/// <summary>
/// Write a message to the MmfWriter. Message is queued and sent in a thread loop.
/// </summary>
/// <param name="message">Message to write</param>
public void WriteData(NiawaMmfContainer message)
{
try
{
if (!_threadStatus.IsThreadEnabled || !_threadStatus.IsThreadActive) { throw new Exception("Cannot write data - writer is not active"); };
//get next serial ID
id = Niawa.Utilities.IdGeneratorUtils.IncrementSerialId(id);
message.SerialID = id.ToString();
logger.Debug("[" + _description + "-M] Writing data: " + message.SerialID);
_sendQueue.Enqueue(message);
}
catch (Exception ex)
{
logger.Error("[" + _description + "-M] Exception while writing data: " + ex.Message, ex);
if (!_ignoreExceptions)
throw ex;
}
}
/// <summary>
/// Loop thread that reads the memory mapped file and adds items to the read queue.
/// </summary>
/// <param name="data"></param>
private void ListenThreadImpl(object data)
{
try
{
_threadStatus.IsThreadActive = true;
logger.Info("[" + _description + "-T] Reader active");
try
{
while (_threadStatus.IsThreadEnabled == true)
{
_threadStatus.ThreadHealthDate = DateTime.Now;
DateTime duplicateErrorDate = DateTime.MinValue;
//listening
try
{
/* Memory Mapped File:
* accessor1Len: bytes 0-4 total length of file
* accessor2ID: bytes 8-12 ID number of message
* accessor3Data: variable bytes payload
* */
int msgLength;
int msgID;
//open mmf
mmf = MemoryMappedFile.OpenExisting(_ipcType);
MemoryMappedViewAccessor accessor1Len = mmf.CreateViewAccessor(0, 4);
MemoryMappedViewAccessor accessor2ID = mmf.CreateViewAccessor(8, 4);
MemoryMappedViewAccessor accessor3Data;
//locked section
using (new Niawa.Utilities.SingleGlobalInstance(1000, _ipcType)) //1000ms timeout on global lock
{
//get length, ID, and data
msgLength = accessor1Len.ReadInt32(0);
msgID = accessor2ID.ReadInt32(0);
accessor3Data = mmf.CreateViewAccessor(16, msgLength);
}
System.Diagnostics.Debug.WriteLine("MmfReader: MsgID: " + msgID);
System.Diagnostics.Debug.WriteLine("MmfReader: LastMsgID: " + _lastMsgID);
//check if ID changed
if (msgID == _lastMsgID)
{
System.Diagnostics.Debug.WriteLine("MmfReader: There is no work to do");
//do nothing
System.Threading.Thread.Sleep(10);
}
else
{
System.Diagnostics.Debug.WriteLine("MmfReader: Reading message");
//set ID
_lastMsgID = msgID;
//check if message is too long
if (msgLength + 16 > _bufferLength)
{
logger.Error("[" + _description + "-T] Not reading message [" + msgID + "]: Message length [" + (msgLength + 16).ToString() + "] is greater than the buffer length [" + _bufferLength.ToString() + "]");
_threadStatus.MessageErrorCount += 1;
}
else
{
//get data
byte[] buffer = new byte[msgLength];
accessor3Data.ReadArray<byte>(0, buffer, 0, msgLength);
NiawaMmfContainer msg = new NiawaMmfContainer(buffer);
logger.Debug("[" + _description + "-T] Received data [" + msgID + "]: " + msg.SerialID);
_threadStatus.MessageCount += 1;
_receiveQueue.Enqueue(msg);
}
}
}
catch (System.IO.FileNotFoundException)
{
//file does not exist
System.Diagnostics.Debug.WriteLine("MmfReader [" + _ipcType + "]: File was not found");
//log message every 10 seconds
TimeSpan ts = DateTime.Now - duplicateErrorDate;
if (ts.TotalSeconds > 10)
{
duplicateErrorDate = DateTime.Now;
logger.Debug("[" + _description + "-T] Mmf not initiated by provider");
