static int read_data_port(ushort_t port, void * dst, uint_t length, struct vm_device * dev) {
struct serial_state * state = (struct serial_state *)dev->private_data;
char * val = (char *)dst;
PrintDebug("Read from Data Port 0x%x\n", port);
if (length != 1) {
PrintDebug("Invalid length(%d) in write to 0x%x\n", length, port);
return -1;
}
switch (port) {
case COM1_DATA_PORT:
dequeue_data(&(state->com1.tx_buffer), val);
break;
case COM2_DATA_PORT:
dequeue_data(&(state->com2.tx_buffer), val);
break;
case COM3_DATA_PORT:
dequeue_data(&(state->com3.tx_buffer), val);
break;
case COM4_DATA_PORT:
dequeue_data(&(state->com4.tx_buffer), val);
break;
default:
return -1;
}
return length;
}
bool_t
receive_data(DTQCB *p_dtqcb, intptr_t *p_data, bool_t *p_reqdsp)
{
TCB *p_tcb;
intptr_t data;
if (p_dtqcb->count > 0U) {
dequeue_data(p_dtqcb, p_data);
if (!queue_empty(&(p_dtqcb->swait_queue))) {
p_tcb = (TCB *) queue_delete_next(&(p_dtqcb->swait_queue));
data = ((WINFO_DTQ *)(p_tcb->p_winfo))->data;
enqueue_data(p_dtqcb, data);
*p_reqdsp = wait_complete(p_tcb);
}
else {
*p_reqdsp = false;
}
return(true);
}
else if (!queue_empty(&(p_dtqcb->swait_queue))) {
p_tcb = (TCB *) queue_delete_next(&(p_dtqcb->swait_queue));
*p_data = ((WINFO_DTQ *)(p_tcb->p_winfo))->data;
*p_reqdsp = wait_complete(p_tcb);
return(true);
}
else {
return(false);
}
}
bool message::dequeue(data_chunk& value)
{
if (queue_.empty())
return false;
value = dequeue_data();
return true;
}
