vcl/session: apps with process workers

Allow apps to register child processes as app workers. In particular,
on fork vcl now registers the child process with vpp as a new worker.

Change-Id: I52a65fbc3292962b1f6e1fe0f6153f739e6e0d4a
Signed-off-by: Florin Coras <fcoras@cisco.com>

5 files changed, 118 insertions, 44 deletions

diff --git a/src/vcl/vcl_bapi.c b/src/vcl/vcl_bapi.c
index ea8f2ce5651..7dd601cf737 100644
--- a/src/vcl/vcl_bapi.c
+++ b/src/vcl/vcl_bapi.c
@@ -148,17 +148,13 @@ vl_api_app_worker_add_del_reply_t_handler (vl_api_app_worker_add_del_reply_t *
 		    format_api_error, ntohl (mp->retval));
       goto failed;
     }
-  wrk_index = clib_net_to_host_u32 (mp->wrk_index);
-  if (mp->context != wrk_index)
-    {
-      clib_warning ("VCL<%d>: wrk numbering doesn't match ours: %u, vpp: %u",
-		    getpid (), mp->context, wrk_index);
-      goto failed;
-    }
+  wrk_index = mp->context;
+  wrk = vcl_worker_get (wrk_index);
+  wrk->vpp_wrk_index = clib_net_to_host_u32 (mp->wrk_index);
+
   if (!mp->is_add)
     return;
 
-  wrk = vcl_worker_get (wrk_index);
   wrk->app_event_queue = uword_to_pointer (mp->app_event_queue_address,
 					   svm_msg_q_t *);
 
@@ -193,6 +189,7 @@ vl_api_app_worker_add_del_reply_t_handler (vl_api_app_worker_add_del_reply_t *
 	goto failed;
     }
   vcm->app_state = STATE_APP_READY;
+  VDBG (0, "worker %u vpp-worker %u added", wrk_index, wrk->vpp_wrk_index);
   return;
 
 failed:
@@ -432,7 +429,7 @@ vcl_send_app_worker_add_del (u8 is_add)
 
   mp->_vl_msg_id = ntohs (VL_API_APP_WORKER_ADD_DEL);
   mp->client_index = vcm->my_client_index;
-  mp->app_api_index = clib_host_to_net_u32 (vcm->my_client_index);
+  mp->app_api_index = clib_host_to_net_u32 (vcm->main_api_client_index);
   mp->context = wrk_index;
   mp->is_add = is_add;
   if (!is_add)
@@ -444,6 +441,7 @@ vcl_send_app_worker_add_del (u8 is_add)
 void
 vppcom_send_connect_sock (vcl_session_t * session)
 {
+  vcl_worker_t *wrk = vcl_worker_get_current ();
   vl_api_connect_sock_t *cmp;
 
   cmp = vl_msg_api_alloc (sizeof (*cmp));
@@ -451,7 +449,7 @@ vppcom_send_connect_sock (vcl_session_t * session)
   cmp->_vl_msg_id = ntohs (VL_API_CONNECT_SOCK);
   cmp->client_index = vcm->my_client_index;
   cmp->context = session->session_index;
-  cmp->wrk_index = vcl_get_worker_index ();
+  cmp->wrk_index = wrk->vpp_wrk_index;
   cmp->is_ip4 = session->transport.is_ip4;
   clib_memcpy_fast (cmp->ip, &session->transport.rmt_ip, sizeof (cmp->ip));
   cmp->port = session->transport.rmt_port;
@@ -479,6 +477,7 @@ vppcom_send_disconnect_session (u64 vpp_handle)
 void
 vppcom_send_bind_sock (vcl_session_t * session)
 {
+  vcl_worker_t *wrk = vcl_worker_get_current ();
   vl_api_bind_sock_t *bmp;
 
   /* Assumes caller has acquired spinlock: vcm->sessions_lockp */
@@ -488,7 +487,7 @@ vppcom_send_bind_sock (vcl_session_t * session)
   bmp->_vl_msg_id = ntohs (VL_API_BIND_SOCK);
   bmp->client_index = vcm->my_client_index;
   bmp->context = session->session_index;
-  bmp->wrk_index = vcl_get_worker_index ();
+  bmp->wrk_index = wrk->vpp_wrk_index;
   bmp->is_ip4 = session->transport.is_ip4;
   clib_memcpy_fast (bmp->ip, &session->transport.lcl_ip, sizeof (bmp->ip));
   bmp->port = session->transport.lcl_port;
@@ -500,6 +499,7 @@ vppcom_send_bind_sock (vcl_session_t * session)
 void
 vppcom_send_unbind_sock (u64 vpp_handle)
 {
+  vcl_worker_t *wrk = vcl_worker_get_current ();
   vl_api_unbind_sock_t *ump;
 