}
//sleep for 250 ms
System.Threading.Thread.Sleep(250);
}
catch (System.Threading.ThreadAbortException) // ex1)
{
//thread was aborted; re-enter loop
logger.Info("[" + _description + "-T] Thread aborted");
break;
}
catch (System.Threading.ThreadInterruptedException) // ex1)
{
//thread was interrupted; re-enter loop
logger.Info("[" + _description + "-T] Thread interrupted");
break;
}
catch (Exception ex)
{
//exception
logger.Error("[" + _description + "-T] Exception while listening for next message: " + ex.Message, ex);
_threadStatus.ErrorCount += 1;
System.Threading.Thread.Sleep(100);
}
System.Threading.Thread.Sleep(50);
}
//done listening
}
finally
{
_threadStatus.IsThreadActive = false;
_threadStatus.IsThreadEnabled = false;
logger.Info("[" + _description + "-T] Reader inactive");
}
}
catch (Exception ex)
{
logger.Error("[" + _description + "-T] Exception in listen thread: " + ex.Message, ex);
if (!_ignoreExceptions)
throw ex;
}
}
/// <summary>
/// Reads data from Mmf file and inserts into read queue
/// </summary>
private void ReadFromMmfFile(int entryID)
{
/* Memory Mapped File:
* accessor1Len: bytes 0-4 total length of file
* accessor2ID: bytes 8-12 ID number of message
* accessor3Data: variable bytes payload
* */
int msgLength;
int msgID;
try
{
//System.Diagnostics.Debug.WriteLine("MmfBufferedReader [File " + entryID + "]: Filename " + _ipcType + "_" + entryID);
//open mmf
MemoryMappedFile mmf = MemoryMappedFile.OpenExisting(_ipcType + "_" + entryID);
MemoryMappedViewAccessor accessor1Len = mmf.CreateViewAccessor(0, 4);
MemoryMappedViewAccessor accessor2ID = mmf.CreateViewAccessor(8, 4);
MemoryMappedViewAccessor accessor3Data;
//locked section
using (new Niawa.Utilities.SingleGlobalInstance(1000, _ipcType)) //1000ms timeout on global lock
{
//get length, ID, and data
msgLength = accessor1Len.ReadInt32(0);
msgID = accessor2ID.ReadInt32(0);
accessor3Data = mmf.CreateViewAccessor(16, msgLength);
}
//System.Diagnostics.Debug.WriteLine("MmfBufferedReader [File " + entryID + "]: MsgID: " + msgID);
//System.Diagnostics.Debug.WriteLine("MmfBufferedReader [File " + entryID + "]: LastMsgID: " + _lastMsgID);
//check if ID changed
if (msgID == _lastMsgID)
{
//System.Diagnostics.Debug.WriteLine("MmfBufferedReader [File " + entryID + "]: There is no work to do");
//do nothing
System.Threading.Thread.Sleep(10);
}
else
{
//System.Diagnostics.Debug.WriteLine("MmfBufferedReader [File " + entryID + "]: Reading message");
//set ID
_lastMsgID = msgID;
//check if message is too long
if (msgLength + 16 > _bufferLength)
{
logger.Error("[" + _description + "-T] Not reading message [" + msgID + "]: Message length [" + (msgLength + 16).ToString() + "] is greater than the buffer length [" + _bufferLength.ToString() + "]");
_threadStatus.MessageErrorCount += 1;
}
else
{
//get data
byte[] buffer = new byte[msgLength];
accessor3Data.ReadArray<byte>(0, buffer, 0, msgLength);
NiawaMmfContainer msg = new NiawaMmfContainer(buffer);
logger.Debug("[" + _description + "-T] Received data [" + msgID + "]: " + msg.SerialID);
_threadStatus.MessageCount += 1;
_receiveQueue.Enqueue(msg);
}
}
}
catch (System.IO.FileNotFoundException)
{
System.Diagnostics.Debug.WriteLine("MmfBufferedReader [" + _ipcType + "][File " + entryID + "]: File was not found");
}
}
