session: use clib rwlocks instead of custom implementation

Change-Id: I68933d709ce9cc686ba06466e136434b663920ef
Signed-off-by: Florin Coras <fcoras@cisco.com>

2 files changed, 9 insertions, 27 deletions

diff --git a/src/vnet/session/session.c b/src/vnet/session/session.c
index ec6d7812f0b..ae8c42aa32b 100644
--- a/src/vnet/session/session.c
+++ b/src/vnet/session/session.c
@@ -85,12 +85,12 @@ session_alloc (u32 thread_index)
   pool_get_aligned_will_expand (smm->sessions[thread_index], will_expand,
 				CLIB_CACHE_LINE_BYTES);
   /* If we have peekers, let them finish */
-  if (PREDICT_FALSE (will_expand))
+  if (PREDICT_FALSE (will_expand && vlib_num_workers ()))
     {
-      clib_spinlock_lock_if_init (&smm->peekers_write_locks[thread_index]);
+      clib_rwlock_writer_lock (&smm->peekers_rw_locks[thread_index]);
       pool_get_aligned (session_manager_main.sessions[thread_index], s,
 			CLIB_CACHE_LINE_BYTES);
-      clib_spinlock_unlock_if_init (&smm->peekers_write_locks[thread_index]);
+      clib_rwlock_writer_unlock (&smm->peekers_rw_locks[thread_index]);
     }
   else
     {
@@ -1133,9 +1133,7 @@ session_manager_main_enable (vlib_main_t * vm)
   vec_validate (smm->pending_disconnects, num_threads - 1);
   vec_validate (smm->free_event_vector, num_threads - 1);
   vec_validate (smm->vpp_event_queues, num_threads - 1);
-  vec_validate (smm->session_peekers, num_threads - 1);
-  vec_validate (smm->peekers_readers_locks, num_threads - 1);
-  vec_validate (smm->peekers_write_locks, num_threads - 1);
+  vec_validate (smm->peekers_rw_locks, num_threads - 1);
 
   for (i = 0; i < TRANSPORT_N_PROTO; i++)
     for (j = 0; j < num_threads; j++)
@@ -1153,10 +1151,7 @@ session_manager_main_enable (vlib_main_t * vm)
       vec_validate (smm->pending_disconnects[i], 0);
       _vec_len (smm->pending_disconnects[i]) = 0;
       if (num_threads > 1)
-	{
-	  clib_spinlock_init (&smm->peekers_readers_locks[i]);
-	  clib_spinlock_init (&smm->peekers_write_locks[i]);
-	}
+	clib_rwlock_init (&smm->peekers_rw_locks[i]);
     }
 
 #if SESSION_DBG
diff --git a/src/vnet/session/session.h b/src/vnet/session/session.h
index da9332a2a10..d0bf95c41e4 100644
--- a/src/vnet/session/session.h
+++ b/src/vnet/session/session.h
@@ -118,12 +118,8 @@ struct _session_manager_main
   /** Per worker thread session pools */
   stream_session_t **sessions;
 
-  /** Per worker-thread count of threads peeking into the session pool */
-  u32 *session_peekers;
-
-  /** Per worker-thread rw peekers locks */
-  clib_spinlock_t *peekers_readers_locks;
-  clib_spinlock_t *peekers_write_locks;
+  /** Per worker-thread session pool peekers rw locks */
+  clib_rwlock_t *peekers_rw_locks;
 
   /** Pool of listen sessions. Same type as stream sessions to ease lookups */
   stream_session_t **listen_sessions;
@@ -316,11 +312,7 @@ session_pool_add_peeker (u32 thread_index)
   session_manager_main_t *smm = &session_manager_main;
   if (thread_index == vlib_get_thread_index ())
     return;
-  clib_spinlock_lock_if_init (&smm->peekers_readers_locks[thread_index]);
-  smm->session_peekers[thread_index] += 1;
-  if (smm->session_peekers[thread_index] == 1)
-    clib_spinlock_lock_if_init (&smm->peekers_write_locks[thread_index]);
-  clib_spinlock_unlock_if_init (&smm->peekers_readers_locks[thread_index]);
+  clib_rwlock_reader_lock (&smm->peekers_rw_locks[thread_index]);
 }
 
 always_inline void
@@ -329,12 +321,7 @@ session_pool_remove_peeker (u32 thread_index)
   session_manager_main_t *smm = &session_manager_main;
   if (thread_index == vlib_get_thread_index ())
     return;
-  ASSERT (session_manager_main.session_peekers[thread_index] > 0);
-  clib_spinlock_lock_if_init (&smm->peekers_readers_locks[thread_index]);
-  smm->session_peekers[thread_index] -= 1;
-  if (smm->session_peekers[thread_index] == 0)
-    clib_spinlock_unlock_if_init (&smm->peekers_write_locks[thread_index]);
-  clib_spinlock_unlock_if_init (&smm->peekers_readers_locks[thread_index]);
+  clib_rwlock_reader_unlock (&smm->peekers_rw_locks[thread_index]);
 }
 
 /**