OpenVMS System Services Reference Manual

Updated: 11 December 1998

OpenVMS System Services Reference Manual

Contents

Index

$LKWSET_64 (Alpha Only)

On Alpha systems, locks a range of virtual addresses in the working set; if the pages are not already in the working set, the service brings them in and locks them. A page locked in the working set does not become a candidate for replacement.
This service accepts 64-bit addresses.

Format

SYS$LKWSET_64 start_va_64 ,length_64 ,acmode ,return_va_64 ,return_length_64

C Prototype

int sys$lkwset_64 (void *start_va_64, unsigned __int64 length_64, unsigned int acmode, void *(*(return_va_64)), unsigned __int64 *return_length_64);

Arguments

start_va_64

OpenVMS usage: address

type: quadword address

access: read only

mechanism: by value

The starting virtual address of the pages to be locked in the working set. The specified virtual address will be rounded down to a CPU-specific page boundary.
length_64

OpenVMS usage: byte count

type: quadword (unsigned)

access: read only

mechanism: by value

Length of the virtual address space to be locked in the working set. The specified length will be rounded up to a CPU-specific page boundary so that it includes all CPU-specific pages in the requested range.
acmode

OpenVMS usage: access_mode

type: longword (unsigned)

access: read only

mechanism: by value

Access mode associated with the pages to be locked. The acmode argument is a longword containing the access mode.
The $PSLDEF macro in STARLET.MLB and the file PSLDEF.H in SYS$STARLET_C.TLB define the following symbols and their values for the four access modes:

Value Symbolic Name Access Mode

0 PSL$C_KERNEL Kernel

1 PSL$C_EXEC Executive

2 PSL$C_SUPER Supervisor

3 PSL$C_USER User

The most privileged access mode used is the access mode of the caller. For the $LKWSET_64 service to complete successfully, the resultant access mode must be equal to or more privileged than the access mode already associated with the pages to be locked.
return_va_64

OpenVMS usage: address

type: quadword address

access: write only

mechanism: by 32- or 64-bit reference

The lowest process virtual address of the pages locked in the working set. The return_va_64 argument is the 32- or 64-bit virtual address of a naturally aligned quadword into which the service returns the virtual address.
return_length_64

OpenVMS usage: byte count

type: quadword (unsigned)

access: write only

mechanism: by 32- or 64-bit reference

The length of the virtual address range locked in the working set. The return_length_64 argument is the 32- or 64-bit virtual address of a naturally aligned quadword into which the service returns the length of the virtual address range in bytes.

Value	Symbolic Name	Access Mode
0	PSL$C_KERNEL	Kernel
1	PSL$C_EXEC	Executive
2	PSL$C_SUPER	Supervisor
3	PSL$C_USER	User

Description

The Lock Pages in Working Set service locks a range of pages in the working set; if the pages are not already in the working set, it brings them in and locks them. A page locked in the working set does not become a candidate for replacement.
If the condition value SS$_ACCVIO is returned by this service, a value cannot be returned in the memory locations pointed to by the return_va_64 and return_length_64 arguments. If a condition value other than SS$_ACCVIO is returned, the returned address and returned length indicate the pages that were successfully locked before the error occurred. If no pages were locked, the return_va_64 argument will contain the value -1, and a value cannot be returned in the memory location pointed to by the return_length_64 argument.
Global pages with write access cannot be locked into the working set.
Required Privileges

None
Required Quota

None
Related Services

$LKWSET, $ULWSET, $ULWSET_64

Condition Values Returned

SS$_WASCLR The service completed successfully. All of the specified pages were previously unlocked.

SS$_WASSET The service completed successfully. At least one of the specified pages was previously locked in the working set.

SS$_ACCVIO The return_va_64 or return_length_64 argument cannot be written by the caller, or an attempt was made to lock pages by a caller whose access mode is less privileged than the access mode associated with the pages.

SS$_LKWSETFUL The locked working set is full. If any more pages are locked, not enough dynamic pages will be available to continue execution.

