无法关闭从服务中的用户会话的过程

问题描述:

体系结构是一个服务可以与系统特权,代码段1无法关闭从服务中的用户会话的过程

用户会话的处理组内启动一个进程当服务需要停止本身,我想发送一个信号给子进程,使它有机会优雅地关闭代码片段2.

问题是它似乎没有发送信号,没有任何明显的错误代码。我测试了从命令提示符运行的子进程,ctrl + break工作得很好。

代码片段

PROCESS_INFORMATION processInfo; 
ZeroMemory(&processInfo, sizeof(PROCESS_INFORMATION)); 

STARTUPINFO si; 
ZeroMemory(&si, sizeof(STARTUPINFO)); 
si.cb = sizeof(STARTUPINFO); 
si.lpDesktop = "winsta0\\Default"; 
si.dwFlags |= STARTF_USESTDHANDLES; 

LPVOID environment; 
BOOL createRet = CreateEnvironmentBlock(&environment, userToken, FALSE); 
if (!createRet) { 
    throw std::runtime_error("Failed to create environment block"); 
} 

DWORD creationFlags = 
    NORMAL_PRIORITY_CLASS | 
    CREATE_NO_WINDOW | 
    CREATE_UNICODE_ENVIRONMENT | 
    CREATE_NEW_PROCESS_GROUP; // this create a process in a group 

// launch a process in the user session 
// the toke is a system privilege toke within the user session 
createRet = CreateProcessAsUser(
    userToken, NULL, LPSTR(command.c_str()), 
    sa, NULL, TRUE, creationFlags, 
    environment, NULL, &si, &processInfo); 

if (!createRet) { 
    throw std::runtime_error("Failed to create the service in user session"); 
} 

m_serviceGroupId = processInfo.dwProcessId; 

DestroyEnvironmentBlock(environment); 
CloseHandle(userToken); 

代码片段2

if (m_serviceGroupId == 0) { 
    return; 
} 

HANDLE process; 
const UINT kExitCode = 0; 
const UINT kShutdownTimeout = 3000; 
if (findProcessInSession(kServiceProcess, &process, getActiveSession())) { 
    BOOL r = GenerateConsoleCtrlEvent(CTRL_BREAK_EVENT, m_serviceGroupId); 
    // this won't success if I don't specifically call AllocConsole() in the constructor 
    if (!r) { 
     writeEventErrorLog(GetLastErrorAsString().c_str()); 
    } 

    DWORD exitCode = WaitForSingleObject(process, kShutdownTimeout); 
    if (exitCode != WAIT_OBJECT_0) { 
     // always fall into forceful shutdown 
     writeEventErrorLog("Forcefully shutdown synergy service"); 
     // GetLastErrorAsString returns empty string 
     writeEventErrorLog(GetLastErrorAsString().c_str()); 
     if (!TerminateProcess(process, kExitCode)) { 
      writeEventErrorLog("Failed to shutdown synergy service"); 
     } 
    } 
} 

m_serviceGroupId = 0; 
+0

'GenerateConsoleCtrlEvent'远程调用'csrss'。但您的服务附加到另一个“csrss”进程 - 每个会话都有自己的“csrss”。所以'GenerateConsoleCtrlEvent'不能用于另一个会话中的发送控制事件 – RbMm

+0

@RbMm谢谢。我有办法管理子进程吗? RPC调用? – Jerry

+1

您需要做的只是从服务向孩子发送一次性消息,因此命名事件对象可能是最合适的选择。在更复杂的情况下,您可以使用命名管道。还有其他的选择。 –

你的方法是行不通的,因为服务进程和子进程不在同一个会话,因此考虑使用Windows事件。看看CreateEventSetEvent

当你的服务过程开始时,调用CreateEvent(),例如:

HANDLE hEvent = CreateEvent(NULL, FALSE, FALSE, "Global\\myevent"); 

当你的子进程启动,调用CreateEvent(),并启动一个线程来捕获信号:

//The lpName should be identical with that in service process 
HANDLE hEvent = CreateEvent(NULL, FALSE, FALSE, "Global\\myevent"); 

std::thread mythread([hEvent] { 
    WaitForSingleObject(hEvent, INFINITE); 
    //then exit your child process gracefully 
}); 

每当你打算停止子进程,只需调用SetEvent的()在您的服务流程:

SetEvent(hEvent); 

将bManualReset设置为TRUE,然后您的服务可以同时向不同的子进程发送信号。