gRPC: disabled keepalive when sending control frames was blocked.

If sending request body was not completed (u->request_body_sent is not set),
the upstream keepalive module won't save such a connection.  However, it
is theoretically possible (though highly unlikely) that sending of some
control frames can be blocked after the request body was sent.  The
ctx->output_blocked flag introduced to disable keepalive in such cases.
This commit is contained in:
Maxim Dounin 2018-09-03 19:34:02 +03:00
parent 71e152debe
commit 07dbfd00ff

View File

@ -109,6 +109,7 @@ typedef struct {
unsigned header_sent:1; unsigned header_sent:1;
unsigned output_closed:1; unsigned output_closed:1;
unsigned output_blocked:1;
unsigned parsing_headers:1; unsigned parsing_headers:1;
unsigned end_stream:1; unsigned end_stream:1;
unsigned done:1; unsigned done:1;
@ -1073,6 +1074,7 @@ ngx_http_grpc_reinit_request(ngx_http_request_t *r)
ctx->state = 0; ctx->state = 0;
ctx->header_sent = 0; ctx->header_sent = 0;
ctx->output_closed = 0; ctx->output_closed = 0;
ctx->output_blocked = 0;
ctx->parsing_headers = 0; ctx->parsing_headers = 0;
ctx->end_stream = 0; ctx->end_stream = 0;
ctx->done = 0; ctx->done = 0;
@ -1410,6 +1412,13 @@ ngx_http_grpc_body_output_filter(void *data, ngx_chain_t *in)
rc = NGX_AGAIN; rc = NGX_AGAIN;
} }
if (rc == NGX_AGAIN) {
ctx->output_blocked = 1;
} else {
ctx->output_blocked = 0;
}
if (ctx->done) { if (ctx->done) {
/* /*
@ -1424,6 +1433,7 @@ ngx_http_grpc_body_output_filter(void *data, ngx_chain_t *in)
if (ctx->in == NULL if (ctx->in == NULL
&& ctx->out == NULL && ctx->out == NULL
&& ctx->output_closed && ctx->output_closed
&& !ctx->output_blocked
&& ctx->state == ngx_http_grpc_st_start) && ctx->state == ngx_http_grpc_st_start)
{ {
u->keepalive = 1; u->keepalive = 1;
@ -1774,6 +1784,7 @@ ngx_http_grpc_process_header(ngx_http_request_t *r)
if (ctx->in == NULL if (ctx->in == NULL
&& ctx->out == NULL && ctx->out == NULL
&& ctx->output_closed && ctx->output_closed
&& !ctx->output_blocked
&& b->last == b->pos) && b->last == b->pos)
{ {
u->keepalive = 1; u->keepalive = 1;
@ -1876,6 +1887,7 @@ ngx_http_grpc_filter(void *data, ssize_t bytes)
if (ctx->in == NULL if (ctx->in == NULL
&& ctx->output_closed && ctx->output_closed
&& !ctx->output_blocked
&& ctx->state == ngx_http_grpc_st_start) && ctx->state == ngx_http_grpc_st_start)
{ {
u->keepalive = 1; u->keepalive = 1;