createProcess Restart when closed/crashed - c++

Question

I would like to know how would i restart a program that i have created with CreateProcess.
I need the program to restart if its closed or if it crashed
int main(int argc, char* argv[])
{
HANDLE ghJob = CreateJobObject(NULL, NULL); // GLOBAL
if (ghJob == NULL)
::MessageBox(0, "Could not create job object", "TEST", MB_OK);
else {
JOBOBJECT_EXTENDED_LIMIT_INFORMATION jeli = { 0 };
// Configure all child processes associated with the job to terminate when the
jeli.BasicLimitInformation.LimitFlags = JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE;
if (0 == SetInformationJobObject(ghJob, JobObjectExtendedLimitInformation, &jeli, sizeof(jeli)))
::MessageBox(0, "Could not SetInformationJobObject", "TEST", MB_OK);
}
STARTUPINFO info = { sizeof(info) };
PROCESS_INFORMATION processInfo;
char cmdArgs[] = "notepad.exe";
// Launch child process - example is notepad.exe
if (::CreateProcess(NULL, cmdArgs, NULL, NULL, TRUE, 0, NULL, NULL, &info, &processInfo)) {
::MessageBox(0, "CreateProcess succeeded.", "TEST", MB_OK);
if (ghJob) {
if (0 == AssignProcessToJobObject(ghJob, processInfo.hProcess))
::MessageBox(0, "Could not AssignProcessToObject", "TEST", MB_OK);
}
WaitForSingleObject(processInfo.hProcess, INFINITE);
//Restart process here if its closed
CloseHandle(processInfo.hProcess);
CloseHandle(processInfo.hThread);
}
return 0;
}

Answer 1

You can run the code in a cycle. WaitForSingleObject waits till child process exits, CloseHandle calls are closing the handles and the child process code is running another time. I've created an eternal cycle, so this program will never exit. Add exiting conditions to this cycle according to your requirements, for example a MessageBox asking if it should exit or run another time
int main(int argc, char* argv[])
{
HANDLE ghJob = CreateJobObject(NULL, NULL); // GLOBAL
if (ghJob == NULL)
::MessageBox(0, "Could not create job object", "TEST", MB_OK);
else {
JOBOBJECT_EXTENDED_LIMIT_INFORMATION jeli = { 0 };
// Configure all child processes associated with the job to terminate when the
jeli.BasicLimitInformation.LimitFlags = JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE;
if (0 == SetInformationJobObject(ghJob, JobObjectExtendedLimitInformation, &jeli, sizeof(jeli)))
::MessageBox(0, "Could not SetInformationJobObject", "TEST", MB_OK);
}
STARTUPINFO info = { sizeof(info) };
PROCESS_INFORMATION processInfo;
char cmdArgs[] = "notepad.exe";
// Launch child process - example is notepad.exe
do
{
if (::CreateProcess(NULL, cmdArgs, NULL, NULL, TRUE, 0, NULL, NULL, &info, &processInfo)) {
::MessageBox(0, "CreateProcess succeeded.", "TEST", MB_OK);
if (ghJob) {
if (0 == AssignProcessToJobObject(ghJob, processInfo.hProcess))
::MessageBox(0, "Could not AssignProcessToObject", "TEST", MB_OK);
}
WaitForSingleObject(processInfo.hProcess, INFINITE);
//Restart process here if its closed
CloseHandle(processInfo.hProcess);
CloseHandle(processInfo.hThread);
}
} while (1);
return 0;
}