BUG/MEDIUM: spoe: Create a SPOE applet if necessary when the last one is released

On a thread, when the last SPOE applet is released, if there are still
pending streams, a new one is created. Of course, HAproxy must not be
stopping. It is important to start a new applet in this case to not abort
in-progress jobs, especially when a maxconn is set. Because applets may be
closed to be fair with connections waiting for a free slot.

This patch should partely fix the issue #1340. It depends on the commit
"MINOR: spoe: Create a SPOE applet if necessary when the last one on a
thread is closed". Both must be backported as far as 2.0.

(cherry picked from commit 6f1296b5c70d2f513836b61cfb9a06aed2db10eb)
[wt: previous patch to be picked is in fact "MINOR: spoe: Add a pointer
     on the filter config in the spoe_agent structure"]
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 4d350af9da9a417717468d49c45d5c59ff740c80)
[wt: context updates (LIST_DEL vs LISTçDELETE): reindent displaced block
     instead]
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/src/flt_spoe.c b/src/flt_spoe.c
index e8a696f..b6c6c4e 100644 (file)
--- a/src/flt_spoe.c
+++ b/src/flt_spoe.c
@@ -102,6 +102,7 @@ struct flt_ops spoe_ops;
 static int  spoe_queue_context(struct spoe_context *ctx);
 static int  spoe_acquire_buffer(struct buffer *buf, struct buffer_wait *buffer_wait);
 static void spoe_release_buffer(struct buffer *buf, struct buffer_wait *buffer_wait);
+static struct appctx *spoe_create_appctx(struct spoe_config *conf);
 
 /********************************************************************
  * helper functions/globals
@@ -1286,27 +1287,37 @@ spoe_release_appctx(struct appctx *appctx)
                }
                goto end;
        }
+       else {
+               /* It is the last running applet and the sending and waiting
+                * queues are not empty. Try to start a new one if HAproxy is
+                * not stopping.
+                */
+               if (!stopping &&
+                   (!LIST_ISEMPTY(&agent->rt[tid].sending_queue) || !LIST_ISEMPTY(&agent->rt[tid].waiting_queue)) &&
+                   spoe_create_appctx(agent->spoe_conf))
+                       goto end;
 
-       /* If this was the last running applet, notify all waiting streams */
-       list_for_each_entry_safe(ctx, back, &agent->rt[tid].sending_queue, list) {
-               LIST_DEL(&ctx->list);
-               LIST_INIT(&ctx->list);
-               _HA_ATOMIC_SUB(&agent->counters.nb_sending, 1);
-               spoe_update_stat_time(&ctx->stats.tv_queue, &ctx->stats.t_queue);
-               ctx->spoe_appctx = NULL;
-               ctx->state = SPOE_CTX_ST_ERROR;
-               ctx->status_code = (spoe_appctx->status_code + 0x100);
-               task_wakeup(ctx->strm->task, TASK_WOKEN_MSG);
-       }
-       list_for_each_entry_safe(ctx, back, &agent->rt[tid].waiting_queue, list) {
-               LIST_DEL(&ctx->list);
-               LIST_INIT(&ctx->list);
-               _HA_ATOMIC_SUB(&agent->counters.nb_waiting, 1);
-               spoe_update_stat_time(&ctx->stats.tv_wait, &ctx->stats.t_waiting);
-               ctx->spoe_appctx = NULL;
-               ctx->state = SPOE_CTX_ST_ERROR;
-               ctx->status_code = (spoe_appctx->status_code + 0x100);
-               task_wakeup(ctx->strm->task, TASK_WOKEN_MSG);
+               /* otherwise, notify all waiting streams */
+               list_for_each_entry_safe(ctx, back, &agent->rt[tid].sending_queue, list) {
+                       LIST_DEL(&ctx->list);
+                       LIST_INIT(&ctx->list);
+                       _HA_ATOMIC_SUB(&agent->counters.nb_sending, 1);
+                       spoe_update_stat_time(&ctx->stats.tv_queue, &ctx->stats.t_queue);
+                       ctx->spoe_appctx = NULL;
+                       ctx->state = SPOE_CTX_ST_ERROR;
+                       ctx->status_code = (spoe_appctx->status_code + 0x100);
+                       task_wakeup(ctx->strm->task, TASK_WOKEN_MSG);
+               }
+               list_for_each_entry_safe(ctx, back, &agent->rt[tid].waiting_queue, list) {
+                       LIST_DEL(&ctx->list);
+                       LIST_INIT(&ctx->list);
+                       _HA_ATOMIC_SUB(&agent->counters.nb_waiting, 1);
+                       spoe_update_stat_time(&ctx->stats.tv_wait, &ctx->stats.t_waiting);
+                       ctx->spoe_appctx = NULL;
+                       ctx->state = SPOE_CTX_ST_ERROR;
+                       ctx->status_code = (spoe_appctx->status_code + 0x100);
+                       task_wakeup(ctx->strm->task, TASK_WOKEN_MSG);
+               }
        }
 
   end: