SPI_connect, SPI_connect_ext — connect a C function to the SPI manager
int SPI_connect(void)
int SPI_connect_ext(int options)
SPI_connect opens a connection from a
C function invocation to the SPI manager. You must call this
function if you want to execute commands through SPI. Some utility
SPI functions can be called from unconnected C functions.
SPI_connect_ext does the same but has an argument that
allows passing option flags. Currently, the following option values are
available:
SPI_OPT_NONATOMIC
Sets the SPI connection to be nonatomic, which
means that transaction control calls SPI_commit,
SPI_rollback, and
SPI_start_transaction are allowed. Otherwise,
calling these functions will result in an immediate error.
SPI_connect() is equivalent to
SPI_connect_ext(0).
SPI_OK_CONNECTon success
SPI_ERROR_CONNECTon error