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From: 이병우 <bw80.lee@samsung.com> 

I found a bug in ecore main loop while debuging cpu 100% issue on RSS
application.
 
 1. [RSS] RSS application register two io watch callbacks(for G_IO_IN,
    G_IO_OUT seperately)  for a GIOChannel with g_io_add_watch().
 2. [ecore] In _ecore_glib_context_query() function, g_main_context_query()
    returns a fd list, and it has 2 fd items for the GIOChannel (channel
    id = 20).

    itr[0] (16, 1, 0)
    itr[1] (15, 1, 0)
    itr[2] (20, 1, 0) (G_IO_IN, 0)
    itr[3] (20, 4, 0) (G_IO_OUT, 0)
    itr[4] (18, 1, 0)

3. [ecore] In _ecore_glib_context_poll_from() function, create read, write,
   exception fd list according to the events flags of each fd item.

   [6 15 16 18 20], [20], []

4. [ecore] in _ecore_glib_select__locked() function, get active fd number from
   select() call

   select(21, [6 15 16 18 20], [20], [], NULL) = 1 (out [20])
 
5. [ecore] In _ecore_glib_context_poll_to() function, there is a bug on
   setting revents flag.

   (because of incorrect condition check - currently, the logic of the
   function cannot handle this case)

   itr[0] (16, 1, 0)
   itr[1] (15, 1, 0)
   itr[2] (20, 1, 4) (set incorrectly)
   itr[3] (20, 4, 0)  => this should be set as (20, 4, 4)!!!!
   itr[4] (18, 1, 0)

6. [ecore] In _ecore_glib_select__locked(), g_main_context_check() function
   returns false because of the above bug, so g_main_context_dispatch()
   function will not be called.

>> After this, the 2~6 flow is executed repeatedly on ecore main loop
   (because 20 out is still active fd) and this makes cpu 100% problem.



SVN revision: 69739
This commit is contained in:
이병우 2012-03-29 10:36:23 +00:00 committed by Carsten Haitzler
parent f0792f360f
commit 707da8b620
1 changed files with 3 additions and 3 deletions
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6
legacy/ecore/src/lib/ecore/ecore_glib.c
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@ -111,17 +111,17 @@ _ecore_glib_context_poll_to(GPollFD *pfds,
for (; (itr < itr_end) && (ready > 0); itr++)
{
itr->revents = 0;
if (FD_ISSET(itr->fd, rfds))
if (FD_ISSET(itr->fd, rfds) && (itr->events & G_IO_IN))
{
itr->revents |= G_IO_IN;
ready--;
}
if (FD_ISSET(itr->fd, wfds))
if (FD_ISSET(itr->fd, wfds) && (itr->events & G_IO_OUT))
{
itr->revents |= G_IO_OUT;
ready--;
}
if (FD_ISSET(itr->fd, efds))
if (FD_ISSET(itr->fd, efds) && (itr->events & (G_IO_HUP | G_IO_ERR)))
{
itr->revents |= G_IO_ERR;
ready--;