SS$_NOPRIV No privilege; global pages with write access cannot be locked into the working set.

SS$_PAGNOTINREG A page in the specified range is not within the specified region.

SS$_PAGOWNVIO The pages could not be locked because the access mode associated with the call to $LKWSET_64 was less privileged than the access mode associated with the pages that were to be locked.

$MGBLSC

Establishes a correspondence between pages (maps) in the virtual address space of the process and physical pages occupied by a global section.

Format

SYS$MGBLSC inadr ,[retadr] ,[acmode] ,[flags] ,gsdnam ,[ident] ,[relpag]

C Prototype

int sys$mgblsc (struct _va_range *inadr, struct _va_range *retadr, unsigned int acmode, unsigned int flags, void *gsdnam, struct _secid *ident, unsigned int relpag);

Arguments

inadr

OpenVMS usage: address_range

type: longword (unsigned)

access: read only

mechanism: by reference

Starting and ending virtual addresses into which the section is to be mapped. The inadr argument is the address of a 2-longword array containing, in order, the starting and ending process virtual addresses. Only the virtual page number portion of each virtual address is used to specify which pages are to be mapped; the low-order byte-within-page bits are ignored for this purpose.
retadr

OpenVMS usage: address_range

type: longword (unsigned)

access: write only

mechanism: by reference

Starting and ending process virtual addresses into which the section was actually mapped by $MGBLSC. The retadr argument is the address of a 2-longword array containing, in order, the starting and ending process virtual addresses.
On Alpha systems, the retadr argument returns the starting and ending addresses of the usable range of addresses. This might differ from the total amount mapped. The retadr argument is required when the relpag argument is specified. If the section being mapped does not completely fill the last page used to map the section, the retadr argument indicates the highest address that actually maps the section. If the relpag argument is used to specify an offset into the section, the retadr argument reflects the offset.
acmode

OpenVMS usage: access_mode

type: longword (unsigned)

access: read only

mechanism: by value

Access mode to be associated with the pages mapped into the process virtual address space. The acmode argument is a longword containing the access mode. The $PSLDEF macro defines symbols for the four access modes.
The most privileged access mode used is the access mode of the caller.
flags

OpenVMS usage: mask_longword

type: longword (unsigned)

access: read only

mechanism: by value

Flag mask specifying options for the operation. The flags argument is a longword bit vector wherein a bit when set specifies the corresponding option.
The $SECDEF macro defines symbolic names for the flag bits. You construct the flags argument by specifying the symbolic names of each desired option in a logical OR operation. The following table describes each flag option.

Flag Option Description

SEC$M_WRT Map the section with read/write access. By default, the section is mapped with read-only access. If SEC$M_WRT is specified and the section is not copy-on-reference, write access is required.

SEC$M_SYSGBL Map a system global section. By default, the section is a group global section.

SEC$M_EXPREG Map the section into the first available virtual address range. By default, the section is mapped into the range specified by the inadr argument.
See the inadr argument description for a complete explanation of how to set the SEC$M_EXPREG flag.

gsdnam

OpenVMS usage: section_name

type: character-coded text string

access: read only

mechanism: by descriptor--fixed-length string descriptor

Name of the global section. The gsdnam argument is the address of a character string descriptor pointing to this name string.
For group global sections, the operating system interprets the group UIC as part of the global section name; thus, the names of global sections are unique to UIC groups. Further, all global section names are implicitly qualified by their identification fields.
ident

OpenVMS usage: section_id

type: quadword (unsigned)

access: read only

mechanism: by reference

Identification value specifying the version number of a global section, and, for processes mapping to an existing global section, the criteria for matching the identification. The ident argument is the address of a quadword structure containing three fields.
The first longword specifies, in the low-order two bits, the matching criteria. Their valid values, the symbolic names by which they can be specified, and their meanings are as follows.

