IConsolePower::SetExecutionState method (mmc.h)

The SetExecutionState method sets the execution state for the current thread.

Syntax

HRESULT SetExecutionState(
  [in] DWORD dwAdd,
  [in] DWORD dwRemove
);

Parameters

[in] dwAdd

Flags to add to the snap-in execution state. This can be a combination of 0 or more of the following flags.

ES_DISPLAY_REQUIRED

The display (monitor) power-management requirement. If specified in dwAdd, the snap-in prohibits the operating system from invoking the power management routine for the display.

ES_SYSTEM_REQUIRED

The system power-management requirement. If specified in dwAdd, the snap-in prohibits the operating system from invoking the power management routine for the system.

[in] dwRemove

Flags to remove from the snap-in's execution-state. This can be a combination of 0 or more of the preceding flags. Specifying one or more of the flags enables a snap-in to turn off a power management requirement established by an earlier call to SetExecutionState.

Return value

If successful, the return value is S_OK. This method will return S_FALSE when invoked on a system that does not support power management. Other return values indicate an error code.

Remarks

Call IConsolePower::SetExecutionState instead of SetThreadExecutionState. Snap-ins must not call the SetThreadExecutionState function directly, doing so causes conflicts if multiple snap-ins are running on the same thread.

A snap-in defines its power requirements and sends them to MMC by calling SetExecutionState. After the snap-in calls SetExecutionState, its execution state remains in effect until the snap-in makes another call to SetExecutionState. Be aware that after SetExecutionState is called, the same instance of the IConsolePower interface must be used for subsequent calls to SetExecutionState. If a snap-in does not use the same instance of IConsolePower, then MMC cannot effectively call SetThreadExecutionState. MMC maintains an array to track each snap-in's execution state, and calls SetThreadExecutionState for all snap-ins running on the thread.

Examples

HRESULT hr;

// Specify that the display and system are required.
// pConsolePower was created previously by
// the CoCreateInstance method.
hr = pConsolePower->SetExecutionState(ES_DISPLAY_REQUIRED | ES_SYSTEM_REQUIRED,0);
switch (hr)
{
    case S_OK:
        OutputDebugString(_T("SetExecutionState: Succeeded\n"));
        break;

    case S_FALSE:
        // The system does not support power management.
        OutputDebugString(_T("SetExecutionState: Unsupported\n"));
        break;

    default:
        // Unexpected error occurred.
        OutputDebugString(_T("SetExecutionState: Failure\n"));
        break;
}

Requirements

See also

IConsolePower::ResetIdleTimer

SetThreadExecutionState