test/sysperf/pipe2.c

   1 /*
   2  * pipe2.c
   3  *
   4  * $DragonFly: src/test/sysperf/pipe2.c,v 1.5 2004/04/29 16:05:21 dillon Exp $
   5  */
   6
   7 #include <sys/types.h>
   8 #include <sys/wait.h>
   9 #include <sys/resource.h>
  10 #include "blib.h"
  11
  12 #define PAGE_SIZE       4096
  13 #define PAGE_MASK       (PAGE_SIZE - 1)
  14
  15 int
  16 main(int ac, char **av)
  17 {
  18     long long count = 0;
  19     long long max;
  20     char c;
  21     int j;
  22     int loops;
  23     int bytes;
  24     int ppri = 999;
  25     int fds[2];
  26     char *buf;
  27     char *ptr;
  28     char *msg = "datarate";
  29
  30     if (ac == 1) {
  31         fprintf(stderr, "%s blocksize[k,m] [pipe_writer_pri] [msg]\n", av[0]);
  32         exit(1);
  33     }
  34     bytes = strtol(av[1], &ptr, 0);
  35     if (*ptr == 'k' || *ptr == 'K') {
  36         bytes *= 1024;
  37     } else if (*ptr == 'm' || *ptr == 'M') {
  38         bytes *= 1024 * 1024;
  39     } else if (*ptr) {
  40         fprintf(stderr, "Illegal numerical suffix: %s\n", ptr);
  41         exit(1);
  42     }
  43     if (bytes <= 0) {
  44         fprintf(stderr, "I can't handle %d sized buffers\n", bytes);
  45         exit(1);
  46     }
  47     if (ac >= 3)
  48         ppri = strtol(av[2], NULL, 0);
  49     if (ac >= 4)
  50         msg = av[3];
  51
  52     buf = mmap(NULL, bytes * 2 + PAGE_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANON, -1, 0);
  53     if (buf == MAP_FAILED) {
  54         perror("mmap/buffer");
  55         exit(1);
  56     }
  57
  58     bzero(buf, bytes * 2 + PAGE_SIZE);
  59
  60     printf("tests one-way pipe using direct-write buffer\n");
  61     if (pipe(fds)) {
  62         perror("pipe");
  63         exit(1);
  64     }
  65     if (fork() == 0) {
  66         /*
  67          * child process
  68          */
  69         int n;
  70         int i;
  71
  72         close(fds[0]);
  73         buf += (bytes + PAGE_MASK) & ~PAGE_MASK;
  74         i = 0;
  75         for (;;) {
  76             n = read(fds[1], buf + i, bytes - i);
  77             if (n <= 0)
  78                 break;
  79             if (n + i == bytes)
  80                 i = 0;
  81             else
  82                 i += n;
  83         }
  84         _exit(0);
  85     } else {
  86         /*
  87          * parent process.
  88          */
  89         if (ppri != 999) {
  90             if (setpriority(PRIO_PROCESS, getpid(), ppri) < 0) {
  91                 perror("setpriority");
  92                 exit(1);
  93             }
  94         }
  95         close(fds[1]);
  96
  97         /*
  98          * Figure out how many loops it takes for 1 second's worth.
  99          */
 100         start_timing();
 101         for (j = 0; ; ++j) {
 102             if (write(fds[0], buf, bytes) != bytes) {
 103                 perror("write");
 104                 exit(1);
 105             }
 106             if ((j & 31) == 0 && stop_timing(0, NULL))
 107                 break;
 108         }
 109         loops = j * 2 + 1;
 110         loops *= 2;
 111         usleep(1000000 / 10);
 112         start_timing();
 113
 114         for (j = loops; j; --j) {
 115             if (write(fds[0], buf, bytes) != bytes) {
 116                 perror("write");
 117                 exit(1);
 118             }
 119         }
 120         close(fds[0]);
 121         while(wait(NULL) >= 0)
 122             ;
 123         stop_timing(loops, "full duplex pipe / %dK bufs:", bytes / 1024);
 124         printf("%s: blkSize %d %5.2f MBytes/sec\n",
 125                 msg,
 126                 bytes,
 127                 (double)loops * bytes * 1000000.0 /
 128                 (1024.0 * 1024.0 * get_timing()));
 129     }
 130     return(0);
 131 }
 132