Value/Name Match Criteria

0 SEC$K_MATALL Match all versions of the section.

1 SEC$K_MATEQU Match only if major and minor identifications match.

2 SEC$K_MATLEQ Match if the major identifications are equal and the minor identification of the mapper is less than or equal to the minor identification of the global section.

The version number is in the second longword and contains two fields: a minor identification in the low-order 24 bits and a major identification in the high-order 8 bits.
If you do not specify ident or specify it as the value 0 (the default), the version number and match control fields default to the value 0.
relpag

OpenVMS usage: longword_unsigned

type: longword (unsigned)

access: read only

mechanism: by value

Relative page number within the section of the first page to be mapped. The relpag argument is a longword containing this number.
On Alpha systems, the relpag argument is interpreted as an index into the section file, measured in pagelets for a file-backed section or CPU-specific pages for a PFN-mapped section.
On Alpha and VAX systems, if you do not specify relpag or specify it as the value 0 (the default), the global section is mapped beginning with the first virtual block in a file-backed section or the first CPU-specific page in a PFN-mapped section.

Flag Option	Description
SEC$M_WRT	Map the section with read/write access. By default, the section is mapped with read-only access. If SEC$M_WRT is specified and the section is not copy-on-reference, write access is required.
SEC$M_SYSGBL	Map a system global section. By default, the section is a group global section.
SEC$M_EXPREG	Map the section into the first available virtual address range. By default, the section is mapped into the range specified by the inadr argument. See the inadr argument description for a complete explanation of how to set the SEC$M_EXPREG flag.

Value/Name	Match Criteria
0 SEC$K_MATALL	Match all versions of the section.
1 SEC$K_MATEQU	Match only if major and minor identifications match.
2 SEC$K_MATLEQ	Match if the major identifications are equal and the minor identification of the mapper is less than or equal to the minor identification of the global section.

Description

The Map Global Section service establishes a correspondence between pages (maps) in the virtual address space of the process and physical pages occupied by a global section. The protection mask specified at the time the global section is created determines the type of access (for example, read/write or read only) that a particular process has to the section.
When $MGBLSC maps a global section, it adds pages to the virtual address space of the process. The section is mapped from a low address to a high address, whether the section is mapped in the program or control region.
If an error occurs during the mapping of a global section, the return address array, if specified, indicates the pages that were successfully mapped when the error occurred. If no pages were mapped, both longwords of the return address array contain the value --1.
Required Access or Privileges

Read access is required. If the SEC$M_WRT flag is specified, write access is required.
Required Quota

The working set quota (WSQUOTA) of the process must be sufficient to accommodate the increased size of the virtual address space when the $MGBLSC service maps a section.
If the section pages are copy-on-reference, the process must also have sufficient paging file quota (PGFLQUOTA).
This system service causes the working set of the calling process to be adjusted to the size specified by the working set quota (WSQUOTA). If the working set size of the process is less than quota, the working set size is increased; if the working set size of the process is greater than quota, the working set size is decreased.
Related Services

$ADJSTK, $ADJWSL, $CRETVA, $CRMPSC, $DELTVA, $DGBLSC, $EXPREG, $LCKPAG, $LKWSET, $PURGWS, $SETPRT, $SETSTK, $SETSWM, $ULKPAG, $ULWSET, $UPDSEC, $UPDSECW
For more information, see the chapter on memory management in the OpenVMS Programming Concepts Manual.

Condition Values Returned

SS$_NORMAL The service completed successfully.

SS$_ACCVIO The input address array, the global section name or name descriptor, or the section identification field cannot be read by the caller; or the return address array cannot be written by the caller.

SS$_ENDOFFILE The starting virtual block number specified is beyond the logical end-of-file.

SS$_EXQUOTA The process exceeded its paging file quota, creating copy-on-reference pages.

SS$_INSFWSL The working set limit of the process is not large enough to accommodate the increased virtual address space.

SS$_IVLOGNAM The global section name has a length of 0 or has more than 43 characters.

SS$_IVSECFLG You set a reserved flag.

