add doc & error check

Author: plerros

helsing/src/main.c

@@ -47,6 +47,8 @@ int main(int argc, char *argv[])
 		goto out;
 
 	pthread_t *threads = malloc(sizeof(pthread_t) * options.threads);
+	if (threads == NULL)
+		abort();
 	struct targs_handle *thhandle = NULL;
 	targs_handle_new(&thhandle, options, interval.min, interval.max, progress);
 

helsing/src/vampire/vargs.c

@@ -189,6 +189,9 @@ void vampire(vamp_t min, vamp_t max, struct vargs *args, fang_t fmax)
 			multiplicand++;
 
 		if (multiplicand <= multiplicand_max) {
+			/*
+			 * If multiplier has n digits, then product_iterator has at most n+1 digits.
+			 */
 			vamp_t product_iterator = multiplier;
 			product_iterator *= BASE - 1; // <= (BASE-1) * (2^32)
 			vamp_t product = multiplier;