[SurfaceFlinger] Fix crash in SurfaceTracing

mThread is guarded by a lock, so acquire the lock to steal the thread
when tracing finishes.

Bug: 147319235
Test: winscope
Change-Id: Id0e103c66c8937272aa9a1c02f153eea2e2f9859

parent f4f7283f

services/surfaceflinger/SurfaceTracing.cpp

+6 −1

Original line number	Diff line number	Diff line
		@@ -129,7 +129,12 @@ void SurfaceTracing::enable() {
		}

		status_t SurfaceTracing::writeToFile() {
		mThread.join();
		std::thread thread;
		{
		std::scoped_lock lock(mTraceLock);
		thread = std::move(mThread);
		}
		thread.join();
		return mLastErr;
		}