SS$_IVSECIDCTL The match control field of the global section identification is invalid.

SS$_NOPRIV The file protection mask specified when the global section was created prohibits the type of access requested by the caller; or a page in the input address range is in the system address space.

SS$_NOSHPTS The region ID of a shared page-table region was specified.

SS$_NOSUCHSEC The specified global section does not exist.

SS$_PAGOWNVIO A page in the specified input address range is owned by a more privileged access mode.

SS$_SECREFOVF The maximum number of references for a global section has been reached (2,147,483,647).

SS$_TOOMANYLNAM Logical name translation of the gsdnam string exceeded the allowed depth.

SS$_VA_IN_USE The existing underlying page cannot be deleted because it is associated with a buffer object.

SS$_VASFULL The virtual address space of the process is full; no space is available in the page tables for the pages created to contain the mapped global section.

$MGBLSC_64 (Alpha Only)

On Alpha systems, establishes a correspondence between pages in the virtual address space of the process and the pages occupied by a global disk file, page file, or demand-zero section and can map to a demand-zero section with shared page tables.
This service accepts 64-bit addresses.

Format

SYS$MGBLSC_64 gs_name_64 ,ident_64 ,region_id_64 ,section_offset_64 ,length_64 ,acmode ,flags ,return_va_64 ,return_length_64
[,start_va_64]

C Prototype

int sys$mgblsc_64 (void *gsdnam_64, struct _secid *ident_64, struct _generic_64 *region_id_64, unsigned __int64 section_offset_64, unsigned __int64 length_64, unsigned int acmode, unsigned int flags, void *(*(return_va_64)), unsigned __int64 *return_length_64,...);

Arguments

gs_name_64

OpenVMS usage: section_name

type: character-coded text string

access: read only

mechanism: by 32- or 64-bit descriptor--fixed-length string descriptor

Name of the global section. The gs_name_64 argument is the 32- or 64-bit virtual address of a naturally aligned 32-bit or 64-bit string descriptor pointing to this name string.
ident_64

OpenVMS usage: section_id

type: quadword (unsigned)

access: read only

mechanism: by 32- or 64-bit reference

Identification value specifying the version number of a global section. The ident_64 argument is a quadword containing three fields. The ident_64 argument is the 32- or 64-bit virtual address of a naturally aligned quadword that contains the identification value.
The first longword specifies the matching criteria in its low-order two bits. The valid values, symbolic names by which they can be specified, and their meanings are as follows:

Value Symbolic Name Match Criteria

0 SEC$K_MATALL Match all versions of the section.

1 SEC$K_MATEQU Match only if major and minor identifications match.

2 SEC$K_MATLEQ Match if the major identifications are equal and the minor identification of the mapper is less than or equal to the minor identification of the global section.

If you specify the ident_64 argument as 0, the version number and match control fields default to 0.
The version number is in the second longword. The version number contains two fields: a minor identification in the low-order 24 bits and a major identification in the high-order 8 bits. You can assign values for these fields by installation convention to differentiate versions of global sections. If no version number is specified when a section is created, processes that specify a version number when mapping cannot access the global section.
region_id_64

OpenVMS usage: region identifier

type: quadword (unsigned)

access: read only

mechanism: by 32- or 64-bit reference

The region ID associated with the region to map the global section. The file VADEF.H in SYS$STARLET_C.TLB and the $VADEF macro in STARLET.MLB define a symbolic name for each of the three default regions in P0, P1, and P2 space. The following region IDs are defined:

Symbol Region

VA$C_P0 Program region

VA$C_P1 Control region

VA$C_P2 64-bit program region

Other region IDs, as returned by the $CREATE_REGION_64 service, can be specified.
section_offset_64

