ControlServiceExA function (winsvc.h)

Sends a control code to a service.

Syntax

BOOL ControlServiceExA(
  [in]      SC_HANDLE hService,
  [in]      DWORD     dwControl,
  [in]      DWORD     dwInfoLevel,
  [in, out] PVOID     pControlParams
);

Parameters

[in] hService

A handle to the service. This handle is returned by the OpenService or CreateService function. The access rights required for this handle depend on the dwControl code requested.

[in] dwControl

This parameter can be one of the following control codes.

Control code Meaning
SERVICE_CONTROL_CONTINUE
0x00000003
Notifies a paused service that it should resume. The hService handle must have the SERVICE_PAUSE_CONTINUE access right.
SERVICE_CONTROL_INTERROGATE
0x00000004
Notifies a service that it should report its current status information to the service control manager. The hService handle must have the SERVICE_INTERROGATE access right.

Note that this control is not generally useful as the SCM is aware of the current state of the service.

SERVICE_CONTROL_NETBINDADD
0x00000007
Notifies a network service that there is a new component for binding. The hService handle must have the SERVICE_PAUSE_CONTINUE access right. However, this control code has been deprecated; use Plug and Play functionality instead.
SERVICE_CONTROL_NETBINDDISABLE
0x0000000A
Notifies a network service that one of its bindings has been disabled. The hService handle must have the SERVICE_PAUSE_CONTINUE access right. However, this control code has been deprecated; use Plug and Play functionality instead.
SERVICE_CONTROL_NETBINDENABLE
0x00000009
Notifies a network service that a disabled binding has been enabled. The hService handle must have the SERVICE_PAUSE_CONTINUE access right. However, this control code has been deprecated; use Plug and Play functionality instead.
SERVICE_CONTROL_NETBINDREMOVE
0x00000008
Notifies a network service that a component for binding has been removed. The hService handle must have the SERVICE_PAUSE_CONTINUE access right. However, this control code has been deprecated; use Plug and Play functionality instead.
SERVICE_CONTROL_PARAMCHANGE
0x00000006
Notifies a service that its startup parameters have changed. The hService handle must have the SERVICE_PAUSE_CONTINUE access right.
SERVICE_CONTROL_PAUSE
0x00000002
Notifies a service that it should pause. The hService handle must have the SERVICE_PAUSE_CONTINUE access right.
SERVICE_CONTROL_STOP
0x00000001
Notifies a service that it should stop. The hService handle must have the SERVICE_STOP access right.

After sending the stop request to a service, you should not send other controls to the service.

 

This parameter can also be a user-defined control code, as described in the following table.

Control code Meaning
Range 128 to 255
The service defines the action associated with the control code. The hService handle must have the SERVICE_USER_DEFINED_CONTROL access right.

[in] dwInfoLevel

The information level for the service control parameters. This parameter must be set to SERVICE_CONTROL_STATUS_REASON_INFO (1).

[in, out] pControlParams

A pointer to the service control parameters. If dwInfoLevel is SERVICE_CONTROL_STATUS_REASON_INFO, this member is a pointer to a SERVICE_CONTROL_STATUS_REASON_PARAMS structure.

Return value

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

The following error codes can be set by the service control manager. Other error codes can be set by the registry functions that are called by the service control manager.

Return code Description
ERROR_ACCESS_DENIED
The handle does not have the required access right.
ERROR_DEPENDENT_SERVICES_RUNNING
The service cannot be stopped because other running services are dependent on it.
ERROR_INVALID_HANDLE
The specified handle was not obtained using CreateService or OpenService, or the handle is no longer valid.
ERROR_INVALID_PARAMETER
The requested control code in the dwControl parameter is undefined, or dwControl is SERVICE_CONTROL_STOP but the dwReason or pszComment members of the SERVICE_CONTROL_STATUS_REASON_PARAMS structure are not valid.
ERROR_INVALID_SERVICE_CONTROL
The requested control code is not valid, or it is unacceptable to the service.
ERROR_SERVICE_CANNOT_ACCEPT_CTRL
The requested control code cannot be sent to the service because the state of the service is SERVICE_STOPPED, SERVICE_START_PENDING, or SERVICE_STOP_PENDING.
ERROR_SERVICE_NOT_ACTIVE
The service has not been started.
ERROR_SERVICE_REQUEST_TIMEOUT
The process for the service was started, but it did not call StartServiceCtrlDispatcher, or the thread that called StartServiceCtrlDispatcher may be blocked in a control handler function.
ERROR_SHUTDOWN_IN_PROGRESS
The system is shutting down.

Remarks

The ControlServiceEx function asks the Service Control Manager (SCM) to send the requested control code to the service. The SCM sends the code if the service has specified that it will accept the code, and is in a state in which a control code can be sent to it.

The SCM processes service control notifications in a serial fashion — it waits for one service to complete processing a service control notification before sending the next one. Because of this, a call to ControlServiceEx blocks for 30 seconds if any service is busy handling a control code. If the busy service still has not returned from its handler function when the timeout expires, ControlServiceEx fails with ERROR_SERVICE_REQUEST_TIMEOUT.

To stop and start a service requires a security descriptor that allows you to do so. The default security descriptor allows the LocalSystem account, and members of the Administrators and Power Users groups to stop and start services. To change the security descriptor of a service, see Modifying the DACL for a Service.

The QueryServiceStatusEx function returns a SERVICE_STATUS_PROCESS structure whose dwCurrentState and dwControlsAccepted members indicate the current state and controls accepted by a running service. All running services accept the SERVICE_CONTROL_INTERROGATE control code by default. Drivers do not accept control codes other than SERVICE_CONTROL_STOP and SERVICE_CONTROL_INTERROGATE. Each service specifies the other control codes that it accepts when it calls the SetServiceStatus function to report its status. A service should always accept these codes when it is running, no matter what it is doing.

The following table shows the action of the SCM in each of the possible service states.

Service state Stop Other controls
STOPPED (c) (c)
STOP_PENDING (b) (b)
START_PENDING (a) (b)
RUNNING (a) (a)
CONTINUE_PENDING (a) (a)
PAUSE_PENDING (a) (a)
PAUSED (a) (a)
(a)
If the service accepts this control code, send the request to the service; otherwise, ControlServiceEx returns zero and GetLastError returns ERROR_INVALID_SERVICE_CONTROL.
(b)
The service is not in a state in which a control can be sent to it, so ControlServiceEx returns zero and GetLastError returns ERROR_SERVICE_CANNOT_ACCEPT_CTRL.
(c)
The service is not active, so ControlServiceEx returns zero and GetLastError returns ERROR_SERVICE_NOT_ACTIVE.

Note

The winsvc.h header defines ControlServiceEx as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement Value
Minimum supported client Windows Vista [desktop apps only]
Minimum supported server Windows Server 2008 [desktop apps only]
Target Platform Windows
Header winsvc.h (include Windows.h)
Library Advapi32.lib
DLL Advapi32.dll

See also

CreateService

OpenService

QueryServiceStatusEx

SERVICE_CONTROL_STATUS_REASON_PARAMS

SERVICE_STATUS

Service Control Requests

Service Functions

SetServiceObjectSecurity

SetServiceStatus