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ExAllocatePool3 function (wdm.h)

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The ExAllocatePool3 routine allocates pool memory of the specified type and returns a pointer to the allocated block. This routine is similar to ExAllocatePool2 but it adds extended parameters.

Syntax

DECLSPEC_RESTRICT PVOID ExAllocatePool3(
  POOL_FLAGS                Flags,
  SIZE_T                    NumberOfBytes,
  ULONG                     Tag,
  PCPOOL_EXTENDED_PARAMETER ExtendedParameters,
  ULONG                     ExtendedParametersCount
);

Parameters

Flags

A ULONG64-typed value specifying the type of pool memory along with required and optional attributes. Multiple flag values can be combined using bit-wise OR. See POOL_FLAGS for possible values.

NumberOfBytes

Specifies a non-zero number of bytes to allocate.

Tag

The pool tag to use for the allocated memory. Specify the pool tag as a non-zero character literal of one to four characters delimited by single quotation marks (for example, Tag1). The string is usually specified in reverse order (for example, 1gaT). Each ASCII character in the tag must be a value in the range 0x20 (space) to 0x7E (tilde). Each allocation code path should use a unique pool tag to help debuggers and verifiers identify the code path.

ExtendedParameters

A pointer to an array of POOL_EXTENDED_PARAMETER structures that specify additional attributes for the allocation.

ExtendedParametersCount

A ULONG value specifying the number of parameters in ExtendedParameters.

Return value

ExAllocatePool3 returns a pointer to the allocated memory.

The following conditions cause the function to return NULL by default. If POOL_FLAG_RAISE_ON_FAILURE is specified, the function raises an exception.

  • Insufficient memory
  • Tag is set to 0 or invalid POOL_FLAGS are specified
  • Invalid POOL_EXTENDED_PARAMETER structures

Remarks

If you are building a driver that targets versions of Windows prior to Windows 10, version 2004, use ExAllocatePoolPriorityZero or ExAllocatePoolPriorityUninitialized.

See the remarks of ExAllocatePool2 for additional information.

Requirements

Requirement Value
Minimum supported client Windows 10, version 2004
Target Platform Universal
Header wdm.h (include Wdm.h, Ntddk.h, Ntifs.h)
Library NtosKrnl.lib
DLL NtosKrnl.exe
IRQL <= DISPATCH_LEVEL (see Remarks section)
DDI compliance rules HwStorPortProhibitedDDIs, SpNoWait, StorPortStartIo

See also

ExAllocatePool2