Document revision date: 30 March 2001

## OpenVMS RTL Library (LIB$) Manual

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Any condition values returned by system services $ASSIGN, $DASSGN, $PARSE, and $QIO, and RTL routines LIB$ANALYZE_SDESC, LIB$ANALYZE_SDESC_64, and LIB$GET_EF.

## LIB$CREATE_USER_VM_ZONE

> The Create User-Defined Storage Zone routine creates a new user-defined storage zone in the 32-bit virtual address space.

> Note No support for arguments passed by 64-bit address reference or for use of 64-bit descriptors, if applicable, is planned for this routine.

### Format

> LIB$CREATE_USER_VM_ZONE zone-id [,user-argument] [,user-allocation-procedure] [,user-deallocation-procedure] [,user-reset-procedure] [,user-delete-procedure] [,zone-name]

### RETURNS

> OpenVMS usage: | cond_value
> type: | longword (unsigned)
> access: | write only
> mechanism: | by value

### Arguments

> #### zone-id

> OpenVMS usage: | identifier
> type: | longword (unsigned)
> access: | write only
> mechanism: | by reference

> Zone identifier. The zone-id argument is the address of a longword that receives the identifier of the newly created zone.

> #### user-argument

> OpenVMS usage: | user_arg
> type: | longword (unsigned)
> access: | read only
> mechanism: | by reference

> User argument. The user-argument argument is the address of an unsigned longword containing the user argument. LIB$CREATE_USER_VM_ZONE copies the value of user-argument and supplies the value to all user procedures invoked.

> #### user-allocation-procedure

> OpenVMS usage: | procedure
> type: | procedure value
> access: | function call (before return)
> mechanism: | by value

> User allocation routine.

> #### user-deallocation-procedure

> OpenVMS usage: | procedure
> type: | procedure value
> access: | function call (before return)
> mechanism: | by value

> User deallocation routine.

> #### user-reset-procedure

> OpenVMS usage: | procedure
> type: | procedure value
> access: | function call (before return)
> mechanism: | by value

> User routine invoked each time LIB$RESET_VM_ZONE is called for the zone.

> #### user-delete-procedure

> OpenVMS usage: | procedure
> type: | procedure value
> access: | function call (before return)
> mechanism: | by value

> User routine invoked when LIB$DELETE_VM_ZONE is called for the zone.

> #### zone-name

> OpenVMS usage: | char_string
> type: | character string
> access: | read only
> mechanism: | by descriptor

> Name to be associated with the zone being created. The optional zone-name argument is the address of a descriptor pointing to the zone name. If zone-name is not specified, the zone will not have an associated name.

### Description

> LIB$CREATE_USER_VM_ZONE creates a user-defined zone in the 32-bit virtual address space. If an error status is returned, the zone is not created.

> Each time that one of the heap management routines (LIB$GET_VM, LIB$FREE_VM, LIB$RESET_VM_ZONE, or LIB$DELETE_VM_ZONE) is called to perform an operation on a user-defined zone, the corresponding user routine that you supplied is used.

> You may omit any of the optional user routines. However, if you omit a routine and later call the corresponding heap management routine, the error status LIB$_INVOPEZON will be returned.

> Call Format for User Routines

> The user routines are called with arguments similar to those passed to LIB$GET_VM, LIB$FREE_VM, LIB$RESET_VM_ZONE, or LIB$DELETE_VM_ZONE. In each case, the user-argument argument from LIB$CREATE_USER_VM_ZONE is passed to the user routine rather than a zone-id argument.

> The call format for a user get or free routine is as follows:

> `user-rtn num-bytes ,base-adr ,user-argument`

> > #### num-bytes

> > OpenVMS usage: | longword_signed
> > type: | longword integer (signed)
> > access: | read only
> > mechanism: | by reference

> > Number of contiguous bytes to allocate or free. The num-bytes argument is the address of a longword integer containing the number of bytes. The value of num-bytes must be greater than zero.

> > #### base-adr

> > OpenVMS usage: | address
> > type: | longword (unsigned)
> > access: | modify
> > mechanism: | by reference

> > Virtual address of the first contiguous block of bytes allocated or freed. The base-adr argument is the address of an unsigned longword containing this base address. (This argument is write-only for a get routine and read-only for a free routine.)

