The aio_write() function allows the calling process to write aiocbp->aio_nbytes to the file associated with aiocbp->aio_fildes from the buffer pointed to by aiocbp->aio_buf. The function call returns when the write request has been initiated or, at a minimum, queued
to the file or device. If _POSIX_PRIORITIZED_IO is defined and prioritized I/O is supported for this file, then the asynchronous operation is submitted at a priority
equal to the scheduling priority of the process minus aiocbp->aio_reqprio. The aiocbp may be used as an argument to aio_error(3RT) and aio_return(3RT) in order to determine the error status and return status, respectively, of the asynchronous operation while it is proceeding.
The aiocbp argument points to an aiocb structure. If the buffer pointed to by aiocbp->aio_buf or the control block
pointed to by aiocbp becomes an illegal address prior to asynchronous I/O completion, then the behavior is undefined.
If O_APPEND is not set for the file descriptor aio_fildes, then the requested operation takes place at the absolute position in the
file as given by aio_offset, as if lseek(2)
were called immediately prior to the operation with an offset equal to aio_offset and a whence equal to SEEK_SET. If O_APPEND is set for the file descriptor, write operations append to the file in the same order as the calls were made. After a successful
call to enqueue an asynchronous I/O operation, the value of the file offset for the file is unspecified.
The aiocbp->aio_lio_opcode field is ignored by aio_write().
Simultaneous asynchronous operations using the same aiocbp produce undefined results.
If _POSIX_SYNCHRONIZED_IO is defined and synchronized I/O is enabled on the file associated with aiocbp->aio_fildes,
the behavior of this function shall be according to the definitions of synchronized I/O data integrity completion and synchronized I/O file integrity completion.
For any system action that changes the process memory space while an asynchronous I/O is outstanding to the address range being changed, the result of that action is undefined.
For regular files, no data transfer will occur past the offset maximum established in the open file description associated with aiocbp->aio_fildes.
|