MINOR: applet: Add API to start applet on a thread subset

In the same way than for the tasks, the applets api was changed to be able
to start a new appctx on a thread subset. For now the feature is
disabled. Only appctx_new_here() is working. But it will be possible to
start an appctx on a specific thread or a subset via a mask.

include/haproxy/applet.h

@@ -40,10 +40,25 @@ int appctx_buf_available(void *arg);
 void *applet_reserve_svcctx(struct appctx *appctx, size_t size);
 void appctx_shut(struct appctx *appctx);
 
-struct appctx *appctx_new(struct applet *applet, struct cs_endpoint *endp);
+struct appctx *appctx_new(struct applet *applet, struct cs_endpoint *endp, unsigned long thread_mask);
 int appctx_finalize_startup(struct appctx *appctx, struct proxy *px, struct buffer *input);
 void appctx_free_on_early_error(struct appctx *appctx);
 
+static inline struct appctx *appctx_new_on(struct applet *applet, struct cs_endpoint *endp, uint thr)
+{
+	return appctx_new(applet, endp, 1UL << thr);
+}
+
+static inline struct appctx *appctx_new_here(struct applet *applet, struct cs_endpoint *endp)
+{
+	return appctx_new(applet, endp, tid_bit);
+}
+
+static inline struct appctx *appctx_new_anywhere(struct applet *applet, struct cs_endpoint *endp)
+{
+	return appctx_new(applet, endp, MAX_THREADS_MASK);
+}
+
 /* Helper function to call .init applet callback function, if it exists. Returns 0
  * on success and -1 on error.
  */

src/applet.c

@@ -31,10 +31,13 @@ DECLARE_POOL(pool_head_appctx,  "appctx",  sizeof(struct appctx));
  * appctx_free(). <applet> is assigned as the applet, but it can be NULL. The
  * applet's task is always created on the current thread.
  */
-struct appctx *appctx_new(struct applet *applet, struct cs_endpoint *endp)
+struct appctx *appctx_new(struct applet *applet, struct cs_endpoint *endp, unsigned long thread_mask)
 {
 	struct appctx *appctx;
 
+	/* Disable the feature for now ! */
+	BUG_ON(thread_mask != tid_bit);
+
 	appctx = pool_zalloc(pool_head_appctx);
 	if (unlikely(!appctx))
 		goto fail_appctx;
@@ -53,7 +56,7 @@ struct appctx *appctx_new(struct applet *applet, struct cs_endpoint *endp)
 	}
 	appctx->endp = endp;
 
-	appctx->t = task_new_here();
+	appctx->t = task_new(thread_mask);
 	if (unlikely(!appctx->t))
 		goto fail_task;
 	appctx->t->process = task_run_applet;

src/conn_stream.c

@@ -476,7 +476,7 @@ struct appctx *cs_applet_create(struct conn_stream *cs, struct applet *app)
 
 	DPRINTF(stderr, "registering handler %p for cs %p (was %p)\n", app, cs, cs_strm_task(cs));
 
-	appctx = appctx_new(app, cs->endp);
+	appctx = appctx_new_here(app, cs->endp);
 	if (!appctx)
 		return NULL;
 	cs_attach_applet(cs, appctx, appctx);

src/dns.c

@@ -955,7 +955,7 @@ static struct appctx *dns_session_create(struct dns_session *ds)
 {
 	struct appctx *appctx;
 
-	appctx = appctx_new(&dns_session_applet, NULL);
+	appctx = appctx_new_here(&dns_session_applet, NULL);
 	if (!appctx)
 		goto out_close;
 	appctx->svcctx = (void *)ds;

src/flt_spoe.c

@@ -2053,7 +2053,7 @@ spoe_create_appctx(struct spoe_config *conf)
 	LIST_INIT(&spoe_appctx->waiting_queue);
 
 
-	if ((appctx = appctx_new(&spoe_applet, NULL)) == NULL)
+	if ((appctx = appctx_new_here(&spoe_applet, NULL)) == NULL)
 		goto out_free_spoe_appctx;
 
 	appctx->svcctx = spoe_appctx;

src/hlua.c

@@ -2999,7 +2999,7 @@ __LJMP static int hlua_socket_new(lua_State *L)
 	lua_setmetatable(L, -2);
 
 	/* Create the applet context */
-	appctx = appctx_new(&update_applet, NULL);
+	appctx = appctx_new_here(&update_applet, NULL);
 	if (!appctx) {
 		hlua_pusherror(L, "socket: out of memory");
 		goto out_fail_conf;

src/http_client.c

@@ -538,7 +538,7 @@ struct appctx *httpclient_start(struct httpclient *hc)
 
 	/* The HTTP client will be created in the same thread as the caller,
 	 * avoiding threading issues */
-	appctx = appctx_new(applet, NULL);
+	appctx = appctx_new_here(applet, NULL);
 	if (!appctx)
 		goto out;
 	appctx->svcctx = hc;

src/peers.c

@@ -3199,7 +3199,7 @@ static struct appctx *peer_session_create(struct peers *peers, struct peer *peer
 	peer->statuscode = PEER_SESS_SC_CONNECTCODE;
 	peer->last_hdshk = now_ms;
 
-	appctx = appctx_new(&peer_applet, NULL);
+	appctx = appctx_new_here(&peer_applet, NULL);
 	if (!appctx)
 		goto out_close;
 	appctx->svcctx = (void *)peer;

src/sink.c

@@ -673,7 +673,7 @@ static struct appctx *sink_forward_session_create(struct sink *sink, struct sink
 	if (sft->srv->log_proto == SRV_LOG_PROTO_OCTET_COUNTING)
 		applet = &sink_forward_oc_applet;
 
-	appctx = appctx_new(applet, NULL);
+	appctx = appctx_new_here(applet, NULL);
 	if (!appctx)
 		goto out_close;
 	appctx->svcctx = (void *)sft;