> > #### user-argument

> > OpenVMS usage: | user_arg
> > type: | longword (unsigned)
> > access: | read only
> > mechanism: | by reference

> > User argument. LIB$CREATE_USER_VM_ZONE copies user-argument as it is supplied to all user routines invoked.

> The status value returned by your routine is returned as the status value for the corresponding call to LIB$GET_VM or LIB$FREE_VM.

> The zone-id value that is returned can be used in calls to LIB$SHOW_VM_ZONE and LIB$VERIFY_VM_ZONE.

> The call format for a user reset or delete routine is as follows:

> `user-rtn user-argument`

> > #### user-argument

> > OpenVMS usage: | user_arg
> > type: | longword (unsigned)
> > access: | read only
> > mechanism: | by reference

> > User argument. LIB$CREATE_USER_VM_ZONE copies user-argument as it is supplied to all user routines invoked.

> The status value returned by your routine is returned as the status value for the corresponding call to LIB$RESET_VM_ZONE or LIB$DELETE_VM_ZONE.

### Condition Values Returned

> SS$_NORMAL | Routine successfully completed.
> LIB$_INSVIRMEM | Insufficient virtual memory.
> LIB$_INVSTRDES | Invalid string descriptor for zone-name.

## LIB$CREATE_USER_VM_ZONE_64 (Alpha Only)

> The Create User-Defined Storage Zone routine creates a new user-defined storage zone in the 64-bit virtual address space.

### Format

> LIB$CREATE_USER_VM_ZONE_64 zone-id [,user-argument] [,user-allocation-procedure] [,user-deallocation-procedure] [,user-reset-procedure] [,user-delete-procedure] [,zone-name]

### RETURNS

> OpenVMS usage: | cond_value
> type: | longword (unsigned)
> access: | write only
> mechanism: | by value

### Arguments

> #### zone-id

> OpenVMS usage: | identifier
> type: | quadword (unsigned)
> access: | write only
> mechanism: | by reference

> Zone identifier. The zone-id argument is the address of a quadword that receives the identifier of the newly created zone.

> #### user-argument

> OpenVMS usage: | user_arg
> type: | quadword (unsigned)
> access: | read only
> mechanism: | by reference

> User argument. The user-argument argument is the address of an unsigned quadword containing the user argument. LIB$CREATE_USER_VM_ZONE_64 copies the value of user-argument and supplies the value to all user procedures invoked.

> #### user-allocation-procedure

> OpenVMS usage: | procedure
> type: | procedure value
> access: | function call (before return)
> mechanism: | by value

> User allocation routine.

> #### user-deallocation-procedure

> OpenVMS usage: | procedure
> type: | procedure value
> access: | function call (before return)
> mechanism: | by value

> User deallocation routine.

> #### user-reset-procedure

> OpenVMS usage: | procedure
> type: | procedure value
> access: | function call (before return)
> mechanism: | by value

> User routine invoked each time LIB$RESET_VM_ZONE_64 is called for the zone.

> #### user-delete-procedure

> OpenVMS usage: | procedure
> type: | procedure value
> access: | function call (before return)
> mechanism: | by value

> User routine invoked when LIB$DELETE_VM_ZONE_64 is called for the zone.

> #### zone-name

> OpenVMS usage: | char_string
> type: | character string
> access: | read only
> mechanism: | by descriptor

> Name to be associated with the zone being created. The optional zone-name argument is the address of a descriptor pointing to the zone name. If zone-name is not specified, the zone will not have an associated name.

### Description

> LIB$CREATE_USER_VM_ZONE_64 creates a user-defined zone in the 64-bit virtual address space. If an error status is returned, the zone is not created.

> Each time that one of the heap management routines (LIB$GET_VM_64, LIB$FREE_VM_64, LIB$RESET_VM_ZONE_64, or LIB$DELETE_VM_ZONE_64) is called to perform an operation on a user-defined zone, the corresponding user routine that you supplied is used.

> You may omit any of the optional user routines. However, if you omit a routine and later call the corresponding heap management routine, the error status LIB$_INVOPEZON will be returned.

> Call Format for User Routines

> The user routines are called with arguments similar to those passed to LIB$GET_VM_64, LIB$FREE_VM_64, LIB$RESET_VM_ZONE_64, or LIB$DELETE_VM_ZONE_64. In each case, the user-argument argument from LIB$CREATE_USER_VM_ZONE_64 is passed to the user routine rather than a zone-id argument.

