X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=src%2Fsvm%2Fsvm_fifo.h;h=4a119341d8b3cb3a519e360c4ab6c56331e86e26;hb=c5df8c71c;hp=613e0cad5ebf49b67bcb39a0a48b8cfb5a0fb0cc;hpb=1bcad5cdb78fb04d41f97603312161b2bc2e7bae;p=vpp.git

diff --git a/src/svm/svm_fifo.h b/src/svm/svm_fifo.h
index 613e0cad5eb..4a119341d8b 100644
--- a/src/svm/svm_fifo.h
+++ b/src/svm/svm_fifo.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Copyright (c) 2016-2019 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:
@@ -40,6 +40,7 @@ format_function_t format_ooo_list;
 #define OOO_SEGMENT_INVALID_INDEX 	((u32)~0)
 #define SVM_FIFO_INVALID_SESSION_INDEX 	((u32)~0)
 #define SVM_FIFO_INVALID_INDEX		((u32)~0)
+#define SVM_FIFO_MAX_EVT_SUBSCRIBERS	8
 
 enum
 {
@@ -57,13 +58,13 @@ typedef struct
 
 typedef struct _svm_fifo
 {
+  CLIB_CACHE_LINE_ALIGN_MARK (shared_first);
   volatile u32 cursize;		/**< current fifo size */
   u32 nitems;
-    CLIB_CACHE_LINE_ALIGN_MARK (end_cursize);
 
+    CLIB_CACHE_LINE_ALIGN_MARK (shared_second);
   volatile u32 has_event;	/**< non-zero if deq event exists */
 
-  /* Backpointers */
   u32 master_session_index;
   u32 client_session_index;
   u8 master_thread_index;
@@ -71,13 +72,15 @@ typedef struct _svm_fifo
   u32 segment_manager;
   u32 segment_index;
   u32 ct_session_index;		/**< Local session index for vpp */
-    CLIB_CACHE_LINE_ALIGN_MARK (end_shared);
+  u32 freelist_index;		/**< aka log2(allocated_size) - const. */
+  i8 refcnt;			/**< reference count  */
+
+    CLIB_CACHE_LINE_ALIGN_MARK (consumer);
   u32 head;
   volatile u32 want_tx_ntf;	/**< producer wants nudge */
   volatile u32 has_tx_ntf;
-    CLIB_CACHE_LINE_ALIGN_MARK (end_consumer);
 
-  /* producer */
+    CLIB_CACHE_LINE_ALIGN_MARK (producer);
   u32 tail;
 
   ooo_segment_t *ooo_segments;	/**< Pool of ooo segments */
@@ -85,11 +88,13 @@ typedef struct _svm_fifo
   u32 ooos_newest;		/**< Last segment to have been updated */
   struct _svm_fifo *next;	/**< next in freelist/active chain */
   struct _svm_fifo *prev;	/**< prev in active chain */
+  volatile u8 n_subscribers;
+  u8 subscribers[SVM_FIFO_MAX_EVT_SUBSCRIBERS];
+
 #if SVM_FIFO_TRACE
   svm_fifo_trace_elem_t *trace;
 #endif
-  u32 freelist_index;		/**< aka log2(allocated_size) - const. */
-  i8 refcnt;			/**< reference count  */
+
     CLIB_CACHE_LINE_ALIGN_MARK (data);
 } svm_fifo_t;
 
@@ -168,18 +173,18 @@ svm_fifo_set_event (svm_fifo_t * f)
 {
   /* return __sync_lock_test_and_set (&f->has_event, 1) == 0;
      return __sync_bool_compare_and_swap (&f->has_event, 0, 1); */
-  return !__atomic_exchange_n (&f->has_event, 1, __ATOMIC_RELEASE);
+  return !clib_atomic_swap_rel_n (&f->has_event, 1);
 }
 
 /**
  * Unsets fifo event flag.
  *
- * Also acts as a release barrier.
+ * Also acts as an acquire barrier.
  */
 always_inline void
 svm_fifo_unset_event (svm_fifo_t * f)
 {
-  clib_atomic_release (&f->has_event);
+  clib_atomic_swap_acq_n (&f->has_event, 0);
 }
 
 svm_fifo_t *svm_fifo_create (u32 data_size_in_bytes);
@@ -198,6 +203,8 @@ int svm_fifo_segments (svm_fifo_t * f, svm_fifo_segment_t * fs);
 void svm_fifo_segments_free (svm_fifo_t * f, svm_fifo_segment_t * fs);
 void svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer);
 void svm_fifo_overwrite_head (svm_fifo_t * f, u8 * data, u32 len);
+void svm_fifo_add_subscriber (svm_fifo_t * f, u8 subscriber);
+void svm_fifo_del_subscriber (svm_fifo_t * f, u8 subscriber);
 format_function_t format_svm_fifo;
 
 /**
@@ -228,7 +235,7 @@ svm_fifo_enqueue_nocopy (svm_fifo_t * f, u32 bytes)
 {
   ASSERT (bytes <= svm_fifo_max_enqueue (f));
   f->tail = (f->tail + bytes) % f->nitems;
-  f->cursize += bytes;
+  clib_atomic_fetch_add_rel (&f->cursize, bytes);
 }
 
 always_inline u8 *
@@ -297,6 +304,12 @@ svm_fifo_needs_tx_ntf (svm_fifo_t * f, u32 n_last_deq)
   return 0;
 }
 
+always_inline u8
+svm_fifo_n_subscribers (svm_fifo_t * f)
+{
+  return f->n_subscribers;
+}
+
 u32 svm_fifo_number_ooo_segments (svm_fifo_t * f);
 ooo_segment_t *svm_fifo_first_ooo_segment (svm_fifo_t * f);