utils.c

#include <sys/mman.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "utils.h"


/*
 * Use this allocator if you have an object a child writes to that you want
 * all other processes to see.
 */
void * alloc_shared(unsigned int size)
{
	void *ret;

	ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_ANON | MAP_SHARED, -1, 0);
	if (ret == MAP_FAILED)
		return NULL;
	return ret;
}

void * zmalloc(size_t size)
{
	void *p;

	p = malloc(size);
	if (p == NULL) {
		printf("malloc(%zu) failure.\n", size);
		exit(EXIT_FAILURE);
	}

	memset(p, 0, size);
	return p;
}

void sizeunit(unsigned long size, char *buf)
{
	if (size < 1024 * 1024) {
		sprintf(buf, "%lu bytes", size);
		return;
	}

	if (size < (1024 * 1024 * 1024)) {
		sprintf(buf, "%ldMB", (size / 1024) / 1024);
		return;
	}

	sprintf(buf, "%ldGB", ((size / 1024) / 1024) / 1024);
}