Vaguely useful tool for measuring the rate at which a server accepts

connections.

diff --git a/blast.c b/blast.c
new file mode 100644 (file)
index 0000000..fdad3dd
--- /dev/null
+++ b/blast.c
@@ -0,0 +1,192 @@
+#include <assert.h>
+#include <ctype.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <sys/types.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+
+#include <mLib/alloc.h>
+#include <mLib/conn.h>
+#include <mLib/mdwopt.h>
+#include <mLib/quis.h>
+#include <mLib/report.h>
+#include <mLib/sel.h>
+#include <mLib/tv.h>
+
+typedef struct blast {
+  conn c;
+  sel_timer t;
+} blast;
+
+static struct sockaddr_in sin;
+static sel_state sel;
+static struct timeval ctv = { 0, 500000 };
+static sel_timer sec;
+static unsigned count = 0;
+
+static void timers(void);
+
+static void stats(struct timeval *tv, void *p)
+{
+  static char baton[5] = "/-\\|";
+  static char *bt = baton;
+  struct timeval ttv;
+  printf("\r%c %u connections/second", *bt++, count);
+  if (!*bt)
+    bt = baton;
+  fflush(stdout);
+  count = 0;
+  TV_ADDL(&ttv, tv, 1, 0);
+  sel_addtimer(&sel, &sec, &ttv, stats, p);
+}
+
+static void newconn(blast *b);
+
+static void retry(struct timeval *tv, void *p)
+{
+  blast *b = p;
+  newconn(b);
+}
+
+static void backoff(blast *b)
+{
+  struct timeval tv;
+  unsigned r = rand();
+  double q = RAND_MAX / 5;
+  gettimeofday(&tv, 0);
+  TV_ADDL(&tv, &tv, r / q, (r % (unsigned)q) * (MILLION / q));
+  sel_addtimer(&sel, &b->t, &tv, retry, b);
+}
+
+static void connected(int fd, void *p)
+{
+  blast *b = p;
+  sel_rmtimer(&b->t);
+  if (fd == -1)
+    backoff(b);
+  else {
+    count++;
+    close(fd);
+    newconn(b);
+  }
+}
+
+static void timeout(struct timeval *tv, void *p)
+{
+  blast *b = p;
+  conn_kill(&b->c);
+  newconn(b);
+}
+
+static void timers(void)
+{
+  struct tab { void (*func)(struct timeval *tv, void *p); const char *name; }
+  tab[] = { { retry, "retry" }, {timeout, "timeout"}, { stats, "stats" }, { 0,
+  0 }};
+  sel_timer *t = sel.timers;
+  while (t) {
+    struct tab *q; for (q = tab; q->func != t->func; q++) ;
+    assert(t->prev->next == t);
+    printf("%i.%06i  %p  %s\n", t->tv.tv_sec, t->tv.tv_usec, t->p, q->name);
+    assert(t != t->next);
+    t = t->next;
+  }
+  puts("");
+}
+    
+static void newconn(blast *b)
+{
+  int fd = socket(PF_INET, SOCK_STREAM, 0);
+  struct timeval tv;
+  if (fd < 0)
+    goto fail;
+  gettimeofday(&tv, 0);
+  TV_ADD(&tv, &tv, &ctv);
+  sel_addtimer(&sel, &b->t, &tv, timeout, b);
+  conn_init(&b->c, &sel, fd, (struct sockaddr *)&sin, sizeof(sin),
+           connected, b);
+  return;
+
+fail:
+  backoff(b);
+}
+
+int main(int argc, char *argv[])
+{
+  blast *b;
+  size_t n = 256;
+
+  ego(argv[0]);
+
+  for (;;) {
+    int i = getopt(argc, argv, "t:n:");
+    if (i < 0)
+      break;
+    switch (i) {
+      case 't': {
+       double t = strtod(optarg, 0);
+       double s = modf(t, &t);
+       ctv.tv_sec = t;
+       ctv.tv_usec = s * MILLION;
+      } break;
+      case 'n':
+       n = atoi(optarg);
+       break;
+      default:
+       exit(1);
+    }
+  }
+
+  argv += optind;
+  argc -= optind;
+  if (argc != 2) {
+    pquis(stderr, "Usage: $ [-t time] [-n count] host port\n");
+    exit(1);
+  }
+
+  sel_init(&sel);
+  sin.sin_family = AF_INET;
+
+  {
+    struct hostent *h = gethostbyname(argv[0]);
+    if (!h)
+      die(1, "bad hostname `%s'", argv[0]);
+    memcpy(&sin.sin_addr, h->h_addr, sizeof(struct in_addr));
+  }
+
+  if (isdigit((unsigned char)argv[1][0]))
+    sin.sin_port = htons(atoi(argv[1]));
+  else {
+    struct servent *s = getservbyname(argv[1], "tcp");
+    if (!s)
+      die(1, "bad service name `%s'", argv[1]);
+    sin.sin_port = s->s_port;
+  }
+
+  b = xmalloc(n * sizeof(blast));
+
+  {
+    int i;
+    for (i = 0; i < n; i++)
+      newconn(&b[i]);
+  }
+
+  {
+    struct timeval tv;
+    gettimeofday(&tv, 0);
+    tv.tv_sec++;
+    sel_addtimer(&sel, &sec, &tv, stats, 0);
+  }
+
+  for (;;) {
+    sel_select(&sel);
+  }
+}