test_gc.lua

local mode = ...
mode = mode and tonumber(mode) or 1

local ffi = require 'ffi'
ffi.cdef 'struct ss{ int i ; }'
local ss_t = ffi.typeof('struct ss')
local noop = function(t) end
if mode == 1 then
    local mtt = {__gc=noop}
    ffi.metatype(ss_t, mtt)
end
for i=1,20000000 do
    if mode == 1 then
        local g = ffi.new(ss_t)
    elseif mode == 2 then
        local g = ffi.new(ss_t)
        ffi.gc(g, noop)
    elseif mode == 3 then
        local g = ffi.new(ss_t)
    end
end