lua实现sleep

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解决方案
1.在一个死循环中设置一个跳出条件，但是这样的做法会占用大量CPU资源
代码:

[xluren@test time_sleep]$ cat demo.lua local old_time=os.time()function demo()     new_time=os.time()    while  true     do        if new_time - old_time >100        then             break        end    end end demo()    [xluren@test time_sleep]$

cpu消耗结果：

[xluren@test ~]$ pidstat -p 30993 1 60Linux 2.6.32-220.el6.x86_64 (test.145) 12/07/2014 _x86_64_(1 CPU)03:17:37 PM       PID    %usr %system  %guest    %CPU   CPU  Command03:17:38 PM     30993   97.00    1.00    0.00   98.00     0  lua03:17:39 PM     30993   97.98    0.00    0.00   97.98     0  lua03:17:40 PM     30993   98.02    0.00    0.00   98.02     0  lua03:17:41 PM     30993   99.00    1.00    0.00  100.00     0  lua03:17:42 PM     30993   97.00    1.00    0.00   98.00     0  lua^C[xluren@test ~]$ ps axf |grep 30993 30993 pts/0    R+     0:38  |                       \_ lua demo.lua31039 pts/2    S+     0:00                                                                  \_ grep 30993[xluren@test ~]$

如此的耗费cpu，所以这种方式我们直接pass了

2.调用系统命令

代码：

[xluren@test time_sleep]$ vim demo_os_cmd.lua [xluren@test time_sleep]$ lua !$lua demo_os_cmd.lua^C[xluren@test time_sleep]$ cat demo_os_cmd.lua function demo()     os.execute("sleep 100")end demo()    [xluren@test time_sleep]$

cpu消耗结果：

[xluren@test ~]$ ps axf |grep demo_os_cmd.lua31144 pts/0    S+     0:00  |                       \_ lua demo_os_cmd.lua31158 pts/2    S+     0:00                                                                  \_ grep demo_os_cmd.lua[xluren@test ~]$ pidstat -p 31144 1 60Linux 2.6.32-220.el6.x86_64 (test.145) 12/07/2014 _x86_64_(1 CPU)03:20:54 PM       PID    %usr %system  %guest    %CPU   CPU  Command03:20:55 PM     31144    0.00    0.00    0.00    0.00     0  lua03:20:56 PM     31144    0.00    0.00    0.00    0.00     0  lua03:20:57 PM     31144    0.00    0.00    0.00    0.00     0  lua03:20:58 PM     31144    0.00    0.00    0.00    0.00     0  lua03:20:59 PM     31144    0.00    0.00    0.00    0.00     0  lua03:21:00 PM     31144    0.00    0.00    0.00    0.00     0  lua^C[xluren@test ~]$

简单，方便，几乎不耗费cpu，可以考虑
3.借助posix库
代码：

[xluren@test time_sleep]$ cat demo_posix.lua require("posix")function demo()     posix.sleep(100)end demo()    [xluren@test time_sleep]$

cpu消耗结果：

[xluren@test ~]$ ps axf |grep demo_posix31327 pts/0    S+     0:00  |                       \_ lua demo_posix.lua31352 pts/2    S+     0:00                                                                  \_ grep demo_posix[xluren@test ~]$ pidstat -p 31327 1 60Linux 2.6.32-220.el6.x86_64 (test.145) 12/07/2014 _x86_64_(1 CPU)03:25:06 PM       PID    %usr %system  %guest    %CPU   CPU  Command03:25:07 PM     31327    0.00    0.00    0.00    0.00     0  lua03:25:08 PM     31327    0.00    0.00    0.00    0.00     0  lua03:25:09 PM     31327    0.00    0.00    0.00    0.00     0  lua03:25:10 PM     31327    0.00    0.00    0.00    0.00     0  lua^C[xluren@test ~]$

也非常的不错，但是需要安装lua-posix软件包。
4.借助socket的select
代码：

[xluren@test time_sleep]$ cat demo_socket.lua require("socket")function demo()     socket.select(nil,nil,100)end demo()    [xluren@test time_sleep]$

同样超级的简单，具体的cpu消耗就不贴了，方法很多。

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