From 3ab93592c35c4bb9f87be809ce858e6ba48003c1 Mon Sep 17 00:00:00 2001
From: Jarek Kobus <jaroslaw.kobus@qt.io>
Date: Tue, 9 Mar 2021 13:53:34 +0100
Subject: [PATCH] CppLocatorData: Don't use recursive mutex

Don't use recursive mutex in CppLocatorData class,
as this is more expensive to construct than simple
QMutex. Refactor the code so that every call to
flushPendingDocument() is done with already locked
m_pendingDocumentsMutex. This eliminates the need
for recursive mutex.

Remove unused allIndexItems() method.

Change-Id: Ic7cb45bc3301d83768e69ee52f84ae159cb731a5
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
---
 src/plugins/cpptools/cpplocatordata.cpp | 10 ----------
 src/plugins/cpptools/cpplocatordata.h   |  6 +++---
 2 files changed, 3 insertions(+), 13 deletions(-)

diff --git a/src/plugins/cpptools/cpplocatordata.cpp b/src/plugins/cpptools/cpplocatordata.cpp
index be2b948a96b..3154f66ddba 100644
--- a/src/plugins/cpptools/cpplocatordata.cpp
+++ b/src/plugins/cpptools/cpplocatordata.cpp
@@ -86,7 +86,6 @@ void CppLocatorData::onAboutToRemoveFiles(const QStringList &files)
 void CppLocatorData::flushPendingDocument(bool force) const
 {
     // TODO: move this off the UI thread and into a future.
-    QMutexLocker locker(&m_pendingDocumentsMutex);
     if (!force && m_pendingDocuments.size() < MaxPendingDocuments)
         return;
     if (m_pendingDocuments.isEmpty())
@@ -98,12 +97,3 @@ void CppLocatorData::flushPendingDocument(bool force) const
     m_pendingDocuments.clear();
     m_pendingDocuments.reserve(MaxPendingDocuments);
 }
-
-QList<IndexItem::Ptr> CppLocatorData::allIndexItems(
-        const QHash<QString, QList<IndexItem::Ptr>> &items) const
-{
-    QList<IndexItem::Ptr> result;
-    for (const QList<IndexItem::Ptr> &subItems : items)
-        result.append(subItems);
-    return result;
-}
diff --git a/src/plugins/cpptools/cpplocatordata.h b/src/plugins/cpptools/cpplocatordata.h
index b41bce07bfb..f8c853471f6 100644
--- a/src/plugins/cpptools/cpplocatordata.h
+++ b/src/plugins/cpptools/cpplocatordata.h
@@ -46,8 +46,8 @@ class CppLocatorData : public QObject
 public:
     void filterAllFiles(IndexItem::Visitor func) const
     {
-        flushPendingDocument(true);
         QMutexLocker locker(&m_pendingDocumentsMutex);
+        flushPendingDocument(true);
         QHash<QString, IndexItem::Ptr> infosByFile = m_infosByFile;
         locker.unlock();
         for (auto i = infosByFile.constBegin(), ei = infosByFile.constEnd(); i != ei; ++i)
@@ -60,13 +60,13 @@ public slots:
     void onAboutToRemoveFiles(const QStringList &files);
 
 private:
+    // Ensure to protect every call to this method with m_pendingDocumentsMutex
     void flushPendingDocument(bool force) const;
-    QList<IndexItem::Ptr> allIndexItems(const QHash<QString, QList<IndexItem::Ptr>> &items) const;
 
     mutable SearchSymbols m_search;
     mutable QHash<QString, IndexItem::Ptr> m_infosByFile;
 
-    mutable QRecursiveMutex m_pendingDocumentsMutex;
+    mutable QMutex m_pendingDocumentsMutex;
     mutable QVector<CPlusPlus::Document::Ptr> m_pendingDocuments;
 };