5 files changed, 179 insertions, 1 deletions

diff --git a/async/src/CMakeLists.txt b/async/src/CMakeLists.txt
index 6f8ab63..becc8ee 100644
--- a/async/src/CMakeLists.txt
+++ b/async/src/CMakeLists.txt
@@ -5,6 +5,7 @@ include_directories(${CMAKE_CURRENT_BINARY_DIR})
 set(async_SRCS
     async.cpp
     future.cpp
+    debug.cpp
 )
 
 add_library(${PROJECT_NAME} SHARED ${async_SRCS})
diff --git a/async/src/async.cpp b/async/src/async.cpp
index 6f28084..e92d333 100644
--- a/async/src/async.cpp
+++ b/async/src/async.cpp
@@ -21,7 +21,6 @@
 #include <QDebug>
 #include <QEventLoop>
 
-
 using namespace Async;
 
 Private::Execution::Execution(const Private::ExecutorBasePtr &executor)
@@ -45,6 +44,11 @@ void Private::Execution::setFinished()
 {
     isFinished = true;
     //executor.clear();
+#ifndef QT_NO_DEBUG
+    if (tracer) {
+        delete tracer;
+    }
+#endif
 }
 
 void Private::Execution::releaseFuture()
diff --git a/async/src/async.h b/async/src/async.h
index 2243046..73eeaa0 100644
--- a/async/src/async.h
+++ b/async/src/async.h
@@ -25,6 +25,7 @@
 #include <iterator>
 
 #include "future.h"
+#include "debug.h"
 #include "async_impl.h"
 
 #include <QVector>
@@ -115,8 +116,13 @@ struct Execution {
     bool isFinished;
 
     ExecutionPtr prevExecution;
+
+#ifndef QT_NO_DEBUG
+    Tracer *tracer;
+#endif
 };
 
+
 typedef QSharedPointer<Execution> ExecutionPtr;
 
 class ExecutorBase
@@ -128,6 +134,7 @@ class ExecutorBase
     friend class Async::Job;
 
     friend class Execution;
+    friend class Async::Tracer;
 
 public:
     virtual ~ExecutorBase();
@@ -143,6 +150,10 @@ protected:
     virtual bool handleError(const ExecutionPtr &execution) = 0;
 
     ExecutorBasePtr mPrev;
+
+#ifndef QT_NO_DEBUG
+    QString mExecutorName;
+#endif
 };
 
 template<typename PrevOut, typename Out, typename ... In>
@@ -581,6 +592,9 @@ ExecutionPtr Executor<PrevOut, Out, In ...>::exec(const ExecutorBasePtr &self)
     // 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 = new Tracer(execution.data()); // owned by execution
+#endif
 
     // chainup
     execution->prevExecution = mPrev ? mPrev->exec(mPrev) : ExecutionPtr();
@@ -667,6 +681,7 @@ ThenExecutor<Out, In ...>::ThenExecutor(ThenTask<Out, In ...> then, ErrorHandler
     : Executor<typename detail::prevOut<In ...>::type, Out, In ...>(error, parent)
     , mFunc(then)
 {
+    STORE_EXECUTOR_NAME("ThenExecutor", Out, In ...);
 }
 
 template<typename Out, typename ... In>
@@ -686,6 +701,7 @@ EachExecutor<PrevOut, Out, In>::EachExecutor(EachTask<Out, In> each, ErrorHandle
     : Executor<PrevOut, Out, In>(error, parent)
     , mFunc(each)
 {
+    STORE_EXECUTOR_NAME("EachExecutor", PrevOut, Out, In);
 }
 
 template<typename PrevOut, typename Out, typename In>
@@ -727,6 +743,7 @@ template<typename Out, typename In>
 ReduceExecutor<Out, In>::ReduceExecutor(ReduceTask<Out, In> reduce, ErrorHandler errorFunc, const ExecutorBasePtr &parent)
     : ThenExecutor<Out, In>(reduce, errorFunc, parent)
 {
+    STORE_EXECUTOR_NAME("ReduceExecutor", Out, In);
 }
 
 template<typename Out, typename ... In>
@@ -734,6 +751,7 @@ SyncThenExecutor<Out, In ...>::SyncThenExecutor(SyncThenTask<Out, In ...> then,
     : Executor<typename detail::prevOut<In ...>::type, Out, In ...>(errorFunc, parent)
     , mFunc(then)
 {
+    STORE_EXECUTOR_NAME("SyncThenExecutor", Out, In ...);
 }
 