OpenVMS usage: byte offset

type: quadword (unsigned)

access: read only

mechanism: by value

Offset into the global section at which to start mapping into the process's virtual address space.
If a map to a global disk file section is being requested, the section_offset_64 argument specifies an even multiple of disk blocks. If a map to a global page file or demand-zero section is being requested, the section_offset_64 argument specifies an even multiple of CPU-specific pages. If zero is specified, the global section is mapped beginning with the first page of the section.
If the region_id_64 argument specifies a shared page table region, section_offset_64 must be an even multiple of pages mapped by a page table page.
length_64

OpenVMS usage: byte count

type: quadword (unsigned)

access: read only

mechanism: by value

Length, in bytes, of the desired mapping of the global disk file section.
If a map to a global section is being requested, the length_64 argument must specify an even multiple of disk blocks. If a map to a global page file or demand-zero section is being requested, the length_64 argument must specify an even multiple of CPU-specific pages. If zero is specified, the size of the disk file is used.
If a shared page-table region is specified by the region_id_64 argument, length_64 must be an even multiple of the number of bytes that can be mapped by a CPU-specific page-table page or must include the last page within the memory-resident global section.
acmode

OpenVMS usage: access_mode

type: longword (unsigned)

access: read only

mechanism: by value

Access mode that is to be the owner of the pages created during the mapping. This is also the read access mode and, if the SEC$M_WRT flag is specified, the write access mode. The acmode argument is a longword containing the access mode.
The $PSLDEF macro in STARLET.MLB and the file PSLDEF.H in SYS$STARLET_C.TLB define the following symbols and their values for the four access modes:

Value Symbolic Name Access Mode

0 PSL$C_KERNEL Kernel

1 PSL$C_EXEC Executive

2 PSL$C_SUPER Supervisor

3 PSL$C_USER User

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OpenVMS usage:	address
type:	quadword address
access:	read only
mechanism:	by value

OpenVMS usage:	byte count
type:	quadword (unsigned)
access:	read only
mechanism:	by value

OpenVMS usage:	access_mode
type:	longword (unsigned)
access:	read only
mechanism:	by value

SS$_WASCLR	The service completed successfully. All of the specified pages were previously unlocked.
SS$_WASSET	The service completed successfully. At least one of the specified pages was previously locked in the working set.
SS$_ACCVIO	The return_va_64 or return_length_64 argument cannot be written by the caller, or an attempt was made to lock pages by a caller whose access mode is less privileged than the access mode associated with the pages.
SS$_LKWSETFUL	The locked working set is full. If any more pages are locked, not enough dynamic pages will be available to continue execution.
SS$_NOPRIV	No privilege; global pages with write access cannot be locked into the working set.
SS$_PAGNOTINREG	A page in the specified range is not within the specified region.
SS$_PAGOWNVIO	The pages could not be locked because the access mode associated with the call to $LKWSET_64 was less privileged than the access mode associated with the pages that were to be locked.

OpenVMS usage:	address_range
type:	longword (unsigned)
access:	read only
mechanism:	by reference

OpenVMS usage:	mask_longword
type:	longword (unsigned)
access:	read only
mechanism:	by value

OpenVMS usage:	section_name
type:	character-coded text string
access:	read only
mechanism:	by descriptor--fixed-length string descriptor

OpenVMS usage:	section_id
type:	quadword (unsigned)
access:	read only
mechanism:	by reference

OpenVMS usage:	longword_unsigned
type:	longword (unsigned)
access:	read only
mechanism:	by value

