sane_set_io_mode

This function is used to set the I/O mode of handle h. The I/O mode can be either blocking or non-blocking. If argument m is SANE_TRUE, the mode is set to non-blocking mode, otherwise it's set to blocking mode.

SANE_Status sane_set_io_mode (SANE_Handle h, SANE_Bool m);

By default, newly opened handles operate in blocking mode. A backend may elect not to support non-blocking I/O mode. In such a case the status value SANE_STATUS_UNSUPPORTED is returned. Blocking I/O must be supported by all backends, so calling this function with argument m set to SANE_FALSE is guaranteed to complete successfully.

This function may fail with one of the following status codes:

SANE_STATUS_INVAL:

No image acquisition is pending.

SANE_STATUS_UNSUPPORTED:

The backend does not support this operation.