MINOR: connection: add a new CO_FL_WANT_DRAIN flag to force drain on close

Sometimes we'd like to do our best to drain pending data before closing
in order to save the peer from risking to receive an RST on close.

This adds a new connection flag CO_FL_WANT_DRAIN that is used to
trigger a call to conn_ctrl_drain() from conn_ctrl_close(), and the
sock_drain() function ignores fd_recv_ready() if this flag is set,
in order to catch latest data. It's not used for now.

diff --git a/include/haproxy/connection-t.h b/include/haproxy/connection-t.h
index 0ba8555ff3d9e4bdf02290f04aaa364111d36824..68ab91ae8ae5df60cab7540fedb879fb2e7b3864 100644 (file)
--- a/include/haproxy/connection-t.h
+++ b/include/haproxy/connection-t.h
@@ -131,7 +131,7 @@ enum {
        CO_FL_CTRL_READY    = 0x00000100, /* FD was registered, fd_delete() needed */
        CO_FL_XPRT_READY    = 0x00000200, /* xprt_start() done, xprt can be used */
 
-       /* unused : 0x00000400 */
+       CO_FL_WANT_DRAIN    = 0x00000400, /* try to drain pending data when closing */
 
        /* This flag is used by data layers to indicate they had to stop
         * receiving data because a buffer was full. The connection handler

diff --git a/include/haproxy/connection.h b/include/haproxy/connection.h
index 17dad4bdaf15f819e2b4a4bf5c55fb17059907f2..7c970e2bdd9c7659d24b655cfce7d0a4c215b5f2 100644 (file)
--- a/include/haproxy/connection.h
+++ b/include/haproxy/connection.h
@@ -174,6 +174,8 @@ static inline void conn_ctrl_init(struct connection *conn)
 static inline void conn_ctrl_close(struct connection *conn)
 {
        if (!conn->xprt && (conn->flags & CO_FL_CTRL_READY)) {
+               if ((conn->flags & (CO_FL_WANT_DRAIN | CO_FL_SOCK_RD_SH)) == CO_FL_WANT_DRAIN)
+                       conn_ctrl_drain(conn);
                conn->flags &= ~CO_FL_CTRL_READY;
                if (conn->ctrl->ctrl_close)
                        conn->ctrl->ctrl_close(conn);

diff --git a/src/sock.c b/src/sock.c
index d05cf7e6917c509ed76c40313cb384125e91800c..e546d8f4a1365d481a5bd29264317c2d111ca600 100644 (file)
--- a/src/sock.c
+++ b/src/sock.c
@@ -836,7 +836,7 @@ int sock_drain(struct connection *conn)
        if (fdtab[fd].state & (FD_POLL_ERR|FD_POLL_HUP))
                goto shut;
 
-       if (!fd_recv_ready(fd))
+       if (!(conn->flags & CO_FL_WANT_DRAIN) && !fd_recv_ready(fd))
                return 0;
 
        /* no drain function defined, use the generic one */