     explicit JobBase(const Private::ExecutorBasePtr &executor)
         : mExecutor(executor)
     {}
 
     virtual ~JobBase() = default;
 
 protected:
     Private::ExecutorBasePtr mExecutor;
 };
 //@endcond
 
 /**
  * @brief An Asynchronous job
  *
  * A single instance of Job represents a single method that will be executed
  * asynchronously. The Job is started by exec(), which returns Future
  * immediatelly. The Future will be set to finished state once the asynchronous
  * task has finished. You can use Future::waitForFinished() to wait for
  * for the Future in blocking manner.
  *
  * It is possible to chain multiple Jobs one after another in different fashion
  * (sequential, parallel, etc.). Calling exec() will then return a pending
  * Future, and will execute the entire chain of jobs.
  *
  * @code
  * auto job = Job::start<QList<int>>(
  *     [](KAsync::Future<QList<int>> &future) {
  *         MyREST::PendingUsers *pu = MyREST::requestListOfUsers();
  *         QObject::connect(pu, &PendingOperation::finished,
  *                          [&](PendingOperation *pu) {
  *                              future->setValue(dynamic_cast<MyREST::PendingUsers*>(pu)->userIds());
  *                              future->setFinished();
  *                          });
  *      })
  * .each<QList<MyREST::User>, int>(
  *      [](const int &userId, KAsync::Future<QList<MyREST::User>> &future) {
  *          MyREST::PendingUser *pu = MyREST::requestUserDetails(userId);
  *          QObject::connect(pu, &PendingOperation::finished,
  *                           [&](PendingOperation *pu) {
  *                              future->setValue(Qlist<MyREST::User>() << dynamic_cast<MyREST::PendingUser*>(pu)->user());
  *                              future->setFinished();
  *                           });
  *      });
  *
  * KAsync::Future<QList<MyREST::User>> usersFuture = job.exec();
  * usersFuture.waitForFinished();
  * QList<MyRest::User> users = usersFuture.value();
  * @endcode
  *
  * In the example above, calling @p job.exec() will first invoke the first job,
  * which will retrieve a list of IDs and then will invoke the second function
  * for each single entry in the list returned by the first function.
  */
 template<typename Out, typename ... In>
 class Job : public JobBase
 {
     //@cond PRIVATE
     template<typename OutOther, typename ... InOther>
     friend class Job;
 
     template<typename OutOther, typename ... InOther>
     friend Job<OutOther, InOther ...> startImpl(Private::ContinuationHolder<OutOther, InOther ...> &&);
 
     template<typename OutOther, typename ... InOther>
     friend Job<OutOther, InOther ...> syncStartImpl(SyncContinuation<OutOther, InOther ...> &&);
 
     template<typename List, typename ValueType>
     friend  Job<void, List> forEach(KAsync::Job<void, ValueType> job);
 
     template<typename List, typename ValueType>
     friend Job<void, List> serialForEach(KAsync::Job<void, ValueType> job);
 
     // Used to disable implicit conversion of Job<void to Job<void> which triggers
     // comiler warning.
     struct IncompleteType;
     //@endcond
 
 public:
     typedef Out OutType;
 
     ///A continuation
     template<typename OutOther, typename ... InOther>
     Job<OutOther, In ...> then(const Job<OutOther, InOther ...> &job) const;
 
     ///Shorthands for a job that returns another job from it's continuation
     //
     //OutOther and InOther are only there fore backwards compatibility, but are otherwise ignored.
     //It should never be neccessary to specify any template arguments, as they are automatically deduced from the provided argument.
     //
     //We currently have to write a then overload for:
     //* One argument in the continuation
     //* No argument in the continuation
     //* One argument + error in the continuation
     //* No argument + error in the continuation
     //This is due to how we extract the return type with "decltype(func(std::declval<Out>()))".
     //Ideally we could conflate this into at least fewer overloads, but I didn't manage so far and this at least works as expected.
 
     ///Continuation returning job: [] (Arg) -> KAsync::Job<...> { ... }
     template<typename OutOther = void, typename ... InOther, typename F>
     auto then(F &&func) const -> std::enable_if_t<std::is_base_of<JobBase, decltype(func(std::declval<Out>()))>::value,
                                                   Job<typename decltype(func(std::declval<Out>()))::OutType, In...>>
     {
         using ResultJob = decltype(func(std::declval<Out>())); //Job<QString, int>
         return thenImpl<typename ResultJob::OutType, Out>(
                 {JobContinuation<typename ResultJob::OutType, Out>(std::forward<F>(func))}, Private::ExecutionFlag::GoodCase);
     }
 
     ///Void continuation with job: [] () -> KAsync::Job<...> { ... }
     template<typename OutOther = void, typename ... InOther, typename F>
     auto then(F &&func) const -> std::enable_if_t<std::is_base_of<JobBase, decltype(func())>::value,
                                                   Job<typename decltype(func())::OutType, In...>>
     {
         using ResultJob = decltype(func()); //Job<QString, void>
         return thenImpl<typename ResultJob::OutType>(
                 {JobContinuation<typename ResultJob::OutType>(std::forward<F>(func))}, Private::ExecutionFlag::GoodCase);
     }
 
     ///Error continuation returning job: [] (KAsync::Error, Arg) -> KAsync::Job<...> { ... }
     template<typename OutOther = void, typename ... InOther, typename F>
     auto then(F &&func) const -> std::enable_if_t<std::is_base_of<JobBase, decltype(func(KAsync::Error{}, std::declval<Out>()))>::value,
                                                   Job<typename decltype(func(KAsync::Error{}, std::declval<Out>()))::OutType, In...>>
     {
         using ResultJob = decltype(func(KAsync::Error{}, std::declval<Out>())); //Job<QString, int>
         return thenImpl<typename ResultJob::OutType, Out>(
                 {JobErrorContinuation<typename ResultJob::OutType, Out>(std::forward<F>(func))}, Private::ExecutionFlag::Always);
     }
 
     ///Error void continuation returning job: [] (KAsync::Error) -> KAsync::Job<...> { ... }
     template<typename OutOther = void, typename ... InOther, typename F>
     auto then(F &&func) const -> std::enable_if_t<std::is_base_of<JobBase, decltype(func(KAsync::Error{}))>::value,
                                                   Job<typename decltype(func(KAsync::Error{}))::OutType, In...>>
     {
         using ResultJob = decltype(func(KAsync::Error{}));
         return thenImpl<typename ResultJob::OutType>(
                 {JobErrorContinuation<typename ResultJob::OutType>(std::forward<F>(func))}, Private::ExecutionFlag::Always);
     }
 
