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CreateProcess in Thread problem


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Hi guys,

have a new problem and need some advice.

Problem: I created a thread and in this thread I also use a CreateProcess API to start a exe file and right after this API in my thread comes a loop to write bytes into hStdOutput handlle into new created process.All working so far but the problem is this...if the new created process does run and I do exit this process manually with mouse button then the remaining codes / following codes will not executed anymore.So thats the problem and I dont know why.I checked this also in Olly and did set soft BPs right after the loop and on thread exit but it will never reached.Does anyone have a idea why my thread will no more executed?Below a short code of my thread.

    mov SECURITY.nLength,sizeof SECURITY
    mov SECURITY.bInheritHandle,TRUE
    mov SECURITY.lpSecurityDescriptor,NULL
    invoke CreatePipe,addr HREAD,addr HWRITE,addr SECURITY,0
    .if eax == 0h
    invoke MessageBox,NULL,chr$("Can't create a pipe!"),chr$("Problem!"),MB_ICONWARNING
    mov eax, -1h
    mov eax,HWRITE
    mov PIPEHANDLE,eax
    invoke SetHandleInformation,HWRITE,HANDLE_FLAG_INHERIT,0
    .if eax == 0h
    invoke MessageBox,NULL,chr$("Can't set handle information!"),chr$("Problem!"),MB_ICONWARNING
    invoke CloseHandle,HWRITE
    invoke CloseHandle,HREAD
    mov eax, -1h    
    invoke RtlZeroMemory, addr startupinfo1, sizeof startupinfo1
    invoke RtlZeroMemory, addr pinfo, sizeof pinfo
    mov startupinfo1.cb,sizeof STARTUPINFO
    mov eax, HREAD
    mov startupinfo1.hStdInput,eax
    mov eax, PIPEHANDLE
    mov startupinfo1.hStdOutput,eax
    mov startupinfo1.hStdError,eax
    mov startupinfo1.dwFlags, STARTF_USESTDHANDLES    	
    invoke CreateProcess,NULL ,offset MPC_PLAYPATH ,NULL,NULL,TRUE,NULL,NULL,NULL,addr startupinfo1,addr pinfo
    .if eax == 0h
    invoke MessageBox,NULL,chr$("Can't create process!"),chr$("Problem!"),MB_ICONWARNING
    jmp CLOSE      


WriteFile (nsize)

.until  nsize==0

...Rest of my code what gets no more accessed

You see what the problem could be in that case and why I not get reached the code after loop?Also in the loop I cant stop anyymore so it seems the thread was just closed or anything like this etc.Maybe you can see the problem and help.

Thank you

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CreateProcess returns without waiting for the new process to finish its initialization.

I suggest using WaitForInputIdle function to wait until the new process has finished its initialization.

This is just a possible cause and may be wrong.

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Hi again,

so the problem seems to be at the write API.It hangs inside and does not come back anymore if I close or stop the created file.I also tried to add GetExitCodeProcess / GetExitCodeThread before write API but this also dont work and gives still_active back.So somehow I need to check whether I can still write on the handle or not.All these problems I dont get using ShellExecuteEx API but in this case I cant use it.

Has anyone any another hints?


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Hi again,

ok I found the problem.So I forgot to close the hStdInput handle right after CreateProcess API. :) Now its working and if I exit the player manually then it will also come back from WriteFile API and the code after in my thread gets executed / continue as it should be. :)


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