Optimized chain link usage (ticket #2614).

Previously chain links could sometimes be dropped instead of being reused,
which could result in increased memory consumption during long requests.

A similar chain link issue in ngx_http_gzip_filter_module was fixed in
da46bfc484ef (1.11.10).

Based on a patch by Sangmin Lee.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/http/modules/ngx_http_grpc_module.c b/src/http/modules/ngx_http_grpc_module.c
index dfe49c586..e7726f314 100644
--- a/src/http/modules/ngx_http_grpc_module.c
+++ b/src/http/modules/ngx_http_grpc_module.c
@@ -1231,7 +1231,7 @@ ngx_http_grpc_body_output_filter(void *data, ngx_chain_t *in)
     ngx_buf_t              *b;
     ngx_int_t               rc;
     ngx_uint_t              next, last;
-    ngx_chain_t            *cl, *out, **ll;
+    ngx_chain_t            *cl, *out, *ln, **ll;
     ngx_http_upstream_t    *u;
     ngx_http_grpc_ctx_t    *ctx;
     ngx_http_grpc_frame_t  *f;
@@ -1459,7 +1459,10 @@ ngx_http_grpc_body_output_filter(void *data, ngx_chain_t *in)
             last = 1;
         }
 
+        ln = in;
         in = in->next;
+
+        ngx_free_chain(r->pool, ln);
     }
 
     ctx->in = in;