   ump = vl_msg_api_alloc (sizeof (*ump));
@@ -507,7 +507,7 @@ vppcom_send_unbind_sock (u64 vpp_handle)
 
   ump->_vl_msg_id = ntohs (VL_API_UNBIND_SOCK);
   ump->client_index = vcm->my_client_index;
-  ump->wrk_index = vcl_get_worker_index ();
+  ump->wrk_index = wrk->vpp_wrk_index;
   ump->handle = vpp_handle;
   vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & ump);
 }
@@ -556,15 +556,13 @@ vppcom_connect_to_vpp (char *app_name)
       if (vl_socket_client_connect ((char *) vcl_cfg->vpp_api_socket_name,
 				    app_name, 0 /* default rx/tx buffer */ ))
 	{
-	  clib_warning ("VCL<%d>: app (%s) socket connect failed!",
-			getpid (), app_name);
+	  VERR ("app (%s) socket connect failed!", app_name);
 	  return VPPCOM_ECONNREFUSED;
 	}
 
       if (vl_socket_client_init_shm (0))
 	{
-	  clib_warning ("VCL<%d>: app (%s) init shm failed!",
-			getpid (), app_name);
+	  VERR ("app (%s) init shm failed!", app_name);
 	  return VPPCOM_ECONNREFUSED;
 	}
     }
@@ -573,14 +571,13 @@ vppcom_connect_to_vpp (char *app_name)
       if (!vcl_cfg->vpp_api_filename)
 	vcl_cfg->vpp_api_filename = format (0, "/vpe-api%c", 0);
 
-      VDBG (0, "VCL<%d>: app (%s) connecting to VPP api (%s)...", getpid (),
+      VDBG (0, "app (%s) connecting to VPP api (%s)...",
 	    app_name, vcl_cfg->vpp_api_filename);
 
       if (vl_client_connect_to_vlib ((char *) vcl_cfg->vpp_api_filename,
 				     app_name, vcm->cfg.vpp_api_q_length) < 0)
 	{
-	  clib_warning ("VCL<%d>: app (%s) connect failed!", getpid (),
-			app_name);
+	  VERR ("app (%s) connect failed!", app_name);
 	  return VPPCOM_ECONNREFUSED;
 	}
 
@@ -590,8 +587,7 @@ vppcom_connect_to_vpp (char *app_name)
   vcm->my_client_index = (u32) am->my_client_index;
   vcm->app_state = STATE_APP_CONN_VPP;
 
-  VDBG (0, "VCL<%d>: app (%s) is connected to VPP!", getpid (), app_name);
-
+  VDBG (0, "app (%s) is connected to VPP!", app_name);
   vcl_evt (VCL_EVT_INIT, vcm);
   return VPPCOM_OK;
 }
diff --git a/src/vcl/vcl_cfg.c b/src/vcl/vcl_cfg.c
index e39e5177908..3e92941d720 100644
--- a/src/vcl/vcl_cfg.c
+++ b/src/vcl/vcl_cfg.c
@@ -22,6 +22,7 @@
 static vppcom_main_t _vppcom_main = {
   .debug = VPPCOM_DEBUG_INIT,
   .is_init = 0,
+  .main_api_client_index = ~0,
   .my_client_index = ~0
 };
 
@@ -170,6 +171,7 @@ vppcom_cfg_heapsize (char *conf_fname)
 	      goto defaulted;
 	    }
 	}
+      free (argv[i]);
     }
 
 defaulted:
@@ -231,8 +233,7 @@ vppcom_cfg_read_file (char *conf_fname)
 
   if (fstat (fd, &s) < 0)
     {
-      VCFG_DBG (0,
-		"VCL<%d>: failed to stat `%s', using default configuration",
+      VCFG_DBG (0, "VCL<%d>: failed to stat `%s' using default configuration",
 		getpid (), conf_fname);
       goto file_done;
     }
@@ -254,17 +255,21 @@ vppcom_cfg_read_file (char *conf_fname)
       if (unformat (line_input, "vcl {"))
 	{
 	  vc_cfg_input = 1;
+	  unformat_free (line_input);
 	  continue;
 	}
 
