Core: idle connections now closed only once on exiting. Iterating through all connections takes a lot of CPU time, especially with large number of worker connections configured. As a result nginx processes used to consume CPU time during graceful shutdown. To mitigate this we now only do a full scan for idle connections when shutdown signal is received. Transitions of connections to idle ones are now expected to be avoided if the ngx_exiting flag is set. The upstream keepalive module was modified to follow this.

/*
 * 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;
}