X-Git-Url: https://git.llucax.com/software/libev.git/blobdiff_plain/6800c1e86d28e4bc573747e6d327c770b2e00df4..bd14babf134e551f28f49193bf20705933c772c8:/ev.html?ds=inline diff --git a/ev.html b/ev.html index 5bcffd0..bb4c00e 100644 --- a/ev.html +++ b/ev.html @@ -6,7 +6,7 @@ - + @@ -68,7 +68,47 @@

SYNOPSIS

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-
  #include <ev.h>
+
  /* this is the only header you need */
+  #include <ev.h>
+
+  /* what follows is a fully working example program */
+  ev_io stdin_watcher;
+  ev_timer timeout_watcher;
+
+  /* called when data readable on stdin */
+  static void
+  stdin_cb (EV_P_ struct ev_io *w, int revents)
+  {
+    /* puts ("stdin ready"); */
+    ev_io_stop (EV_A_ w); /* just a syntax example */
+    ev_unloop (EV_A_ EVUNLOOP_ALL); /* leave all loop calls */
+  }
+
+  static void
+  timeout_cb (EV_P_ struct ev_timer *w, int revents)
+  {
+    /* puts ("timeout"); */
+    ev_unloop (EV_A_ EVUNLOOP_ONE); /* leave one loop call */
+  }
+
+  int
+  main (void)
+  {
+    struct ev_loop *loop = ev_default_loop (0);
+
+    /* initialise an io watcher, then start it */
+    ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ);
+    ev_io_start (loop, &stdin_watcher);
+
+    /* simple non-repeating 5.5 second timeout */
+    ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.);
+    ev_timer_start (loop, &timeout_watcher);
+
+    /* loop till timeout or data ready */
+    ev_loop (loop, 0);
+
+    return 0;
+  }
 
 
@@ -181,20 +221,20 @@ might be supported on the current system, you would need to look at recommended ones.

See the description of ev_embed watchers for more info.

-
ev_set_allocator (void *(*cb)(void *ptr, long size))
+
ev_set_allocator (void *(*cb)(void *ptr, size_t size))
-

Sets the allocation function to use (the prototype is similar to the -realloc C function, the semantics are identical). It is used to allocate -and free memory (no surprises here). If it returns zero when memory -needs to be allocated, the library might abort or take some potentially -destructive action. The default is your system realloc function.

+

Sets the allocation function to use (the prototype and semantics are +identical to the realloc C function). It is used to allocate and free +memory (no surprises here). If it returns zero when memory needs to be +allocated, the library might abort or take some potentially destructive +action. The default is your system realloc function.

You could override this function in high-availability programs to, say, free some memory if it cannot allocate memory, to use a special allocator, or even to sleep a while and retry until some memory is available.

Example: replace the libev allocator with one that waits a bit and then retries: better than mine).

   static void *
-   persistent_realloc (void *ptr, long size)
+   persistent_realloc (void *ptr, size_t size)
    {
      for (;;)
        {