C / C++ / MFC Discussion Boards

calling convention stdcalll and cdecl call

George_George16-Jul-08 23:26

16-Jul-08 23:26

Hello everyone,

Both stdcall and cdecl calling convention could support variable input parameters? Is that correct?

(I think stdcall is using RET N and cdecl is using ESP - N, so both are capable to handle variable number of input parameter, like printf?)

BTW: I have this question because I have something in mind that only one of them supports variable number of parameters, but after reading assembly language code, I think both of them are able to support this feature?

thanks in advance,
George

Re: calling convention stdcalll and cdecl call [modified]

Naveen16-Jul-08 23:48

Naveen

16-Jul-08 23:48

George_George wrote:
Both stdcall and cdecl calling convention could support variable input parameters? Is that correct?

I dont think so. Only cdecl will be able to support variable number of arguments. Because in stdcall, the stack is cleaned by the called function. That means that function should know how much variables it accepts at the compile time it self.

But in the case of cdecl, the caller should clean the stack. Since the caller is pushing the variables to stack, it correctly know how much size to should pop from stack

nave

[OpenedFileFinder]

modified on Thursday, July 17, 2008 5:58 AM

Re: calling convention stdcalll and cdecl call

George_George17-Jul-08 19:52

George_George

17-Jul-08 19:52

Thanks nave,

What is the root cause why stdcall does not support variable number of input parameter? Maybe from generated assembly, we could find out?

(I think both caller and callee could get # of input parameters from stack in theory?)

regards,
George

Re: calling convention stdcalll and cdecl call

Naveen17-Jul-08 20:09

Naveen

17-Jul-08 20:09

how could callee found out the number of paremeters from the stack in the case of variable arguments? Also the size of each argument also need to be known isn't it?

nave

[OpenedFileFinder]

Re: calling convention stdcalll and cdecl call

George_George20-Jul-08 19:18

George_George

20-Jul-08 19:18

Thanks nave,

I think the reason why stdcall can not have variable number of input parameter is, we can not have a common code which is capable to pop variable number of input parameters (a specific function is common code base, and needs common code to pop a specific number (not variable) of elements from stack, but if input parameter number is variable, it is impossible to have such a common code base), correct?

regards,
George

Re: calling convention stdcalll and cdecl call

Naveen20-Jul-08 19:20

Naveen

20-Jul-08 19:20

Excatly!!

nave

[OpenedFileFinder]

Re: calling convention stdcalll and cdecl call

George_George20-Jul-08 20:08

George_George

20-Jul-08 20:08

Thanks Naveen,

Question answered. Smile | :)

regards,
George

Re: calling convention stdcalll and cdecl call

Nemanja Trifunovic17-Jul-08 3:25

Nemanja Trifunovic

17-Jul-08 3:25

George_George wrote:
Both stdcall and cdecl calling convention could support variable input parameters? Is that correct?

No[^]

Programming Blog

utf8-cpp

Re: calling convention stdcalll and cdecl call

George_George17-Jul-08 19:52

George_George

17-Jul-08 19:52

Thanks Nemanja,

What is the root cause why stdcall does not support variable number of input parameter? Maybe from generated assembly, we could find out?

(I think both caller and callee could get # of input parameters from stack in theory?)

regards,
George

Re: calling convention stdcalll and cdecl call

Nemanja Trifunovic18-Jul-08 4:00

Nemanja Trifunovic

18-Jul-08 4:00

You can see the detailed explanation in the article. Basically, stdcall functions have to clean up stack themselves (as opposed to the caller function) and at compile time they have no knowledge how many parameters are there going to be passed.

Programming Blog

utf8-cpp

Re: calling convention stdcalll and cdecl call

George_George20-Jul-08 19:20

George_George

20-Jul-08 19:20

Thanks Nemanja!

I write my further comments here. Any ideas?

http://www.codeproject.com/script/Forums/View.aspx?fid=1647&msg=2645227[^]

regards,
George

RPC and IOCP tutorial?

George_George16-Jul-08 23:20

George_George

16-Jul-08 23:20

Hello everyone,

I am new to RPC (TCP based) and IOCP, any recommended tutorials?

thanks in advance,
George

Re: RPC and IOCP tutorial?

Hamid_RT17-Jul-08 0:26

Hamid_RT

17-Jul-08 0:26

Introduction to RPC - Part 2
[^]
A simple IOCP Server/Client Class[^](May I ask a question are you student?)

Re: RPC and IOCP tutorial?

led mike17-Jul-08 6:09

led mike

17-Jul-08 6:09

Hamid. wrote:
(May I ask a question are you student?)

Doubtful. There was some speculation a while back that he is not even human, that he is a bot.

led mike

Re: RPC and IOCP tutorial?

George_George17-Jul-08 19:31

George_George

17-Jul-08 19:31

No, I am not. Smile | :)

regards,
George

Re: RPC and IOCP tutorial?

George_George17-Jul-08 19:30

George_George

17-Jul-08 19:30

Cool, Hamid!

I like both of them. I am your student. Smile | :)

regards,
George

Re: RPC and IOCP tutorial?

Hamid_RT17-Jul-08 20:37

Hamid_RT

17-Jul-08 20:37

No you are not,but you are a good china man,right? Smile | :)

Re: RPC and IOCP tutorial?

George_George17-Jul-08 20:59

George_George

17-Jul-08 20:59

Thanks Hamid,

Good man means? Smile | :)

regards,
George

Re: RPC and IOCP tutorial?

Hamid_RT18-Jul-08 3:02

Hamid_RT

18-Jul-08 3:02

Mean=Lin George. Wink | ;)

Controlling Sound?

ritz123416-Jul-08 23:03

ritz1234

16-Jul-08 23:03

Hello dear friend,

How can we control the system sound.

I want to control sound from my application.
I want following things to handle from the application
1)Mute/Unmute
2)Play/Pause
3)Adjustring the system volume.

How can I do these things?

Sample code would be appreciated.

Thanks in Advance.

ritz1234

Re: Controlling Sound?

Hamid_RT17-Jul-08 0:23

Hamid_RT

17-Jul-08 0:23

See Audio Mixer Functions Demo[^].

Re: Controlling Sound?

ritz123417-Jul-08 0:49

ritz1234

17-Jul-08 0:49

Thanks for the help Hamid Rose | [Rose]

I've checked the exe's for mute and volume control and it works.I'll integrate it with my application.

But what about the play/pause?

Thanks very much.

ritz1234

Re: Controlling Sound?

Hamid_RT17-Jul-08 1:18

Hamid_RT

17-Jul-08 1:18

Play and puase of other programs or your program?

Re: Controlling Sound?

ritz123417-Jul-08 1:33

ritz1234

17-Jul-08 1:33

As in the windows xp media player we can play/pause the song this what I want should be handled from the application.

ritz1234