Hi, On Fri, 4 Apr 2025 at 14:35, Marco Cavenati <marco.caven...@eurecom.fr> wrote: > Almost. Unlike lseek(2), pread(2) and co. do not have side effects on the > fd's offset. > From the man page: > > The pread() and pwrite() system calls are especially useful in > > multithreaded applications. They allow multiple threads to > > perform I/O on the same file descriptor without being affected by > > changes to the file offset by other threads.
* If the r/w pointer adjustment (lseek(2)) is not required, then why set the '*_FEATURE_SEEKABLE' flag? > It is a first step in making QIOChannelBlock compatible with > mapped-ram feature that requires it since mapped-ram uses > io_preadv and io_pwritev methods. * The qio_channel_block_preadv/pwritev functions defined above, which shall be called via '->io_preadv' and '->io_pwritev' methods, appear to call bdrv_readv/writev_vmstate() functions. Do those functions need to adjust (lseek(2)) the stream r/w pointers? Thank you. --- - Prasad
