fix: remove send_blocked_inflight — per-link inflight gate was blocking input_send_q and ACK send, causing bidirectional deadlock

src/etcp.c

@@ -864,7 +864,7 @@ static void etcp_conn_process_send_queue(struct ETCP_CONN* etcp) {// вызыв
         char l_status[256]={0};
         struct ETCP_LINK* link = etcp->links;
         while (link) {
-            snprintf (l_status+strlen(l_status), 256-strlen(l_status), "L%d%d%s,%s ", link->recv_keepalive,  link->remote_keepalive, (link->shaper_timer)?"wait":"rdy", link->send_blocked_inflight?"inf_block":"rdy");
+            snprintf (l_status+strlen(l_status), 256-strlen(l_status), "L%d%d%s ", link->recv_keepalive,  link->remote_keepalive, (link->shaper_timer)?"wait":"rdy");
             link = link->next;
         }
         DEBUG_DEBUG(DEBUG_CATEGORY_ETCP, "[%s] TX state: %d (link not ready, skip send) %s", etcp->log_name, etcp->tx_state, l_status);
@@ -934,8 +934,6 @@ struct ETCP_DGRAM* etcp_request_pkt(struct ETCP_CONN* etcp) {
             bbr_note_loss(inf_pkt->last_link->bbr);
             inf_pkt->last_link->inflight_bytes -= inf_pkt->ll.len;
             inf_pkt->last_link->inflight_packets--;
-            if (inf_pkt->last_link->send_blocked_inflight && inf_pkt->last_link->inflight_bytes < inf_pkt->last_link->inflight_lim_bytes)
-                loadbalancer_link_ready(inf_pkt->last_link);
         }
 
         // Always add to the CURRENT link (first send or retransmission)

src/etcp_connections.c

@@ -869,16 +869,8 @@ void etcp_link_update_inflight_lim(struct ETCP_LINK* link, uint32_t new_lim) {
     if (new_lim < INFLIGHT_LIM_MIN) new_lim = INFLIGHT_LIM_MIN;
     if (new_lim > link->etcp->max_inflight) new_lim = link->etcp->max_inflight;
 
-    uint32_t old = link->inflight_lim_bytes;
     link->inflight_lim_bytes = new_lim;
-
-    if (link->inflight_bytes < new_lim && link->send_blocked_inflight) {// разблокируем линк
-        DEBUG_DEBUG(DEBUG_CATEGORY_ETCP, "[%s] unblocking link %p (inflight_lim %u -> %u)", link->etcp->log_name, link, old, new_lim);
-        etcp_conn_on_inflight_lim_changed(link->etcp);// сперва обновим inflight в etcp
-        link->send_blocked_inflight = 0;
-        if (!link->shaper_timer) loadbalancer_link_ready(link);// потом вызовем ready -> разблок
-    } else etcp_conn_on_inflight_lim_changed(link->etcp);// 
-
+    etcp_conn_on_inflight_lim_changed(link->etcp);
 }
 
 void etcp_link_close(struct ETCP_LINK* link) {

src/etcp_connections.h

@@ -171,9 +171,6 @@ struct ETCP_LINK {
     uint32_t inflight_packets;
     uint32_t inflight_lim_bytes;
 
-    /* Биты блокировки отправки по причине (для корректного resume) */
-    unsigned send_blocked_inflight    : 1;
-
     // statistics
     size_t encrypt_errors;
     size_t decrypt_errors;

src/etcp_dump.c

@@ -161,9 +161,8 @@ void etcp_dump_conn_state(struct ETCP_CONN* conn) {
                   link->keepalive_sent_count > 0 ? "has_sent" : "idle");
 