     ///Sync continuation: [] (Arg) -> void { ... }
     template<typename OutOther = void, typename ... InOther, typename F>
     auto then(F &&func) const -> std::enable_if_t<!std::is_base_of<JobBase, decltype(func(std::declval<Out>()))>::value,
                                                   Job<decltype(func(std::declval<Out>())), In...>>
     {
         using ResultType = decltype(func(std::declval<Out>())); //QString
         return thenImpl<ResultType, Out>(
                 {SyncContinuation<ResultType, Out>(std::forward<F>(func))}, Private::ExecutionFlag::GoodCase);
     }
 
     ///Sync void continuation: [] () -> void { ... }
     template<typename OutOther = void, typename ... InOther, typename F>
     auto then(F &&func) const -> std::enable_if_t<!std::is_base_of<JobBase, decltype(func())>::value,
                                                   Job<decltype(func()), In...>>
     {
         using ResultType = decltype(func()); //QString
         return thenImpl<ResultType>(
                 {SyncContinuation<ResultType>(std::forward<F>(func))}, Private::ExecutionFlag::GoodCase);
     }
 
     ///Sync error continuation: [] (KAsync::Error, Arg) -> void { ... }
     template<typename OutOther = void, typename ... InOther, typename F>
     auto then(F &&func) const -> std::enable_if_t<!std::is_base_of<JobBase, decltype(func(KAsync::Error{}, std::declval<Out>()))>::value,
                                                   Job<decltype(func(KAsync::Error{}, std::declval<Out>())),In...>>
     {
         using ResultType = decltype(func(KAsync::Error{}, std::declval<Out>())); //QString
         return thenImpl<ResultType, Out>(
                 {SyncErrorContinuation<ResultType, Out>(std::forward<F>(func))}, Private::ExecutionFlag::Always);
     }
 
     ///Sync void error continuation: [] (KAsync::Error) -> void { ... }
     template<typename OutOther = void, typename ... InOther, typename F>
     auto then(F &&func) const -> std::enable_if_t<!std::is_base_of<JobBase, decltype(func(KAsync::Error{}))>::value,
                                                   Job<decltype(func(KAsync::Error{})), In...>>
     {
         using ResultType = decltype(func(KAsync::Error{}));
         return thenImpl<ResultType>(
                 {SyncErrorContinuation<ResultType>(std::forward<F>(func))}, Private::ExecutionFlag::Always);
     }
 
     ///Shorthand for a job that receives the error and a handle
     template<typename OutOther, typename ... InOther>
     Job<OutOther, In ...> then(AsyncContinuation<OutOther, InOther ...> &&func) const
     {
         return thenImpl<OutOther, InOther ...>({std::forward<AsyncContinuation<OutOther, InOther ...>>(func)},
                                                Private::ExecutionFlag::GoodCase);
     }
 
     ///Shorthand for a job that receives the error and a handle
     template<typename OutOther, typename ... InOther>
     Job<OutOther, In ...> then(AsyncErrorContinuation<OutOther, InOther ...> &&func) const
     {
         return thenImpl<OutOther, InOther ...>({std::forward<AsyncErrorContinuation<OutOther, InOther ...>>(func)}, Private::ExecutionFlag::Always);
     }
 
     ///Shorthand for a job that receives the error only
     Job<Out, In ...> onError(SyncErrorContinuation<void> &&errorFunc) const;
 
     /**
      * Shorthand for a forEach loop that automatically uses the return type of
      * this job to deduce the type exepected.
      */
     template<typename OutOther = void, typename ListType = Out, typename ValueType = typename ListType::value_type, std::enable_if_t<!std::is_void<ListType>::value, int> = 0>
     Job<void, In ...> each(JobContinuation<void, ValueType> &&func) const
     {
         eachInvariants<OutOther>();
         return then<void, In ...>(forEach<Out, ValueType>(std::forward<JobContinuation<void, ValueType>>(func)));
     }
 
     /**
      * Shorthand for a serialForEach loop that automatically uses the return type
      * of this job to deduce the type exepected.
      */
     template<typename OutOther = void, typename ListType = Out, typename ValueType = typename ListType::value_type, std::enable_if_t<!std::is_void<ListType>::value, int> = 0>
     Job<void, In ...> serialEach(JobContinuation<void, ValueType> &&func) const
     {
         eachInvariants<OutOther>();
         return then<void, In ...>(serialForEach<Out, ValueType>(std::forward<JobContinuation<void, ValueType>>(func)));
     }
 
     /**
      * Enable implicit conversion to Job<void>.
      *
      * This is necessary in assignments that only use the return value (which is the normal case).
      * This avoids constructs like:
      * auto job = KAsync::start<int>( ... )
      *  .then<void, int>( ... )
      *  .then<void>([](){}); //Necessary for the assignment without the implicit conversion
      */
     template<typename ... InOther>
     operator std::conditional_t<std::is_void<OutType>::value, IncompleteType, Job<void>>();
 
     /**
      * Adds an unnamed value to the context.
      * The context is guaranteed to persist until the jobs execution has finished.
      *
      * Useful for setting smart pointer to manage lifetime of objects required
      * during the execution of the job.
      */
     template<typename T>
     Job<Out, In ...> &addToContext(const T &value)
     {
         assert(mExecutor);
         mExecutor->addToContext(QVariant::fromValue<T>(value));
         return *this;
     }
 
     /**
      * Adds a guard.
      * It is guaranteed that no callback is executed after the guard vanishes.
      *
      * Use this i.e. ensure you don't call-back into an already destroyed object.
      */
     Job<Out, In ...> &guard(const QObject *o)
     {
         assert(mExecutor);
         mExecutor->guard(o);
         return *this;
     }
 
     /**
      * @brief Starts execution of the job chain.
      *
      * This will start the execution of the task chain, starting from the
      * first one. It is possible to call this function multiple times, each
      * invocation will start a new processing and provide a new Future to
      * watch its status.
      *
      * @param in Argument to be passed to the very first task
      * @return Future&lt;Out&gt; object which will contain result of the last
      * task once if finishes executing. See Future documentation for more details.
      *
      * @see exec(), Future
      */
     template<typename FirstIn>
     KAsync::Future<Out> exec(FirstIn in);
 
