totally rewrote the async signal, notification and oplock notification

handling in Samba. This was needed due to several limitations and
races in the previous code - as a side effect the new code is much
cleaner :)

in summary:

- changed sys_select() to avoid a signal/select race condition. It is a
  rare race but once we have signals doing notification and oplocks it
  is important.

- changed our main processing loop to take advantage of the new
  sys_select semantics

- split the notify code into implementaion dependent and general
  parts. Added the following structure that defines an implementation:

struct cnotify_fns {
	void * (*register_notify)(connection_struct *conn, char *path, uint32 flags);
	BOOL (*check_notify)(connection_struct *conn, uint16 vuid, char *path, uint32 flags, void *data, time_t t);
	void (*remove_notify)(void *data);
};


then I wrote two implementations, one using hash/poll (like our old
code) and the other using the new Linux kernel change notify. It
should be easy to add other change notify implementations by creating
a sructure of the above type.

- fixed a bug in change notify where we were returning the wrong error
  code.

- rewrote the core change notify code to be much simpler

- moved to real-time signals for leases and change notify

Amazingly, it all seems to work. I was very surprised!

1 files changed, 3 insertions, 0 deletions

diff --git a/source/include/config.h.in b/source/include/config.h.in
index b4a4f134e48..e3afd6a66a9 100644
--- a/source/include/config.h.in
+++ b/source/include/config.h.in
@@ -544,6 +544,9 @@
 /* Define if you have the pipe function.  */
 #undef HAVE_PIPE
 
+/* Define if you have the poll function.  */
+#undef HAVE_POLL
+
 /* Define if you have the pread function.  */
 #undef HAVE_PREAD