 template<typename Out, typename ... In>
@@ -775,6 +793,7 @@ SyncEachExecutor<PrevOut, Out, In>::SyncEachExecutor(SyncEachTask<Out, In> each,
     : Executor<PrevOut, Out, In>(errorFunc, parent)
     , mFunc(each)
 {
+    STORE_EXECUTOR_NAME("SyncEachExecutor", PrevOut, Out, In);
 }
 
 template<typename PrevOut, typename Out, typename In>
@@ -812,6 +831,7 @@ template<typename Out, typename In>
 SyncReduceExecutor<Out, In>::SyncReduceExecutor(SyncReduceTask<Out, In> reduce, ErrorHandler errorFunc, const ExecutorBasePtr &parent)
     : SyncThenExecutor<Out, In>(reduce, errorFunc, parent)
 {
+    STORE_EXECUTOR_NAME("SyncReduceExecutor", Out, In);
 }
 
 
diff --git a/async/src/debug.cpp b/async/src/debug.cpp
new file mode 100644
index 0000000..9dfad1a
--- /dev/null
+++ b/async/src/debug.cpp
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2015  Daniel Vrátil <dvratil@redhat.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 "debug.h"
+#include "async.h"
+
+#include <QStringBuilder>
+
+#ifdef __GNUG__
+#include <cxxabi.h>
+#include <memory>
+#endif
+
+namespace Async
+{
+
+Q_LOGGING_CATEGORY(Debug, "org.kde.async", QtWarningMsg);
+Q_LOGGING_CATEGORY(Trace, "org.kde.async.trace", QtWarningMsg);
+
+QString demangleName(const char *name)
+{
+#ifdef __GNUG__
+    int status = 1; // uses -3 to 0 error codes
+    std::unique_ptr<char, void(*)(void*)> demangled(abi::__cxa_demangle(name, 0, 0, &status), std::free);
+    if (status == 0) {
+        return QString(demangled.get());
+    }
+#endif
+    return QString(name);
+}
+
+}
+
+using namespace Async;
+
+int Tracer::lastId = 0;
+
+Tracer::Tracer(Private::Execution *execution)
+    : mId(lastId++)
+    , mExecution(execution)
+{
+    msg(Async::Tracer::Start);
+}
+
+Tracer::~Tracer()
+{
+    msg(Async::Tracer::End);
+    // FIXME: Does this work on parallel executions?
+    --lastId;
+    --mId;
+}
+
+void Tracer::msg(Tracer::MsgType msgType)
+{
+    qCDebug(Trace).nospace() << (QString().fill(QLatin1Char(' '), mId * 2) % 
+                                 (msgType == Async::Tracer::Start ? " START " : " END   ") %
+                                 QString::number(mId) % " " %
+                                 mExecution->executor->mExecutorName);
+}
diff --git a/async/src/debug.h b/async/src/debug.h
new file mode 100644
index 0000000..c453eb3
--- /dev/null
+++ b/async/src/debug.h
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2015  Daniel Vrátil <dvratil@redhat.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 ASYNC_DEBUG_H
+#define ASYNC_DEBUG_H
+
+#include <QLoggingCategory>
+#include <QStringBuilder>
+
+#ifndef QT_NO_DEBUG
+#include <typeinfo>
+#endif
+
+namespace Async
+{
+
+Q_DECLARE_LOGGING_CATEGORY(Debug)
+Q_DECLARE_LOGGING_CATEGORY(Trace)
+
+QString demangleName(const char *name);
+
+namespace Private
+{
+class Execution;
+}
+
+class Tracer
+{
+public:
+    Tracer(Private::Execution *execution);
+    ~Tracer();
+
+private:
+    enum MsgType {
+        Start,
+        End
+    };
+    void msg(MsgType);
+
+    int mId;
+    Private::Execution *mExecution;
+
+    static int lastId;
+};
+
+}
+
+#ifndef QT_NO_DEBUG
+    template<typename T>
+    QString storeExecutorNameExpanded() {
+        return Async::demangleName(typeid(T).name());
+    }
+
+    template<typename T, typename ... Tail>
+    typename std::enable_if<sizeof ... (Tail) != 0, QString>::type
+    storeExecutorNameExpanded() {
+        return storeExecutorNameExpanded<T>() % QStringLiteral(", ") % storeExecutorNameExpanded<Tail ...>();
+    }
+
+    #define STORE_EXECUTOR_NAME(name, ...) \
+        ExecutorBase::mExecutorName = QStringLiteral(name) % QStringLiteral("<") % storeExecutorNameExpanded<__VA_ARGS__>() % QStringLiteral(">")
+#else
+    #define STORE_EXECUTOR_NAME(...)
+#endif
+
+#endif // ASYNC_DEBUG_H
\ No newline at end of file