void
MSWindowsWatchdog::mainLoop(void*)
{
shutdownExistingProcesses();
SendSas sendSasFunc = NULL;
HINSTANCE sasLib = LoadLibrary("sas.dll");
if (sasLib) {
LOG((CLOG_DEBUG "found sas.dll"));
sendSasFunc = (SendSas)GetProcAddress(sasLib, "SendSAS");
}
SECURITY_ATTRIBUTES saAttr;
saAttr.nLength = sizeof(SECURITY_ATTRIBUTES);
saAttr.bInheritHandle = TRUE;
saAttr.lpSecurityDescriptor = NULL;
if (!CreatePipe(&m_stdOutRead, &m_stdOutWrite, &saAttr, 0)) {
throw XArch(new XArchEvalWindows());
}
ZeroMemory(&m_processInfo, sizeof(PROCESS_INFORMATION));
while (m_monitoring) {
try {
if (m_processRunning && getCommand().empty()) {
LOG((CLOG_INFO "process started but command is empty, shutting down"));
shutdownExistingProcesses();
m_processRunning = false;
continue;
}
if (m_processFailures != 0) {
// increasing backoff period, maximum of 10 seconds.
int timeout = (m_processFailures * 2) < 10 ? (m_processFailures * 2) : 10;
LOG((CLOG_INFO "backing off, wait=%ds, failures=%d", timeout, m_processFailures));
ARCH->sleep(timeout);
}
if (!getCommand().empty() && ((m_processFailures != 0) || m_session.hasChanged() || m_commandChanged)) {
startProcess();
}
if (m_processRunning && !isProcessActive()) {
m_processFailures++;
m_processRunning = false;
LOG((CLOG_WARN "detected application not running, pid=%d",
m_processInfo.dwProcessId));
}
if (sendSasFunc != NULL) {
HANDLE sendSasEvent = CreateEvent(NULL, FALSE, FALSE, "Global\\SendSAS");
if (sendSasEvent != NULL) {
// use SendSAS event to wait for next session (timeout 1 second).
if (WaitForSingleObject(sendSasEvent, 1000) == WAIT_OBJECT_0) {
LOG((CLOG_DEBUG "calling SendSAS"));
sendSasFunc(FALSE);
}
CloseHandle(sendSasEvent);
continue;
}
}
// if the sas event failed, wait by sleeping.
ARCH->sleep(1);
}
catch (std::exception& e) {
LOG((CLOG_ERR "failed to launch, error: %s", e.what()));
m_processFailures++;
m_processRunning = false;
continue;
}
catch (...) {
LOG((CLOG_ERR "failed to launch, unknown error."));
m_processFailures++;
m_processRunning = false;
continue;
}
}
if (m_processRunning) {
LOG((CLOG_DEBUG "terminated running process on exit"));
shutdownProcess(m_processInfo.hProcess, m_processInfo.dwProcessId, 20);
}
LOG((CLOG_DEBUG "watchdog main thread finished"));
}
void
CMSWindowsRelauncher::mainLoop(void*)
{
shutdownExistingProcesses();
SendSas sendSasFunc = NULL;
HINSTANCE sasLib = LoadLibrary("sas.dll");
if (sasLib) {
LOG((CLOG_DEBUG "found sas.dll"));
sendSasFunc = (SendSas)GetProcAddress(sasLib, "SendSAS");
}
DWORD sessionId = -1;
bool launched = false;
SECURITY_ATTRIBUTES saAttr;
saAttr.nLength = sizeof(SECURITY_ATTRIBUTES);
saAttr.bInheritHandle = TRUE;
saAttr.lpSecurityDescriptor = NULL;
if (!CreatePipe(&m_stdOutRead, &m_stdOutWrite, &saAttr, 0)) {
throw XArch(new XArchEvalWindows());
}
PROCESS_INFORMATION pi;
ZeroMemory(&pi, sizeof(PROCESS_INFORMATION));
int failures = 0;
while (m_running) {
HANDLE sendSasEvent = 0;
if (sasLib && sendSasFunc) {
// can't we just create one event? seems weird creating a new
// event every second...
sendSasEvent = CreateEvent(NULL, FALSE, FALSE, "Global\\SendSAS");
}
DWORD newSessionId = getSessionId();
bool running = false;
if (launched) {
DWORD exitCode;
GetExitCodeProcess(pi.hProcess, &exitCode);
running = (exitCode == STILL_ACTIVE);
if (!running) {
failures++;
LOG((CLOG_INFO "detected application not running, pid=%d, failures=%d", pi.dwProcessId, failures));
// increasing backoff period, maximum of 10 seconds.
int timeout = (failures * 2) < 10 ? (failures * 2) : 10;
LOG((CLOG_DEBUG "waiting, backoff period is %d seconds", timeout));
ARCH->sleep(timeout);
// double check, in case process started after we waited.