       if (vc_cfg_input)
 	{
-	  if (unformat (line_input, "heapsize %lu", &vcl_cfg->heapsize))
+	  if (unformat (line_input, "heapsize %U", unformat_memory_size,
+			&vcl_cfg->heapsize))
 	    {
 	      VCFG_DBG (0, "VCL<%d>: configured heapsize %lu", getpid (),
 			vcl_cfg->heapsize);
 	    }
-	  if (unformat (line_input, "max-workers %u", &vcl_cfg->max_workers))
+	  else
+	    if (unformat
+		(line_input, "max-workers %u", &vcl_cfg->max_workers))
 	    {
 	      VCFG_DBG (0, "VCL<%d>: configured max-workers %u", getpid (),
 			vcl_cfg->max_workers);
@@ -490,6 +495,7 @@ vppcom_cfg_read_file (char *conf_fname)
 	      vc_cfg_input = 0;
 	      VCFG_DBG (0, "VCL<%d>: completed parsing vppcom config!",
 			getpid ());
+	      unformat_free (line_input);
 	      goto input_done;
 	    }
 	  else
@@ -501,6 +507,7 @@ vppcom_cfg_read_file (char *conf_fname)
 				&line_input->buffer[line_input->index]);
 		}
 	    }
+	  unformat_free (line_input);
 	}
     }
 
diff --git a/src/vcl/vcl_debug.h b/src/vcl/vcl_debug.h
index 7b284166503..48ff21af1de 100644
--- a/src/vcl/vcl_debug.h
+++ b/src/vcl/vcl_debug.h
@@ -23,7 +23,16 @@
 
 #define VDBG(_lvl, _fmt, _args...) 					\
   if (VCL_DBG_ON && vcm->debug > _lvl)					\
-    clib_warning ("vcl<w%d>: " _fmt, __vcl_worker_index, ##_args)
+    clib_warning ("vcl<%d:%d>: " _fmt, vcm->current_pid, 		\
+		  __vcl_worker_index, ##_args)
+
+#define VWRN(_fmt, _args...)						\
+clib_warning ("vcl<%d:%d>: " _fmt, vcm->current_pid, 			\
+		__vcl_worker_index, ##_args)
+
+#define VERR(_fmt, _args...)						\
+  clib_warning ("vcl<%d:%d>: ERROR " _fmt, vcm->current_pid, 		\
+		__vcl_worker_index, ##_args)
 
 #define foreach_vcl_dbg_evt						\
   _(INIT, "vcl init track")						\
diff --git a/src/vcl/vcl_private.h b/src/vcl/vcl_private.h
index d1a40b933a7..7bb0dbc5a66 100644
--- a/src/vcl/vcl_private.h
+++ b/src/vcl/vcl_private.h
@@ -219,8 +219,12 @@ typedef struct vcl_worker_
   /* Session pool */
   vcl_session_t *sessions;
 
+  /** Worker/thread index in current process */
   u32 wrk_index;
 
+  /** Worker index in vpp*/
+  u32 vpp_wrk_index;
+
   /** Message queues epoll fd. Initialized only if using mqs with eventfds */
   int mqs_epfd;
 
@@ -272,15 +276,26 @@ typedef struct vppcom_main_t_
   u32 debug;
   pthread_t main_cpu;
 
-  /** VPP binary api input queue */
-  svm_queue_t *vl_input_queue;
+  /** Main process pid */
+  pid_t main_pid;
+
+  /** Current pid, may be different from main_pid if forked child */
+  pid_t current_pid;
+
+  /** Main process api client index. It's used by vpp to identify the app */
+  u32 main_api_client_index;
 
   /** API client handle */
   u32 my_client_index;
 
+  /** VPP binary api input queue */
+  svm_queue_t *vl_input_queue;
+
   /** State of the connection, shared between msg RX thread and main thread */
   volatile app_state_t app_state;
 
+  u8 *app_name;
+
   /** VCL configuration */
   vppcom_cfg_t cfg;
 
diff --git a/src/vcl/vppcom.c b/src/vcl/vppcom.c
index 99547377523..669f04fe1e3 100644
--- a/src/vcl/vppcom.c
+++ b/src/vcl/vppcom.c
@@ -688,6 +688,52 @@ vppcom_session_disconnect (u32 session_handle)
   return VPPCOM_OK;
 }
 
+static void
+vcl_cleanup_bapi (void)
+{
+  api_main_t *am = &api_main;
+
+  am->my_client_index = ~0;
+  am->my_registration = 0;
+  am->vl_input_queue = 0;
+  am->msg_index_by_name_and_crc = 0;
+
+  vl_client_api_unmap ();
+}
+
+void
+vcl_app_fork_child_handler (void)
+{
+  u8 *child_name;
+  int rv;
+
+  vcm->current_pid = getpid ();
+  vcl_set_worker_index (0);
+
+  VDBG (0, "initializing forked child");
+  child_name = format (0, "%v-child-%u%c", vcm->app_name, getpid (), 0);
+
+  vcl_cleanup_bapi ();
+  vppcom_api_hookup ();
+  vcm->app_state = STATE_APP_START;
+  rv = vppcom_connect_to_vpp ((char *) child_name);
+  vec_free (child_name);
+  if (rv)
+    {
+      VERR ("couldn't connect to VPP!");
+      return;
+    }
+
+  vcm->app_state = STATE_APP_ADDING_WORKER;
+  vcl_send_app_worker_add_del (1 /* is_add */ );
+  if (vcl_wait_for_app_state_change (STATE_APP_READY))
+    {
+      VERR ("failed to add worker to vpp");
+      return;
+    }
+  VDBG (0, "forked child main worker initialized");
+}
+
 /*
  * VPPCOM Public API functions
  */
@@ -704,12 +750,15 @@ vppcom_app_create (char *app_name)
       vcl_cfg = &vcm->cfg;
 
