StartService info  Overview  Group

The StartService function starts a service.

BOOL StartService(

Parameters

hService

Identifies the service. This handle is returned by the OpenService or CreateService function, and it must have SERVICE_START access.

dwNumServiceArgs

Specifies the number of argument strings in the lpServiceArgVectors array. If lpServiceArgVectors is NULL, this parameter can be zero.

lpServiceArgVectors

Points to an array of pointers that point to null-terminated argument strings passed to a service. Driver services do not receive these arguments. If no arguments are passed to the service being started, this parameter can be NULL. The service accesses these arguments through its ServiceMain function. The first argument (argv[0]) is the name of the service by default, followed by the arguments, if any, in the lpServiceArgVectors array.

Return Values

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.

Errors

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

Remarks

When a driver service is started, the StartService function does not return until the device driver has finished initializing.

When a Win32-based service is started, the service control manager spawns the service process, if necessary. If the specified service shares a process with other services, the required process may already exist. The StartService function does not wait for the first status update from the new service, because it can take a while. Instead, it returns when the service control manager receives notification from the service control dispatcher that the ServiceMain thread for this service was created successfully.

The service control manager sets the following default status values before returning from StartService:

• Current state of the service is set to SERVICE_START_PENDING.

• Controls accepted is set to none (zero).

• The CheckPoint value is set to zero.

• The WaitHint time is set to 2 seconds.

The calling process can determine if the new service has finished its initialization by calling the QueryServiceStatus function periodically to query the service’s status.

A service cannot call StartService during initialization. The reason is that the service control manager locks the service control database during initialization, so a call to StartService will block. Once the service reports to the service control manager that it has successfully started, it can call StartService.

See Also

ControlService, CreateService, OpenService, QueryServiceStatus, ServiceMain