     /**
      * @brief Starts execution of the job chain.
      *
      * This will start the execution of the task chain, starting from the
      * first one. It is possible to call this function multiple times, each
      * invocation will start a new processing and provide a new Future to
      * watch its status.
      *
      * @return Future&lt;Out&gt; object which will contain result of the last
      * task once if finishes executing. See Future documentation for more details.
      *
      * @see exec(FirstIn in), Future
      */
     KAsync::Future<Out> exec();
 
     explicit Job(JobContinuation<Out, In ...> &&func);
     explicit Job(AsyncContinuation<Out, In ...> &&func);
 
 private:
     //@cond PRIVATE
     explicit Job(Private::ExecutorBasePtr executor);
 
     template<typename OutOther, typename ... InOther>
     Job<OutOther, In ...> thenImpl(Private::ContinuationHolder<OutOther, InOther ...> helper,
                                    Private::ExecutionFlag execFlag = Private::ExecutionFlag::GoodCase) const;
 
     template<typename InOther, typename ... InOtherTail>
     void thenInvariants() const;
 
     //Base case for an empty parameter pack
     template<typename ... InOther>
     auto thenInvariants() const -> std::enable_if_t<(sizeof...(InOther) == 0)>;
 
     template<typename OutOther>
     void eachInvariants() const;
     //@endcond
 };
 
 } // namespace KAsync
 
 
 // out-of-line definitions of Job methods
 #include "job_impl.h"
 
