Session layer refactoring

Major refactoring of the session layer api
- Add attatch api for application binding to the the session layer
- Simplify listen/connect calls
- Update application CLI
- Add transport endpoint to accept callback
- Associate segment manager to application and allow for multiple
  binds/connects per app

Additional:
- svm fifo cleanup
- add fifo free, format fns
- add fifo offset enqueue unit test

Change-Id: Id93a65047de61afc2bf3d58c9b544339c02065af
Signed-off-by: Florin Coras <fcoras@cisco.com>
Signed-off-by: Dave Barach <dave@barachs.net>

1 files changed, 342 insertions, 0 deletions

diff --git a/src/vnet/session/segment_manager.c b/src/vnet/session/segment_manager.c
new file mode 100644
index 00000000000..16e5bc56736
--- /dev/null
+++ b/src/vnet/session/segment_manager.c
@@ -0,0 +1,342 @@
+/*
+ * Copyright (c) 2017 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/session/segment_manager.h>
+#include <vnet/session/session.h>
+#include <vnet/session/application.h>
+
+/**
+ * Counter used to build segment names
+ */
+u32 segment_name_counter = 0;
+
+/**
+ * Pool of segment managers
+ */
+segment_manager_t *segment_managers = 0;
+
+/**
+ * Default fifo and segment size. TODO config.
+ */
+u32 default_fifo_size = 1 << 16;
+u32 default_segment_size = 1 << 20;
+
+void
+segment_manager_get_segment_info (u32 index, u8 ** name, u32 * size)
+{
+  svm_fifo_segment_private_t *s;
+  s = svm_fifo_get_segment (index);
+  *name = s->h->segment_name;
+  *size = s->ssvm.ssvm_size;
+}
+
+always_inline int
+session_manager_add_segment_i (segment_manager_t * sm, u32 segment_size,
+			       u8 * segment_name)
+{
+  svm_fifo_segment_create_args_t _ca, *ca = &_ca;
+  int rv;
+
+  memset (ca, 0, sizeof (*ca));
+
+  ca->segment_name = (char *) segment_name;
+  ca->segment_size = segment_size;
+
+  rv = svm_fifo_segment_create (ca);
+  if (rv)
+    {
+      clib_warning ("svm_fifo_segment_create ('%s', %d) failed",
+		    ca->segment_name, ca->segment_size);
+      vec_free (segment_name);
+      return VNET_API_ERROR_SVM_SEGMENT_CREATE_FAIL;
+    }
+
+  vec_add1 (sm->segment_indices, ca->new_segment_index);
+
+  return 0;
+}
+
+int
+session_manager_add_segment (segment_manager_t * sm)
+{
+  u8 *segment_name;
+  svm_fifo_segment_create_args_t _ca, *ca = &_ca;
+  u32 add_segment_size;
+  int rv;
+
+  memset (ca, 0, sizeof (*ca));
+  segment_name = format (0, "%d-%d%c", getpid (), segment_name_counter++, 0);
+  add_segment_size = sm->properties->add_segment_size ?
+    sm->properties->add_segment_size : default_segment_size;
+
+  rv = session_manager_add_segment_i (sm, add_segment_size, segment_name);
+  vec_free (segment_name);
+  return rv;
+}
+
+int
+session_manager_add_first_segment (segment_manager_t * sm, u32 segment_size)
+{
+  svm_fifo_segment_create_args_t _ca, *ca = &_ca;
+  u8 *segment_name;
+  int rv;
+
+  memset (ca, 0, sizeof (*ca));
+  segment_name = format (0, "%d-%d%c", getpid (), segment_name_counter++, 0);
+  rv = session_manager_add_segment_i (sm, segment_size, segment_name);
+  vec_free (segment_name);
+  return rv;
+}
+
+/**
+ * Initializes segment manager based on options provided.
+ * Returns error if svm segment allocation fails.
+ */
+int
