C++ CreateProcess with arguments deadlock - c++

Question

I have two applications (exe).
The first one (client.exe) just prints out the arguments:
#include <iostream>
int main(int argc, char** argv)
{
std::cout << "Have " << argc << " arguments:" << std::endl;
for (int i = 0; i < argc; ++i)
{
std::cout << argv[i] << std::endl;
}
return 0;
}
The second one (SandBox.exe) executes the first one with some arguments:
#include <iostream>
#include <Windows.h>
void startup(LPCTSTR lpApplicationName, LPSTR param)
{
// additional information
STARTUPINFO si;
PROCESS_INFORMATION pi;
// set the size of the structures
ZeroMemory(&si, sizeof(si));
si.cb = sizeof(si);
ZeroMemory(&pi, sizeof(pi));
// start the program up
CreateProcess(lpApplicationName, // the path
param,//NULL,//argv[1], // Command line
NULL, // Process handle not inheritable
NULL, // Thread handle not inheritable
FALSE, // Set handle inheritance to FALSE
0, // No creation flags
NULL, // Use parent's environment block
NULL, // Use parent's starting directory
&si, // Pointer to STARTUPINFO structure
&pi // Pointer to PROCESS_INFORMATION structure
);
// Close process and thread handles.
CloseHandle(pi.hProcess);
CloseHandle(pi.hThread);
}
int main()
{
startup(TEXT("client.exe"), TEXT("client.exe thisIsMyFirstParaMeter AndTheSecond"));
return 0;
}
By executing the client.exe from the SandBox.exe, the output is very strange, and the client.exe never ends and stays in a deadlock.
What is the problem here?
I was expecting some output like (like when I run the client.exe isolated):
Thank you

Answer 1

Your controlling application should wait until the client exits. https://msdn.microsoft.com/en-us/library/windows/desktop/ms682512(v=vs.85).aspx
// start the program up
CreateProcess(lpApplicationName, // the path
param, // Command line
NULL, // Process handle not inheritable
NULL, // Thread handle not inheritable
FALSE, // Set handle inheritance to FALSE
0, // No creation flags
NULL, // Use parent's environment block
NULL, // Use parent's starting directory
&si, // Pointer to STARTUPINFO structure
&pi // Pointer to PROCESS_INFORMATION structure
);
// Wait until child process exits.
WaitForSingleObject( pi.hProcess, INFINITE ); // <--- this
// Close process and thread handles.
CloseHandle(pi.hProcess);
CloseHandle(pi.hThread);