malloc のテストする時に書いたの

gistfile1.txt

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <dispatch/dispatch.h>
#include <sys/types.h> 
#include <unistd.h>


#define NUMBER_OF_LOOP 10000000
#define BUFFER_SIZE 1000
int times = 1;
int main(void)
{


   void (^bench)(void) = ^{
      size_t size = BUFFER_SIZE * times;
      long startTime = clock();
      int i=0;
      for(; i < NUMBER_OF_LOOP; i++) {
   void *p = malloc(size);
	 if (p != NULL)
	    free(p);
      }
      printf("%10dKB %ld\n", times, clock() - startTime);
   };

   printf("sigle thread\n");
   bench();
   times=2;
   bench();
   times=5;
   bench();
   times=10;
   bench();
   times=100;
   bench();
   times=1000;
   bench();
   times=10000;
   bench();

   printf("multi thread\n");
   dispatch_queue_t gQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
   dispatch_group_t group = dispatch_group_create();
   long startTime = clock();

   int j=0;
   for(; j < NUMBER_OF_LOOP/100; j++) {
      dispatch_group_async(group, gQueue, ^{
	    int k=0;
	    for(;k < 100; k++){
	 void *p = malloc(BUFFER_SIZE*10000);
	 if (p != NULL) free(p);
	 }
      });
   }
   dispatch_group_notify(group, gQueue, ^{
      printf("multi %ld\n", clock() - startTime);
   });
   dispatch_group_wait(group,DISPATCH_TIME_FOREVER);

   dispatch_release(group);

   return 0;
}