Clean up manual reference counting of blob dependencies

The manual addref() and then release() in notifyComplete() are hard to
read. It's simpler to let m_waitingFor store QQmlRefPointer instances,
at the expense of iteration code that's harer to read.

Change-Id: Idc51fbb1b24e0bd466381b9a1ad10fbd38fc8ac1
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

2 files changed, 16 insertions, 12 deletions

diff --git a/src/qml/qml/qqmltypeloader.cpp b/src/qml/qml/qqmltypeloader.cpp
index 7023bb98c6..61bcf6a663 100644
--- a/src/qml/qml/qqmltypeloader.cpp
+++ b/src/qml/qml/qqmltypeloader.cpp
@@ -501,11 +501,12 @@ void QQmlDataBlob::addDependency(QQmlDataBlob *blob)
 
     if (!blob ||
         blob->status() == Error || blob->status() == Complete ||
-        status() == Error || status() == Complete || m_isDone ||
-        m_waitingFor.contains(blob))
+        status() == Error || status() == Complete || m_isDone)
         return;
 
-    blob->addref(); // balanced in notifyComplete
+    for (auto existingDep: qAsConst(m_waitingFor))
+        if (existingDep.data() == blob)
+            return;
 
     m_data.setStatus(WaitingForDependencies);
 
@@ -688,13 +689,11 @@ void QQmlDataBlob::tryDone()
 void QQmlDataBlob::cancelAllWaitingFor()
 {
     while (m_waitingFor.count()) {
-        QQmlDataBlob *blob = m_waitingFor.takeLast();
+        QQmlRefPointer<QQmlDataBlob> blob = m_waitingFor.takeLast();
 
         Q_ASSERT(blob->m_waitingOnMe.contains(this));
 
         blob->m_waitingOnMe.removeOne(this);
-
-        blob->release();
     }
 }
 
@@ -703,7 +702,8 @@ void QQmlDataBlob::notifyAllWaitingOnMe()
     while (m_waitingOnMe.count()) {
         QQmlDataBlob *blob = m_waitingOnMe.takeLast();
 
-        Q_ASSERT(blob->m_waitingFor.contains(this));
+        Q_ASSERT(std::any_of(blob->m_waitingFor.constBegin(), blob->m_waitingFor.constEnd(),
+                             [this](const QQmlRefPointer<QQmlDataBlob> &waiting) { return waiting.data() == this; }));
 
         blob->notifyComplete(this);
     }
@@ -711,13 +711,19 @@ void QQmlDataBlob::notifyAllWaitingOnMe()
 
 void QQmlDataBlob::notifyComplete(QQmlDataBlob *blob)
 {
-    Q_ASSERT(m_waitingFor.contains(blob));
     Q_ASSERT(blob->status() == Error || blob->status() == Complete);
     QQmlCompilingProfiler prof(typeLoader()->profiler(), blob);
 
     m_inCallback = true;
 
-    m_waitingFor.removeOne(blob);
+    QQmlRefPointer<QQmlDataBlob> blobRef;
+    for (int i = 0; i < m_waitingFor.count(); ++i) {
+        if (m_waitingFor.at(i).data() == blob) {
+            blobRef = m_waitingFor.takeAt(i);
+            break;
+        }
+    }
+    Q_ASSERT(blobRef);
 
     if (blob->status() == Error) {
         dependencyError(blob);
@@ -725,8 +731,6 @@ void QQmlDataBlob::notifyComplete(QQmlDataBlob *blob)
         dependencyComplete(blob);
     }
 
-    blob->release();
-
     if (!isError() && m_waitingFor.isEmpty())
         allDependenciesDone();
 
diff --git a/src/qml/qml/qqmltypeloader_p.h b/src/qml/qml/qqmltypeloader_p.h
index 11e211012d..2418f3f716 100644
--- a/src/qml/qml/qqmltypeloader_p.h
+++ b/src/qml/qml/qqmltypeloader_p.h
@@ -217,7 +217,7 @@ private:
     QList<QQmlDataBlob *> m_waitingOnMe;
 
     // List of QQmlDataBlob's that I am waiting for to complete.
-    QList<QQmlDataBlob *> m_waitingFor;
+    QVector<QQmlRefPointer<QQmlDataBlob>> m_waitingFor;
 
     int m_redirectCount:30;
     bool m_inCallback:1;