 #endif // KASYNC_H
diff --git a/src/execution_p.h b/src/execution_p.h
new file mode 100644
index 0000000..8b8d7c9
--- /dev/null
+++ b/src/execution_p.h
@@ -0,0 +1,116 @@
+/*
+ * Copyright 2014 - 2015 Daniel Vrátil <dvratil@redhat.com>
+ * Copyright 2016  Daniel Vrátil <dvratil@kde.org>
+ * Copyright 2016  Christian Mollekopf <mollekopf@kolabsystems.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This library 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 Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef KASYNC_EXECUTION_P_H_
+#define KASYNC_EXECUTION_P_H_
+
+#include "debug.h"
+
+#include <QSharedPointer>
+#include <QPointer>
+#include <QVector>
+#include <QObject>
+
+#include <memory>
+
+namespace KAsync {
+
+class FutureBase;
+
+template<typename T>
+class Future;
+
+class Tracer;
+
+//@cond PRIVATE
+namespace Private
+{
+
+class ExecutorBase;
+using ExecutorBasePtr = QSharedPointer<ExecutorBase>;
+
+struct Execution;
+using ExecutionPtr = QSharedPointer<Execution>;
+
+class ExecutionContext;
+
+enum ExecutionFlag {
+    Always,
+    ErrorCase,
+    GoodCase
+};
+
+struct Execution {
+    explicit Execution(const ExecutorBasePtr &executor)
+        : executor(executor)
+    {}
+
+    virtual ~Execution()
+    {
+        if (resultBase) {
+            resultBase->releaseExecution();
+            delete resultBase;
+        }
+        prevExecution.reset();
+    }
+
+    void setFinished()
+    {
+        tracer.reset();
+    }
+
+    template<typename T>
+    KAsync::Future<T>* result() const
+    {
+        return static_cast<KAsync::Future<T>*>(resultBase);
+    }
+
+    void releaseFuture()
+    {
+        resultBase = nullptr;
+    }
+
+    ExecutorBasePtr executor;
+    ExecutionPtr prevExecution;
+    std::unique_ptr<Tracer> tracer;
+    FutureBase *resultBase = nullptr;
+};
+
+class ExecutionContext {
+public:
+    using Ptr = QSharedPointer<ExecutionContext>;
+
+    QVector<QPointer<const QObject>> guards;
+    bool guardIsBroken() const
+    {
+        for (const auto &g : guards) {
+            if (!g) {
+                return true;
+            }
+        }
+        return false;
+    }
+};
+
+} // namespace Private
+//@endcond
+
+} // namespace KAsync
+
+#endif
diff --git a/src/executor_p.h b/src/executor_p.h
new file mode 100644
index 0000000..5cb250b
--- /dev/null
+++ b/src/executor_p.h
@@ -0,0 +1,321 @@
+/*
+ * Copyright 2014 - 2015 Daniel Vrátil <dvratil@redhat.com>
+ * Copyright 2015 - 2019 Daniel Vrátil <dvratil@kde.org>
+ * Copyright 2016  Christian Mollekopf <mollekopf@kolabsystems.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This library 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 Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef KASYNC_EXECUTOR_P_H
+#define KASYNC_EXECUTOR_P_H
+
+#include "async_impl.h"
+#include "execution_p.h"
+#include "continuations_p.h"
+#include "debug.h"
+
+namespace KAsync {
+
+template<typename T>
+class Future;
+
+template<typename T>
+class FutureWatcher;
+
+template<typename Out, typename ... In>
+class ContinuationHolder;
+
+template<typename Out, typename ... In>
+class Job;
+
+class Tracer;
+
+namespace Private {
+
+class ExecutorBase;
+using ExecutorBasePtr = QSharedPointer<ExecutorBase>;
+
+class ExecutorBase
+{
+    template<typename Out, typename ... In>
+    friend class Executor;
+
+    template<typename Out, typename ... In>
+    friend class KAsync::Job;
+
+    friend struct Execution;
+    friend class KAsync::Tracer;
+
+public:
+    virtual ~ExecutorBase() = default;
+
+    virtual ExecutionPtr exec(const ExecutorBasePtr &self, QSharedPointer<Private::ExecutionContext> context) = 0;
+
+protected:
+    ExecutorBase(const ExecutorBasePtr &parent)
+        : mPrev(parent)
+    {}
+
+    template<typename T>
+    KAsync::Future<T>* createFuture(const ExecutionPtr &execution) const
+    {
+        return new KAsync::Future<T>(execution);
+    }
+
+    void prepend(const ExecutorBasePtr &e)
+    {
+        if (mPrev) {
+            mPrev->prepend(e);
+        } else {
+            mPrev = e;
+        }
+    }
+
+    void addToContext(const QVariant &entry)
+    {
+        mContext.push_back(entry);
+    }
+
+    void guard(const QObject *o)
+    {
+        mGuards.push_back(QPointer<const QObject>{o});
+    }
+
+    QString mExecutorName;
+    QVector<QVariant> mContext;
+    QVector<QPointer<const QObject>> mGuards;
+    ExecutorBasePtr mPrev;
+};
+
+template<typename Out, typename ... In>
+class Executor : public ExecutorBase
+{
+    using PrevOut = typename detail::prevOut<In ...>::type;
+
+public:
+    explicit Executor(ContinuationHolder<Out, In ...> &&workerHelper, const ExecutorBasePtr &parent = {},
+                      ExecutionFlag executionFlag = ExecutionFlag::GoodCase)
+        : ExecutorBase(parent)
+        , mContinuationHolder(std::move(workerHelper))
+        , executionFlag(executionFlag)
+    {
+        STORE_EXECUTOR_NAME("Executor", Out, In ...);
+    }
+
+    virtual ~Executor() = default;
+
+    void run(const ExecutionPtr &execution)
+    {
+        KAsync::Future<typename detail::prevOut<In ...>::type> *prevFuture = nullptr;
+        if (execution->prevExecution) {
+            prevFuture = execution->prevExecution->result<typename detail::prevOut<In ...>::type>();
+            assert(prevFuture->isFinished());
+        }
+
+        //Execute one of the available workers
+        KAsync::Future<Out> *future = execution->result<Out>();
+
+        const auto &continuation = Executor<Out, In ...>::mContinuationHolder;
+        if (continuationIs<AsyncContinuation<Out, In ...>>(continuation)) {
+            continuationGet<AsyncContinuation<Out, In ...>>(continuation)(prevFuture ? prevFuture->value() : In() ..., *future);
+        } else if (continuationIs<AsyncErrorContinuation<Out, In ...>>(continuation)) {
+            continuationGet<AsyncErrorContinuation<Out, In ...>>(continuation)(
+                    prevFuture->hasError() ? prevFuture->errors().first() : Error(),
+                    prevFuture ? prevFuture->value() : In() ..., *future);
+        } else if (continuationIs<SyncContinuation<Out, In ...>>(continuation)) {
+            callAndApply(prevFuture ? prevFuture->value() : In() ...,
+                         continuationGet<SyncContinuation<Out, In ...>>(continuation), *future, std::is_void<Out>());
+            future->setFinished();
+        } else if (continuationIs<SyncErrorContinuation<Out, In ...>>(continuation)) {
+            assert(prevFuture);
+            callAndApply(prevFuture->hasError() ? prevFuture->errors().first() : Error(),
+                         prevFuture ? prevFuture->value() : In() ...,
+                         continuationGet<SyncErrorContinuation<Out, In ...>>(continuation), *future, std::is_void<Out>());
+            future->setFinished();
+        } else if (continuationIs<JobContinuation<Out, In ...>>(continuation)) {
+            executeJobAndApply(prevFuture ? prevFuture->value() : In() ...,
+                               continuationGet<JobContinuation<Out, In ...>>(continuation), *future, std::is_void<Out>());
+        } else if (continuationIs<JobErrorContinuation<Out, In ...>>(continuation)) {
+            executeJobAndApply(prevFuture->hasError() ? prevFuture->errors().first() : Error(),
+                               prevFuture ? prevFuture->value() : In() ...,
+                               continuationGet<JobErrorContinuation<Out, In ...>>(continuation), *future, std::is_void<Out>());
+        }
+
+    }
+
+    ExecutionPtr exec(const ExecutorBasePtr &self, QSharedPointer<Private::ExecutionContext> context) override