> The call format for a user get or free routine is as follows:

> `user-rtn num-bytes ,base-adr ,user-argument`

> > #### num-bytes

> > OpenVMS usage: | quadword_signed
> > type: | quadword integer (signed)
> > access: | read only
> > mechanism: | by reference

> > Number of contiguous bytes to allocate or free. The num-bytes argument is the address of a quadword integer containing the number of bytes. The value of num-bytes must be greater than zero.

> > #### base-adr

> > OpenVMS usage: | address
> > type: | quadword (unsigned)
> > access: | modify
> > mechanism: | by reference

> > Virtual address of the first contiguous block of bytes allocated or freed. The base-adr argument is the address of an unsigned quadword containing this base address. (This argument is write-only for a get routine and read-only for a free routine.)

> > #### user-argument

> > OpenVMS usage: | user_arg
> > type: | quadword (unsigned)
> > access: | read only
> > mechanism: | by reference

> > User argument. LIB$CREATE_USER_VM_ZONE_64 copies user-argument as it is supplied to all user routines invoked.

> The status value returned by your routine is returned as the status value for the corresponding call to LIB$GET_VM_64 or LIB$FREE_VM_64.

> The zone-id value that is returned can be used in calls to LIB$SHOW_VM_ZONE_64 and LIB$VERIFY_VM_ZONE_64.

> The call format for a user reset or delete routine is as follows:

> `user-rtn user-argument`

> > #### user-argument

> > OpenVMS usage: | user_arg
> > type: | quadword (unsigned)
> > access: | read only
> > mechanism: | by reference

> > User argument. LIB$CREATE_USER_VM_ZONE_64 copies user-argument as it is supplied to all user routines invoked.

> The status value returned by your routine is returned as the status value for the corresponding call to LIB$RESET_VM_ZONE_64 or LIB$DELETE_VM_ZONE_64.

### Condition Values Returned

> SS$_NORMAL | Routine successfully completed.
> LIB$_INSVIRMEM | Insufficient virtual memory.
> LIB$_INVSTRDES | Invalid string descriptor for zone-name.

## LIB$CREATE_VM_ZONE

> The Create a New Zone routine creates a new storage zone in the 32-bit virtual address space, according to specified arguments.

> Note No support for arguments passed by 64-bit address reference or for use of 64-bit descriptors, if applicable, is planned for this routine.

### Format

> LIB$CREATE_VM_ZONE zone-id [,algorithm] [,algorithm-argument] [,flags] [,extend-size] [,initial-size] [,block-size] [,alignment] [,page-limit] [,smallest-block-size] [,zone-name] [,get-page] [,free-page]

### RETURNS

> OpenVMS usage: | cond_value
> type: | longword (unsigned)
> access: | write only
> mechanism: | by value

### Arguments

> #### zone-id

> OpenVMS usage: | identifier
> type: | longword (unsigned)
> access: | write only
> mechanism: | by reference

> Zone identifier. The zone-id argument is the address of a longword that is set to the zone identifier of the newly created zone.

> #### algorithm

> OpenVMS usage: | longword_signed
> type: | longword integer (signed)
> access: | read only
> mechanism: | by reference

> Algorithm. The algorithm argument is the address of a longword integer that contains a value representing one of the LIB$VM algorithms. Use one of the predefined symbols to specify this value.

> Symbol | Value | Algorithm
> --- | --- | ---
> LIB$K_VM_FIRST_FIT | 1 | First fit
> LIB$K_VM_QUICK_FIT | 2 | Quick fit, lookaside list
> LIB$K_VM_FREQ_SIZES | 3 | Frequent sizes, lookaside list
> LIB$K_VM_FIXED | 4 | Fixed-size blocks

> If algorithm is not specified, a default of 1 (first fit) is used.

> #### algorithm-argument

> OpenVMS usage: | longword_signed
> type: | longword integer (signed)
> access: | read only
> mechanism: | by reference

> Algorithm argument. The algorithm-argument argument is the address of a longword integer that contains a value specific to the particular allocation algorithm as shown in the following table.

