[ViewVC] Diff of: cvs/libev/ev.c

Comparing libev/ev.c (file contents):
Revision 1.287 by root, Mon Apr 20 19:45:58 2009 UTC vs.
Revision 1.288 by root, Sat Apr 25 14:12:48 2009 UTC

 #define ev_malloc(size) ev_realloc (0, (size))
 #define ev_free(ptr)    ev_realloc ((ptr), 0)
 /*****************************************************************************/
+/* file descriptor info structure */
 typedef struct
 {
   WL head;
-  unsigned char events;
+  unsigned char events; /* the events watched for */
-  unsigned char reify;
+  unsigned char reify;  /* flag set when this ANFD needs reification */
-  unsigned char emask; /* the epoll backend stores the actual kernel mask in here */
+  unsigned char emask;  /* the epoll backend stores the actual kernel mask in here */
   unsigned char unused;
 #if EV_USE_EPOLL
-  unsigned int egen;  /* generation counter to counter epoll bugs */
+  unsigned int egen;    /* generation counter to counter epoll bugs */
 #endif
 #if EV_SELECT_IS_WINSOCKET
   SOCKET handle;
 #endif
 } ANFD;
+/* stores the pending event set for a given watcher */
 typedef struct
 {
   W w;
-  int events;
+  int events; /* the pending event set for the given watcher */
 } ANPENDING;
 #if EV_USE_INOTIFY
 /* hash table entry per inotify-id */
 typedef struct
 } ANFS;
 #endif
 /* Heap Entry */
 #if EV_HEAP_CACHE_AT
+  /* a heap element */
   typedef struct {
     ev_tstamp at;
     WT w;
   } ANHE;
   #define ANHE_w(he)        (he).w     /* access watcher, read-write */
   #define ANHE_at(he)       (he).at    /* access cached at, read-only */
   #define ANHE_at_cache(he) (he).at = (he).w->at /* update at from watcher */
 #else
+  /* a heap element */
   typedef WT ANHE;
   #define ANHE_w(he)        (he)
   #define ANHE_at(he)       (he)->at
   #define ANHE_at_cache(he)
 /*****************************************************************************/
 #define MALLOC_ROUND 4096 /* prefer to allocate in chunks of this size, must be 2**n and >> 4 longs */
+/* find a suitable new size for the given array, */
+/* hopefully by rounding to a ncie-to-malloc size */
 inline_size int
 array_nextsize (int elem, int cur, int cnt)
 {
   int ncur = cur + 1;
 #define array_free(stem, idx) \
   ev_free (stem ## s idx); stem ## cnt idx = stem ## max idx = 0; stem ## s idx = 0
 /*****************************************************************************/
+/* dummy callback for pending events */
+static void noinline
+pendingcb (EV_P_ ev_prepare *w, int revents)
+{
+}
 void noinline
 ev_feed_event (EV_P_ void *w, int revents)
 {
   W w_ = (W)w;
   int pri = ABSPRI (w_);
 {
   if (fd >= 0 && fd < anfdmax)
     fd_event (EV_A_ fd, revents);
 }
+/* make sure the external fd watch events are in-sync */
+/* with the kernel/libev internal state */
 inline_size void
 fd_reify (EV_P)
 {
   int i;
     }
   fdchangecnt = 0;
 }
+/* something about the given fd changed */
 inline_size void
 fd_change (EV_P_ int fd, int flags)
 {
   unsigned char reify = anfds [fd].reify;
   anfds [fd].reify |= flags;
       array_needsize (int, fdchanges, fdchangemax, fdchangecnt, EMPTY2);
       fdchanges [fdchangecnt - 1] = fd;
     }
 }
+/* the given fd is invalid/unusable, so make sure it doesn't hurt us anymore */
 inline_speed void
 fd_kill (EV_P_ int fd)
 {
   ev_io *w;
       ev_io_stop (EV_A_ w);
       ev_feed_event (EV_A_ (W)w, EV_ERROR | EV_READ | EV_WRITE);
     }
 }
+/* check whether the given fd is atcually valid, for error recovery */
 inline_size int
 fd_valid (int fd)
 {
 #ifdef _WIN32
   return _get_osfhandle (fd) != -1;
   heap [k] = he;
   ev_active (ANHE_w (he)) = k;
 }
+/* move an element suitably so it is in a correct place */
 inline_size void
 adjustheap (ANHE *heap, int N, int k)
