*** empty log message ***

Changes

@@ -4,10 +4,12 @@ TODO: ev_loop_wakeup
 TODO: EV_STANDALONE == NO_HASSEL (do not use clock_gettime in ev_standalone)
 TODO: faq, process a thing in each iteration
 TODO: dbeugging tips, ev_verify, ev_init twice
-
+TODO: ev_break for immediate exit (EVBREAK_NOW?)
 TODO: ev_feed_child_event
+
 TODO: document the special problem of signals around fork.
 TODO: store pid for each signal
+TODO: document file descriptor usage per loop
         - destroying a non-default loop would stop the global waitpid
           watcher (Denis Bilenko).
 	- queueing pending watchers of higher priority from a watcher now invokes
@@ -41,6 +43,9 @@ TODO: store pid for each signal
         - work around recent glibc versions that leak memory in realloc.
         - rename ev::embed::set to ev::embed::set_embed to avoid clashing
           the watcher base set (loop) method.
+        - rewrite the async/signal pipe logic to always keep a valid fd, which
+          simplifies (and hopefuly correctifies :) the race checking
+          on fork, at the cost of one extra fd.
 
 4.11 Sat Feb  4 19:52:39 CET 2012
 	- INCOMPATIBLE CHANGE: ev_timer_again now clears the pending status, as

ev.c

@@ -1869,28 +1869,41 @@ evpipe_init (EV_P)
 {
   if (!ev_is_active (&pipe_w))
     {
+      int fds [2];
+
 # if EV_USE_EVENTFD
-      evfd = eventfd (0, EFD_NONBLOCK | EFD_CLOEXEC);
-      if (evfd < 0 && errno == EINVAL)
-        evfd = eventfd (0, 0);
+      fds [0] = -1;
+      fds [1] = eventfd (0, EFD_NONBLOCK | EFD_CLOEXEC);
+      if (fds [1] < 0 && errno == EINVAL)
+        fds [1] = eventfd (0, 0);
 
-      if (evfd >= 0)
+      if (fds [1] < 0)
+# endif
         {
-          evpipe [0] = -1;
-          fd_intern (evfd); /* doing it twice doesn't hurt */
-          ev_io_set (&pipe_w, evfd, EV_READ);
+          while (pipe (fds))
+            ev_syserr ("(libev) error creating signal/async pipe");
+
+          fd_intern (fds [0]);
         }
+
+      fd_intern (fds [1]);
+
+      evpipe [0] = fds [0];
+
+      if (evpipe [1] < 0)
+        evpipe [1] = fds [1]; /* first call, set write fd */
       else
-# endif
         {
-          while (pipe (evpipe))
-            ev_syserr ("(libev) error creating signal/async pipe");
+          /* on subsequent calls, do not change evpipe [1] */
+          /* so that evpipe_write can always rely on its value. */
+          /* this branch does not do anything sensible on windows, */
+          /* so must not be executed on windows */
 
-          fd_intern (evpipe [0]);
-          fd_intern (evpipe [1]);
-          ev_io_set (&pipe_w, evpipe [0], EV_READ);
+          dup2 (fds [1], evpipe [1]);
+          close (fds [1]);
         }
 
+      ev_io_set (&pipe_w, evpipe [0] < 0 ? evpipe [1] : evpipe [0], EV_READ);
       ev_io_start (EV_A_ &pipe_w);
       ev_unref (EV_A); /* watcher should not keep loop alive */
     }
@@ -1921,10 +1934,10 @@ evpipe_write (EV_P_ EV_ATOMIC_T *flag)
       old_errno = errno; /* save errno because write will clobber it */
 
 #if EV_USE_EVENTFD
-      if (evfd >= 0)
+      if (evpipe [0] < 0)
         {
           uint64_t counter = 1;
-          write (evfd, &counter, sizeof (uint64_t));
+          write (evpipe [1], &counter, sizeof (uint64_t));
         }
       else
 #endif
@@ -1954,10 +1967,10 @@ pipecb (EV_P_ ev_io *iow, int revents)
   if (revents & EV_READ)
     {
 #if EV_USE_EVENTFD
-      if (evfd >= 0)
+      if (evpipe [0] < 0)
         {
           uint64_t counter;
-          read (evfd, &counter, sizeof (uint64_t));
+          read (evpipe [1], &counter, sizeof (uint64_t));
         }
       else
 #endif
@@ -2023,9 +2036,6 @@ ev_feed_signal (int signum) EV_THROW
     return;
 #endif
 
-  if (!ev_active (&pipe_w))
-    return;
-
   signals [signum - 1].pending = 1;
   evpipe_write (EV_A_ &sig_pending);
 }
@@ -2353,6 +2363,8 @@ loop_init (EV_P_ unsigned int flags) EV_THROW
 #endif
       pipe_write_skipped = 0;
       pipe_write_wanted  = 0;
+      evpipe [0]         = -1;
+      evpipe [1]         = -1;
 #if EV_USE_INOTIFY
       fs_fd              = flags & EVFLAG_NOINOTIFY ? -1 : -2;
 #endif
@@ -2425,16 +2437,8 @@ ev_loop_destroy (EV_P)
       /*ev_ref (EV_A);*/
       /*ev_io_stop (EV_A_ &pipe_w);*/
 
-#if EV_USE_EVENTFD
-      if (evfd >= 0)
-        close (evfd);
-#endif
-
-      if (evpipe [0] >= 0)
-        {
-          EV_WIN32_CLOSE_FD (evpipe [0]);
-          EV_WIN32_CLOSE_FD (evpipe [1]);
-        }
+      if (evpipe [0] >= 0) EV_WIN32_CLOSE_FD (evpipe [0]);
+      if (evpipe [1] >= 0) EV_WIN32_CLOSE_FD (evpipe [1]);
     }
 
 #if EV_USE_SIGNALFD
@@ -2530,6 +2534,7 @@ loop_fork (EV_P)
   infy_fork (EV_A);
 #endif
 
+#if EV_SIGNAL_ENABLE || EV_ASYNC_ENABLE
   if (ev_is_active (&pipe_w))
     {
       /* pipe_write_wanted must be false now, so modifying fd vars should be safe */
@@ -2537,23 +2542,14 @@ loop_fork (EV_P)
       ev_ref (EV_A);
       ev_io_stop (EV_A_ &pipe_w);
 
-#if EV_USE_EVENTFD
-      if (evfd >= 0)
-        close (evfd);
-#endif
-
       if (evpipe [0] >= 0)
-        {
-          EV_WIN32_CLOSE_FD (evpipe [0]);
-          EV_WIN32_CLOSE_FD (evpipe [1]);
-        }
+        EV_WIN32_CLOSE_FD (evpipe [0]);
 
-#if EV_SIGNAL_ENABLE || EV_ASYNC_ENABLE
       evpipe_init (EV_A);
       /* iterate over everything, in case we missed something before */
       ev_feed_event (EV_A_ &pipe_w, EV_CUSTOM);
-#endif
     }
+#endif
 
   postfork = 0;
 }

ev_vars.h

@@ -69,9 +69,6 @@ VAR (backend_poll  , void (*backend_poll)(EV_P_ ev_tstamp timeout))
 VARx(ANFD *, anfds)
 VARx(int, anfdmax)
 
-#if EV_USE_EVENTFD || EV_GENWRAP
-VARx(int, evfd)
-#endif
 VAR (evpipe, int evpipe [2])
 VARx(ev_io, pipe_w)
 VARx(EV_ATOMIC_T, pipe_write_wanted)