Camera2: Fix deadlock on shutdown due to client getting killed.
When the binder connection dies and is the only holder of a strong
pointer to the Camera2Client, disconnect is called from the
destructor. At this point, all weak pointers to Camera2Client are no
longer promotable, and lots of cleanup code paths are broken as a
result.
Rework all such code paths to not need the client pointer, and to
discard image buffers that arrive during shutdown.
Bug: 8696047
Change-Id: Ic0672ecde7c1baaf65079f925a45bd5be45f1fb3
diff --git a/services/camera/libcameraservice/Camera2Client.cpp b/services/camera/libcameraservice/Camera2Client.cpp
index 9421a77..eae7461 100644
--- a/services/camera/libcameraservice/Camera2Client.cpp
+++ b/services/camera/libcameraservice/Camera2Client.cpp
@@ -135,6 +135,7 @@
Camera2Client::~Camera2Client() {
ATRACE_CALL();
+ ALOGV("~Camera2Client");
mDestructionStarted = true;
@@ -369,6 +370,12 @@
ALOGV("Camera %d: Shutting down", mCameraId);
+ /**
+ * disconnect() cannot call any methods that might need to promote a
+ * wp<Camera2Client>, since disconnect can be called from the destructor, at
+ * which point all such promotions will fail.
+ */
+
stopPreviewL();
{
@@ -538,7 +545,12 @@
break;
case Parameters::PREVIEW:
// Already running preview - need to stop and create a new stream
- mStreamingProcessor->stopStream();
+ res = stopStream();
+ if (res != OK) {
+ ALOGE("%s: Unable to stop preview to swap windows: %s (%d)",
+ __FUNCTION__, strerror(-res), res);
+ return res;
+ }
state = Parameters::WAITING_FOR_PREVIEW_WINDOW;
break;
}
@@ -745,7 +757,11 @@
// no break
case Parameters::RECORD:
case Parameters::PREVIEW:
- mStreamingProcessor->stopStream();
+ res = stopStream();
+ if (res != OK) {
+ ALOGE("%s: Camera %d: Can't stop streaming: %s (%d)",
+ __FUNCTION__, mCameraId, strerror(-res), res);
+ }
res = mDevice->waitUntilDrained();
if (res != OK) {
ALOGE("%s: Camera %d: Waiting to stop streaming failed: %s (%d)",