epoll: edge triggered and multi-threaded epoll

- edge triggered (oneshot) polling with epoll
- pick one event to avoid multiple events getting picked up by same
  thread
  and so get better distribution of events against multiple threads
- wire support for multiple poll threads to epoll_wait in parallel
- evdata to store absolute index and not hint for epoll
- store index and gen of slot instead of fd and index hint
- perform fd close asynchronously inside event.c for multithread safety
- poll is still single threaded

Change-Id: I536851dda0ab224c5d5a1b130a571397c9cace8f
BUG: 1104462
Signed-off-by: Anand Avati <avati@redhat.com>
Signed-off-by: Vijaikumar M <vmallika@redhat.com>
Signed-off-by: Jeff Darcy <jdarcy@redhat.com>
Signed-off-by: Shyam <srangana@redhat.com>
Reviewed-on: http://review.gluster.org/3842
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 16 insertions, 2 deletions

diff --git a/libglusterfs/src/event.c b/libglusterfs/src/event.c
index 0197e7948b5..6c253df3c1a 100644
--- a/libglusterfs/src/event.c
+++ b/libglusterfs/src/event.c
@@ -32,10 +32,10 @@ struct event_pool *
 event_pool_new (int count)
 {
         struct event_pool *event_pool = NULL;
-        extern struct event_ops event_ops_poll;
+	extern struct event_ops event_ops_poll;
 
 #ifdef HAVE_SYS_EPOLL_H
-        extern struct event_ops event_ops_epoll;
+	extern struct event_ops event_ops_epoll;
 
         event_pool = event_ops_epoll.new (count);
 
@@ -89,6 +89,20 @@ out:
 
 
 int
+event_unregister_close (struct event_pool *event_pool, int fd, int idx)
+{
+        int ret = -1;
+
+        GF_VALIDATE_OR_GOTO ("event", event_pool, out);
+
+        ret = event_pool->ops->event_unregister_close (event_pool, fd, idx);
+
+out:
+        return ret;
+}
+
+
+int
 event_select_on (struct event_pool *event_pool, int fd, int idx_hint,
                  int poll_in, int poll_out)
 {