Zero count of consumers/tail readers of CBUFF is handled now.

The CBUFF semantic is changed so that the first
(re-)attached reader is supplied by all messages
held in buffer during time when no reader is attached.

Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>

diff --git a/ulut/ul_cbuff.h b/ulut/ul_cbuff.h
index e9a74e3b5a00138399e5978161a20655108ba0a3..a6fd8d8c06cc64a80d196cb6828bdbc58e1e803a 100644 (file)
--- a/ulut/ul_cbuff.h
+++ b/ulut/ul_cbuff.h
@@ -189,6 +189,8 @@ ul_cbuff_head_alloc(ul_cbuff_t *buff, ul_cbuff_put_info_t *put_info, unsigned in
   put_info->msg_head->flags|=flags;
   if(buff->state->readers>0)
     put_info->msg_head->flags+=buff->state->readers;
+  else if (buff->state->readers==0)
+    put_info->msg_head->flags+=1;
 
   put_info->msg_head->length=length;
 
@@ -262,7 +264,10 @@ ul_cbuff_tail_attach(ul_cbuff_t *buff, ul_cbuff_tail_info_t *tail_info, int mode
   ul_cbuff_state_t *state=buff->state;
   ul_cbuff_msg_head_t *msg_head;
 
-  msg_head=(ul_cbuff_msg_head_t *)(buff->buff_start+state->head);
+  if(state->readers>0)
+    msg_head=(ul_cbuff_msg_head_t *)(buff->buff_start+state->head);
+  else if(state->readers==0)
+    msg_head=(ul_cbuff_msg_head_t *)(buff->buff_start+state->lasttail);
   if(state->readers>=0)
     state->readers++;
   tail_info->msg_head=msg_head;