       vcm->main_cpu = pthread_self ();
+      vcm->main_pid = vcm->current_pid = getpid ();
+      vcm->app_name = format (0, "%s", app_name);
       vppcom_init_error_string_table ();
       svm_fifo_segment_main_init (vcl_cfg->segment_baseva,
 				  20 /* timeout in secs */ );
       pool_init_fixed (vcm->workers, vcl_cfg->max_workers);
       clib_spinlock_init (&vcm->workers_lock);
       vcl_worker_alloc_and_init ();
+      pthread_atfork (NULL, NULL, vcl_app_fork_child_handler);
     }
 
   if (vcm->my_client_index == ~0)
@@ -721,31 +770,28 @@ vppcom_app_create (char *app_name)
       rv = vppcom_connect_to_vpp (app_name);
       if (rv)
 	{
-	  clib_warning ("VCL<%d>: ERROR: couldn't connect to VPP!",
-			getpid ());
+	  VERR ("couldn't connect to VPP!");
 	  return rv;
 	}
-
-      VDBG (0, "VCL<%d>: sending session enable", getpid ());
+      vcm->main_api_client_index = vcm->my_client_index;
+      VDBG (0, "sending session enable");
       rv = vppcom_app_session_enable ();
       if (rv)
 	{
-	  clib_warning ("VCL<%d>: ERROR: vppcom_app_session_enable() "
-			"failed!", getpid ());
+	  VERR ("vppcom_app_session_enable() failed!");
 	  return rv;
 	}
 
-      VDBG (0, "VCL<%d>: sending app attach", getpid ());
+      VDBG (0, "sending app attach");
       rv = vppcom_app_attach ();
       if (rv)
 	{
-	  clib_warning ("VCL<%d>: ERROR: vppcom_app_attach() failed!",
-			getpid ());
+	  VERR ("vppcom_app_attach() failed!");
 	  return rv;
 	}
 
-      VDBG (0, "VCL<%d>: app_name '%s', my_client_index %d (0x%x)",
-	    getpid (), app_name, vcm->my_client_index, vcm->my_client_index);
+      VDBG (0, "app_name '%s', my_client_index %d (0x%x)",
+	    app_name, vcm->my_client_index, vcm->my_client_index);
     }
 
   return VPPCOM_OK;
@@ -760,8 +806,8 @@ vppcom_app_destroy (void)
   if (vcm->my_client_index == ~0)
     return;
 
-  VDBG (0, "VCL<%d>: detaching from VPP, my_client_index %d (0x%x)",
-	getpid (), vcm->my_client_index, vcm->my_client_index);
+  VDBG (0, "detaching from VPP, my_client_index %d (0x%x)",
+	vcm->my_client_index, vcm->my_client_index);
   vcl_evt (VCL_EVT_DETACH, vcm);
 
   vppcom_app_send_detach ();
@@ -770,11 +816,12 @@ vppcom_app_destroy (void)
   rv = vcl_wait_for_app_state_change (STATE_APP_ENABLED);
   vcm->cfg.app_timeout = orig_app_timeout;
   if (PREDICT_FALSE (rv))
-    VDBG (0, "VCL<%d>: application detach timed out! returning %d (%s)",
-	  getpid (), rv, vppcom_retval_str (rv));
+    VDBG (0, "application detach timed out! returning %d (%s)",
+	  rv, vppcom_retval_str (rv));
 
   vcl_elog_stop (vcm);
   vl_client_disconnect_from_vlib ();
+  vec_free (vcm->app_name);
   vcm->my_client_index = ~0;
   vcm->app_state = STATE_APP_START;
 }
@@ -798,7 +845,7 @@ vppcom_session_create (u8 proto, u8 is_nonblocking)
   vcl_evt (VCL_EVT_CREATE, session, session_type, session->session_state,
 	   is_nonblocking, session_index);
 
-  VDBG (0, "VCL<%d>: sid %u", getpid (), session->session_index);
+  VDBG (0, "created sid %u", session->session_index);
 
   return vcl_session_handle (session);
 }