+    {
+        /*
+         * One executor per job, created with the construction of the Job object.
+         * One execution per job per exec(), created only once exec() is called.
+         *
+         * The executors make up the linked list that makes up the complete execution chain.
+         *
+         * The execution then tracks the execution of each executor.
+         */
+
+        // Passing 'self' to execution ensures that the Executor chain remains
+        // valid until the entire execution is finished
+        ExecutionPtr execution = ExecutionPtr::create(self);
+#ifndef QT_NO_DEBUG
+        execution->tracer = std::make_unique<Tracer>(execution.data()); // owned by execution
+#endif
+
+        context->guards += mGuards;
+
+        // chainup
+        execution->prevExecution = mPrev ? mPrev->exec(mPrev, context) : ExecutionPtr();
+
+        execution->resultBase = ExecutorBase::createFuture<Out>(execution);
+        //We watch our own future to finish the execution once we're done
+        auto fw = new KAsync::FutureWatcher<Out>();
+        QObject::connect(fw, &KAsync::FutureWatcher<Out>::futureReady,
+                         [fw, execution]() {
+                             execution->setFinished();
+                             delete fw;
+                         });
+        fw->setFuture(*execution->result<Out>());
+
+        KAsync::Future<PrevOut> *prevFuture = execution->prevExecution ? execution->prevExecution->result<PrevOut>()
+                                                                       : nullptr;
+        if (!prevFuture || prevFuture->isFinished()) { //The previous job is already done
+            runExecution(prevFuture, execution, context->guardIsBroken());
+        } else { //The previous job is still running and we have to wait for it's completion
+            auto prevFutureWatcher = new KAsync::FutureWatcher<PrevOut>();
+            QObject::connect(prevFutureWatcher, &KAsync::FutureWatcher<PrevOut>::futureReady,
+                             [prevFutureWatcher, execution, this, context]() {
+                                 auto prevFuture = prevFutureWatcher->future();
+                                 assert(prevFuture.isFinished());
+                                 delete prevFutureWatcher;
+                                 runExecution(&prevFuture, execution, context->guardIsBroken());
+                             });
+
+            prevFutureWatcher->setFuture(*static_cast<KAsync::Future<PrevOut>*>(prevFuture));
+        }
+
+        return execution;
+    }
+
+private:
+    void runExecution(const KAsync::Future<PrevOut> *prevFuture, const ExecutionPtr &execution, bool guardIsBroken)
+    {
+        if (guardIsBroken) {
+            execution->resultBase->setFinished();
+            return;
+        }
+        if (prevFuture) {
+            if (prevFuture->hasError() && executionFlag == ExecutionFlag::GoodCase) {
+                //Propagate the error to the outer Future
+                Q_ASSERT(prevFuture->errors().size() == 1);
+                execution->resultBase->setError(prevFuture->errors().first());
+                return;
+            }
+            if (!prevFuture->hasError() && executionFlag == ExecutionFlag::ErrorCase) {
+                //Propagate the value to the outer Future
+                KAsync::detail::copyFutureValue<PrevOut>(*prevFuture, *execution->result<PrevOut>());
+                execution->resultBase->setFinished();
+                return;
+            }
+        }
+        run(execution);
+    }
+
+    void executeJobAndApply(In && ... input, const JobContinuation<Out, In ...> &func,
+                            Future<Out> &future, std::false_type)
+    {
+        func(std::forward<In>(input) ...)
+            .template then<void, Out>([&future](const KAsync::Error &error, const Out &v,
+                                                KAsync::Future<void> &f) {
+                if (error) {
+                    future.setError(error);
+                } else {
+                    future.setResult(v);
+                }
+                f.setFinished();
+            }).exec();
+    }
+
+    void executeJobAndApply(In && ... input, const JobContinuation<Out, In ...> &func,
+                            Future<Out> &future, std::true_type)
+    {
+        func(std::forward<In>(input) ...)
+            .template then<void>([&future](const KAsync::Error &error, KAsync::Future<void> &f) {
+                if (error) {
+                    future.setError(error);
+                } else {
+                    future.setFinished();
+                }
+                f.setFinished();
+            }).exec();
+    }
+
+    void executeJobAndApply(const Error &error, In && ... input, const JobErrorContinuation<Out, In ...> &func,
+                            Future<Out> &future, std::false_type)
+    {
+        func(error, std::forward<In>(input) ...)
+            .template then<void, Out>([&future](const KAsync::Error &error, const Out &v,
+                                                KAsync::Future<void> &f) {
+                if (error) {
+                    future.setError(error);
+                } else {
+                    future.setResult(v);
+                }
+                f.setFinished();
+            }).exec();
+    }
+
+    void executeJobAndApply(const Error &error, In && ... input, const JobErrorContinuation<Out, In ...> &func,
+                            Future<Out> &future, std::true_type)
+    {
+        func(error, std::forward<In>(input) ...)
+            .template then<void>([&future](const KAsync::Error &error, KAsync::Future<void> &f) {
+                if (error) {
+                    future.setError(error);
+                } else {
+                    future.setFinished();
+                }
+                f.setFinished();
+            }).exec();
+    }
+
+    void callAndApply(In && ... input, const SyncContinuation<Out, In ...> &func, Future<Out> &future, std::false_type)
+    {
+        future.setValue(func(std::forward<In>(input) ...));
+    }
+
+    void callAndApply(In && ... input, const SyncContinuation<Out, In ...> &func, Future<Out> &, std::true_type)
+    {
+        func(std::forward<In>(input) ...);
+    }
+
+    void callAndApply(const Error &error, In && ... input, const SyncErrorContinuation<Out, In ...> &func, Future<Out> &future, std::false_type)
+    {
+        future.setValue(func(error, std::forward<In>(input) ...));
+    }
+
+    void callAndApply(const Error &error, In && ... input, const SyncErrorContinuation<Out, In ...> &func, Future<Out> &, std::true_type)
+    {
+        func(error, std::forward<In>(input) ...);
+    }
+
+private:
+    ContinuationHolder<Out, In ...> mContinuationHolder;
+    const ExecutionFlag executionFlag;
+};
+
+} // namespace Private
+} // nameapce KAsync
+
+#endif
+
diff --git a/src/job_impl.h b/src/job_impl.h
index c0e4ec0..b44cae6 100644
--- a/src/job_impl.h
+++ b/src/job_impl.h
@@ -1,556 +1,317 @@
 /*
  * Copyright 2014 - 2015 Daniel Vrátil <dvratil@redhat.com>
  * Copyright 2015 - 2016 Daniel Vrátil <dvratil@kde.org>
  * Copyright 2016  Christian Mollekopf <mollekopf@kolabsystems.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public License as
  * published by the Free Software Foundation; either version 2 of
  * the License, or (at your option) any later version.
  *
  * This library 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 Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library. If not, see <http://www.gnu.org/licenses/>.
  */
 
