The ExAllocatePoolWithQuota routine is obsolete, and is exported only for existing driver binaries. Use ExAllocatePoolWithQuotaTag instead.

ExAllocatePoolWithQuota allocates pool memory, charging quota against the current process.

PVOID 
  ExAllocatePoolWithQuota(
    IN POOL_TYPE  PoolType,
    IN SIZE_T  NumberOfBytes
    );

Parameters

PoolType

Specifies the type of pool memory to allocate. For a description of the available pool memory types, see POOL_TYPE.

You can modify PoolType by using a bitwise OR with the POOL_COLD_ALLOCATION flag as a hint to the kernel to allocate the memory from pages that are likely to be paged out quickly. To reduce the amount of resident pool memory as much as possible, you should not reference these allocations frequently. The POOL_COLD_ALLOCATION flag is only advisory and is available for Windows XP and later versions of the Windows operating system.

NumberOfBytes

Specifies the number of bytes to allocate.

Return Value

ExAllocatePoolWithQuota returns a pointer to the allocated pool.

If the request cannot be satisfied, ExAllocatePoolWithQuota raises an exception.

If the request cannot be satisfied, ExAllocatePoolWithQuotaTag raises an exception unless POOL_QUOTA_FAIL_INSTEAD_OF_RAISE is specified. Using POOL_QUOTA_FAIL_INSTEAD_OF_RAISE is preferred for performance reasons.

Comments

This routine is called by highest-level drivers that allocate memory to satisfy a request in the context of the process that originally made the I/O request. Lower-level drivers call ExAllocatePoolWithTag instead.

If NumberOfBytes is PAGE_SIZE or greater, a page-aligned buffer is allocated. Quota is not charged to the process for allocations of PAGE_SIZE or greater.

Memory allocations of less than PAGE_SIZE are allocated within a page and do not cross page boundaries. Memory allocations of PAGE_SIZE or less are not necessarily page-aligned but are aligned to 8-byte boundaries in 32-bit systems and to 16-byte boundaries in 64-bit systems.

Avoid calling with NumberOfBytes == 0. Doing so will result in pool header wastage.

The system automatically sets certain standard event objects when the amount of pool (paged or nonpaged) is high or low. Drivers can wait for these events to tune their pool usage. For more information, see Standard Event Objects.

Warning  Memory that ExAllocatePoolWithQuota allocates is uninitialized. A kernel-mode driver must first zero this memory if it is going to make it visible to user-mode software (to avoid leaking potentially privileged contents).

Requirements

Versions: Obsolete. This routine is exported only for existing driver binaries. Use ExAllocatePoolWithQuotaTag instead.

IRQL: <=APC_LEVEL

Headers: Declared in Wdm.h. Include Wdm.h, Ntddk.h, or Ntifs.h.

See Also

ExAllocatePoolWithTag, ExAllocatePoolWithQuotaTag, ExFreePool