Ensure cancelling a download is done in the same thread it started

This prevent Qt to crash with "Cannot send events to objects owned by a different thread." Fixes #11663
MythTV · Jul 24, 2013 · 997f7aa · 997f7aa
1 parent ea99443
commit 997f7aa
Show file tree

Hide file tree

Showing 2 changed files with 24 additions and 8 deletions.
diff --git a/mythtv/libs/libmythbase/mythdownloadmanager.cpp b/mythtv/libs/libmythbase/mythdownloadmanager.cpp
@@ -276,12 +276,15 @@ void MythDownloadManager::run(void)
         }
         m_infoLock->lock();
         downloading = !m_downloadInfos.isEmpty();
-        itemsInQueue = !m_downloadQueue.isEmpty();
         m_infoLock->unlock();
 
         if (downloading)
             QCoreApplication::processEvents();
 
+        m_infoLock->lock();
+        itemsInQueue = !m_downloadQueue.isEmpty();
+        m_infoLock->unlock();
+
         if (!itemsInQueue || waitAnyway)
         {
             waitAnyway = false;
@@ -835,7 +838,7 @@ bool MythDownloadManager::downloadNow(MythDownloadInfo *dlInfo, bool deleteInfo)
         if ((dlInfo->m_reply) &&
             (dlInfo->m_errorCode == QNetworkReply::NoError))
         {
-            LOG(VB_FILE, LOG_DEBUG, 
+            LOG(VB_FILE, LOG_DEBUG,
                 LOC + QString("Aborting download - lack of data transfer"));
             dlInfo->m_reply->abort();
         }
@@ -855,6 +858,12 @@ bool MythDownloadManager::downloadNow(MythDownloadInfo *dlInfo, bool deleteInfo)
  *  \param url for download to cancel
  */
 void MythDownloadManager::cancelDownload(const QString &url)
+{
+    QMetaObject::invokeMethod(this, "downloadCanceled",
+                              Qt::QueuedConnection, Q_ARG(const QString&, url));
+}
+
+void MythDownloadManager::downloadCanceled(const QString  &url)
 {
     QMutexLocker locker(m_infoLock);
     MythDownloadInfo *dlInfo;
@@ -869,11 +878,13 @@ void MythDownloadManager::cancelDownload(const QString &url)
             // this shouldn't happen
             if (dlInfo->m_reply)
             {
-                LOG(VB_FILE, LOG_DEBUG, 
+                LOG(VB_FILE, LOG_DEBUG,
                     LOC + QString("Aborting download - user request"));
                 dlInfo->m_reply->abort();
             }
             lit.remove();
+            if (dlInfo->IsDone())
+                continue;
             dlInfo->m_lock.lock();
             dlInfo->m_errorCode = QNetworkReply::OperationCanceledError;
             dlInfo->m_done = true;
@@ -886,16 +897,19 @@ void MythDownloadManager::cancelDownload(const QString &url)
         dlInfo = m_downloadInfos[url];
         if (dlInfo->m_reply)
         {
-            LOG(VB_FILE, LOG_DEBUG, 
+            LOG(VB_FILE, LOG_DEBUG,
                 LOC + QString("Aborting download - user request"));
             m_downloadReplies.remove(dlInfo->m_reply);
             dlInfo->m_reply->abort();
         }
         m_downloadInfos.remove(url);
-        dlInfo->m_lock.lock();
-        dlInfo->m_errorCode = QNetworkReply::OperationCanceledError;
-        dlInfo->m_done = true;
-        dlInfo->m_lock.unlock();
+        if (!dlInfo->IsDone())
+        {
+            dlInfo->m_lock.lock();
+            dlInfo->m_errorCode = QNetworkReply::OperationCanceledError;
+            dlInfo->m_done = true;
+            dlInfo->m_lock.unlock();
+        }
     }
 }
 

diff --git a/mythtv/libs/libmythbase/mythdownloadmanager.h b/mythtv/libs/libmythbase/mythdownloadmanager.h
@@ -97,6 +97,8 @@ class MBASE_PUBLIC MythDownloadManager : public QObject, public MThread
     void downloadError(QNetworkReply::NetworkError errorCode);
     void downloadProgress(qint64 bytesReceived, qint64 bytesTotal);
 
+    void downloadCanceled(const QString &url);
+
   private:
     // Notification from RemoteFile downloads
     void downloadFinished(MythDownloadInfo *dlInfo);