From c7d8b9b01c140a44abf2c93a4354ac0f66a68590 Mon Sep 17 00:00:00 2001
From: Christian Kandeler <christian.kandeler@qt.io>
Date: Fri, 31 Jan 2020 15:52:20 +0100
Subject: QMakeProjectManager: Move some parsing code out of the UI thread

When parsing larger qmake project, the callbacks from the parser threads
are currently overloading the UI thread, often rendering the application
non-responsive until the project is completely loaded.
This patch moves some expensive operations from the UI thread into the
parser threads, at the cost of a somewhat ugly two-stage setup for some
types of objects.
On my Linux machine, I measured that the time spent in parser callback code
went down by almost 50% when loading the Qt Creator super project.

Task-number: QTCREATORBUG-18533
Change-Id: If9624da5b07e81a50c180693580b20a70e1aaea7
Reviewed-by: hjk <hjk@qt.io>
---
 src/plugins/qmakeprojectmanager/qmakeparsernodes.h | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

(limited to 'src/plugins/qmakeprojectmanager/qmakeparsernodes.h')

diff --git a/src/plugins/qmakeprojectmanager/qmakeparsernodes.h b/src/plugins/qmakeprojectmanager/qmakeparsernodes.h
index 61620e59fcf..9a5977348af 100644
--- a/src/plugins/qmakeprojectmanager/qmakeparsernodes.h
+++ b/src/plugins/qmakeprojectmanager/qmakeparsernodes.h
@@ -125,8 +125,10 @@ class QMAKEPROJECTMANAGER_EXPORT QmakePriFile
 {
 public:
     QmakePriFile(QmakeBuildSystem *buildSystem, QmakeProFile *qmakeProFile, const Utils::FilePath &filePath);
+    explicit QmakePriFile(const Utils::FilePath &filePath);
     virtual ~QmakePriFile();
 
+    void finishInitialization(QmakeBuildSystem *buildSystem, QmakeProFile *qmakeProFile);
     Utils::FilePath filePath() const;
     Utils::FilePath directoryPath() const;
     virtual QString displayName() const;
@@ -241,6 +243,7 @@ private:
     QMap<ProjectExplorer::FileType, SourceFiles> m_files;
     QSet<Utils::FilePath> m_recursiveEnumerateFiles; // FIXME: Remove this?!
     QSet<QString> m_watchedFolders;
+    const Utils::FilePath m_filePath;
     bool m_includedInExactParse = true;
 
     friend class QmakeProFile;
@@ -294,8 +297,11 @@ class QMAKEPROJECTMANAGER_EXPORT QmakeProFile : public QmakePriFile
 {
 public:
     QmakeProFile(QmakeBuildSystem *buildSystem, const Utils::FilePath &filePath);
+    explicit QmakeProFile(const Utils::FilePath &filePath);
     ~QmakeProFile() override;
 
+    void setupFutureWatcher();
+
     bool isParent(QmakeProFile *node);
     QString displayName() const final;
 
@@ -390,7 +396,7 @@ private:
     QMap<QString, QStringList> m_wildcardDirectoryContents;
 
     // Async stuff
-    QFutureWatcher<Internal::QmakeEvalResult *> m_parseFutureWatcher;
+    QFutureWatcher<Internal::QmakeEvalResult *> *m_parseFutureWatcher = nullptr;
     QtSupport::ProFileReader *m_readerExact = nullptr;
     QtSupport::ProFileReader *m_readerCumulative = nullptr;
 };
-- 
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