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.

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>


int
ngx_nonblocking(ngx_socket_t s)
{
    unsigned long  nb = 1;

    return ioctlsocket(s, FIONBIO, &nb);
}


int
ngx_blocking(ngx_socket_t s)
{
    unsigned long  nb = 0;

    return ioctlsocket(s, FIONBIO, &nb);
}


int
ngx_tcp_push(ngx_socket_t s)
{
    return 0;
}