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+--- Thread: HOWTO: Inter-plugin communication (/thread-579.html)
RE: HOWTO: Inter-plugin communication - xoft - 10-23-2013
Yes, on its own it's not slow, but it causes lock convoys - each such call must lock an additional plugin's critical section. If the plugin is busy, with lots of hooks, this will become costly.
RE: HOWTO: Inter-plugin communication - NiLSPACE - 11-25-2013
Is the cPlugin::Call function able to parse functions as parameter?
RE: HOWTO: Inter-plugin communication - xoft - 11-25-2013
No, it cannot, mainly because functions in Lua are really closures - they take with them the local values of their containing functions and are able to modify those; this cannot be safely ported to another Lua state structure. Consider the following example:
function FnOuter(ParamOuter)
local VarOuter = 10;
local FnInner = function(ParamInner)
local VarInner = VarOuter + 1; -- It can read FnOuter's local variables
VarOuter = VarOuter * 3; -- It can modify them
local VarInner2 = ParamOuter + 1; -- It can even read FnOuter's parameters
end
SomeOtherFunction(FnInner); -- Perfeclt valid Lua code, SomeOtherFunction() can call FnInner however it wants
end
RE: HOWTO: Inter-plugin communication - FakeTruth - 11-25-2013
(11-25-2013, 12:29 AM)STR_Warrior Wrote: Is the cPlugin::Call function able to parse functions as parameter?
No, you can however pass a function name and a plugin instance, so the other plugin can call the function on your plugin.
RE: HOWTO: Inter-plugin communication - NiLSPACE - 11-25-2013
(11-25-2013, 04:44 AM)FakeTruth Wrote: No, you can however pass a function name and a plugin instance, so the other plugin can call the function on your plugin.
Yea I know but I hoped you could use a local function as parameter.
RE: HOWTO: Inter-plugin communication - NiLSPACE - 12-07-2013
I just realized that you can parse a function as a string and then use the loadstring() function to execute it. for example:
------------------------------------------------
--Plugin 1
local Callback = [[
return type(500)
]]
Plugin:Call("Example", Callback)
------------------------------------------------
--Plugin 2
function Example(Callback)
local Function = loadstring(Callback)
if Function then --If the string is loaded correctly then execute it. Otherwise it's a nil value.
Test = Function()
end
print(Test)
end
now Test should be equal to 'number'.Hmm wait now i'm suddenly unsure if it works..
RE: HOWTO: Inter-plugin communication - xoft - 12-07-2013
That might work but is pretty much useless. Such a function won't have the upvalues, so it won't see neither the first plugin's globals nor the locals. Consider this example:
-- Plugin 1:
function CallMe() ... end
g_UseMe = 1;
local SomeVar = 2;
local Callback = [[
g_UseMe = 2;
SomeVar = 3;
CallMe();
]]
Plugin2:Call("Executor", Callback);
-- The call has failed inside Plugin2, but that doesn't propagate here
-- However, g_UseMe is still 1, SomeVar is still 2 and CallMe() hasn't been called.
-- Plugin 2:
function Executor(Callback)
local Function = loadstring(Callback);
Function(); -- will set Plugin2's globals g_UseMe to 2 and SomeVar to 3 and then fail with message "CallMe not defined"
end;
I'm not sure now whether Plugin2 will fail on the actual execution, or if the loadstring() will already complain about the undefined function. But the end result is the same - the callback just cannot access Plugin1's data in any way.
RE: HOWTO: Inter-plugin communication - NiLSPACE - 12-07-2013
Yea I posted it and then suddenly I was like: "Wait... It's nog going to work isn't it..."