EnumProcessModules在32位win7上失败，错误299

Question

My code is running on win7 32bit, but when I use EnumProcessModules , it returned false and getlasterror() return error code 299, which declare that the program is 32bit and this statement can not be running on 64bit system.

I wonder why this happens, and why the system thinks that I am running on a 64bit OS?

The code I use:

         HANDLE hProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, dwPid);
         if (hProcess)
         {
            HMODULE hMod = NULL;
            DWORD cbNeeded = 0;
            if (EnumProcessModules(hProcess, &hMod, sizeof(hMod), &cbNeeded))
            {
              //do something here...
            }
         }

dwPid is the id of the process I want to manipulate.

PS.This error just happen on one of my test machine, others are fine. So This problem may be related to that specific machine or system configration?

Answer 1

Though It has been a while since you posted this question.But I thought of giving it a try .

Reason might be because You are using CreateProcessA in your code.. and suddenly calling EnumProcessModules.Thus windows is not able to create ModuleInfo by that time.And it returns error 299(Thinking its a 64 bit system.. as it fails to read the memory).

Actually I was stuck at this too and figured it out..after looking at your post. Thanks

http://msdn.microsoft.com/en-us/library/windows/desktop/ms682425(v=vs.85).aspx CreatProcess Remarks.. It ask to call WaitforInput Idle before proceeding.;-)

The calling thread can use the WaitForInputIdle function to wait until the new process has finished its initialization and is waiting for user input with no input pending. This can be useful for synchronization between parent and child processes, because CreateProcess returns without waiting for the new process to finish its initialization. For example, the creating process would use WaitForInputIdle before trying to find a window associated with the new process.