我在一个跟踪进程的程序中遇到了以下代码:
void StartProcess(const std::wstring& processName, const CString& argument)
{
...
STARTUPINFO stInfo;
PROCESS_INFORMATION prInfo;
ZeroMemory( &stInfo, sizeof(stInfo) );
stInfo.cb = sizeof(stInfo);
stInfo.dwFlags=STARTF_USESHOWWINDOW;
stInfo.wShowWindow=SW_SHOWDEFAULT;
bRet = CreateProcess(NULL,
(LPTSTR)(LPCTSTR)sCmdline,
NULL,
NULL,
TRUE,
CREATE_NEW_CONSOLE | NORMAL_PRIORITY_CLASS,
NULL,
_T("."),
&stInfo,
&prInfo);
// Create process has gone OK and we have to wait.
if (bRet)
{
bRet = FALSE;
int nRetWait = WaitForSingleObject(prInfo.hProcess,0);
if (nRetWait == WAIT_OBJECT_0)
{
// Get the exit code of the process
DWORD dwExitCode = 0;
::GetExitCodeProcess(prInfo.hProcess, &dwExitCode);
if (0 == dwExitCode)
{
// The program succeeded
m_StartedServices.push_back(prInfo.dwProcessId;);
bRet = TRUE;
}
}
}
}
代码应该启动一个进程,然后在稍后的体育场中终止它(使用m_StartedServices
)。但是我想知道WaitForSingleObject
和GetExitCodeProcess
的调用有什么附加价值。我看了一下,似乎超时为0的WaitForSingleObject
用于检查进程是否仍在运行,但它刚刚创建,那么为什么要检查?为什么要检查仍在运行的进程的退出代码?
有人可以清楚说明吗?
我也发现了电话:
CloseHandle(prInfo.hThread);
CloseHandle(prInfo.hProcess);
此功能中缺少。我是否发现了手柄泄漏,或者是否有一些会自动关闭手柄的魔法?