vcl: store libc_epfd in vls instead of vcl

ldp stores the libc epfds it uses in conjunction with vcl epfds in vcl
attributes. Apart from being an ldp, as opposed to vcl, specific
attribute, the epfd is retrieved on session close with vls locks that
could be acquired from multiple threads.

Avoid grabbing locks when retrieving the attribute.

Type: improvement

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: I5fc52d72667a7693b1557d209c3890a968422f1e

1 files changed, 7 insertions, 13 deletions

diff --git a/src/vcl/ldp.c b/src/vcl/ldp.c
index befb30851cd..e8cabd2a2cd 100644
--- a/src/vcl/ldp.c
+++ b/src/vcl/ldp.c
@@ -327,19 +327,17 @@ close (int fd)
   vlsh = ldp_fd_to_vlsh (fd);
   if (vlsh != VLS_INVALID_HANDLE)
     {
-      epfd = vls_attr (vlsh, VPPCOM_ATTR_GET_LIBC_EPFD, 0, 0);
+      epfd = vls_get_libc_epfd (vlsh);
       if (epfd > 0)
 	{
 	  ldp_worker_ctx_t *ldpw = ldp_worker_get_current ();
-	  u32 size = sizeof (epfd);
 
 	  LDBG (0, "fd %d: calling libc_close: epfd %u", fd, epfd);
 
 	  libc_close (epfd);
 	  ldpw->mq_epfd_added = 0;
 
-	  epfd = 0;
-	  (void) vls_attr (vlsh, VPPCOM_ATTR_SET_LIBC_EPFD, &epfd, &size);
+	  vls_set_libc_epfd (vlsh, 0);
 	}
       else if (PREDICT_FALSE (epfd < 0))
 	{
@@ -2460,9 +2458,8 @@ epoll_ctl (int epfd, int op, int fd, struct epoll_event *event)
   else
     {
       int libc_epfd;
-      u32 size = sizeof (epfd);
 
-      libc_epfd = vls_attr (vep_vlsh, VPPCOM_ATTR_GET_LIBC_EPFD, 0, 0);
+      libc_epfd = vls_get_libc_epfd (vep_vlsh);
       if (!libc_epfd)
 	{
 	  LDBG (1, "epfd %d, vep_vlsh %d calling libc_epoll_create1: "
@@ -2475,8 +2472,7 @@ epoll_ctl (int epfd, int op, int fd, struct epoll_event *event)
 	      goto done;
 	    }
 
-	  rv = vls_attr (vep_vlsh, VPPCOM_ATTR_SET_LIBC_EPFD, &libc_epfd,
-			 &size);
+	  rv = vls_set_libc_epfd (vep_vlsh, libc_epfd);
 	  if (rv < 0)
 	    {
 	      errno = -rv;
@@ -2538,7 +2534,7 @@ ldp_epoll_pwait (int epfd, struct epoll_event *events, int maxevents,
   time_to_wait = ((timeout >= 0) ? (double) timeout / 1000 : 0);
   max_time = clib_time_now (&ldpw->clib_time) + time_to_wait;
 
-  libc_epfd = vls_attr (ep_vlsh, VPPCOM_ATTR_GET_LIBC_EPFD, 0, 0);
+  libc_epfd = vls_get_libc_epfd (ep_vlsh);
   if (PREDICT_FALSE (libc_epfd < 0))
     {
       errno = -libc_epfd;
@@ -2616,11 +2612,9 @@ ldp_epoll_pwait_eventfd (int epfd, struct epoll_event *events,
       return -1;
     }
 
-  libc_epfd = vls_attr (ep_vlsh, VPPCOM_ATTR_GET_LIBC_EPFD, 0, 0);
+  libc_epfd = vls_get_libc_epfd (ep_vlsh);
   if (PREDICT_FALSE (!libc_epfd))
     {
-      u32 size = sizeof (epfd);
-
       LDBG (1, "epfd %d, vep_vlsh %d calling libc_epoll_create1: "
 	    "EPOLL_CLOEXEC", epfd, ep_vlsh);
       libc_epfd = libc_epoll_create1 (EPOLL_CLOEXEC);
@@ -2630,7 +2624,7 @@ ldp_epoll_pwait_eventfd (int epfd, struct epoll_event *events,
 	  goto done;
 	}
 
-      rv = vls_attr (ep_vlsh, VPPCOM_ATTR_SET_LIBC_EPFD, &libc_epfd, &size);
+      rv = vls_set_libc_epfd (ep_vlsh, libc_epfd);
       if (rv < 0)
 	{
 	  errno = -rv;