> Algorithm | Value
> --- | ---
> First fit | Not used, may be omitted.
> Quick fit | The number of lookaside lists used. The number of lists must be between 1 and 128.
> Frequent sizes | The number of lookaside lists used. The number of lists must be between 1 and 16.
> Fixed size blocks | The fixed request size (in bytes) for each get or free request. The request size must be greater than 0.

> The algorithm-argument argument must be specified if you are using the quick-fit, frequent-sizes or fixed-size-blocks algorithms. However, this argument is optional, but ignored, if you are using the first-fit algorithm.

> #### flags

> OpenVMS usage: | mask_longword
> type: | longword (unsigned)
> access: | read only
> mechanism: | by reference

> Flags. The flags argument is the address of a longword integer that contains flag bits that control various options, as follows:

> Bit | Value | Description
> --- | --- | ---
> 0 | LIB$M_VM_BOUNDARY_TAGS | Boundary tags for faster freeing.
> |  | Adds a minimum of 8 bytes to each block.
> 1 | LIB$M_VM_GET_FILL0 | LIB$GET_VM; fill with bytes of 0.
> 2 | LIB$M_VM_GET_FILL1 | LIB$GET_VM; fill with bytes of FF (hexadecimal).
> 3 | LIB$M_VM_FREE_FILL0 | LIB$FREE_VM; fill with bytes of 0.
> 4 | LIB$M_VM_FREE_FILL1 | LIB$FREE_VM; fill with bytes of FF (hexadecimal).
> 5 | LIB$M_VM_EXTEND_AREA | Adds extents to existing areas if possible.
> 6 | LIB$M_VM_NO_EXTEND | Prevents zone from being extended beyond its initial size. If you specify this flag, you must also specify an initial-size. The extend-size argument is not used.
> 7 | LIB$M_VM_TAIL_LARGE | Adds areas larger than extend-size areas to the end of the area list. Allocations that are larger than extend-size can result in new areas. These areas are added to the end of the area list. (This provides better memory reuse when allocating small and very large blocks from the same zone.)

> Bits 8 through 31 are reserved and must be 0.

> This is an optional argument. If flags is omitted, the default of 0 (no fill and no boundary tags) is used.

> #### extend-size

> OpenVMS usage: | longword_signed
> type: | longword integer (signed)
> access: | read only
> mechanism: | by reference

> Zone extend size. The extend-size argument is the address of a longword integer that contains the number of (512-byte) pages on VAX systems or pagelets on Alpha systems to be added to the zone each time it is extended.

> The value of extend-size must be greater than or equal to 1.

> This is an optional argument. If extend-size is not specified, a default of 16 pages on VAX systems or pagelets on Alpha systems is used.

> Note The extend-size argument does not limit the number of blocks that can be allocated from the zone. The actual extension size is the greater of extend-size and the number of pages on VAX systems or pagelets on Alpha systems needed to satisfy the LIB$GET_VM call that caused the extension.

> #### initial-size

> OpenVMS usage: | longword_signed
> type: | longword integer (signed)
> access: | read only
> mechanism: | by reference

> Initial size for the zone. The initial-size argument is the address of a longword integer that contains the number of (512-byte) pages on VAX systems or pagelets on Alpha systems to be allocated for the zone as the zone is created.

> This is an optional argument. If you specify a value for initial-size, the value must be greater than or equal to 0; otherwise, LIB$_INVARG is returned. If initial-size is not specified or is specified as 0, no pages on VAX systems or pagelets on Alpha systems are allocated when the zone is created. The first call to LIB$GET_VM for the zone allocates extend-size pages on VAX systems or pagelets on Alpha systems.

> #### block-size

> OpenVMS usage: | longword_signed
> type: | longword integer (signed)
> access: | read only
> mechanism: | by reference

> Block size of the zone. The block-size argument is the address of a longword integer specifying the allocation quantum (in bytes) for the zone. All blocks allocated are rounded up to a multiple of block-size.

> The value of block-size must be a power of 2 between 8 and 512. This is an optional argument. If block-size is not specified, a default of 8 is used.

> #### alignment

> OpenVMS usage: | longword_signed
> type: | longword integer (signed)
> access: | read only
> mechanism: | by reference

> Block alignment. The alignment argument is the address of a longword integer that specifies the required address alignment (in bytes) for each block allocated.

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