GetExitCodeProcess(pi.hProcess, &exitCode);
running = (exitCode == STILL_ACTIVE);
}
else {
// reset failures when running.
failures = 0;
}
}
// only enter here when id changes, and the session isn't -1, which
// may mean that there is no active session.
bool sessionChanged = ((newSessionId != sessionId) && (newSessionId != -1));
// relaunch if it was running but has stopped unexpectedly.
bool stoppedRunning = (launched && !running);
if (stoppedRunning || sessionChanged || m_commandChanged) {
m_commandChanged = false;
if (launched) {
LOG((CLOG_DEBUG "closing existing process to make way for new one"));
shutdownProcess(pi.hProcess, pi.dwProcessId, 20);
launched = false;
}
// ok, this is now the active session (forget the old one if any)
sessionId = newSessionId;
SECURITY_ATTRIBUTES sa;
ZeroMemory(&sa, sizeof(SECURITY_ATTRIBUTES));
// get the token for the user in active session, which is the
// one receiving input from mouse and keyboard.
HANDLE userToken = getCurrentUserToken(sessionId, &sa);
if (userToken != 0) {
LOG((CLOG_DEBUG "got user token to launch new process"));
std::string cmd = command();
if (cmd == "") {
// this appears on first launch when the user hasn't configured
// anything yet, so don't show it as a warning, only show it as
// debug to devs to let them know why nothing happened.
LOG((CLOG_DEBUG "nothing to launch, no command specified."));
continue;
}
// in case reusing process info struct
ZeroMemory(&pi, sizeof(PROCESS_INFORMATION));
STARTUPINFO si;
ZeroMemory(&si, sizeof(STARTUPINFO));
si.cb = sizeof(STARTUPINFO);
si.lpDesktop = "winsta0\\default";
si.hStdError = m_stdOutWrite;
si.hStdOutput = m_stdOutWrite;
si.dwFlags |= STARTF_USESTDHANDLES;
LPVOID environment;
BOOL blockRet = CreateEnvironmentBlock(&environment, userToken, FALSE);
if (!blockRet) {
LOG((CLOG_ERR "could not create environment block (error: %i)",
GetLastError()));
continue;
}
else {
DWORD creationFlags =
NORMAL_PRIORITY_CLASS |
CREATE_NO_WINDOW |
CREATE_UNICODE_ENVIRONMENT;
// re-launch in current active user session
LOG((CLOG_INFO "starting new process"));
BOOL createRet = CreateProcessAsUser(
userToken, NULL, LPSTR(cmd.c_str()),
&sa, NULL, TRUE, creationFlags,
environment, NULL, &si, &pi);
DestroyEnvironmentBlock(environment);
CloseHandle(userToken);
if (!createRet) {
LOG((CLOG_ERR "could not launch (error: %i)", GetLastError()));
continue;
}
else {
LOG((CLOG_DEBUG "launched in session %i (cmd: %s)",
sessionId, cmd.c_str()));
launched = true;
}
}
}
}
if (sendSasEvent) {
// use SendSAS event to wait for next session.
if (WaitForSingleObject(sendSasEvent, 1000) == WAIT_OBJECT_0 && sendSasFunc) {
LOG((CLOG_DEBUG "calling SendSAS"));
sendSasFunc(FALSE);
}
CloseHandle(sendSasEvent);
}
else {
// check for session change every second.
ARCH->sleep(1);
}
}
if (launched) {
LOG((CLOG_DEBUG "terminated running process on exit"));
shutdownProcess(pi.hProcess, pi.dwProcessId, 20);
}
LOG((CLOG_DEBUG "relauncher main thread finished"));
}
