Attempt to redefine 'timeout' at line 2 solution

Original code

local ffi = require("ffi")


ffi.cdef[[
    struct timeval {
        long int tv_sec;
        long int tv_usec;
    };
    int gettimeofday(struct timeval *tv, void *tz);
]];

local gettimeofday_struct = ffi.new("struct timeval")

local function gettimeofday()
        ffi.C.gettimeofday(gettimeofday_struct, nil)
        return tonumber(gettimeofday_struct.tv_sec) * 1000000 + tonumber(gettimeofday_struct.tv_usec)
end

Operation error reporting

[error] 4028#0: *5 lua entry thread aborted: runtime error: /opt/olwaf/olaccess.lua:126: attempt to redefine 'timeval' at line 2
stack traceback:
coroutine 0: 
        [C]: in function 'cdef'
        /opt/olwaf/olaccess.lua:126: in main chunk, client: 127.0.0.1, server: www.olwaf.com, request: "POST /api/v2/dict_info HTTP/1.1", host: "www.olwaf.com"

Normal after modification

local ffi = require("ffi")

if pcall(ffi.typeof, "struct timeval") then
        -- check if already defined.
else
        ffi.cdef[[
           typedef struct timeval {
                long tv_sec;
                long tv_usec;
           } timeval;
        int gettimeofday(struct timeval* t, void* tzp);
]]
end
local gettimeofday_struct = ffi.new("struct timeval")

local function gettimeofday()
        ffi.C.gettimeofday(gettimeofday_struct, nil)
        return tonumber(gettimeofday_struct.tv_sec) * 1000000 + tonumber(gettimeofday_struct.tv_usec)
end