         /* inflight (BBR) */
-        DUMP_LINE("BBR: bytes=%u pkts=%u lim=%u blocked=%d mode=%d cycle=%d pacing=%u",
+        DUMP_LINE("BBR: bytes=%u pkts=%u lim=%u mode=%d cycle=%d pacing=%u",
                   link->inflight_bytes, link->inflight_packets, link->inflight_lim_bytes,
-                  link->send_blocked_inflight,
                   link->bbr ? link->bbr->mode : -1,
                   link->bbr ? link->bbr->cycle_idx : -1,
                   link->bbr_pacing_rate);

src/etcp_loadbalancer.c

@@ -57,8 +57,8 @@ struct ETCP_LINK* etcp_loadbalancer_select_link(struct ETCP_CONN* etcp) {
     
     if (available_count == 0) {
         if (etcp->links)
-            DEBUG_WARN(DEBUG_CATEGORY_ETCP, "[%s] no suitable link found: inf:%s, tmr:%s", 
-                       etcp->log_name, etcp->links->send_blocked_inflight?"wait":"rdy", etcp->links->shaper_timer?"wait":"rdy");
+            DEBUG_WARN(DEBUG_CATEGORY_ETCP, "[%s] no suitable link found: tmr:%s",
+                       etcp->log_name, etcp->links->shaper_timer?"wait":"rdy");
         return NULL;
     }
     
@@ -181,20 +181,8 @@ void etcp_loadbalancer_send(struct ETCP_DGRAM* dgram) {
 int loadbalancer_link_can_send(struct ETCP_LINK* link) {
     if (!link) return 0;
     if (link->burst_active) return 1; // burst bypasses all limits
-    int can = 1;
-    if (link->inflight_bytes >= link->inflight_lim_bytes) {
-        link->send_blocked_inflight = 1;
-        can = 0;
-    } else {
-        link->send_blocked_inflight = 0;
-    }
-    if (link->shaper_timer) {
-//        link->send_blocked_bandwidth = 1;
-        can = 0;
-    } else {
-//        link->send_blocked_bandwidth = 0;
-    }
-    return can;
+    if (link->shaper_timer) return 0;
+    return 1;
 }
 
 void loadbalancer_link_ready(struct ETCP_LINK* link) {
@@ -202,8 +190,8 @@ void loadbalancer_link_ready(struct ETCP_LINK* link) {
         DEBUG_WARN(DEBUG_CATEGORY_ETCP, "invalid link (%p)", link);
         return;
     }
-    if (loadbalancer_link_can_send(link) == 0) {
-        DEBUG_DEBUG(DEBUG_CATEGORY_ETCP, "link still blocked");
+    if (link->shaper_timer) {
+        DEBUG_DEBUG(DEBUG_CATEGORY_ETCP, "link still blocked by shaper");
         return;
     }
     DEBUG_TRACE(DEBUG_CATEGORY_ETCP, "link=%p now ready, notifying ETCP_CONN", link);

tests/test_etcp_reinit_inflight.c

@@ -144,7 +144,7 @@ static int buffers_full(struct test_ctx* ctx) {
     struct ETCP_CONN* conn = ctx->sender->connections;
     if (!conn) return 0;
     struct ETCP_LINK* link = conn->links;
-    return link && link->send_blocked_inflight
+    return link && link->inflight_bytes >= link->inflight_lim_bytes
         && conn->input_wait_ack->count > 5
         && ctx->total_packets_sent >= TOTAL_PACKETS;
 }
@@ -190,8 +190,9 @@ static void monitor(void* arg) {
         break;
     case 2: // fill buffers
         if (buffers_full(ctx)) {
-            printf("  buffers full: inflight_blocked=%d wait_ack=%d sent=%d\n",
-                   ctx->sender->connections->links->send_blocked_inflight,
+            printf("  buffers full: inflight=%u/%u wait_ack=%d sent=%d\n",
+                   ctx->sender->connections->links->inflight_bytes,
+                   ctx->sender->connections->links->inflight_lim_bytes,
                    ctx->sender->connections->input_wait_ack->count,
                    ctx->total_packets_sent);
             ctx->phase = 3;