[PATCH 1 of 4] QUIC: automatically add and never delete stream events

[Roman Arutyunyan]

# HG changeset patch
# User Roman Arutyunyan <arut at nginx.com>
# Date 1673345118 -14400
#      Tue Jan 10 14:05:18 2023 +0400
# Branch quic
# Node ID f89ce033b2fa161f7258f824dcf3c6ef2051f45f
# Parent  987bee4363d10895f4bd1a40fc4347c49763e90f
QUIC: automatically add and never delete stream events.

Previously, stream events were added and deleted by ngx_handle_read_event() and
ngx_handle_write_event() in a way similar to level-triggered events.  However,
QUIC stream events are effectively edge-triggered and can stay active all time.
Moreover, the events are now active since the moment a stream is created.

diff --git a/src/event/ngx_event.c b/src/event/ngx_event.c
--- a/src/event/ngx_event.c
+++ b/src/event/ngx_event.c
@@ -274,7 +274,7 @@ ngx_handle_read_event(ngx_event_t *rev, 
     c = rev->data;
 
     if (c->quic) {
-        return ngx_quic_handle_read_event(rev, flags);
+        return NGX_OK;
     }
 
 #endif
@@ -353,7 +353,7 @@ ngx_handle_write_event(ngx_event_t *wev,
 
 #if (NGX_QUIC)
     if (c->quic) {
-        return ngx_quic_handle_write_event(wev, lowat);
+        return NGX_OK;
     }
 #endif
 
diff --git a/src/event/quic/ngx_event_quic.h b/src/event/quic/ngx_event_quic.h
--- a/src/event/quic/ngx_event_quic.h
+++ b/src/event/quic/ngx_event_quic.h
@@ -123,8 +123,6 @@ void ngx_quic_shutdown_connection(ngx_co
 ngx_int_t ngx_quic_reset_stream(ngx_connection_t *c, ngx_uint_t err);
 ngx_int_t ngx_quic_shutdown_stream(ngx_connection_t *c, int how);
 void ngx_quic_cancelable_stream(ngx_connection_t *c);
-ngx_int_t ngx_quic_handle_read_event(ngx_event_t *rev, ngx_uint_t flags);
-ngx_int_t ngx_quic_handle_write_event(ngx_event_t *wev, size_t lowat);
 ngx_int_t ngx_quic_get_packet_dcid(ngx_log_t *log, u_char *data, size_t len,
     ngx_str_t *dcid);
 ngx_int_t ngx_quic_derive_key(ngx_log_t *log, const char *label,
diff --git a/src/event/quic/ngx_event_quic_streams.c b/src/event/quic/ngx_event_quic_streams.c
--- a/src/event/quic/ngx_event_quic_streams.c
+++ b/src/event/quic/ngx_event_quic_streams.c
@@ -699,9 +699,16 @@ ngx_quic_create_stream(ngx_connection_t 
     if ((id & NGX_QUIC_STREAM_UNIDIRECTIONAL) == 0
         || (id & NGX_QUIC_STREAM_SERVER_INITIATED))
     {
+        sc->write->active = 1;
         sc->write->ready = 1;
     }
 
+    if ((id & NGX_QUIC_STREAM_UNIDIRECTIONAL) == 0
+        || (id & NGX_QUIC_STREAM_SERVER_INITIATED) == 0)
+    {
+        sc->read->active = 1;
+    }
+
     if (id & NGX_QUIC_STREAM_UNIDIRECTIONAL) {
         if (id & NGX_QUIC_STREAM_SERVER_INITIATED) {
             qs->send_max_data = qc->ctp.initial_max_stream_data_uni;
@@ -1745,31 +1752,3 @@ ngx_quic_set_event(ngx_event_t *ev)
         ngx_post_event(ev, &ngx_posted_events);
     }
 }
-
-
-ngx_int_t
-ngx_quic_handle_read_event(ngx_event_t *rev, ngx_uint_t flags)
-{
-    if (!rev->active && !rev->ready) {
-        rev->active = 1;
-
-    } else if (rev->active && (rev->ready || (flags & NGX_CLOSE_EVENT))) {
-        rev->active = 0;
-    }
-
-    return NGX_OK;
-}
-
-
-ngx_int_t
-ngx_quic_handle_write_event(ngx_event_t *wev, size_t lowat)
-{
-    if (!wev->active && !wev->ready) {
-        wev->active = 1;
-
-    } else if (wev->active && wev->ready) {
-        wev->active = 0;
-    }
-
-    return NGX_OK;
-}