 #ifndef KASYNC_JOB_IMPL_H
 #define KASYNC_JOB_IMPL_H
 
 #include "async.h"
 
 //@cond PRIVATE
 
 namespace KAsync
 {
 
-namespace Private {
-
-template<typename Out, typename ... In>
-class ThenExecutor: public Executor<typename detail::prevOut<In ...>::type, Out, In ...>
-{
-public:
-    ThenExecutor(ContinuationHolder<Out, In ...> &&workerHelper, const ExecutorBasePtr &parent = {},
-                 ExecutionFlag executionFlag = ExecutionFlag::GoodCase)
-        : Executor<typename detail::prevOut<In ...>::type, Out, In ...>(parent, executionFlag)
-        , mContinuationHolder(std::move(workerHelper))
-    {
-        STORE_EXECUTOR_NAME("ThenExecutor", Out, In ...);
-    }
-
-    void run(const ExecutionPtr &execution) Q_DECL_OVERRIDE
-    {
-        KAsync::Future<typename detail::prevOut<In ...>::type> *prevFuture = nullptr;
-        if (execution->prevExecution) {
-            prevFuture = execution->prevExecution->result<typename detail::prevOut<In ...>::type>();
-            assert(prevFuture->isFinished());
-        }
-
-        //Execute one of the available workers
-        KAsync::Future<Out> *future = execution->result<Out>();
-
-        const auto &continuation = ThenExecutor<Out, In ...>::mContinuationHolder;
-        if (continuationIs<AsyncContinuation<Out, In ...>>(continuation)) {
-            continuationGet<AsyncContinuation<Out, In ...>>(continuation)(prevFuture ? prevFuture->value() : In() ..., *future);
-        } else if (continuationIs<AsyncErrorContinuation<Out, In ...>>(continuation)) {
-            continuationGet<AsyncErrorContinuation<Out, In ...>>(continuation)(
-                    prevFuture->hasError() ? prevFuture->errors().first() : Error(),
-                    prevFuture ? prevFuture->value() : In() ..., *future);
-        } else if (continuationIs<SyncContinuation<Out, In ...>>(continuation)) {
-            callAndApply(prevFuture ? prevFuture->value() : In() ...,
-                         continuationGet<SyncContinuation<Out, In ...>>(continuation), *future, std::is_void<Out>());
-            future->setFinished();
-        } else if (continuationIs<SyncErrorContinuation<Out, In ...>>(continuation)) {
-            assert(prevFuture);
-            callAndApply(prevFuture->hasError() ? prevFuture->errors().first() : Error(),
-                         prevFuture ? prevFuture->value() : In() ...,
-                         continuationGet<SyncErrorContinuation<Out, In ...>>(continuation), *future, std::is_void<Out>());
-            future->setFinished();
-        } else if (continuationIs<JobContinuation<Out, In ...>>(continuation)) {
-            executeJobAndApply(prevFuture ? prevFuture->value() : In() ...,
-                               continuationGet<JobContinuation<Out, In ...>>(continuation), *future, std::is_void<Out>());
-        } else if (continuationIs<JobErrorContinuation<Out, In ...>>(continuation)) {
-            executeJobAndApply(prevFuture->hasError() ? prevFuture->errors().first() : Error(),
-                               prevFuture ? prevFuture->value() : In() ...,
-                               continuationGet<JobErrorContinuation<Out, In ...>>(continuation), *future, std::is_void<Out>());
-        }
-    }
-
-private:
-
-    void executeJobAndApply(In && ... input, const JobContinuation<Out, In ...> &func,
-                            Future<Out> &future, std::false_type)
-    {
-        func(std::forward<In>(input) ...)
-            .template then<void, Out>([&future](const KAsync::Error &error, const Out &v,
-                                                KAsync::Future<void> &f) {
-                if (error) {
-                    future.setError(error);
-                } else {
-                    future.setResult(v);
-                }
-                f.setFinished();
-            }).exec();
-    }
-
-    void executeJobAndApply(In && ... input, const JobContinuation<Out, In ...> &func,
-                            Future<Out> &future, std::true_type)
-    {
-        func(std::forward<In>(input) ...)
-            .template then<void>([&future](const KAsync::Error &error, KAsync::Future<void> &f) {
-                if (error) {
-                    future.setError(error);
-                } else {
-                    future.setFinished();
-                }
-                f.setFinished();
-            }).exec();
-    }
-
-    void executeJobAndApply(const Error &error, In && ... input, const JobErrorContinuation<Out, In ...> &func,
-                            Future<Out> &future, std::false_type)
-    {
-        func(error, std::forward<In>(input) ...)
-            .template then<void, Out>([&future](const KAsync::Error &error, const Out &v,
-                                                KAsync::Future<void> &f) {
-                if (error) {
-                    future.setError(error);
-                } else {
-                    future.setResult(v);
-                }
-                f.setFinished();
-            }).exec();
-    }
-
-    void executeJobAndApply(const Error &error, In && ... input, const JobErrorContinuation<Out, In ...> &func,
-                            Future<Out> &future, std::true_type)
-    {
-        func(error, std::forward<In>(input) ...)
-            .template then<void>([&future](const KAsync::Error &error, KAsync::Future<void> &f) {
-                if (error) {
-                    future.setError(error);
-                } else {
-                    future.setFinished();
-                }
-                f.setFinished();
-            }).exec();
-    }
-
-    void callAndApply(In && ... input, const SyncContinuation<Out, In ...> &func, Future<Out> &future, std::false_type)
-    {
-        future.setValue(func(std::forward<In>(input) ...));
-    }
-
-    void callAndApply(In && ... input, const SyncContinuation<Out, In ...> &func, Future<Out> &, std::true_type)
-    {
-        func(std::forward<In>(input) ...);
-    }
-
-    void callAndApply(const Error &error, In && ... input, const SyncErrorContinuation<Out, In ...> &func, Future<Out> &future, std::false_type)
-    {
-        future.setValue(func(error, std::forward<In>(input) ...));
-    }
-
-    void callAndApply(const Error &error, In && ... input, const SyncErrorContinuation<Out, In ...> &func, Future<Out> &, std::true_type)
-    {
-        func(error, std::forward<In>(input) ...);
-    }
-
-    ContinuationHolder<Out, In ...> mContinuationHolder;
-};
-
-template<typename T>
-KAsync::Future<T>* ExecutorBase::createFuture(const ExecutionPtr &execution) const
-{
-    return new KAsync::Future<T>(execution);
-}
-
-template<typename PrevOut, typename Out, typename ... In>
-void Executor<PrevOut, Out, In ...>::runExecution(const KAsync::Future<PrevOut> *prevFuture,
-                                                  const ExecutionPtr &execution, bool guardIsBroken)
-{
-    if (guardIsBroken) {
-        execution->resultBase->setFinished();
-        return;
-    }
-    if (prevFuture) {
-        if (prevFuture->hasError() && executionFlag == ExecutionFlag::GoodCase) {
-            //Propagate the error to the outer Future
-            Q_ASSERT(prevFuture->errors().size() == 1);
-            execution->resultBase->setError(prevFuture->errors().first());
-            return;
-        }
-        if (!prevFuture->hasError() && executionFlag == ExecutionFlag::ErrorCase) {
-            //Propagate the value to the outer Future
-            KAsync::detail::copyFutureValue<PrevOut>(*prevFuture, *execution->result<PrevOut>());
-            execution->resultBase->setFinished();
-            return;
-        }
-    }
-    run(execution);
-}
-
-class ExecutionContext {
-public:
-    typedef QSharedPointer<ExecutionContext> Ptr;
-
-    QVector<QPointer<const QObject>> guards;
-    bool guardIsBroken() const
-    {
-        for (const auto &g : guards) {
-            if (!g) {
-                return true;
-            }
-        }
-        return false;
-    }
-};
-
-template<typename PrevOut, typename Out, typename ... In>
-ExecutionPtr Executor<PrevOut, Out, In ...>::exec(const ExecutorBasePtr &self, ExecutionContext::Ptr context)
-{
-    /*
-     * One executor per job, created with the construction of the Job object.
-     * One execution per job per exec(), created only once exec() is called.
-     *
-     * The executors make up the linked list that makes up the complete execution chain.
-     *
-     * The execution then tracks the execution of each executor.
-     */
-
-    // Passing 'self' to execution ensures that the Executor chain remains
-    // valid until the entire execution is finished
-    ExecutionPtr execution = ExecutionPtr::create(self);
-#ifndef QT_NO_DEBUG
-    execution->tracer = std::make_unique<Tracer>(execution.data()); // owned by execution
-#endif
-
-    context->guards += mGuards;
-
-    // chainup
-    execution->prevExecution = mPrev ? mPrev->exec(mPrev, context) : ExecutionPtr();
-
-    execution->resultBase = ExecutorBase::createFuture<Out>(execution);
-    //We watch our own future to finish the execution once we're done
-    auto fw = new KAsync::FutureWatcher<Out>();
-    QObject::connect(fw, &KAsync::FutureWatcher<Out>::futureReady,
-                     [fw, execution]() {
-                         execution->setFinished();
-                         delete fw;
-                     });
-    fw->setFuture(*execution->result<Out>());
-
-    KAsync::Future<PrevOut> *prevFuture = execution->prevExecution ? execution->prevExecution->result<PrevOut>()
-                                                                   : nullptr;
-    if (!prevFuture || prevFuture->isFinished()) { //The previous job is already done
-        runExecution(prevFuture, execution, context->guardIsBroken());
-    } else { //The previous job is still running and we have to wait for it's completion
-        auto prevFutureWatcher = new KAsync::FutureWatcher<PrevOut>();
-        QObject::connect(prevFutureWatcher, &KAsync::FutureWatcher<PrevOut>::futureReady,
-                         [prevFutureWatcher, execution, this, context]() {
-                             auto prevFuture = prevFutureWatcher->future();
-                             assert(prevFuture.isFinished());
-                             delete prevFutureWatcher;
-                             runExecution(&prevFuture, execution, context->guardIsBroken());
-                         });
-
-        prevFutureWatcher->setFuture(*static_cast<KAsync::Future<PrevOut>*>(prevFuture));
-    }
-
-    return execution;
-}
-
-} // namespace Private
-
-
 template<typename Out, typename ... In>
 template<typename ... InOther>
 Job<Out, In ...>::operator std::conditional_t<std::is_void<OutType>::value, IncompleteType, Job<void>> ()
 {
     return thenImpl<void, InOther ...>({JobContinuation<void, InOther ...>([](InOther ...){ return KAsync::null<void>(); })}, {});
 }
 
