connect() to unix:/tmp/php-fpm.sock failed (2: No such file or directory)

Question

On my vagrant box , centtos 7, i had installed php7.0.3 and nginx 1.9.12. the php config www.conf. this file in the /usr/local/php/etc/php-fpm.d/ directory, Its configuration like this

user = www
group = www
;listen = /tmp/php-fpm.sock
listen = 127.0.0.1:9000
listen.owner = www
listen.group = www

and the nginx config. the file vm.demo.com.conf in the /usr/local/nginx/conf/vhost/ directory. Its configuration like this

server {
    listen       80;
    server_name vm.demo.com;
    index index.html index.htm index.php;
    root  /data/wwwroot/demo;

    location / {
        if (-f $request_filename/index.html){
            rewrite (.*) $1/index.html break;
        }
        if (-f $request_filename/index.php){
            rewrite (.*) $1/index.php;
        }
        if (!-f $request_filename){
            rewrite (.*) /index.php;
        }
    }
    location ~ .*\.(php|php5)?$ {
        #fastcgi_pass unix:/tmp/php-fpm.sock;
        fastcgi_pass 127.0.0.1:9000;

        fastcgi_index index.php;
        include fastcgi.conf;
    }
    access_log  logs/demo.log main;
}

in the nginx conf, if i use fastcgi_pass 127.0.0.1:9000 and the php-fpm.conf listen 127.0.0.1:9000, They are working properly bug if i use the socket configuration:

php www.conf

user = www
group = www
listen = /tmp/php-fpm.sock
listen.owner = www
listen.group = www 

nginx vm.demo.com.conf

    location ~ .*\.(php|php5)?$ {
        fastcgi_pass unix:/tmp/php-fpm.sock;
        fastcgi_index index.php;
        include fastcgi.conf;
    }

the nginx show 502 Bad gateway. in the nginx error.log show this.

2016/03/14 21:17:04 [crit] 4208#0: *5 connect() to unix:/tmp/php-fpm.sock failed (2: No such file or directory) while 
connecting to upstream, client: 192.168.1.101, server: vm.demo.com, request: "GET /test.php HTTP/1.1", 
upstream: "fastcgi://unix:/tmp/php-fpm.sock:", host: "vm.demo.com"
2016/03/14 21:17:04 [crit] 4208#0: *5 connect() to unix:/tmp/php-fpm.sock failed (2: No such file or directory) while 
connecting to upstream, client: 192.168.1.101, server: vm.demo.com, request: "GET /test.php HTTP/1.1", 
upstream: "fastcgi://unix:/tmp/php-fpm.sock:", host: "vm.demo.com"
2016/03/14 21:18:01 [crit] 4208#0: *5 connect() to unix:/tmp/php-fpm.sock failed (2: No such file or directory) while 
connecting to upstream, client: 192.168.1.101, server: vm.demo.com, request: "GET /test.php HTTP/1.1", 
upstream: "fastcgi://unix:/tmp/php-fpm.sock:", host: "vm.demo.com"

when i check the /tmp/php-fpm.sock file, it's existing

[root@vbox1 vhost]# ll /tmp/php-fpm.sock 
srw-rw---- 1 www www 0 Mar 14 21:06 /tmp/php-fpm.sock

this are php and nginx running status:

[root@vbox1 vhost]# systemctl status php-fpm.service
● php-fpm.service - The PHP FastCGI Process Manager
   Loaded: loaded (/etc/systemd/system/php-fpm.service; enabled; vendor preset: disabled)
   Active: active (running) since Mon 2016-03-14 21:06:27 CST; 42min ago
  Process: 4189 ExecStop=/bin/kill -SIGINT $MAINPID (code=exited, status=0/SUCCESS)
 Main PID: 4198 (php-fpm)
   CGroup: /system.slice/php-fpm.service
           ├─4198 php-fpm: master process (/usr/local/php/etc/php-fpm.conf)
           ├─4199 php-fpm: pool www
           └─4200 php-fpm: pool www

Mar 14 21:06:27 vbox1 systemd[1]: Started The PHP FastCGI Process Manager.
Mar 14 21:06:27 vbox1 systemd[1]: Starting The PHP FastCGI Process Manager...
[root@vbox1 vhost]# systemctl status nginx.service
● nginx.service - nginx
   Loaded: loaded (/etc/systemd/system/nginx.service; enabled; vendor preset: disabled)
   Active: active (running) since Mon 2016-03-14 21:06:35 CST; 42min ago
  Process: 4180 ExecStop=/usr/local/nginx/sbin/nginx -s quit (code=exited, status=0/SUCCESS)
  Process: 4206 ExecStart=/usr/local/nginx/sbin/nginx (code=exited, status=0/SUCCESS)
 Main PID: 4207 (nginx)
   CGroup: /system.slice/nginx.service
           ├─4207 nginx: master process /usr/local/nginx/sbin/nginx
           ├─4208 nginx: worker process
           └─4209 nginx: worker process

Mar 14 21:06:35 vbox1 systemd[1]: Starting nginx...
Mar 14 21:06:35 vbox1 systemd[1]: Started nginx.

Can someone help me? If anyone encountered the same problem