 {
   if (k > HEAP0 && ANHE_at (heap [HPARENT (k)]) >= ANHE_at (heap [k]))
     upheap (heap, k);
     upheap (heap, i + HEAP0);
 }
 /*****************************************************************************/
+/* associate signal watchers to a signal signal */
 typedef struct
 {
   WL head;
   EV_ATOMIC_T gotsig;
 } ANSIG;
 static EV_ATOMIC_T gotsig;
 /*****************************************************************************/
+/* used to prepare libev internal fd's */
+/* this is not fork-safe */
 inline_speed void
 fd_intern (int fd)
 {
 #ifdef _WIN32
   unsigned long arg = 1;
 }
 static void noinline
 evpipe_init (EV_P)
 {
-  if (!ev_is_active (&pipeev))
+  if (!ev_is_active (&pipe_w))
     {
 #if EV_USE_EVENTFD
       if ((evfd = eventfd (0, 0)) >= 0)
         {
           evpipe [0] = -1;
           fd_intern (evfd);
-          ev_io_set (&pipeev, evfd, EV_READ);
+          ev_io_set (&pipe_w, evfd, EV_READ);
         }
       else
 #endif
         {
           while (pipe (evpipe))
             ev_syserr ("(libev) error creating signal/async pipe");
           fd_intern (evpipe [0]);
           fd_intern (evpipe [1]);
-          ev_io_set (&pipeev, evpipe [0], EV_READ);
+          ev_io_set (&pipe_w, evpipe [0], EV_READ);
         }
-      ev_io_start (EV_A_ &pipeev);
+      ev_io_start (EV_A_ &pipe_w);
       ev_unref (EV_A); /* watcher should not keep loop alive */
     }
 }
 inline_size void
       errno = old_errno;
     }
 }
+/* called whenever the libev signal pipe */
+/* got some events (signal, async) */
 static void
 pipecb (EV_P_ ev_io *iow, int revents)
 {
 #if EV_USE_EVENTFD
   if (evfd >= 0)
 #ifndef WIFCONTINUED
 # define WIFCONTINUED(status) 0
 #endif
+/* handle a single child status event */
 inline_speed void
 child_reap (EV_P_ int chain, int pid, int status)
 {
   ev_child *w;
   int traced = WIFSTOPPED (status) || WIFCONTINUED (status);
 #ifndef WCONTINUED
 # define WCONTINUED 0
 #endif
+/* called on sigchld etc., calls waitpid */
 static void
 childcb (EV_P_ ev_signal *sw, int revents)
 {
   int pid, status;
 ev_set_timeout_collect_interval (EV_P_ ev_tstamp interval)
 {
   timeout_blocktime = interval;
 }
+/* initialise a loop structure, must be zero-initialised */
 static void noinline
 loop_init (EV_P_ unsigned int flags)
 {
   if (!backend)
     {
 #endif
 #if EV_USE_SELECT
       if (!backend && (flags & EVBACKEND_SELECT)) backend = select_init (EV_A_ flags);
 #endif
+      ev_prepare_init (&pending_w, pendingcb);
-      ev_init (&pipeev, pipecb);
+      ev_init (&pipe_w, pipecb);
-      ev_set_priority (&pipeev, EV_MAXPRI);
+      ev_set_priority (&pipe_w, EV_MAXPRI);
     }
 }
+/* free up a loop structure */
 static void noinline
 loop_destroy (EV_P)
 {
   int i;
-  if (ev_is_active (&pipeev))
+  if (ev_is_active (&pipe_w))
     {
       ev_ref (EV_A); /* signal watcher */
-      ev_io_stop (EV_A_ &pipeev);
+      ev_io_stop (EV_A_ &pipe_w);
 #if EV_USE_EVENTFD
       if (evfd >= 0)
         close (evfd);
 #endif
 #endif
 #if EV_USE_INOTIFY
   infy_fork (EV_A);
 #endif
-  if (ev_is_active (&pipeev))
+  if (ev_is_active (&pipe_w))
     {
       /* this "locks" the handlers against writing to the pipe */
       /* while we modify the fd vars */
       gotsig = 1;
 #if EV_ASYNC_ENABLE
       gotasync = 1;
 #endif
       ev_ref (EV_A);
-      ev_io_stop (EV_A_ &pipeev);
+      ev_io_stop (EV_A_ &pipe_w);
 #if EV_USE_EVENTFD
       if (evfd >= 0)
         close (evfd);
 #endif
           close (evpipe [1]);
         }
       evpipe_init (EV_A);
       /* now iterate over everything, in case we missed something */
-      pipecb (EV_A_ &pipeev, EV_READ);
+      pipecb (EV_A_ &pipe_w, EV_READ);
     }
   postfork = 0;
 }