 template<typename Out, typename ... In>
 template<typename OutOther, typename ... InOther>
 Job<OutOther, In ...> Job<Out, In ...>::thenImpl(Private::ContinuationHolder<OutOther, InOther ...> workHelper,
                                                  Private::ExecutionFlag execFlag) const
 {
     thenInvariants<InOther ...>();
-    return Job<OutOther, In ...>(QSharedPointer<Private::ThenExecutor<OutOther, InOther ...>>::create(
+    return Job<OutOther, In ...>(QSharedPointer<Private::Executor<OutOther, InOther ...>>::create(
                 std::forward<Private::ContinuationHolder<OutOther, InOther ...>>(workHelper), mExecutor, execFlag));
 }
 
 template<typename Out, typename ... In>
 template<typename OutOther, typename ... InOther>
 Job<OutOther, In ...> Job<Out, In ...>::then(const Job<OutOther, InOther ...> &job) const
 {
     thenInvariants<InOther ...>();
     auto executor = job.mExecutor;
     executor->prepend(mExecutor);
     return Job<OutOther, In ...>(executor);
 }
 
 template<typename Out, typename ... In>
 Job<Out, In ...> Job<Out, In ...>::onError(SyncErrorContinuation<void> &&errorFunc) const
 {
-    return Job<Out, In...>(QSharedPointer<Private::ThenExecutor<Out, Out>>::create(
+    return Job<Out, In...>(QSharedPointer<Private::Executor<Out, Out>>::create(
                 // Extra indirection to allow propagating the result of a previous future when no
                 // error occurs
                 Private::ContinuationHolder<Out, Out>([errorFunc = std::move(errorFunc)](const Error &error, const Out &val) {
                     errorFunc(error);
                     return val;
                 }), mExecutor, Private::ExecutionFlag::ErrorCase));
 }
 
 template<> // Specialize for void jobs
 inline Job<void> Job<void>::onError(SyncErrorContinuation<void> &&errorFunc) const
 {
-    return Job<void>(QSharedPointer<Private::ThenExecutor<void>>::create(
+    return Job<void>(QSharedPointer<Private::Executor<void>>::create(
                 Private::ContinuationHolder<void>(std::forward<SyncErrorContinuation<void>>(errorFunc)),
                 mExecutor, Private::ExecutionFlag::ErrorCase));
 }
 
 
 template<typename Out, typename ... In>
 template<typename FirstIn>
 KAsync::Future<Out> Job<Out, In ...>::exec(FirstIn in)
 {
     // Inject a fake sync executor that will return the initial value
     Private::ExecutorBasePtr first = mExecutor;
     while (first->mPrev) {
         first = first->mPrev;
     }
 
-    first->mPrev = QSharedPointer<Private::ThenExecutor<FirstIn>>::create(
+    first->mPrev = QSharedPointer<Private::Executor<FirstIn>>::create(
             Private::ContinuationHolder<FirstIn>([val = std::move(in)](Future<FirstIn> &future) {
                  future.setResult(val);
             }));
 
     auto result = exec();
     // Remove the injected executor
     first->mPrev.reset();
     return result;
 }
 
 template<typename Out, typename ... In>
 KAsync::Future<Out> Job<Out, In ...>::exec()
 {
     Private::ExecutionPtr execution = mExecutor->exec(mExecutor, Private::ExecutionContext::Ptr::create());
     KAsync::Future<Out> result = *execution->result<Out>();
 
     return result;
 }
 
 template<typename Out, typename ... In>
 Job<Out, In ...>::Job(Private::ExecutorBasePtr executor)
     : JobBase(executor)
 {}
 
 template<typename Out, typename ... In>
 Job<Out, In ...>::Job(JobContinuation<Out, In ...> &&func)
-    : JobBase(new Private::ThenExecutor<Out, In ...>(std::forward<JobContinuation<Out, In ...>>(func), {}))
+    : JobBase(new Private::Executor<Out, In ...>(std::forward<JobContinuation<Out, In ...>>(func), {}))
 {
     qWarning() << "Creating job job";
     static_assert(sizeof...(In) <= 1, "Only one or zero input parameters are allowed.");
 }
 
 template<typename Out, typename ... In>
 template<typename OutOther>
 void Job<Out, In ...>::eachInvariants() const
 {
     static_assert(detail::isIterable<Out>::value,
                     "The 'Each' task can only be connected to a job that returns a list or an array.");
     static_assert(std::is_void<OutOther>::value || detail::isIterable<OutOther>::value,
                     "The result type of 'Each' task must be void, a list or an array.");
 }
 
 template<typename Out, typename ... In>
 template<typename InOtherFirst, typename ... InOtherTail>
 void Job<Out, In ...>::thenInvariants() const
 {
     static_assert(!std::is_void<Out>::value && (std::is_convertible<Out, InOtherFirst>::value || std::is_base_of<Out, InOtherFirst>::value),
                     "The return type of previous task must be compatible with input type of this task");
 }
 
 template<typename Out, typename ... In>
 template<typename ... InOther>
 auto Job<Out, In ...>::thenInvariants() const -> std::enable_if_t<(sizeof...(InOther) == 0)>
 {
 
