io_prep_pread(3) Linux AIO io_prep_pread(3)

io_prep_pread - Set up asynchronous read

#include <errno.h>

#include <libaio.h>

inline void io_prep_pread(struct iocb *iocb, int fd, void *buf, size_t count, long long offset);

struct iocb {
	void		*data;
	unsigned	key;
	short		aio_lio_opcode;
	short		aio_reqprio;
	int		aio_fildes;

io_prep_pread() is an inline convenience function designed to facilitate the initialization of the iocb for an asynchronous read operation.

The first iocb->u.c.nbytes = count bytes of the file for which iocb->aio_fildes = fd is a descriptor are written to the buffer starting at iocb->u.c.buf = buf. Reading starts at the absolute position ioc->u.c.offset = offset in the file.

This function returns immediately. To schedule the operation, the function io_submit(3) must be called.

Simultaneous asynchronous operations using the same iocb produce undefined results.



io(3), io_cancel(3), io_fsync(3), io_getevents(3), io_prep_fsync(3), io_prep_pwrite(3), io_queue_init(3), io_queue_release(3), io_queue_run(3), io_queue_wait(3), io_set_callback(3), io_submit(3), errno(3).

2019-07-23 Linux