From d2ea226229f4039953af48bb7e0599c076f01c1f Mon Sep 17 00:00:00 2001
From: Maxim Dounin <mdounin@mdounin.ru>
Date: Thu, 17 Oct 2019 16:02:13 +0300
Subject: [PATCH] SSL: improved ngx_ssl_recv_chain() to stop if c->read->ready
 is 0.

As long as there are data to read in the socket, yet the amount of data
is less than total size of the buffers in the chain, this saves one
unneeded read() syscall.  Before this change, reading only stopped if
ngx_ssl_recv() returned no data, that is, two read() syscalls in a row
returned EAGAIN.
---
 src/event/ngx_event_openssl.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
index 3737839d8..4e3eb391c 100644
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -1922,6 +1922,10 @@ ngx_ssl_recv_chain(ngx_connection_t *c, ngx_chain_t *cl, off_t limit)
             last += n;
             bytes += n;
 
+            if (!c->read->ready) {
+                return bytes;
+            }
+
             if (last == b->end) {
                 cl = cl->next;