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content_by_lua+require+coroutine throws attempt to yield across C-call boundary #376
Description
Hello.
I have nginx 1.6.0 + luajit 2.0.2 with config:
# nginx.conf
lua_package_path '/path/to/lua/?.lua;;';
location / {
#content_by_lua_file '/path/to/lua/foo.lua'; # works fine
content_by_lua 'require("foo")'; # fail
}
# foo.lua
local function c()
return coroutine.wrap(function()
for i = 1, 10 do
coroutine.yield(i)
end
end)
end
for v in c() do
ngx.say(v)
end
An error occurs "lua entry thread aborted: runtime error: attempt to yield across C-call boundary".
Activity
agentzh commentedon Jun 15, 2014
@atercattus This is a known limitation in LuaJIT (and the standard Lua 5.1 interpreter) that the require() builtin is currently implemented as a C builtin across which you cannot initiate a yield. A work-around is to put your coroutine operations in a function in your Lua module and let the caller call your function explicitly after require(), for example,
or more concisely:
And your
for v in c() do ... endloop should be in the function namedgo(or something else) in yourfoo.luafile.Mike Pall is going to reimplement the
requirebuiltin with LuaJIT bytecode in LuaJIT and by that time this limitation will get removed. You can prod him on the luajit mailing list and/or sponsor him to work on it directly ;)atercattus commentedon Jun 15, 2014
Sponsorship of development is a good option.
Thanks.
pygy commentedon Jun 25, 2014
FWIW, https://github.com/pygy/require.lua implements
requirein plain Lua, sidestepping the problem.I'll test it more thoroughly tomorrow, but AFAICT, it works like the original.
You can sponsor me retroactively, if you want ;-)