multithreading in C, need help

[manontheedge]

I'm trying to learn multithreading in C. I've never done it before, and I've spent several hours reading about it, and looking at examples. I found this example and have been messing with it (I've made a lot of changes, but it still works the same). What my goal is, is to have one thread constantly listening for incoming connections and have another thread where a user can actually send messages (using sockets...I have that stuff working fine).

What I'm asking is, with my extremely limited knowledge of threads, can I accomplish this with this code? I know that _beginthreadex is preferred over CreateThread (from what i've read), but at this moment, I'm interested in CreateThread.

this is a completely new concept to me and i'd appreciate any help or tips.

 
#include <windows.h> 
#include <stdio.h>
 
#define BUF_SIZE 255
 
//------------------------------------------
// A function to Display the message indicating in which tread we are
//------------------------------------------
void DisplayMessage (char *ThreadName, int Data, int Count, char input[80])
{
    printf("Executing iteration %02d of %s having data = %02d and %s \n", Count, ThreadName, Data, input); 
    Sleep(1000);
}
 
//-------------------------------------------
// A function that represents Thread number 1
//-------------------------------------------
DWORD WINAPI Thread_no_1( LPVOID lpParam ) 
{
    int     Data = 0;
    int     count = 0;
 
    char input[80];
    strcpy(input, "thread1");
 
    // Cast the parameter to the correct data type passed by callee i.e main() in our case.
    Data = *((int*)lpParam); 
 
    for (count = 0; count <= 4; count++ )
    {
       DisplayMessage ("Thread_no_1", Data, count, input);
    }
 
    return 0; 
} 
 
//-------------------------------------------
// A function that represents Thread number 2
//-------------------------------------------
DWORD WINAPI Thread_no_2( LPVOID lpParam ) 
{
    int     Data = 0;
    int     count = 0;
 
    char input[80];
    strcpy(input, "thread2");
 
    // Cast the parameter to the correct data type passed by callee i.e main() in our case.
    Data = *((int*)lpParam); 
 
    for (count = 0; count <= 7; count++ )
    {
      DisplayMessage ("Thread_no_2", Data, count, input);
    }
 
    return 0; 
} 
 
void main()
{
    // Data of Threads
    int Data_Of_Thread_1 = 6;
    int Data_Of_Thread_2 = 2;
 
    // variable to hold handle of Threads
    HANDLE Handle_Of_Thread_1 = 0;
    HANDLE Handle_Of_Thread_2 = 0;
 
    // Array to store thread handles 
    HANDLE Array_Of_Thread_Handles[2];
 
    // Create thread 1.
    Handle_Of_Thread_1 = CreateThread( NULL, 0, Thread_no_1, &Data_Of_Thread_1, 0, NULL);  
    if ( Handle_Of_Thread_1 == NULL)
        ExitProcess(Data_Of_Thread_1);
 
    // Create thread 2.
    Handle_Of_Thread_2 = CreateThread( NULL, 0, Thread_no_2, &Data_Of_Thread_2, 0, NULL);  
    if ( Handle_Of_Thread_2 == NULL)
        ExitProcess(Data_Of_Thread_2);
 
    // Store Thread handles in Array of Thread
    // Handles as per the requirement of WaitForMultipleObjects() 
    Array_Of_Thread_Handles[0] = Handle_Of_Thread_1;
    Array_Of_Thread_Handles[1] = Handle_Of_Thread_2;
 
    // Wait until all threads have terminated.
    WaitForMultipleObjects( 2, Array_Of_Thread_Handles, TRUE, INFINITE);
 
    printf("Since All threads executed lets close their handles \n");
 
    // Close all thread handles upon completion.
    CloseHandle(Handle_Of_Thread_1);
    CloseHandle(Handle_Of_Thread_2);
}
 
 

[manontheedge]

I got it to work, yay. I would delete the post, but it's not letting me.

[weaknessforcats]

You should be using CreateThread(). You use _beginthreadx() only if are using errno, etc. Windows doesn't use that.