vcl: basic support for apps that fork

- intercept fork and register a new worker with vpp
- share sessions between parent and forked child
- keep binary api state per worker

Change-Id: Ib177517d661724fa042bd2d98d18e777056352a2
Signed-off-by: Florin Coras <fcoras@cisco.com>

1 files changed, 29 insertions, 9 deletions

diff --git a/src/vcl/vcl_private.h b/src/vcl/vcl_private.h
index 0204bd5493e..0420322d3f4 100644
--- a/src/vcl/vcl_private.h
+++ b/src/vcl/vcl_private.h
@@ -136,6 +136,12 @@ do {                                            \
 #define VCL_SESS_ATTR_TEST(ATTR, VAL)           \
   ((ATTR) & (1 << (VAL)) ? 1 : 0)
 
+typedef struct vcl_shared_session_
+{
+  u32 ss_index;
+  u32 *workers;
+} vcl_shared_session_t;
+
 typedef struct
 {
   CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
@@ -161,6 +167,7 @@ typedef struct
   svm_msg_q_t *our_evt_q;
   u64 options[16];
   vcl_session_msg_t *accept_evts_fifo;
+  u32 shared_index;
 #if VCL_ELOG
   elog_track_t elog_track;
 #endif
@@ -225,6 +232,15 @@ typedef struct vcl_worker_
   /** Worker index in vpp*/
   u32 vpp_wrk_index;
 
+  /** API client handle */
+  u32 my_client_index;
+
+  /** State of the connection, shared between msg RX thread and main thread */
+  volatile app_state_t wrk_state;
+
+  /** VPP binary api input queue */
+  svm_queue_t *vl_input_queue;
+
   /** Message queues epoll fd. Initialized only if using mqs with eventfds */
   int mqs_epfd;
 
@@ -268,6 +284,9 @@ typedef struct vcl_worker_
 
   /** Used also as a thread stop key buffer */
   pthread_t thread_id;
+
+  /** Current pid, may be different from main_pid if forked child */
+  pid_t current_pid;
 } vcl_worker_t;
 
 typedef struct vppcom_main_t_
@@ -279,18 +298,9 @@ typedef struct vppcom_main_t_
   /** Main process pid */
   pid_t main_pid;
 
-  /** Current pid, may be different from main_pid if forked child */
-  pid_t current_pid;
-
   /** App's index in vpp. It's used by vpp to identify the app */
   u32 app_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;
 
@@ -302,12 +312,15 @@ typedef struct vppcom_main_t_
   /** Flag indicating that a new segment is being mounted */
   volatile u32 mounting_segment;
 
+  volatile u32 forking;
+
   /** Workers */
   vcl_worker_t *workers;
 
   /** Lock to protect worker registrations */
   clib_spinlock_t workers_lock;
 
+  vcl_shared_session_t *shared_sessions;
 #ifdef VCL_ELOG
   /* VPP Event-logger */
   elog_main_t elog_main;
@@ -330,6 +343,7 @@ vcl_session_alloc (vcl_worker_t * wrk)
   pool_get (wrk->sessions, s);
   memset (s, 0, sizeof (*s));
   s->session_index = s - wrk->sessions;
+  s->shared_index = ~0;
   return s;
 }
 
@@ -481,6 +495,12 @@ int vcl_mq_epoll_add_evfd (vcl_worker_t * wrk, svm_msg_q_t * mq);
 int vcl_mq_epoll_del_evfd (vcl_worker_t * wrk, u32 mqc_index);
 
 vcl_worker_t *vcl_worker_alloc_and_init (void);
+void vcl_worker_cleanup (void);
+int vcl_worker_register_with_vpp (void);
+int vcl_worker_set_bapi (void);
+void vcl_worker_share_sessions (u32 parent_wrk_index);
+int vcl_worker_unshare_session (vcl_worker_t * wrk, vcl_session_t * s);
+int vcl_session_get_refcnt (vcl_session_t * s);
 
 static inline vcl_worker_t *
 vcl_worker_get (u32 wrk_index)