前文回顾
上一篇文章，简单讲述process_capture_result的过程
一、close 流程
1.1 原文解析
* 12. Alternatively, the framework may call camera3_device_t->common->close()
* to end the camera session. This may be called at any time when no other
* calls from the framework are active, although the call may block until all
* in-flight captures have completed (all results returned, all buffers
* filled). After the close call returns, no more calls to the
* camera3_callback_ops_t functions are allowed from the HAL. Once the
* close() call is underway, the framework may not call any other HAL device
* functions.12、关闭相机：此外，framework可以调用camera3_device_t-> common-> close（）结束camera session。 当没有其他来自framework的调用处于活动状态时，可以随时调用此方法。，尽管所有正在进行的Capture（返回所有结果，填充所有缓冲区）结束前都会阻塞。 close调用返回后，HAL将不再允许调用camera3_callback_ops_t函数。 一旦进行close（）调用，framework就不能调用任何其他HAL设备功能。
1.2 官网文档
《80-pc212-1_a_chi_api_specifications_for_qualcomm_spectra_2xx_camera.pdf》简单介绍close的过程
1.3 代码分析
//TODO，喝口水，远眺下，继续撸代码