+segment_manager_init (segment_manager_t * sm,
+		      segment_manager_properties_t * properties,
+		      u32 first_seg_size)
+{
+  int rv;
+
+  /* app allocates these */
+  sm->properties = properties;
+
+  if (first_seg_size > 0)
+    {
+      rv = session_manager_add_first_segment (sm, first_seg_size);
+      if (rv)
+	{
+	  clib_warning ("Failed to allocate segment");
+	  return rv;
+	}
+    }
+
+  return 0;
+}
+
+/**
+ * Removes segment manager.
+ *
+ * Since the fifos allocated in the segment keep backpointers to the sessions
+ * prior to removing the segment, we call session disconnect. This
+ * subsequently propages into transport.
+ */
+void
+segment_manager_del (segment_manager_t * sm)
+{
+  u32 *deleted_sessions = 0;
+  u32 *deleted_thread_indices = 0;
+  int i, j;
+
+  /* Across all fifo segments used by the server */
+  for (j = 0; j < vec_len (sm->segment_indices); j++)
+    {
+      svm_fifo_segment_private_t *fifo_segment;
+      svm_fifo_t **fifos;
+      /* Vector of fifos allocated in the segment */
+      fifo_segment = svm_fifo_get_segment (sm->segment_indices[j]);
+      fifos = svm_fifo_segment_get_fifos (fifo_segment);
+
+      /*
+       * Remove any residual sessions from the session lookup table
+       * Don't bother deleting the individual fifos, we're going to
+       * throw away the fifo segment in a minute.
+       */
+      for (i = 0; i < vec_len (fifos); i++)
+	{
+	  svm_fifo_t *fifo;
+	  u32 session_index, thread_index;
+	  stream_session_t *session;
+
+	  fifo = fifos[i];
+	  session_index = fifo->server_session_index;
+	  thread_index = fifo->server_thread_index;
+
+	  session = stream_session_get (session_index, thread_index);
+
+	  /* Add to the deleted_sessions vector (once!) */
+	  if (!session->is_deleted)
+	    {
+	      session->is_deleted = 1;
+	      vec_add1 (deleted_sessions, session_index);
+	      vec_add1 (deleted_thread_indices, thread_index);
+	    }
+	}
+
+      for (i = 0; i < vec_len (deleted_sessions); i++)
+	{
+	  stream_session_t *session;
+	  session = stream_session_get (deleted_sessions[i],
+					deleted_thread_indices[i]);
+
+	  /* Instead of directly removing the session call disconnect */
+	  stream_session_disconnect (session);
+
+	  /*
+	     stream_session_table_del (smm, session);
+	     pool_put(smm->sessions[deleted_thread_indices[i]], session);
+	   */
+	}
+
+      vec_reset_length (deleted_sessions);
+      vec_reset_length (deleted_thread_indices);
+
+      /* Instead of removing the segment, test when removing the session if
+       * the segment can be removed
+       */
+      /* svm_fifo_segment_delete (fifo_segment); */
+    }
+
+  vec_free (deleted_sessions);
+  vec_free (deleted_thread_indices);
+  pool_put (segment_managers, sm);
+}
+
+static int
+segment_manager_notify_app_seg_add (segment_manager_t * sm,
+				    u32 fifo_segment_index)
+{
+  application_t *app = application_get (sm->app_index);
+  u32 seg_size = 0;
+  u8 *seg_name;
+
+  /* Send an API message to the external app, to map new segment */
+  ASSERT (app->cb_fns.add_segment_callback);
+
+  segment_manager_get_segment_info (fifo_segment_index, &seg_name, &seg_size);
+  return app->cb_fns.add_segment_callback (app->api_client_index, seg_name,
+					   seg_size);
