[lxc-devel] [PATCH] lua: implement usleep in C module

[Dwight Engen]

On Thu,  5 Sep 2013 14:33:28 +0200
Natanael Copa <ncopa at alpinelinux.org> wrote:

> So we avoid running os.execute
> 
> Signed-off-by: Natanael Copa <ncopa at alpinelinux.org>

This is very nice, thanks. Note this patch is on top of Natanael's
5.1 -> 5.2 patch, it will need to be updated if we apply my 5.1 -> 5.2
instead. Either way, this is much better than os.execute :)

Acked-by: Dwight Engen <dwight.engen at oracle.com>

> ---
>  src/lua-lxc/core.c |  9 +++++++++
>  src/lxc/lxc-top    | 12 ++----------
>  2 files changed, 11 insertions(+), 10 deletions(-)
> 
> diff --git a/src/lua-lxc/core.c b/src/lua-lxc/core.c
> index d404707..504e147 100644
> --- a/src/lua-lxc/core.c
> +++ b/src/lua-lxc/core.c
> @@ -27,11 +27,13 @@
>  #include <lauxlib.h>
>  #include <assert.h>
>  #include <string.h>
> +#include <unistd.h>
>  #include <lxc/lxccontainer.h>
>  
>  #if LUA_VERSION_NUM < 502
>  #define luaL_newlib(L,l) (lua_newtable(L), luaL_register(L,NULL,l))
>  #define luaL_setfuncs(L,l,n) (assert(n==0), luaL_register(L,NULL,l))
> +#define luaL_checkunsigned(L,n) luaL_checknumber(L,n)
>  #endif
>  
>  #ifdef NO_CHECK_UDATA
> @@ -379,10 +381,17 @@ static int
> lxc_default_config_path_get(lua_State *L) { return 1;
>  }
>  
> +/* utility functions */
> +static int lxc_util_usleep(lua_State *L) {
> +    usleep((useconds_t)luaL_checkunsigned(L, 1));
> +    return 0;
> +}
> +
>  static luaL_Reg lxc_lib_methods[] = {
>      {"version_get",		lxc_version_get},
>      {"default_config_path_get",	lxc_default_config_path_get},
>      {"container_new",		container_new},
> +    {"usleep",			lxc_util_usleep},
>      {NULL, NULL}
>  };
>  
> diff --git a/src/lxc/lxc-top b/src/lxc/lxc-top
> index 31aaecf..8e8bafb 100755
> --- a/src/lxc/lxc-top
> +++ b/src/lxc/lxc-top
> @@ -22,6 +22,7 @@
>  --
>  
>  local lxc    = require("lxc")
> +local core   = require("lxc.core")
>  local getopt = require("alt_getopt")
>  local lfs    = require("lfs")
>  
> @@ -95,15 +96,6 @@ function strsisize(size, width)
>      return string.format("%3d.00   ", size)
>  end
>  
> -function usleep(n)
> -    if (n ~= 0) then
> -	ret = os.execute("usleep " .. tonumber(n))
> -	if (ret ~= 0) then
> -	    os.exit(0)
> -	end
> -    end
> -end
> -
>  function tty_lines()
>      local rows = 25
>      local f = assert(io.popen("stty -a | head -n 1"))
> @@ -238,5 +230,5 @@ do
>      end
>      stats_print(string.format("TOTAL (%-2d)", #containers),
> stats_total) io.flush()
> -    usleep(optarg["d"] * 1000000)
> +    core.usleep(optarg["d"] * 1000000)
>  end