C++: Release more documents.

- fix memory leak in find-usages
- do not retain snapshot in search history
- when an editor is invisible for more than 2 minutes, release the
  backing snapshot

Retaining snapshots will retain their documents, and if done for too
long, the memory consumption might grow. This is especially the case
when switching to a different kit (Qt version): in that case, the new
versions of headers will be indexed, while the old ones stay around.

Task-number: QTCREATORBUG-5583
Task-number: QTCREATORBUG-7645
Task-number: QTCREATORBUG-9842

Change-Id: I045eda1565e0a3fa702baeffaab9c12662f90289
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@digia.com>

1 files changed, 5 insertions, 8 deletions

diff --git a/src/plugins/cppeditor/cppfunctiondecldeflink.cpp b/src/plugins/cppeditor/cppfunctiondecldeflink.cpp
index 916dd4b6cb..29c12e7d68 100644
--- a/src/plugins/cppeditor/cppfunctiondecldeflink.cpp
+++ b/src/plugins/cppeditor/cppfunctiondecldeflink.cpp
@@ -60,13 +60,12 @@ using namespace Utils;
 FunctionDeclDefLinkFinder::FunctionDeclDefLinkFinder(QObject *parent)
     : QObject(parent)
 {
-    connect(&m_watcher, SIGNAL(finished()),
-            this, SLOT(onFutureDone()));
 }
 
 void FunctionDeclDefLinkFinder::onFutureDone()
 {
-    QSharedPointer<FunctionDeclDefLink> link = m_watcher.result();
+    QSharedPointer<FunctionDeclDefLink> link = m_watcher->result();
+    m_watcher.reset();
     if (link) {
         link->linkSelection = m_scannedSelection;
         link->nameSelection = m_nameSelection;
@@ -256,7 +255,9 @@ void FunctionDeclDefLinkFinder::startFindLinkAt(
     result->sourceFunctionDeclarator = funcDecl;
 
     // handle the rest in a thread
-    m_watcher.setFuture(QtConcurrent::run(&findLinkHelper, result, refactoringChanges));
+    m_watcher.reset(new QFutureWatcher<QSharedPointer<FunctionDeclDefLink> >());
+    connect(m_watcher.data(), SIGNAL(finished()), this, SLOT(onFutureDone()));
+    m_watcher->setFuture(QtConcurrent::run(&findLinkHelper, result, refactoringChanges));
 }
 
 FunctionDeclDefLink::FunctionDeclDefLink()
@@ -270,10 +271,6 @@ FunctionDeclDefLink::FunctionDeclDefLink()
     targetFunctionDeclarator = 0;
 }
 
-FunctionDeclDefLink::~FunctionDeclDefLink()
-{
-}
-
 bool FunctionDeclDefLink::isValid() const
 {
     return !linkSelection.isNull();