ACPI_EVAL_INPUT_BUFFER_V1_EX structure (acpiioct.h)

The ACPI_EVAL_INPUT_BUFFER_EX structure is used as input to an IOCTL_ACPI_EVAL_METHOD_EX request and to an IOCTL_ACPI_ASYNC_EVAL_METHOD_EX request. The structure supplies the path and name of a control method in an ACPI namespace that does not take an input argument.

Syntax

typedef struct _ACPI_EVAL_INPUT_BUFFER_V1_EX {
  ULONG Signature;
  CHAR  MethodName[256];
} ACPI_EVAL_INPUT_BUFFER_V1_EX, *PACPI_EVAL_INPUT_BUFFER_V1_EX, ACPI_EVAL_INPUT_BUFFER_EX, *PACPI_EVAL_INPUT_BUFFER_EX;

Members

Signature

The signature of an input buffer that does not include an argument, which must be set to ACPI_EVAL_INPUT_BUFFER_SIGNATURE_EX.

MethodName[256]

A NULL-terminated ASCII string that contains the path and name of a control method in an ACPI namespace. The maximum number of characters that the string can contain, including a NULL-terminator, is 256. For more information about how to supply the path and name of a control method, see the Remarks section later in this topic.

Remarks

A driver for a device can use an IOCTL_ACPI_EVAL_METHOD_EX request or an IOCTL_ACPI_ASYNC_EVAL_METHOD_EX request to evaluate a control method that is a descendant child object of the device. If the method does not take input arguments, these requests take an input ACPI_EVAL_INPUT_BUFFER_EX structure as follows:

• Set Signature to ACPI_EVAL_INPUT_BUFFER_SIGNATURE_EX.
• Set MethodName to a NULL-terminated string that supplies either the full path and name to a control method in the ACPI namespace or the path and name of the method that is relative to the device to which the evaluation request is sent.

  For example, assume that a request is sent to a device named 'ABCD' which is an immediate child of the root of an ACPI namespace, that 'ABCD' device supports a child device named 'CHLD,' and that the 'CHLD' device supports a method named '_FOO.' In this case, the evaluation request can supply either '\ABCD.CHLD._FOO,, which is the fully qualified path and name of the control method in the ACPI namespace, or 'CHLD._FOO,' which is the path and name of the control method that is relative to the 'ABCD' device in the ACPI namespace.

  For more information about how to obtain the fully qualified path and name of a control method in an ACPI namespace, see Enumerating Child Devices and Control Methods.

For more information about how to use this structure, see Evaluating ACPI Control Methods.

Requirements

Requirement	Value
Minimum supported client	Windows Vista and later versions of Windows.
Header	acpiioct.h (include Acpiioct.h)

See also

IOCTL_ACPI_ASYNC_EVAL_METHOD_EX

IOCTL_ACPI_EVAL_METHOD_EX