test/interbench/hackbench.c

   1 /* Test groups of 20 processes spraying to 20 receivers */
   2 #include <stdio.h>
   3 #include <string.h>
   4 #include <errno.h>
   5 #include <unistd.h>
   6 #include <stdlib.h>
   7 #include <semaphore.h>
   8 #include <sys/types.h>
   9 #include <sys/socket.h>
  10 #include <sys/wait.h>
  11 #include <sys/time.h>
  12 #include <sys/poll.h>
  13 #include "interbench.h"
  14
  15 #define DATASIZE 100
  16 #define LOOPS   100
  17 #define NUM_FDS 20
  18
  19 static inline void barf(const char *msg)
  20 {
  21         terminal_error(msg);
  22 }
  23
  24 static void fdpair(int fds[2])
  25 {
  26         if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) == -1)
  27                 barf("Creating fdpair");
  28 }
  29
  30 /* Block until we're ready to go */
  31 static void ready(int ready_out, int wakefd)
  32 {
  33         char dummy;
  34         struct pollfd pollfd = { .fd = wakefd, .events = POLLIN };
  35
  36         /* Tell them we're ready. */
  37         if (write(ready_out, &dummy, 1) != 1)
  38                 barf("CLIENT: ready write");
  39
  40         /* Wait for "GO" signal */
  41         if (poll(&pollfd, 1, -1) != 1)
  42                 barf("poll");
  43 }
  44
  45 /* Sender sprays LOOPS messages down each file descriptor */
  46 static void sender(int out_fd[NUM_FDS],
  47                    int ready_out,
  48                    int wakefd)
  49 {
  50         char data[DATASIZE];
  51         unsigned int i, j;
  52
  53         ready(ready_out, wakefd);
  54
  55         /* Now pump to every receiver. */
  56         for (i = 0; i < LOOPS; i++) {
  57                 for (j = 0; j < NUM_FDS; j++) {
  58                         int ret;
  59                         unsigned long done = 0;
  60
  61                 again:
  62                         ret = write(out_fd[j], data + done, sizeof(data)-done);
  63                         if (ret < 0)
  64                                 barf("SENDER: write");
  65                         done += ret;
  66                         if (done < sizeof(data))
  67                                 goto again;
  68                 }
  69         }
  70 }
  71
  72 /* One receiver per fd */
  73 static void receiver(unsigned int num_packets,
  74                      int in_fd,
  75                      int ready_out,
  76                      int wakefd)
  77 {
  78         unsigned int i;
  79
  80         /* Wait for start... */
  81         ready(ready_out, wakefd);
  82
  83         /* Receive them all */
  84         for (i = 0; i < num_packets; i++) {
  85                 char data[DATASIZE];
  86                 int ret, done = 0;
  87
  88         again:
  89                 ret = Read(in_fd, data + done, DATASIZE - done);
  90                 done += ret;
  91                 if (done < DATASIZE)
  92                         goto again;
  93         }
  94 }
  95
  96 /* One group of senders and receivers */
  97 static unsigned int group(int ready_out,
  98                           int wakefd)
  99 {
 100         unsigned int i;
 101         int out_fds[NUM_FDS];
 102
 103         for (i = 0; i < NUM_FDS; i++) {
 104                 int fds[2];
 105
 106                 /* Create the pipe between client and server */
 107                 fdpair(fds);
 108
 109                 /* Fork the receiver. */
 110                 switch (fork()) {
 111                 case -1: barf("fork()");
 112                 case 0:
 113                         close(fds[1]);
 114                         receiver(NUM_FDS*LOOPS, fds[0], ready_out, wakefd);
 115                         exit(0);
 116                 }
 117
 118                 out_fds[i] = fds[1];
 119                 close(fds[0]);
 120         }
 121
 122         /* Now we have all the fds, fork the senders */
 123         for (i = 0; i < NUM_FDS; i++) {
 124                 switch (fork()) {
 125                 case -1: barf("fork()");
 126                 case 0:
 127                         sender(out_fds, ready_out, wakefd);
 128                         exit(0);
 129                 }
 130         }
 131
 132         /* Close the fds we have left */
 133         for (i = 0; i < NUM_FDS; i++)
 134                 close(out_fds[i]);
 135
 136         /* Return number of children to reap */
 137         return NUM_FDS * 2;
 138 }
 139
 140 void *hackbench_thread(void *t)
 141 {
 142         unsigned int i, num_groups, total_children;
 143         int readyfds[2], wakefds[2];
 144         char dummy;
 145
 146         num_groups = 50;
 147         t = NULL;
 148
 149         fdpair(readyfds);
 150         fdpair(wakefds);
 151
 152         while (1) {
 153                 total_children = 0;
 154                 for (i = 0; i < num_groups; i++)
 155                         total_children += group(readyfds[1], wakefds[0]);
 156
 157                 /* Wait for everyone to be ready */
 158                 for (i = 0; i < total_children; i++)
 159                         if (Read(readyfds[0], &dummy, 1) != 1)
 160                                 barf("Reading for readyfds");
 161
 162                 /* Kick them off */
 163                 if (write(wakefds[1], &dummy, 1) != 1)
 164                         barf("Writing to start them");
 165
 166                 /* Reap them all */
 167                 for (i = 0; i < total_children; i++) {
 168                         int status;
 169                         wait(&status);
 170                         if (!WIFEXITED(status))
 171                                 exit(1);
 172                 }
 173                 if (!trywait_sem(&hackthread.sem.stop))
 174                         break;
 175         }
 176
 177         post_sem(&hackthread.sem.complete);
 178         return NULL;
 179 }