Allocate memory in MASM

[Vortex]

Hi deeR44,

Windows programming is based on the API functions. There are a lot of them but don't worry : Step by step, one can study them methodically. A lot of Masm32 modules are using APIs, that's true. That's necessary to communicate with the operating system.

[deeR44]

Hi deeR44,

Windows programming is based on the API functions. There are a lot of them but don't worry : Step by step, one can study them methodically. A lot of Masm32 modules are using APIs, that's true. That's necessary to communicate with the operating system.

Where does one go to learn how to use them, what they do, and what arguments they need?

[TimoVJL]

For example, Win32.chm
https://sourceforge.net/projects/win32-help-chm/

Windows API Index
Memory Management Functions

[hutch--]

deeR44,

API calls are just functions, there are a very large number of them but you only need to remember a couple of dozen, much the same with messages. This is why I recommended getting the old WIN32.HLP help file, it had all of the old core windows API functions and to make life easier, almost every argument is DWORD in size, you just need to keep an eye on the difference between a DWORD value and a DWORD address (pointer) and the rest of it generally makes sense.

It is a messaging architecture, once you get the swing of the basic executable layout, a main, a message loop and a WndProc the rest of it is just detail.

[deeR44]

How does one use the old "WIN32.HLP" file, assuming that I can find it? I have nothing that uses ".hlp" files. Thank you for any advice.

[TouEnMasm]

Help system are numerous but there is one you couldn't avoid it is Internet.
Type "msdn malloc" in a search engine and you will have an answer in a few seconds.
malloc is the favorite function to allocate memory in the CRT,it use heap and there is further functions using it.
Type type "msdn heap" and you will Know all on Heap.

[hutch--]

The reason to have the old WIN32.HLP is that you can have it locally on your own machine. If you are running Win10, you will need to get the file by JimG in the forum to run it. It is between 12 and 24 meg depending on the version you can find and you need to get used to using it but it has all of the messages and functions of the core Windows API.

For later stuff you use MSDN.

[iZ!]

I cannot allocate memory in a project I'm working on.

Try this:

Code Select Expand

invoke GlobalAlloc,0,dataLength
mov  hMem,eax
invoke GlobalLock,hMem
mov  ptrMem,eax
...


And when you're done, free the memory up by:

Code Select Expand

     invoke GlobalFree, hMem