Memory leak with CreateProcess()
in [Win32 Kernel]
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From: qfel on 27 Mar 2006 11:24 > By the way, you're NOT supposed to pass a constant string to > CreateProcess. Applies only to Unicode version.
From: chpichaud on 27 Mar 2006 12:24 The 2nd parameter or CreateProcess is [in, out] so use a local variable. << lpCommandLine [in, out] Pointer to a null-terminated string that specifies the command line to execute. The maximum length of this string is 32K characters. Windows 2000: The maximum length of this string is MAX_PATH characters. The Unicode version of this function, CreateProcessW, will fail if this parameter is a const string. The lpCommandLine parameter can be NULL. In that case, the function uses the string pointed to by lpApplicationName as the command line. >> Else: put your string into a local TCHAR[]. Remove the std::cout function. try it in ANSI and Unicode. Christophe Pichaud
From: Luc Kumps on 27 Mar 2006 12:41 lugeon wrote: > You are right... > > But I write here the simplest code I could wrote. My leak is still > present if I replace my constant string by a LPTSTR. > > Am I the only one to get a leak with this code, or has anybody the > same trouble? I added #include <iostream> #include <windows.h> using namespace std; in front of your code, and compiled with "cl -GX tmp.cpp" Then I made a TestFile.exe which does Sleep(200) and ran the program. Task Manager says VM size=156K. It stays that way forever... Luc K
From: Luc Kumps on 27 Mar 2006 13:33 Luc Kumps wrote: > lugeon wrote: >> You are right... >> >> But I write here the simplest code I could wrote. My leak is still >> present if I replace my constant string by a LPTSTR. >> >> Am I the only one to get a leak with this code, or has anybody the >> same trouble? > > I added > > #include <iostream> > #include <windows.h> > using namespace std; > > in front of your code, and compiled with "cl -GX tmp.cpp" > > Then I made a TestFile.exe which does Sleep(200) and ran the program. > Task Manager says VM size=156K. It stays that way forever... WAIT! I made a mistake! VM size *does* increase, just like you said it does! Luc K
From: Luc Kumps on 27 Mar 2006 15:05
lugeon wrote: > I get a 388bytes memory leak each time I call the CreateProcess() > function. Here is my following code: I was able to reproduce this problem. To my surprise, CreateProcess keeps eating memory!!! I also found a simple workaround, but I would *really* like to get an explanation for this! Simply add #include <objbase.h> to your #include statements and at the start of your main program add one line HRESULT hr = CoInitializeEx(NULL,COINIT_MULTITHREADED); (or any other call that initializes the COM library). Compile with _WIN32_DCOM defined and your leak is gone. Tested on Win2000 and WinXp. Just don't ask me why!!! Even simpler workaround: simply call ::SysAllocString(L"abc"); at the start of your program... BTW, I tried to use CreateProcessW, it has the same 'feature'! Luc K |