MEDIUM: spoe: Remove async mode support

The support for asynchronous mode, the ability to send messages on a
connection and receive the responses on any other connections, is removed.
It appears this feature was a bit overkill. And it is a problem for this
refactoring. This feature is removed and will not be restored at the end.

It is not a big deal for agent supporting the async mode because it is
usable if it is announced on both sides. HAProxy stops to announce it. This
should be transparent for agents.

The related issue is #2502.

diff --git a/include/haproxy/spoe-t.h b/include/haproxy/spoe-t.h
index 2786573be8836569c498074554f594bf26043098..b6099b74b935debcf5656869d9465f249341088a 100644 (file)
--- a/include/haproxy/spoe-t.h
+++ b/include/haproxy/spoe-t.h
@@ -41,7 +41,7 @@
 /* Flags set on the SPOE agent */
 #define SPOE_FL_CONT_ON_ERR       0x00000001 /* Do not stop events processing when an error occurred */
 #define SPOE_FL_PIPELINING        0x00000002 /* Set when SPOE agent supports pipelining (set by default) */
-#define SPOE_FL_ASYNC             0x00000004 /* Set when SPOE agent supports async (set by default) */
+/* unused 0x00000004 */
 /* unsused 0x00000008 */
 /* unused 0x00000010 */
 #define SPOE_FL_FORCE_SET_VAR     0x00000020 /* Set when SPOE agent will set all variables from agent (and not only known variables) */
@@ -57,7 +57,7 @@
 
 /* Flags set on the SPOE applet */
 #define SPOE_APPCTX_FL_PIPELINING    0x00000001 /* Set if pipelining is supported */
-#define SPOE_APPCTX_FL_ASYNC         0x00000002 /* Set if asynchronous frames is supported */
+/* unused 0x00000002 */
 /* unused 0x00000004 */
 
 #define SPOE_APPCTX_ERR_NONE    0x00000000 /* no error yet, leave it to zero */
@@ -310,7 +310,6 @@ struct spoe_agent {
                struct eb_root  idle_applets;   /* idle SPOE applets available to process data */
                struct list     applets;        /* all SPOE applets for this agent */
                struct list     sending_queue;  /* Queue of streams waiting to send data */
-               struct list     waiting_queue;  /* Queue of streams waiting for a ack, in async mode */
                __decl_thread(HA_SPINLOCK_T lock);
        } *rt;
 

diff --git a/src/flt_spoe.c b/src/flt_spoe.c
index dc9c1b6c674104452acb3f11abe367c045a60b1e..ecf1fcc512a02bf303c40446ce62cce0a5a87080 100644 (file)
--- a/src/flt_spoe.c
+++ b/src/flt_spoe.c
@@ -413,11 +413,6 @@ spoe_prepare_hahello_frame(struct appctx *appctx, char *frame, size_t size)
                memcpy(chk->area, "pipelining", 10);
                chk->data += 10;
        }
-       if (agent != NULL && (agent->flags & SPOE_FL_ASYNC)) {
-               if (chk->data) chk->area[chk->data++] = ',';
-               memcpy(chk->area+chk->data, "async", 5);
-               chk->data += 5;
-       }
        if (spoe_encode_buffer(chk->area, chk->data, &p, end) == -1)
                goto too_big;
 
@@ -682,11 +677,6 @@ spoe_handle_agenthello_frame(struct appctx *appctx, char *frame, size_t size)
                                        if (!sz || isspace((unsigned char)*str) || *str == ',')
                                                flags |= SPOE_APPCTX_FL_PIPELINING;
                                }
-                               else if (sz >= 5 && !strncmp(str, "async", 5)) {
-                                       str += 5; sz -= 5;
-                                       if (!sz || isspace((unsigned char)*str) || *str == ',')
-                                               flags |= SPOE_APPCTX_FL_ASYNC;
-                               }
 
                                /* Get the next comma or break */
                                if (!sz || (delim = memchr(str, ',', sz)) == NULL)
@@ -715,12 +705,10 @@ spoe_handle_agenthello_frame(struct appctx *appctx, char *frame, size_t size)
                return -1;
        }
        if (!agent)
-               flags &= ~(SPOE_APPCTX_FL_PIPELINING|SPOE_APPCTX_FL_ASYNC);
+               flags &= ~SPOE_APPCTX_FL_PIPELINING;
        else {
                if ((flags & SPOE_APPCTX_FL_PIPELINING) && !(agent->flags & SPOE_FL_PIPELINING))
                        flags &= ~SPOE_APPCTX_FL_PIPELINING;
-               if ((flags & SPOE_APPCTX_FL_ASYNC) && !(agent->flags & SPOE_FL_ASYNC))
-                       flags &= ~SPOE_APPCTX_FL_ASYNC;
        }
 
        SPOE_APPCTX(appctx)->version        = (unsigned int)vsn;
@@ -885,20 +873,10 @@ spoe_handle_agentack_frame(struct appctx *appctx, struct spoe_context **ctx,
                return 0;
        }
 
