在Linux C中使用Pthread进行数组分区

Question

I want to parallel merge sort's partition part, but I don't know how to continue. Please give me some ideas based on my situation, thank you!

Serial part:

void Partition(int arr[], int low, int high)
{
    int mid;    
    if(low < high)
    {
        mid = (low + high)/2;
        Partition(arr, low, mid); //first half of data
        Partition(arr, mid+1, high);//second half of data
        MergeSort(arr, low, mid, high);
    }
}

What I have for parallel version:

void *PartitionTask(void* rank)
{
    long my_rank = (long)rank;
    if(my_rank == 0)
    {
        int mid;    
        if(low < high)
        {
            mid = (low + high)/2;
            Partition(arr, low, mid); //first half of data
            Partition(arr, mid+1, high);//second half of data
            MergeSort(arr, low, mid, high);
        }
    }
    else
    {

    }
}

Answer 1

The most simple and direct solution would probably be to spawn a new thread for the one partition and entering the other in the calling thread.

pthread_create(&low_pid, NULL, Partition, (void *)ptr_argument)

With the ptr_argument as a pointer to a shared memory struct containing the pointer to arr and low/high values.

When the calling thread returns, call pthread_join with low_pid to synchronize before mergeing.