static byte[] get_response(byte cmd_code, int reply_data_len, int timeout)
{
if (!response_event.WaitOne(timeout))
{
throw new Exception("Command timed out");
}
response_lock.WaitOne();
if (response_queue.Count < 0)
{
throw new Exception("reponse_queue.Count < 0");
}
caPacket pack = (caPacket)response_queue.Dequeue();
if (response_queue.Count < 1)
{
// put threads on hold until new responses appear
response_event.Reset();
}
response_lock.ReleaseMutex();
// check packet contents
if (pack.cmd_code != cmd_code)
{
// response queue messed up due to packet loss or logic fault
throw new Exception("Unexpected response");
}
if (pack.term != term_ack)
{
// adapter reported command failure due to parametre error in
// last command or execution failed
throw new Exception("Command failed");
}
if (pack.data_len != reply_data_len)
{
// faulty program logic; packet damage not likely, ince command
// code and terminator were in place
throw new Exception("Unexpected response data length");
}
return(pack.data_len > 0 ? pack.data : null);
}
protected override void process_usb()
{
int byte_i;
while (usb_queue.Count >= caPacket.min_size)
{
if (!pack_incomplete)
{
// read packet header
in_pack.cmd_code = (byte)usb_queue.Dequeue();
in_pack.data_len =
(ushort)(((byte)usb_queue.Dequeue() << 8) | (byte)usb_queue.Dequeue());
}
if (usb_queue.Count <= in_pack.data_len)
{
// incomplete packet
pack_incomplete = true;
return;
}
if (in_pack.data_len > 0)
{
// read data block
in_pack.data = new byte[in_pack.data_len];
Debug.Assert(in_pack.data != null);
for (byte_i = 0; byte_i < in_pack.data_len; ++byte_i)
{
in_pack.data[byte_i] = (byte)usb_queue.Dequeue();
}
}
// teminator
in_pack.term = (byte)usb_queue.Dequeue();
pack_incomplete = false;
// got CAN frame
if (in_pack.cmd_code == cmd_can_frame)
{
if (in_pack.data_len == 15)
{
// fill frame structure
caCANFrame can_frame = new caCANFrame();
can_frame.id = (uint)BitConverter.ToInt32(in_pack.data, 0);
can_frame.data = (ulong)BitConverter.ToInt64(in_pack.data, 4);
can_frame.length = in_pack.data[12];
can_frame.is_extended = in_pack.data[13];
can_frame.is_remote = in_pack.data[14];
frame_lock.WaitOne();
// store frame in queue and notify waiting threads
frame_queue.Enqueue(can_frame);
frame_event.Set();
frame_lock.ReleaseMutex();
}
}
// got command response
else
{
response_lock.WaitOne();
// save response packet and notify waiting threads
caPacket new_pack = new caPacket();
new_pack.cmd_code = in_pack.cmd_code;
new_pack.data = in_pack.data_len != 0 ? (byte[])in_pack.data.Clone() : null;
new_pack.data_len = in_pack.data_len;
new_pack.term = in_pack.term;
response_queue.Enqueue(new_pack);
response_event.Set();
response_lock.ReleaseMutex();
}
}
}
protected override void process_usb()
{
int byte_i;
while (usb_queue.Count >= caPacket.min_size) {
if (!pack_incomplete)
{
// read packet header
in_pack.cmd_code = (byte)usb_queue.Dequeue();
in_pack.data_len =
(ushort)(((byte)usb_queue.Dequeue() << 8) | (byte)usb_queue.Dequeue());
}
if (usb_queue.Count <= in_pack.data_len)
{
// incomplete packet
pack_incomplete = true;
return;
}
if (in_pack.data_len > 0)
{
// read data block
in_pack.data = new byte[in_pack.data_len];
Debug.Assert(in_pack.data != null);
for (byte_i = 0; byte_i < in_pack.data_len; ++byte_i)
{
in_pack.data[byte_i] = (byte)usb_queue.Dequeue();
}
}
// teminator
in_pack.term = (byte)usb_queue.Dequeue();
pack_incomplete = false;
// got CAN frame
if(in_pack.cmd_code == cmd_can_frame)
{
if(in_pack.data_len == 15)
{
// fill frame structure
caCANFrame can_frame = new caCANFrame();
can_frame.id = (uint)BitConverter.ToInt32(in_pack.data, 0);
can_frame.data = (ulong)BitConverter.ToInt64(in_pack.data, 4);
can_frame.length = in_pack.data[12];
can_frame.is_extended = in_pack.data[13];
can_frame.is_remote = in_pack.data[14];
frame_lock.WaitOne();
// store frame in queue and notify waiting threads
frame_queue.Enqueue(can_frame);
frame_event.Set();
frame_lock.ReleaseMutex();
}
}
// got command response
else
{
response_lock.WaitOne();
// save response packet and notify waiting threads
caPacket new_pack = new caPacket();
new_pack.cmd_code = in_pack.cmd_code;
new_pack.data = in_pack.data_len != 0 ? (byte[])in_pack.data.Clone() : null;
new_pack.data_len = in_pack.data_len;
new_pack.term = in_pack.term;
response_queue.Enqueue(new_pack);
response_event.Set();
response_lock.ReleaseMutex();
}
}
}
