MINOR: ring: support inactivity timeout in show ring CLI handler

This patch implements uninterruptible mode of execution when monitoring
a ring via the CLI. The handler continues to run despite the detection
of the CLI input closure.

The command is still stopped if a send error occurs while reporting new
events. Also, the socket timeout is reused as an inactivity timeout,
refreshed each time new events are detected. The command is stopped if
there is nothing to report during this delay.

diff --git a/src/ring.c b/src/ring.c
index d8e1a8934a0d01882297e3168afd1003f364830a..e15dbb85be134597d7f9e10ab037ca0217bc9715 100644 (file)
--- a/src/ring.c
+++ b/src/ring.c
@@ -773,21 +773,37 @@ int cli_io_handler_show_ring(struct appctx *appctx)
 {
        struct show_ring_ctx *ctx = appctx->svcctx;
        struct ring *ring = ctx->ring;
+       const struct stream *s = appctx_strm(appctx);
+       const int timeout = s->sess->fe->timeout.client;
        size_t last_ofs;
-       size_t ofs;
+       size_t ofs, processed;
        int ret;
 
        MT_LIST_DELETE(&appctx->wait_entry);
 
        ret = ring_dispatch_messages(ring, appctx, &ctx->ofs, &last_ofs, ctx->flags,
                                     (ctx->flags & RING_WF_SANITIZE) ? show_ring_append_sanitized : applet_append_line,
-                                    (ctx->flags & RING_WF_END_ZERO) ? 0 : '\n', NULL);
+                                    (ctx->flags & RING_WF_END_ZERO) ? 0 : '\n', &processed);
 
        if (ret && (ctx->flags & RING_WF_WAIT_MODE)) {
-               /* we've drained everything and are configured to wait for more
-                * data or an event (keypress, close)
+               if (appctx->cli_ctx.cmd_flags & CLI_CMD_FL_UNINTR) {
+                       /* for uninterruptible CLI mode, set inactivity timeout when
+                        * peer is disconnected, or refresh it when new events have
+                        * been retrieved. Note that this requires a non null timeout
+                        * value, otherwise uninterruptible mode won't be activated.
+                        */
+                       if (se_fl_test(appctx->sedesc, SE_FL_SHW) && !tick_isset(appctx->t->expire))
+                               appctx->t->expire = tick_add_ifset(now_ms, timeout);
+                       else if (tick_isset(appctx->t->expire) && processed)
+                               appctx->t->expire = tick_add_ifset(now_ms, timeout);
+               }
+
+               /* Everything is drained but wait mode is active. Register on
+                * new events if peer still connected or if an inactivity
+                * timeout is set and not yet expired.
                 */
-               if (!b_data(&appctx->inbuf) && !se_fl_test(appctx->sedesc, SE_FL_SHW)) {
+               if ((!b_data(&appctx->inbuf) && !se_fl_test(appctx->sedesc, SE_FL_SHW)) ||
+                   (tick_isset(appctx->t->expire) && !tick_is_expired(appctx->t->expire, now_ms))) {
                        /* let's be woken up once new data arrive */
                        MT_LIST_APPEND(&ring->waiters, &appctx->wait_entry);
                        ofs = ring_tail(ring);
@@ -805,6 +821,9 @@ int cli_io_handler_show_ring(struct appctx *appctx)
                b_reset(&appctx->inbuf);
                applet_fl_clr(appctx, APPCTX_FL_INBLK_FULL);
        }
+       else {
+               appctx->t->expire = TICK_ETERNITY;
+       }
 
        applet_will_consume(appctx);
        applet_expect_no_data(appctx);