- The Object Header
- The Object Creator Information
- The Object Name
- The Object Handle Database
- Resource Charges and Quotas
- Object Directories
Resource Charges and Quotas
If a process opens a handle to an object, the process must "pay" for the usage of system resources caused by this operation. The paid dues are called charges, and the upper limit a process may spend for resources is called quota. By default, an object's OBJECT_TYPE determines the charges to be applied for paged/non-paged pool usage and security. However, this default can be overridden by adding an OBJECT_QUOTA_CHARGES structure to the object header. The location of this data relative to the OBJECT_HEADER base address is specified by the QuotaChargesOffset member of the OBJECT_HEADER as an inverse offset, as usual. Listing 5 shows the structure definition. The usages of the paged and non-paged pools are charged separately. If the object requires security, an additional SecurityCharge is added to the paged-pool usage. The default security charge is 0[ts]800.
Listing 5 The OBJECT_QUOTA_CHARGES Structure
#define OB_SECURITY_CHARGE 0x00000800
typedef struct _OBJECT_QUOTA_CHARGES
{
/*000*/ DWORD PagedPoolCharge;
/*004*/ DWORD NonPagedPoolCharge;
/*008*/ DWORD SecurityCharge;
/*00C*/ DWORD Reserved;
/*010*/ }
OBJECT_QUOTA_CHARGES,
* POBJECT_QUOTA_CHARGES,
**PPOBJECT_QUOTA_CHARGES;
If the OB_FLAG_CREATE_INFO bit of the ObjectFlags in the OBJECT_HEADER is zero, the QuotaBlock member points to a QUOTA_BLOCK structure (Listing 6) that contains statistical information about the current resource usage of the object.
Listing 6 The QUOTA_BLOCK Structure
typedef struct _QUOTA_BLOCK
{
/*000*/ DWORD Flags;
/*004*/ DWORD ChargeCount;
/*008*/ DWORD PeakPoolUsage [2]; // NonPagedPool, PagedPool
/*010*/ DWORD PoolUsage [2]; // NonPagedPool, PagedPool
/*018*/ DWORD PoolQuota [2]; // NonPagedPool, PagedPool
/*020*/ }
QUOTA_BLOCK,
* PQUOTA_BLOCK,
**PPQUOTA_BLOCK;