vls: multi-process and multi-threaded apps improvements

- More fine tuning for multi-process applications.
- Experimental support for multi-thread apps. This is meant for app
  whose threads are not vcl workers and the sessions are shared between
  them.

Change-Id: Ie07651da5f2cdcf39f5dead5431f50ad39cf3f74
Signed-off-by: Florin Coras <fcoras@cisco.com>

1 files changed, 64 insertions, 0 deletions

diff --git a/src/vcl/vcl_private.c b/src/vcl/vcl_private.c
index df602b3ce87..5f9ce270508 100644
--- a/src/vcl/vcl_private.c
+++ b/src/vcl/vcl_private.c
@@ -391,6 +391,70 @@ vcl_cleanup_bapi (void)
   vl_client_api_unmap ();
 }
 
+int
+vcl_session_read_ready (vcl_session_t * session)
+{
+  /* Assumes caller has acquired spinlock: vcm->sessions_lockp */
+  if (PREDICT_FALSE (session->is_vep))
+    {
+      VDBG (0, "ERROR: session %u: cannot read from an epoll session!",
+	    session->session_index);
+      return VPPCOM_EBADFD;
+    }
+
+  if (PREDICT_FALSE (!(session->session_state & (STATE_OPEN | STATE_LISTEN))))
+    {
+      session_state_t state = session->session_state;
+      int rv;
+
+      rv = ((state & STATE_DISCONNECT) ? VPPCOM_ECONNRESET : VPPCOM_ENOTCONN);
+
+      VDBG (1, "session %u [0x%llx]: not open! state 0x%x (%s), ret %d (%s)",
+	    session->session_index, session->vpp_handle, state,
+	    vppcom_session_state_str (state), rv, vppcom_retval_str (rv));
+      return rv;
+    }
+
+  if (session->session_state & STATE_LISTEN)
+    return clib_fifo_elts (session->accept_evts_fifo);
+
+  return svm_fifo_max_dequeue (session->rx_fifo);
+}
+
+int
+vcl_session_write_ready (vcl_session_t * session)
+{
+  /* Assumes caller has acquired spinlock: vcm->sessions_lockp */
+  if (PREDICT_FALSE (session->is_vep))
+    {
+      VDBG (0, "session %u [0x%llx]: cannot write to an epoll session!",
+	    session->session_index, session->vpp_handle);
+      return VPPCOM_EBADFD;
+    }
+
+  if (PREDICT_FALSE (session->session_state & STATE_LISTEN))
+    {
+      if (session->tx_fifo)
+	return svm_fifo_max_enqueue (session->tx_fifo);
+      else
+	return VPPCOM_EBADFD;
+    }
+
+  if (PREDICT_FALSE (!(session->session_state & STATE_OPEN)))
+    {
+      session_state_t state = session->session_state;
+      int rv;
+
+      rv = ((state & STATE_DISCONNECT) ? VPPCOM_ECONNRESET : VPPCOM_ENOTCONN);
+      VDBG (0, "session %u [0x%llx]: not open! state 0x%x (%s), ret %d (%s)",
+	    session->session_index, session->vpp_handle, state,
+	    vppcom_session_state_str (state), rv, vppcom_retval_str (rv));
+      return rv;
+    }
+
+  return svm_fifo_max_enqueue (session->tx_fifo);
+}
+
 /*
  * fd.io coding-style-patch-verification: ON
  *