Look into running integration tests with valgrind

[TysonAndre]

1. Identify possible memory leaks (not practical, this exits without cleaning up in most cases)
2. Identify invalid memory accesses

diff --git a/src/event/nc_epoll.c b/src/event/nc_epoll.c
index 33aff85..c5b0a1a 100644
--- a/src/event/nc_epoll.c
+++ b/src/event/nc_epoll.c
@@ -103,6 +103,7 @@ event_add_in(struct event_base *evb, struct conn *c)
     }
 
     event.events = (uint32_t)(EPOLLIN | EPOLLET);
+    memset(&event.data, 0, sizeof(event.data));
     event.data.ptr = c;
 
     status = epoll_ctl(ep, EPOLL_CTL_MOD, c->sd, &event);
@@ -139,6 +140,7 @@ event_add_out(struct event_base *evb, struct conn *c)
     }
 
     event.events = (uint32_t)(EPOLLIN | EPOLLOUT | EPOLLET);
+    memset(&event.data, 0, sizeof(event.data));
     event.data.ptr = c;
 
     status = epoll_ctl(ep, EPOLL_CTL_MOD, c->sd, &event);
@@ -169,6 +171,7 @@ event_del_out(struct event_base *evb, struct conn *c)
     }
 
     event.events = (uint32_t)(EPOLLIN | EPOLLET);
+    memset(&event.data, 0, sizeof(event.data));
     event.data.ptr = c;
 
     status = epoll_ctl(ep, EPOLL_CTL_MOD, c->sd, &event);
@@ -194,6 +197,7 @@ event_add_conn(struct event_base *evb, struct conn *c)
     ASSERT(c->sd > 0);
 
     event.events = (uint32_t)(EPOLLIN | EPOLLOUT | EPOLLET);
+    memset(&event.data, 0, sizeof(event.data));
     event.data.ptr = c;
 
     status = epoll_ctl(ep, EPOLL_CTL_ADD, c->sd, &event);
@@ -307,6 +311,7 @@ event_loop_stats(event_stats_cb_t cb, void *arg)
         return;
     }
 
+    memset(&ev.data, 0, sizeof(ev.data));
     ev.data.fd = st->sd;
     ev.events = EPOLLIN;

Because event.data is a union the stats code for fd is a false positive for valgrind.