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Subj : warning : arg 3 of 'pthread_create' from incompatibe pointer type
To   : comp.programming.threads
From : Jack
Date : Wed Mar 02 2005 10:19 am

dear all

I am a beginner, 5 days-old pthread user. I was trying to write a
simple parallel sorting code. There are 3 nodes (2 leaves, 1 parent). 2
leaves perform sequential quick sorting and parent node perform merge
sort from 2 child nodes. What I did was just to use 'pthread_create'
function. The code is functionally ok (ie, sorting is done). But I feel
there is something not-ok, that I am not careful. Also, there is a
warning : "passing arg 3 of 'pthread_create' from incompatibe pointer
type".
Any correction, critics will be helpful for me.
thankyou


/****************************************/
/* threaded simple parallel sorting  	*/
/* 2 leaves, 1 parent node		*/
/* leaves a1,a2 : quick sort		*/
/* parent b1    : merge sort		*/
/****************************************/

#include <stdio.h>
#include <pthread.h>
#include "3node.h"

int N = 5;	// number of elements in leaves
int MAX = 10;	// maximum number of random value

int main(int argc, char* argv[])
{
	int i;
	int thread_id;
	pthread_t thread1;
	int a1[N],a2[N];		// 2 leaves
	int b1[2*N];			// 1 parent


// a1[] local quick sorting
        for(i=0;i<N;i++)
                a1[i] = (int)rand(0) % MAX;

        for(i=0;i<N;i++)
                a2[i] = (int)rand(0) % MAX;

	printf("\n\nUnsorted array a1[] is:  ");
	for(i = 0; i < N; ++i)
		printf(" %d ", a1[i]);

	quickSort( a1, 0, N-1);

	printf("\n\nSorted array a1[] is:  ");
	for(i = 0; i < N; ++i)
		printf(" %d ", a1[i]);

	printf("\n");


	thread_id = pthread_create(&thread1, NULL, a2_quick, &a2);

	pthread_join(thread1, NULL);

	// Merge sort a1[] and a2[] into b1[]

	merge_sort( a1, a2, b1, N );

	printf("\n\nMerged array b1[] is:  ");
	for(i = 0; i < 2*N; ++i)
		printf(" %d ", b1[i]);

	printf("\n");

}


// a2[] local quick sorting
void a2_quick(int a2[])
{
	int i;

	printf("\n\nUnsorted array a2[] is:  ");
	for(i = 0; i < N; ++i)
		printf(" %d ", a2[i]);

	quickSort( a2, 0, N-1);

	printf("\n\nSorted array a2[] is:  ");
	for(i = 0; i < N; ++i)
		printf(" %d ", a2[i]);
	
	printf("\n");
}

.

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