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, 32 insertions, 0 deletions

diff --git a/src/plugins/cpptools/cpptoolseditorsupport.cpp b/src/plugins/cpptools/cpptoolseditorsupport.cpp
index 631b1c1a44..e9ec1d23a0 100644
--- a/src/plugins/cpptools/cpptoolseditorsupport.cpp
+++ b/src/plugins/cpptools/cpptoolseditorsupport.cpp
@@ -115,6 +115,7 @@ CppEditorSupport::CppEditorSupport(CppModelManager *modelManager, BaseTextEditor
     , m_textEditor(textEditor)
     , m_updateDocumentInterval(UpdateDocumentDefaultInterval)
     , m_revision(0)
+    , m_editorVisible(textEditor->widget()->isVisible())
     , m_cachedContentsEditorRevision(-1)
     , m_fileIsBeingReloaded(false)
     , m_initialized(false)
@@ -152,6 +153,13 @@ CppEditorSupport::CppEditorSupport(CppModelManager *modelManager, BaseTextEditor
     connect(m_textEditor->document(), SIGNAL(reloadFinished(bool)),
             this, SLOT(onReloadFinished()));
 
+    connect(Core::EditorManager::instance(), SIGNAL(currentEditorChanged(Core::IEditor *)),
+            this, SLOT(onCurrentEditorChanged()));
+    m_editorGCTimer = new QTimer(this);
+    m_editorGCTimer->setSingleShot(true);
+    m_editorGCTimer->setInterval(EditorHiddenGCTimeout);
+    connect(m_editorGCTimer, SIGNAL(timeout()), this, SLOT(releaseResources()));
+
     updateDocument();
 }
 
@@ -460,6 +468,30 @@ void CppEditorSupport::updateEditorNow()
     editorWidget->setIfdefedOutBlocks(m_editorUpdates.ifdefedOutBlocks);
 }
 
+void CppEditorSupport::onCurrentEditorChanged()
+{
+    bool editorVisible = m_textEditor->widget()->isVisible();
+
+    if (m_editorVisible != editorVisible) {
+        m_editorVisible = editorVisible;
+        if (editorVisible) {
+            m_editorGCTimer->stop();
+            QMutexLocker locker(&m_lastSemanticInfoLock);
+            if (!m_lastSemanticInfo.doc)
+                updateDocumentNow();
+        } else {
+            m_editorGCTimer->start(EditorHiddenGCTimeout);
+        }
+    }
+}
+
+void CppEditorSupport::releaseResources()
+{
+    snapshotUpdater()->releaseSnapshot();
+    QMutexLocker semanticLocker(&m_lastSemanticInfoLock);
+    m_lastSemanticInfo = SemanticInfo();
+}
+
 SemanticInfo::Source CppEditorSupport::currentSource(bool force)
 {
     int line = 0, column = 0;