git.ozlabs.org Git - ccan/blob - ccan/io/benchmarks/run-loop.c

   1 #include <ccan/io/io.h>
   2 #include <ccan/time/time.h>
   3 #include <sys/wait.h>
   4 #include <stdio.h>
   5 #include <string.h>
   6 #include <assert.h>
   7 #include <err.h>
   8 #include <signal.h>
   9
  10 #define NUM 500
  11 #define NUM_ITERS 10000
  12
  13 struct buffer {
  14         int iters;
  15         struct io_conn *reader, *writer;
  16         char buf[32];
  17 };
  18
  19 static struct io_plan poke_reader(struct io_conn *conn, struct buffer *buf);
  20
  21 static struct io_plan poke_writer(struct io_conn *conn, struct buffer *buf)
  22 {
  23         assert(conn == buf->reader);
  24
  25         if (buf->iters == NUM_ITERS)
  26                 return io_close();
  27
  28         /* You write. */
  29         io_wake(buf->writer,
  30                 io_write(&buf->buf, sizeof(buf->buf), poke_reader, buf));
  31
  32         /* I'll wait until you wake me. */
  33         return io_idle();
  34 }
  35
  36 static struct io_plan poke_reader(struct io_conn *conn, struct buffer *buf)
  37 {
  38         assert(conn == buf->writer);
  39         /* You read. */
  40         io_wake(buf->reader,
  41                 io_read(&buf->buf, sizeof(buf->buf), poke_writer, buf));
  42
  43         if (++buf->iters == NUM_ITERS)
  44                 return io_close();
  45
  46         /* I'll wait until you tell me to write. */
  47         return io_idle();
  48 }
  49
  50 int main(void)
  51 {
  52         unsigned int i;
  53         int fds[2], last_read, last_write;
  54         struct timespec start, end;
  55         struct buffer buf[NUM];
  56
  57         if (pipe(fds) != 0)
  58                 err(1, "pipe");
  59         last_read = fds[0];
  60         last_write = fds[1];
  61
  62         for (i = 1; i < NUM; i++) {
  63                 buf[i].iters = 0;
  64                 if (pipe(fds) < 0)
  65                         err(1, "pipe");
  66                 memset(buf[i].buf, i, sizeof(buf[i].buf));
  67                 sprintf(buf[i].buf, "%i-%i", i, i);
  68
  69                 buf[i].reader = io_new_conn(last_read, io_idle());
  70                 if (!buf[i].reader)
  71                         err(1, "Creating reader %i", i);
  72                 buf[i].writer = io_new_conn(fds[1],
  73                                             io_write(&buf[i].buf,
  74                                                      sizeof(buf[i].buf),
  75                                                      poke_reader, &buf[i]));
  76                 if (!buf[i].writer)
  77                         err(1, "Creating writer %i", i);
  78                 last_read = fds[0];
  79         }
  80
  81         /* Last one completes the cirle. */
  82         i = 0;
  83         buf[i].iters = 0;
  84         sprintf(buf[i].buf, "%i-%i", i, i);
  85         buf[i].reader = io_new_conn(last_read, io_idle());
  86         if (!buf[i].reader)
  87                 err(1, "Creating reader %i", i);
  88         buf[i].writer = io_new_conn(last_write, io_write(&buf[i].buf,
  89                                                          sizeof(buf[i].buf),
  90                                                          poke_reader, &buf[i]));
  91         if (!buf[i].writer)
  92                 err(1, "Creating writer %i", i);
  93
  94         /* They should eventually exit */
  95         start = time_now();
  96         if (io_loop() != NULL)
  97                 errx(1, "io_loop?");
  98         end = time_now();
  99
 100         for (i = 0; i < NUM; i++) {
 101                 char b[sizeof(buf[0].buf)];
 102                 memset(b, i, sizeof(b));
 103                 sprintf(b, "%i-%i", i, i);
 104                 if (memcmp(b, buf[(i + NUM_ITERS) % NUM].buf, sizeof(b)) != 0)
 105                         errx(1, "Buffer for %i was '%s' not '%s'",
 106                              i, buf[(i + NUM_ITERS) % NUM].buf, b);
 107         }
 108
 109         printf("run-many: %u %u iterations: %llu usec\n",
 110                NUM, NUM_ITERS, (long long)time_to_usec(time_sub(end, start)));
 111         return 0;
 112 }