Man page 9 : i2o_msg_get

i2o_msg_get - obtain an I2O message from the IOP

struct i2o_message * i2o_msg_get(struct i2o_controller *  c );

c
    I2O controller

This function tries to get a message frame. If no message frame is available do not wait until one is available (see also i2o_msg_get_wait). The returned pointer to the message frame is not in I/O memory, it is allocated from a mempool. But because a MFA is allocated from the controller too it is guaranteed that i2o_msg_post will never fail.

On a success a pointer to the message frame is returned. If the message queue is empty -EBUSY is returned and if no memory is available -ENOMEM is returned.