Hi, This is Shang Shi from Google. As we are examining the Andorid adb daemon implementation in AOSP, we found that there's a concern on functionfs that an io_submit syscall on IN/OUT endpoint after endpoint becomes disabled could end up blocking [1]. AOSP kills a thread to avoid it blocking on io_submit, which is not an elegant way to exist. Is it true that io_submit syscall could end up blocking after endpoint is disabled? Would opening endpoint file with O_NONBLOCK resolve the issue? >From the ffs-aio-example "aio_simple.c", it seems that as long as we read and process control events before any read/write (with io_submit), we are not worried about any race condition between endpoint becoming disabled and io_submit. Is this true? Really appreciate it for taking time helping us on these questions! Thanks! Shang Shi Reference [1]: https://cs.android.com/android/platform/superproject/+/master:packages/modules/adb/daemon/usb.cpp;drc=bbfaaac52f1321d3b9b67e89ab23303510cd2593;l=247
