third_party/instrumented_libraries/patches/libxcb1.precise.diff

   1 diff -rupN ./src/xcb_conn.c ../libxcb-1.8.1-patched/src/xcb_conn.c
   2 --- ./src/xcb_conn.c    2012-01-11 21:05:41.000000000 +0400
   3 +++ ../libxcb-1.8.1-patched/src/xcb_conn.c      2014-12-10 23:37:44.432834622 +0300
   4 @@ -418,10 +418,20 @@ int _xcb_conn_wait(xcb_connection_t *c,
   5
   6      if(ret)
   7      {
   8 +        /* The code allows two threads to call select()/poll() at the same time.
   9 +         * First thread just wants to read, a second thread wants to write, too.
  10 +         * We have to make sure that we don't steal the reading thread's reply
  11 +         * and let it get stuck in select()/poll().
  12 +         * So a thread may read if either:
  13 +         * - There is no other thread that wants to read (the above situation
  14 +         *   did not occur).
  15 +         * - It is the reading thread (above situation occurred).
  16 +         */
  17 +        int may_read = c->in.reading == 1 || !count;
  18  #if USE_POLL
  19 -        if((fd.revents & POLLIN) == POLLIN)
  20 +        if(may_read && (fd.revents & POLLIN) == POLLIN)
  21  #else
  22 -        if(FD_ISSET(c->fd, &rfds))
  23 +        if(may_read && FD_ISSET(c->fd, &rfds))
  24  #endif
  25              ret = ret && _xcb_in_read(c);
  26