+}
+
+int
+segment_manager_alloc_session_fifos (segment_manager_t * sm,
+				     svm_fifo_t ** server_rx_fifo,
+				     svm_fifo_t ** server_tx_fifo,
+				     u32 * fifo_segment_index)
+{
+  svm_fifo_segment_private_t *fifo_segment;
+  u32 fifo_size, sm_index;
+  u8 added_a_segment = 0;
+  int i;
+
+  /* Allocate svm fifos */
+  ASSERT (vec_len (sm->segment_indices));
+
+again:
+  for (i = 0; i < vec_len (sm->segment_indices); i++)
+    {
+      *fifo_segment_index = sm->segment_indices[i];
+      fifo_segment = svm_fifo_get_segment (*fifo_segment_index);
+
+      fifo_size = sm->properties->rx_fifo_size;
+      fifo_size = (fifo_size == 0) ? default_fifo_size : fifo_size;
+      *server_rx_fifo = svm_fifo_segment_alloc_fifo (fifo_segment, fifo_size);
+
+      fifo_size = sm->properties->tx_fifo_size;
+      fifo_size = (fifo_size == 0) ? default_fifo_size : fifo_size;
+      *server_tx_fifo = svm_fifo_segment_alloc_fifo (fifo_segment, fifo_size);
+
+      if (*server_rx_fifo == 0)
+	{
+	  /* This would be very odd, but handle it... */
+	  if (*server_tx_fifo != 0)
+	    {
+	      svm_fifo_segment_free_fifo (fifo_segment, *server_tx_fifo);
+	      *server_tx_fifo = 0;
+	    }
+	  continue;
+	}
+      if (*server_tx_fifo == 0)
+	{
+	  if (*server_rx_fifo != 0)
+	    {
+	      svm_fifo_segment_free_fifo (fifo_segment, *server_rx_fifo);
+	      *server_rx_fifo = 0;
+	    }
+	  continue;
+	}
+      break;
+    }
+
+  /* See if we're supposed to create another segment */
+  if (*server_rx_fifo == 0)
+    {
+      if (sm->properties->add_segment)
+	{
+	  if (added_a_segment)
+	    {
+	      clib_warning ("added a segment, still cant allocate a fifo");
+	      return SESSION_ERROR_NEW_SEG_NO_SPACE;
+	    }
+
+	  if (session_manager_add_segment (sm))
+	    return VNET_API_ERROR_URI_FIFO_CREATE_FAILED;
+
+	  added_a_segment = 1;
+	  goto again;
+	}
+      else
+	{
+	  clib_warning ("No space to allocate fifos!");
+	  return SESSION_ERROR_NO_SPACE;
+	}
+    }
+
+  if (added_a_segment)
+    return segment_manager_notify_app_seg_add (sm, *fifo_segment_index);
+
+  /* Backpointers to segment manager */
+  sm_index = segment_manager_index (sm);
+  (*server_tx_fifo)->segment_manager = sm_index;
+  (*server_rx_fifo)->segment_manager = sm_index;
+
+  return 0;
+}
+
+void
+segment_manager_dealloc_fifos (u32 svm_segment_index, svm_fifo_t * rx_fifo,
+			       svm_fifo_t * tx_fifo)
+{
+  segment_manager_t *sm;
+  svm_fifo_segment_private_t *fifo_segment;
+
+  fifo_segment = svm_fifo_get_segment (svm_segment_index);
+  svm_fifo_segment_free_fifo (fifo_segment, rx_fifo);
+  svm_fifo_segment_free_fifo (fifo_segment, tx_fifo);
+
+  /* If we have segment manager, try doing some cleanup.
+   * It's possible to have no segment manager if the session was removed
+   * as result of a detach */
+  sm = segment_manager_get_if_valid (rx_fifo->segment_manager);
+  if (sm)
+    {
+      /* Remove segment only if it holds no fifos and not the first */
+      if (sm->segment_indices[0] != svm_segment_index
+	  && !svm_fifo_segment_has_fifos (fifo_segment))
+	{
+	  svm_fifo_segment_delete (fifo_segment);
+	  vec_del1 (sm->segment_indices, svm_segment_index);
+	}
+    }
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */