BUG/MINOR: session: atomically increment the tracked sessions counter

In session_count_new() the tracked counter was still incremented with
a "++" outside of any lock, resulting in occasional slightly off values
such as the following:

    # table: foo, type: string, size:1000, used:1
    0xb2a398: key=127.1.2.3 use=0 exp=86398318 sess_cnt=999959 http_req_cnt=1000004

Now with the correct atomic increment:

    # table: foo, type: string, size:1000, used:1
    0x7f82a4026d38: key=127.1.2.3 use=0 exp=86399294 sess_cnt=1000004 http_req_cnt=1000004

This can be backported to 1.8.

(cherry picked from commit 9805859f245f4f59fc3baa098cb349786e21aaba)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 86eb8369d3c584631e6f4f93a2e2cfcba945bee6)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit e78daa425262e64faf520784e318eb2e35e819e7)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>

diff --git a/src/session.c b/src/session.c
index 111fc61..de8a4f3 100644 (file)
--- a/src/session.c
+++ b/src/session.c
@@ -123,7 +123,7 @@ static void session_count_new(struct session *sess)
 
                ptr = stktable_data_ptr(stkctr->table, stkctr_entry(stkctr), STKTABLE_DT_SESS_CNT);
                if (ptr)
-                       stktable_data_cast(ptr, sess_cnt)++;
+                       HA_ATOMIC_ADD(&stktable_data_cast(ptr, sess_cnt), 1);
 
                ptr = stktable_data_ptr(stkctr->table, stkctr_entry(stkctr), STKTABLE_DT_SESS_RATE);
                if (ptr)