perfstat_netbuffer Interface

Selected fields from the perfstat_netbuffer_t structure include: Several other allocation-related metrics (such as high-water mark and freed) are also returned. For a complete list of other allocation-related metrics, see the perfstat_netbuffer_t section in the libperfstat.h header file.

The following code shows an example of how the perfstat_netbuffer interface is used: The preceding program produces the following output:

#include <stdio.h>
#include <stdlib.h>
#include <libperfstat.h>

int main(int argc, char* argv[]) {
   int i, ret, tot;
   perfstat_netbuffer_t *statp;
   perfstat_id_t first;

   /* check how many perfstat_netbuffer_t structures are available */
   tot = perfstat_netbuffer(NULL, NULL, sizeof(perfstat_netbuffer_t), 0);

   /* check for error */ 
   if (tot <= 0)
   {
	perror("perfstat_netbuffer");
	exit(-1);
   }   
   

   /* allocate enough memory for all the structures */
   statp = calloc(tot, sizeof(perfstat_netbuffer_t));
   if(statp==NULL){
	printf("No sufficient memory\n");
	exit(-1);
   }
   
   /* set name to first interface */
   strcpy(first.name, FIRST_NETBUFFER);
   
   /* ask to get all the structures available in one call */
   /* return code is number of structures returned */
   ret = perfstat_netbuffer(&first, statp,
                          sizeof(perfstat_netbuffer_t), tot);
   /* check for error */
   if (ret <= 0)
   {
	perror("perfstat_netbuffer");
	exit(-1);
   } 				 
   /* print info in netstat -m format */
   printf("%-12s %10s %9s %6s %9s %7s %7s %7s\n",
          "By size", "inuse", "calls", "failed",
          "delayed", "free", "hiwat", "freed");
   for (i = 0; i < ret; i++) {
       printf("%-12s %10llu %9llu %6llu %9llu %7llu %7llu %7llu\n",
           statp[i].name,
           statp[i].inuse,
           statp[i].calls,
           statp[i].delayed,
           statp[i].free,
           statp[i].failed,
           statp[i].highwatermark,
           statp[i].freed);
       }
}

The program displays an output that is similar to the following example output:

By size           inuse     calls failed   delayed    free   hiwat   freed
64                  598     12310     14       682       0   10480       0
128                 577      8457     16       287       0    7860       0
256                1476    287157     88       716       0   15720       0
512                2016   1993915    242       808       0   32750       0
1024                218      8417     81       158       0    7860       0
2048                563      2077    277       307       0   19650       0
4096                 39       127     15       143       0    1310       0
8192                  4        16      4         0       0     327       0
16384               128       257     19         4       0     163       0
32768                25        55      9         4       0      81       0
65536                59       121     35         5       0      81       0
131072                3         7      0       217       0     204       0