Stop thread before deleting object reference

If setPeriodicCapture is called Visualizer will start a thread
and do periodic callbacks. When native_finalize is called the
reference to the class is deleted. If a callback happens after
this the reference is no longer valid and when used from the
callback method the vm crashes. With this patch the thread will
be terminated before deleting the reference.

Change-Id: I30f331437ddad05f8d52c244cdbecb1859a0abd2

2 files changed, 9 insertions, 0 deletions

diff --git a/include/media/Visualizer.h b/include/media/Visualizer.h
index 186e018..f14977b 100644
--- a/include/media/Visualizer.h
+++ b/include/media/Visualizer.h
@@ -97,6 +97,7 @@ public:
     // and the capture format is according to flags  (see callback_flags).
     status_t setCaptureCallBack(capture_cbk_t cbk, void* user, uint32_t flags, uint32_t rate,
                                 bool force = false);
+    void cancelCaptureCallBack();
 
     // set the capture size capture size must be a power of two in the range
     // [VISUALIZER_CAPTURE_SIZE_MAX. VISUALIZER_CAPTURE_SIZE_MIN]
diff --git a/media/libmedia/Visualizer.cpp b/media/libmedia/Visualizer.cpp
index f5c1b1f..8d83c1b 100644
--- a/media/libmedia/Visualizer.cpp
+++ b/media/libmedia/Visualizer.cpp
@@ -94,6 +94,14 @@ status_t Visualizer::setEnabled(bool enabled)
     return status;
 }
 
+void Visualizer::cancelCaptureCallBack()
+{
+    sp<CaptureThread> t = mCaptureThread;
+    if (t != 0) {
+        t->requestExitAndWait();
+    }
+}
+
 status_t Visualizer::setCaptureCallBack(capture_cbk_t cbk, void* user, uint32_t flags,
         uint32_t rate, bool force)
 {