SS$_NORMAL	The service completed successfully.
SS$_ACCVIO	The input address array, the global section name or name descriptor, or the section identification field cannot be read by the caller; or the return address array cannot be written by the caller.
SS$_ENDOFFILE	The starting virtual block number specified is beyond the logical end-of-file.
SS$_EXQUOTA	The process exceeded its paging file quota, creating copy-on-reference pages.
SS$_INSFWSL	The working set limit of the process is not large enough to accommodate the increased virtual address space.
SS$_IVLOGNAM	The global section name has a length of 0 or has more than 43 characters.
SS$_IVSECFLG	You set a reserved flag.
SS$_IVSECIDCTL	The match control field of the global section identification is invalid.
SS$_NOPRIV	The file protection mask specified when the global section was created prohibits the type of access requested by the caller; or a page in the input address range is in the system address space.
SS$_NOSHPTS	The region ID of a shared page-table region was specified.
SS$_NOSUCHSEC	The specified global section does not exist.
SS$_PAGOWNVIO	A page in the specified input address range is owned by a more privileged access mode.
SS$_SECREFOVF	The maximum number of references for a global section has been reached (2,147,483,647).
SS$_TOOMANYLNAM	Logical name translation of the gsdnam string exceeded the allowed depth.
SS$_VA_IN_USE	The existing underlying page cannot be deleted because it is associated with a buffer object.
SS$_VASFULL	The virtual address space of the process is full; no space is available in the page tables for the pages created to contain the mapped global section.

Value	Symbolic Name	Match Criteria
0	SEC$K_MATALL	Match all versions of the section.
1	SEC$K_MATEQU	Match only if major and minor identifications match.
2	SEC$K_MATLEQ	Match if the major identifications are equal and the minor identification of the mapper is less than or equal to the minor identification of the global section.

OpenVMS usage:	region identifier
type:	quadword (unsigned)
access:	read only
mechanism:	by 32- or 64-bit reference

Symbol	Region
VA$C_P0	Program region
VA$C_P1	Control region
VA$C_P2	64-bit program region

OpenVMS usage:	byte offset
type:	quadword (unsigned)
access:	read only
mechanism:	by value

OpenVMS System Services Reference Manual

$LKWSET_64 (Alpha Only)

Format

SYS$LKWSET_64 start_va_64 ,length_64 ,acmode ,return_va_64 ,return_length_64

C Prototype

int sys$lkwset_64 (void *start_va_64, unsigned __int64 length_64, unsigned int acmode, void *(*(return_va_64)), unsigned __int64 *return_length_64);

Arguments

start_va_64

length_64

acmode

return_va_64

return_length_64

Description

Condition Values Returned

$MGBLSC

Format

SYS$MGBLSC inadr ,[retadr] ,[acmode] ,[flags] ,gsdnam ,[ident] ,[relpag]

C Prototype

int sys$mgblsc (struct _va_range *inadr, struct _va_range *retadr, unsigned int acmode, unsigned int flags, void *gsdnam, struct _secid *ident, unsigned int relpag);

Arguments

inadr

retadr

acmode

flags

gsdnam

ident

relpag

Description

Condition Values Returned

$MGBLSC_64 (Alpha Only)

Format

SYS$MGBLSC_64 gs_name_64 ,ident_64 ,region_id_64 ,section_offset_64 ,length_64 ,acmode ,flags ,return_va_64 ,return_length_64 [,start_va_64]

C Prototype

int sys$mgblsc_64 (void *gsdnam_64, struct _secid *ident_64, struct _generic_64 *region_id_64, unsigned __int64 section_offset_64, unsigned __int64 length_64, unsigned int acmode, unsigned int flags, void *(*(return_va_64)), unsigned __int64 *return_length_64,...);

Arguments

gs_name_64

ident_64

region_id_64

section_offset_64

length_64

acmode

int sys$lkwset_64 (void start_va_64, unsigned __int64 length_64, unsigned int acmode, void ((return_va_64)), unsigned __int64 return_length_64);

int sys$mgblsc (struct _va_range inadr, struct _va_range retadr, unsigned int acmode, unsigned int flags, void gsdnam, struct _secid ident, unsigned int relpag);

SYS$MGBLSC_64 gs_name_64 ,ident_64 ,region_id_64 ,section_offset_64 ,length_64 ,acmode ,flags ,return_va_64 ,return_length_64
[,start_va_64]

int sys$mgblsc_64 (void gsdnam_64, struct _secid ident_64, struct _generic_64 region_id_64, unsigned __int64 section_offset_64, unsigned __int64 length_64, unsigned int acmode, unsigned int flags, void ((return_va_64)), unsigned __int64 return_length_64,...);