-       /* Try to find the corresponding SPOE context */
-       if (SPOE_APPCTX(appctx)->flags & SPOE_APPCTX_FL_ASYNC) {
-               list_for_each_entry((*ctx), &agent->rt[tid].waiting_queue, list) {
-                       if ((*ctx)->stream_id == (unsigned int)stream_id &&
-                           (*ctx)->frame_id  == (unsigned int)frame_id)
-                               goto found;
-               }
-       }
-       else {
-               list_for_each_entry((*ctx), &SPOE_APPCTX(appctx)->waiting_queue, list) {
-                       if ((*ctx)->stream_id == (unsigned int)stream_id &&
-                            (*ctx)->frame_id == (unsigned int)frame_id)
-                               goto found;
-               }
+       list_for_each_entry((*ctx), &SPOE_APPCTX(appctx)->waiting_queue, list) {
+               if ((*ctx)->stream_id == (unsigned int)stream_id &&
+                   (*ctx)->frame_id == (unsigned int)frame_id)
+                       goto found;
        }
 
        /* No Stream found, ignore the frame */
@@ -1207,36 +1185,14 @@ spoe_release_appctx(struct appctx *appctx)
                task_wakeup(ctx->strm->task, TASK_WOKEN_MSG);
        }
 
-       if (!LIST_ISEMPTY(&agent->rt[tid].applets)) {
-               /* If there are still some running applets, remove reference on
-                * the current one from streams in the async waiting queue. In
-                * async mode, the ACK may be received from another appctx.
-                */
-               list_for_each_entry_safe(ctx, back, &agent->rt[tid].waiting_queue, list) {
-                       if (ctx->spoe_appctx == spoe_appctx)
-                               ctx->spoe_appctx = NULL;
-               }
-               goto end;
-       }
-       else {
-               /* It is the last running applet and the sending and async
-                * waiting queues are not empty. So try to start a new applet if
-                * HAproxy is not stopping. On success, we remove reference on
-                * the current appctx from streams in the async waiting queue.
-                * In async mode, the ACK may be received from another appctx.
+       if (LIST_ISEMPTY(&agent->rt[tid].applets)) {
+               /* It is the last running applet and the sending queue is not empty.
+                * So try to start a new applet 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)) {
-                       list_for_each_entry_safe(ctx, back, &agent->rt[tid].waiting_queue, list) {
-                               if (ctx->spoe_appctx == spoe_appctx)
-                                       ctx->spoe_appctx = NULL;
-                       }
+               if (!stopping && !LIST_ISEMPTY(&agent->rt[tid].sending_queue) && spoe_create_appctx(agent->spoe_conf))
                        goto end;
-               }
 
-               /* Otherwise, report an error to all streams in the sending and
-                * async waiting queues.
+               /* Otherwise, report an error to all streams in the sending queue.
                 */
                list_for_each_entry_safe(ctx, back, &agent->rt[tid].sending_queue, list) {
                        LIST_DELETE(&ctx->list);
@@ -1248,16 +1204,6 @@ spoe_release_appctx(struct appctx *appctx)
                        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_DELETE(&ctx->list);
-                       LIST_INIT(&ctx->list);
-                       _HA_ATOMIC_DEC(&agent->counters.nb_waiting);
-                       spoe_update_stat_time(&ctx->stats.wait_ts, &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:
@@ -1462,11 +1408,7 @@ spoe_handle_sending_frame_appctx(struct appctx *appctx, int *skip)
        goto end;
 
   frame_sent:
-       if (SPOE_APPCTX(appctx)->flags & SPOE_APPCTX_FL_ASYNC) {
-               appctx->st0 = SPOE_APPCTX_ST_PROCESSING;
-               LIST_APPEND(&agent->rt[tid].waiting_queue, &ctx->list);
-       }
-       else if (SPOE_APPCTX(appctx)->flags & SPOE_APPCTX_FL_PIPELINING) {
+       if (SPOE_APPCTX(appctx)->flags & SPOE_APPCTX_FL_PIPELINING) {
                appctx->st0 = SPOE_APPCTX_ST_PROCESSING;
                LIST_APPEND(&SPOE_APPCTX(appctx)->waiting_queue, &ctx->list);
        }
@@ -2869,7 +2811,6 @@ spoe_check(struct proxy *px, struct flt_conf *fconf)
                conf->agent->rt[i].idles        = 0;
                LIST_INIT(&conf->agent->rt[i].applets);
                LIST_INIT(&conf->agent->rt[i].sending_queue);
-               LIST_INIT(&conf->agent->rt[i].waiting_queue);
                HA_SPIN_INIT(&conf->agent->rt[i].lock);
        }
 
@@ -3163,7 +3104,7 @@ cfg_parse_spoe_agent(const char *file, int linenum, char **args, int kwm)
                curagent->var_on_error   = NULL;
                curagent->var_t_process  = NULL;
                curagent->var_t_total    = NULL;
-               curagent->flags          = (SPOE_FL_ASYNC | SPOE_FL_PIPELINING);
+               curagent->flags          = SPOE_FL_PIPELINING;
                curagent->cps_max        = 0;
                curagent->eps_max        = 0;
                curagent->max_frame_size = MAX_FRAME_SIZE;
@@ -3306,10 +3247,7 @@ cfg_parse_spoe_agent(const char *file, int linenum, char **args, int kwm)
                else if (strcmp(args[1], "async") == 0) {
                        if (alertif_too_many_args(1, file, linenum, args, &err_code))
                                goto out;
-                       if (kwm == 1)
-                               curagent->flags &= ~SPOE_FL_ASYNC;
-                       else
-                               curagent->flags |= SPOE_FL_ASYNC;
+                       /* TODO: Add a warning or a diag ? Ignore it for now */
                        goto out;
                }
                else if (strcmp(args[1], "send-frag-payload") == 0) {