Removing potential crashes from out-of-thread cleanup on Symbian

There have been some crashes seen on Symbian when its
adoptedThreadMonitor attempts to clean up objects created in other, now
dead, threads. Some of these objects simply can't be cleaned up
properly outside of their original thread, so the thread has to be
checked when they are cleaned up, and cleanup skipped in the wrong
thread.

For pthread created threads, we also have the ability to insert cleanup
code during thread shutdown. This was used in the 4.7 implementation of
QThread on Symbian, and is a better solution for pthread based adopted
threads as it gives in-thread cleanup. So the appropriate pthread code
is also used with changes to adoptedThreadMonitor so that it can run
along side the pthread cleanup code.

Change-Id: Iad8207879b1ece62e5cce85f26a616166aa22486
Reviewed-by: Juha Kukkonen <ext-juha.kukkonen@nokia.com>
Reviewed-by: Pasi Pentikäinen <ext-pasi.a.pentikainen@nokia.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/src/gui/text/qfontengine_s60.cpp b/src/gui/text/qfontengine_s60.cpp
index 899b5da..2702ca8 100644
--- a/src/gui/text/qfontengine_s60.cpp
+++ b/src/gui/text/qfontengine_s60.cpp
@@ -298,8 +298,10 @@ QFontEngineS60::QFontEngineS60(const QFontDef &request, const QSymbianTypeFaceEx
 
 QFontEngineS60::~QFontEngineS60()
 {
-    releaseFont(m_originalFont);
-    releaseFont(m_scaledFont);
+    if (QThread::currentThread() == thread()) {
+        releaseFont(m_originalFont);
+        releaseFont(m_scaledFont);
+    }
 }
 
 QFixed QFontEngineS60::emSquareSize() const