 }
 
 
 template<typename Out, typename ... In>
 Job<Out, In ...> startImpl(Private::ContinuationHolder<Out, In ...> &&helper)
 {
     static_assert(sizeof...(In) <= 1, "Only one or zero input parameters are allowed.");
-    return Job<Out, In...>(QSharedPointer<Private::ThenExecutor<Out, In ...>>::create(
+    return Job<Out, In...>(QSharedPointer<Private::Executor<Out, In ...>>::create(
                 std::forward<Private::ContinuationHolder<Out, In...>>(helper), nullptr, Private::ExecutionFlag::GoodCase));
 }
 
 template<typename Out, typename ... In>
 Job<Out, In ...> syncStartImpl(SyncContinuation<Out, In ...> &&func)
 {
     static_assert(sizeof...(In) <= 1, "Only one or zero input parameters are allowed.");
-    return Job<Out, In...>(QSharedPointer<Private::ThenExecutor<Out, In ...>>::create(
+    return Job<Out, In...>(QSharedPointer<Private::Executor<Out, In ...>>::create(
                 Private::ContinuationHolder<Out, In ...>(std::forward<SyncContinuation<Out, In ...>>(func)),
                 nullptr, Private::ExecutionFlag::GoodCase));
 }
 
 static inline KAsync::Job<void> waitForCompletion(QList<KAsync::Future<void>> &futures)
 {
     auto context = new QObject;
     return start<void>([futures, context](KAsync::Future<void> &future) {
             const auto total = futures.size();
             auto count = QSharedPointer<int>::create();
             int i = 0;
             for (KAsync::Future<void> subFuture : futures) {
                 i++;
                 if (subFuture.isFinished()) {
                     *count += 1;
                     continue;
                 }
                 // FIXME bind lifetime all watcher to future (repectively the main job
                 auto watcher = QSharedPointer<KAsync::FutureWatcher<void>>::create();
                 QObject::connect(watcher.data(), &KAsync::FutureWatcher<void>::futureReady,
                                  [count, total, &future, context]() {
                                     *count += 1;
                                     if (*count == total) {
                                         delete context;
                                         future.setFinished();
                                     }
                                 });
                 watcher->setFuture(subFuture);
                 context->setProperty(QString::fromLatin1("future%1").arg(i).toLatin1().data(),
                                      QVariant::fromValue(watcher));
             }
             if (*count == total) {
                 delete context;
                 future.setFinished();
             }
         });
         // .finally<void>([context]() { delete context; });
 }
 
 template<typename List, typename ValueType>
 Job<void, List> forEach(KAsync::Job<void, ValueType> job)
 {
     auto cont = [job] (const List &values) mutable {
             auto error = QSharedPointer<KAsync::Error>::create();
             QList<KAsync::Future<void>> list;
             for (const auto &v : values) {
                 auto future = job
                     .template then<void>([error] (const KAsync::Error &e) {
                         if (e && !*error) {
                             //TODO ideally we would aggregate the errors instead of just using the first one
                             *error = e;
                         }
                     })
                     .exec(v);
                 list << future;
             }
             return waitForCompletion(list)
                 .then<void>([error](KAsync::Future<void> &future) {
                     if (*error) {
                         future.setError(*error);
                     } else {
                         future.setFinished();
                     }
                 });
         };
-    return Job<void, List>(QSharedPointer<Private::ThenExecutor<void, List>>::create(
+    return Job<void, List>(QSharedPointer<Private::Executor<void, List>>::create(
                 Private::ContinuationHolder<void, List>(JobContinuation<void, List>(std::move(cont))), nullptr, Private::ExecutionFlag::GoodCase));
 }
 
 
 template<typename List, typename ValueType>
 Job<void, List> serialForEach(KAsync::Job<void, ValueType> job)
 {
     auto cont = [job] (const List &values) mutable {
             auto error = QSharedPointer<KAsync::Error>::create();
             auto serialJob = KAsync::null<void>();
             for (const auto &value : values) {
                 serialJob = serialJob.then<void>([value, job, error](KAsync::Future<void> &future) {
                     job.template then<void>([&future, error] (const KAsync::Error &e) {
                         if (e && !*error) {
                             //TODO ideally we would aggregate the errors instead of just using the first one
                             *error = e;
                         }
                         future.setFinished();
                     })
                     .exec(value);
                 });
             }
             return serialJob
                 .then<void>([error](KAsync::Future<void> &future) {
                     if (*error) {
                         future.setError(*error);
                     } else {
                         future.setFinished();
                     }
                 });
         };
-    return Job<void, List>(QSharedPointer<Private::ThenExecutor<void, List>>::create(
+    return Job<void, List>(QSharedPointer<Private::Executor<void, List>>::create(
             Private::ContinuationHolder<void, List>(JobContinuation<void, List>(std::move(cont))), nullptr, Private::ExecutionFlag::GoodCase));
 }
 
 template<typename List, typename ValueType>
 Job<void, List> forEach(JobContinuation<void, ValueType> &&func)
 {
     return forEach<List, ValueType>(KAsync::start<void, ValueType>(std::forward<JobContinuation<void, ValueType>>(func)));
 }
 
 template<typename List, typename ValueType>
 Job<void, List> serialForEach(JobContinuation<void, ValueType> &&func)
 {
     return serialForEach<List, ValueType>(KAsync::start<void, ValueType>(std::forward<JobContinuation<void, ValueType>>(func)));
 }
 
 template<typename Out>
 Job<Out> null()
 {
     return KAsync::start<Out>(
         [](KAsync::Future<Out> &future) {
             future.setFinished();
         });
 }
 
 template<typename Out>
 Job<Out> value(Out v)
 {
     return KAsync::start<Out>(
         [val = std::move(v)](KAsync::Future<Out> &future) {
             future.setResult(val);
         });
 }
 
 template<typename Out>
 Job<Out> error(int errorCode, const QString &errorMessage)
 {
     return error<Out>({errorCode, errorMessage});
 }
 
 template<typename Out>
 Job<Out> error(const char *message)
 {
     return error<Out>(Error(message));
 }
 
 template<typename Out>
 Job<Out> error(const Error &error)
 {
     return KAsync::start<Out>(
         [error](KAsync::Future<Out> &future) {
             future.setError(error);
         });
 }
 
 
 } // namespace KAsync
 
 //@endconf
 
 #endif // KASYNC_JOB_IMPL_H