   for (pri = NUMPRI; pri--; )
     while (pendingcnt [pri])
       {
         ANPENDING *p = pendings [pri] + --pendingcnt [pri];
-        if (expect_true (p->w))
-          {
-            /*assert (("libev: non-pending watcher on pending list", p->w->pending));*/
+        /*assert (("libev: non-pending watcher on pending list", p->w->pending));*/
+        /* ^ this is no longer true, as pending_w could be here */
-            p->w->pending = 0;
+        p->w->pending = 0;
-            EV_CB_INVOKE (p->w, p->events);
+        EV_CB_INVOKE (p->w, p->events);
-            EV_FREQUENT_CHECK;
+        EV_FREQUENT_CHECK;
-          }
       }
 }
 #if EV_IDLE_ENABLE
+/* make idle watchers pending. this handles the "call-idle */
+/* only when higher priorities are idle" logic */
 inline_size void
 idle_reify (EV_P)
 {
   if (expect_false (idleall))
     {
         }
     }
 }
 #endif
+/* make timers pending */
 inline_size void
 timers_reify (EV_P)
 {
   EV_FREQUENT_CHECK;
       feed_reverse_done (EV_A_ EV_TIMEOUT);
     }
 }
 #if EV_PERIODIC_ENABLE
+/* make periodics pending */
 inline_size void
 periodics_reify (EV_P)
 {
   EV_FREQUENT_CHECK;
       feed_reverse_done (EV_A_ EV_PERIODIC);
     }
 }
+/* simply recalculate all periodics */
+/* TODO: maybe ensure that at leats one event happens when jumping forward? */
 static void noinline
 periodics_reschedule (EV_P)
 {
   int i;
   reheap (periodics, periodiccnt);
 }
 #endif
+/* adjust all timers by a given offset */
 static void noinline
 timers_reschedule (EV_P_ ev_tstamp adjust)
 {
   int i;
       ANHE_w (*he)->at += adjust;
       ANHE_at_cache (*he);
     }
 }
+/* fetch new monotonic and realtime times from the kernel */
+/* also detetc if there was a timejump, and act accordingly */
 inline_speed void
 time_update (EV_P_ ev_tstamp max_block)
 {
   int i;
   ev_tstamp mn_prev = mn_now;
   ev_now_update (EV_A);
   timers_reschedule (EV_A_ mn_now - mn_prev);
 #if EV_PERIODIC_ENABLE
+  /* TODO: really do this? */
   periodics_reschedule (EV_A);
 #endif
 }
 /*****************************************************************************/
+/* singly-linked list management, used when the expected list length is short */
 inline_size void
 wlist_add (WL *head, WL elem)
 {
   elem->next = *head;
       head = &(*head)->next;
     }
 }
+/* internal, faster, version of ev_clear_pending */
 inline_speed void
 clear_pending (EV_P_ W w)
 {
   if (w->pending)
     {
-      pendings [ABSPRI (w)][w->pending - 1].w = 0;
+      pendings [ABSPRI (w)][w->pending - 1].w = (W)&pending_w;
       w->pending = 0;
     }
 }
 int
   int pending = w_->pending;
   if (expect_true (pending))
     {
       ANPENDING *p = pendings [ABSPRI (w_)] + pending - 1;
+      p->w = (W)&pending_w;
       w_->pending = 0;
-      p->w = 0;
       return p->events;
     }
   else
     return 0;
 }
     }
 }
 /*****************************************************************************/
-#if 0
+#if EV_WALK_ENABLE
 void
 ev_walk (EV_P_ int types, void (*cb)(EV_P_ int type, void *w))
 {
   int i, j;
   ev_watcher_list *wl, *wn;
 #if EV_USE_INOTIFY
           if (ev_cb ((ev_io *)wl) == infy_cb)
             ;
           else
 #endif
-          if ((ev_io *)wl != &pipeev)
+          if ((ev_io *)wl != &pipe_w)
             if (types & EV_IO)
               cb (EV_A_ EV_IO, wl);
           wl = wn;
         }

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing libev/ev.c (file contents): Revision 1.287 by root, Mon Apr 20 19:45:58 2009 UTC vs. Revision 1.288 by root, Sat Apr 25 14:12:48 2009 UTC

Diff Legend

Comparing libev/ev.c (file contents):
Revision 1.287 by root, Mon Apr 20 19:45:58 2009 UTC vs.
Revision 1.288 by root, Sat Apr 25 14:12:48 2009 UTC