vcl: fix vls mt detection and select handling

Make sure num threads is 1 on process create and fork. Multi-thread
locks are applied once num threads exceeds 1.

For select, follow same pattern like epoll and add check for session
migration.

Type: fix

Signed-off-by: Florin Coras <fcoras@cisco.com>
Signed-off-by: Dave Wallace <dwallacelf@gmail.com>
Change-Id: I1edcd6c4c81b6b3caf8b00781b339414e8945b0e

3 files changed, 29 insertions, 3 deletions

diff --git a/src/vcl/ldp.c b/src/vcl/ldp.c
index bd3457fa8fd..4510bf85e1b 100644
--- a/src/vcl/ldp.c
+++ b/src/vcl/ldp.c
@@ -71,6 +71,7 @@
 /* from <linux/netfilter_ipv4.h> */
 #define SO_ORIGINAL_DST 80
 #endif
+
 typedef struct ldp_worker_ctx_
 {
   u8 *io_buffer;
@@ -102,7 +103,6 @@ typedef struct ldp_worker_ctx_
   u8 epoll_wait_vcl;
   u8 mq_epfd_added;
   int vcl_mq_epfd;
-
 } ldp_worker_ctx_t;
 
 /* clib_bitmap_t, fd_mask and vcl_si_set are used interchangeably. Make sure
@@ -674,6 +674,8 @@ ldp_select_init_maps (fd_set * __restrict original,
     vlsh = ldp_fd_to_vlsh (fd);
     if (vlsh == VLS_INVALID_HANDLE)
       clib_bitmap_set_no_check (*libcb, fd, 1);
+    else if (vlsh_to_worker_index (vlsh) != vppcom_worker_index ())
+      clib_warning ("migration currently not supported");
     else
       *vclb = clib_bitmap_set (*vclb, vlsh_to_session_index (vlsh), 1);
   }
@@ -731,10 +733,10 @@ ldp_pselect (int nfds, fd_set * __restrict readfds,
 	     const __sigset_t * __restrict sigmask)
 {
   u32 minbits = clib_max (nfds, BITS (uword)), n_bytes;
-  ldp_worker_ctx_t *ldpw = ldp_worker_get_current ();
   struct timespec libc_tspec = { 0 };
   f64 time_out, vcl_timeout = 0;
   uword si_bits, libc_bits;
+  ldp_worker_ctx_t *ldpw;
   int rv, bits_set = 0;
 
   if (nfds < 0)
@@ -743,6 +745,11 @@ ldp_pselect (int nfds, fd_set * __restrict readfds,
       return -1;
     }
 
+  if (PREDICT_FALSE (vppcom_worker_index () == ~0))
+    vls_register_vcl_worker ();
+
+  ldpw = ldp_worker_get_current ();
+
   if (PREDICT_FALSE (ldpw->clib_time.init_cpu_time == 0))
     clib_time_init (&ldpw->clib_time);
 
diff --git a/src/vcl/vcl_locked.c b/src/vcl/vcl_locked.c
index 93ece0027ff..24cc598694a 100644
--- a/src/vcl/vcl_locked.c
+++ b/src/vcl/vcl_locked.c
@@ -559,6 +559,22 @@ vlsh_to_session_index (vls_handle_t vlsh)
   return vppcom_session_index (sh);
 }
 
+int
+vlsh_to_worker_index (vls_handle_t vlsh)
+{
+  vcl_locked_session_t *vls;
+  u32 wrk_index;
+
+  vls = vls_get_w_dlock (vlsh);
+  if (!vls)
+    wrk_index = INVALID_SESSION_ID;
+  else
+    wrk_index = vls->vcl_wrk_index;
+  vls_dunlock (vls);
+
+  return wrk_index;
+}
+
 vls_handle_t
 vls_si_wi_to_vlsh (u32 session_index, u32 vcl_wrk_index)
 {
@@ -1799,7 +1815,7 @@ vls_app_fork_child_handler (void)
   vls_worker_alloc ();
 
   /* Reset number of threads and set wrk index */
-  vlsl->vls_mt_n_threads = 0;
+  vlsl->vls_mt_n_threads = 1;
   vlsl->vls_wrk_index = vcl_get_worker_index ();
   vlsl->select_mp_check = 0;
   clib_rwlock_init (&vlsl->vls_pool_lock);
@@ -1983,9 +1999,11 @@ vls_app_create (char *app_name)
   atexit (vls_app_exit);
   vls_worker_alloc ();
   vlsl->vls_wrk_index = vcl_get_worker_index ();
+  vlsl->vls_mt_n_threads = 1;
   clib_rwlock_init (&vlsl->vls_pool_lock);
   vls_mt_locks_init ();
   vcm->wrk_rpc_fn = vls_rpc_handler;
+
   return VPPCOM_OK;
 }
 
diff --git a/src/vcl/vcl_locked.h b/src/vcl/vcl_locked.h
index fa3a2735eb7..3d04a36d5c3 100644
--- a/src/vcl/vcl_locked.h
+++ b/src/vcl/vcl_locked.h
@@ -50,6 +50,7 @@ int vls_select (int n_bits, vcl_si_set * read_map, vcl_si_set * write_map,
 		vcl_si_set * except_map, double wait_for_time);
 vcl_session_handle_t vlsh_to_sh (vls_handle_t vlsh);
 vcl_session_handle_t vlsh_to_session_index (vls_handle_t vlsh);
+int vlsh_to_worker_index (vls_handle_t vlsh);
 vls_handle_t vls_session_index_to_vlsh (uint32_t session_index);
 int vls_app_create (char *app_name);
 unsigned char vls_use_eventfd (void);