串口和多线程问题

Question

I am a beginner at C# and would like some advice on how to solve the following problem:

I would like to continuously read from the serial port and store that data in an SQL database and write it to a text file simultaneously.

Is there any way that you can continuously read from the serial port and use that data in two separate threads without them also being in the while loop?

My code for my SQL:

public static void SQL_Logger(string data)
{
    //Connect to database
    PHINS_Connection = new SQLiteConnection("Data Source=PHINSDatabase.sqlite;Version=3;");
    PHINS_Connection.Open();
    SQLiteCommand command = new SQLiteCommand(sql, PHINS_Connection); //creates executing comman
                                                                      //Query for creating the table
    //Execute the query
    command.ExecuteNonQuery();
    if (data.Contains("Ambient"))
    {
        //Query for inserting a column into the table created above with the roll data
        sql = "insert into PHINS_Data (valueType, value) values ('Ambient Temp'," + 199 + ")";

        //Create and execute the insert query
        command = new SQLiteCommand(sql, PHINS_Connection);
        command.ExecuteNonQuery();
    }

And the code for the textLogger:

public static void textLogger(string text, string path)
{
    using (StreamWriter writer = new StreamWriter(path, true))
    {
        writer.WriteLine(text);
    }
}

And the main program:

class Program
{
    static SerialPort newPort = new SerialPort("COM9", 9600);

    static SQLiteConnection PHINS_Connection;

    static string sql = "create table PHINS_Data (valueType varchar(20), value decimal(10, 3 ))"; // Creates table

    static void Main(string[] args)
    {
        SQLiteConnection.CreateFile("PHINSDatabase.sqlite");

        string path = "PHINS-R-" + DateTime.Now.Ticks.ToString() + ".txt";
        using (FileStream fs = File.Create(path)) { }

        newPort.Open();

        Thread myNewThread = new Thread(() => textLogger(data, path));
        Thread myNewThread2 = new Thread(() => SQL_Logger(data));

        while (true)
        {
            data = newPort.ReadLine();

            myNewThread.Start();
            myNewThread2.Start();
        }

Every time I do this it tries to restart the thread every time the loop executes. Is it possible to continuously read the data and pass it to the two threads?

Answer 1

I would use the SerialPort.DataReceived event to add data to some kind of global queue. And than create a thread to process the global queue.

    private Queue<string> MyQueue = new Queue<string>();
    private object _lock = new object();

    public void Worker()
    {
        do
        {
            string val = "";
            lock (_lock)
            {
                if (MyQueue.Count > 0)
                {
                    val = MyQueue.Dequeue();
                }
            }

            if (val == "")
            {
                System.Threading.Thread.Sleep(500);
            }

        } while (true);
    }

    public void Add(string rec)
    {
        lock (_lock)
        {
            MyQueue.Enqueue(rec);
        }
    }

Call Add from SerialPort.DataReceived