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.
 */


#ifndef _NGX_SHMEM_H_INCLUDED_
#define _NGX_SHMEM_H_INCLUDED_


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


typedef struct {
    u_char      *addr;
    size_t       size;
    ngx_str_t    name;
    ngx_log_t   *log;
    ngx_uint_t   exists;   /* unsigned  exists:1;  */
} ngx_shm_t;


ngx_int_t ngx_shm_alloc(ngx_shm_t *shm);
void ngx_shm_free(ngx_shm_t *shm);


#endif /* _NGX_SHMEM_H_INCLUDED_ */