what is the difference when the number of threads is determined and undetermined?

Question

Hi,

what the difference when the number of threads is determined, as e.g.:

for (i*10){   
    ...   
    pthread_create(&thread[i], NULL, ThreadMain[i], (void *) xxx);   
    ...
}

and when it is undetermined, just like this:

    ...  
    pthread_create(&threadID, NULL, ThreadMain, (void *) xxx);   
    ...

In my case the number i can varry from 1 to 10. If e.g. I use the first method, I need to create 10times as e.g.:

void *ThreadMain1(void *xxx)
{  
    ...  
}

until ...

void *ThreadMain10(void *xxx)
{  
    ...  
}

But if I use the second method, I need to create just :

void *ThreadMain(void *xxx)
{  
    ...  
}

So which one is correct?

Thanks for your time and replies,

Answer 1

If the threads are doing the same tasks, they should use the same function (with different input maybe), so one ThreadMain is the correct way.

Answer 2

• threads doing the same tasks should use the same function
• threads doing different tasks should use different functions

Answer 3

The first method is not valid syntax unless ThreadMain has been defined as an array of function pointers. That is:

pthread_create(&thread[i], NULL, ThreadMain[1], (void *) xxx);

does not call a function called ThreadMain1 unless you have previously done something along the lines of:

FuncPtr_t ThreadMain[10];
ThreadMain[1] = &ThreadMain1;

If you are simply trying to create 10 threads running the same task then the second method is correct.