Document revision date: 19 July 1999
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OpenVMS System Services Reference Manual


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All other bits in the flags argument are reserved for future use by Compaq and should be specified as 0. The condition value SS$_IVSECFLG is returned if any undefined bits are set or if an illegal combination of flags is set.

return_length_64


OpenVMS usage: byte count
type: quadword (unsigned)
access: write only
mechanism: by 32- or 64-bit reference

The length of the global section created. 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 global section in bytes.

fault_cluster


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

Page fault cluster in byte units indicating how many pages are to be brought into memory when a page fault occurs for a single page. The fault cluster specified is rounded up to a multiple of CPU-specific pages.

If this argument is specified as 0, the system default page fault cluster is used. If this argument is specified as more than the maximum allowed for the system, no error is returned. The systemwide maximum is used.


Description

The Create Permanent Global Disk File Section service allows a process to create a permanent global disk file section. Creating a global disk file section involves defining all or part of a disk file as a section. The global section is created as entire pages; however, the last page in the section might correspond to less than a full page of virtual disk blocks. Only the number of virtual disk blocks specified by the length_64 argument, or as many as exist in the disk file, will be associated with the disk file section. Upon successful completion of this service, the return_length_64 argument will contain the length of the global section created in even multiples of virtual disk blocks.

The security profile of the file is used to determine access to the global section. For a global disk file section to allow write access to the file during the mapping of the global section, the channel used to open the file must allow write access to the file.

Required Privileges

In order to create a global section, the process must have the following privileges:

Required Quota

None

Related Services

$CRMPSC, $CRMPSC_GFILE_64, $DGBLSC, $MGBLSC, $MGBLSC_64


Condition Values Returned

SS$_CREATED The service completed successfully. The specified global section did not previously exist and has been created.
SS$_ACCVIO The gs_name_64 argument or the return_length_64 argument cannot be read by the caller.
SS$_CHANVIO The specified channel was assigned from a more privileged access mode.
SS$_DUPLNAM A global section of the same name already exists; a new global section was not created.
SS$_ENDOFFILE The file_offset_64 argument specified is beyond the logical end-of-file.
SS$_EXBYTLM Process has exceeded the byte count quota; the system was unable to map the requested file.
SS$_GPTFULL There is no more room in the system global page table to set up page table entries for the section.
SS$_GSDFULL There is no more room in the system space allocated to maintain control information for global sections.
SS$_IVCHAN An invalid channel number was specified; the channel number specified was 0 or a channel that is unassigned.
SS$_IVCHNLSEC The channel number specified is currently active, or there are no files opened on the specified channel.
SS$_IVIDENT An invalid channel number was specified; the channel number specified is larger than the number of channels available.
SS$_IVLOGNAM The specified global section name has a length of 0 or has more than 43 characters.
SS$_IVLVEC The specified section was not installed using the /PROTECT qualifier.
SS$_IVSECFLG An invalid flag, a reserved flag, or an invalid combination of flags was specified.
SS$_IVSECIDCTL The match control field of the global section identification is invalid.
SS$_LEN_NOTBLKMULT The length_64 argument is not a multiple of virtual disk blocks.
SS$_NOPRMGBL The process does not have the privileges to create or delete a permanent group global section (PRMGBL).
SS$_NOSYSGBL The process does not have the privileges to create or delete a system global section (SYSGBL).
SS$_NOTFILEDEV The device is not a file-oriented, random-access, or directory device.
SS$_NOWRT The file is read only, and the flag bit SEC$M_CRF is not set.
SS$_OFF_NOTBLKALGN The file_offset_64 argument is not a multiple of virtual disk blocks.
SS$_SECTBLFUL There are no entries available in the system global section table.
SS$_TOOMANYLNAM The logical name translation of the gs_name_64 argument exceeded the allowed depth of 10.

$CREATE_GPFILE (Alpha Only)

On Alpha systems, creates a permanent global page file section to which processes can map.

This service accepts 64-bit addresses.


Format

SYS$CREATE_GPFILE gs_name_64 ,ident_64 ,prot ,length_64 ,acmode ,flags


C Prototype

int sys$create_gpfile (void *gs_name_64, struct _secid *ident_64, unsigned int prot, unsigned __int64 length_64, unsigned int acmode, unsigned int flags);


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- 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 2 bits. 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.

prot


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

Protection to be applied to the global page file section. The mask contains four 4-bit fields. Bits are read from right to left in each field. The following diagram depicts the mask:

Cleared bits indicate that read, write, execute, and delete access, in that order, are granted to the particular category of user. Only read, write, and execute access are meaningful for section protection. Delete access bits are ignored. Read access also grants execute access for those situations where execute access applies. If 0 is specified, read access and write access are granted to all users.

length_64


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

Length, in bytes, of the global page file section to be created. The length_64 argument must be specified as a multiple of the CPU-specific page size. A length of 0 cannot be specified.

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. 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

flags


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

Flag mask specifying the type of global section to be created as well as its characteristics. The flags argument is a longword bit vector in which each bit corresponds to a flag. The $SECDEF macro and the SECDEF.H file define a symbolic name for each flag. You construct the flags argument by performing a logical OR operation on the symbol names for all desired flags. The following table describes the flags that are valid for the $CREATE_GPFILE service:
Flag Description
SEC$M_DZRO Pages are demand-zero pages.
SEC$M_GBL Pages form a global section. By default, this flag is always present in this service and cannot be disabled.
SEC$M_PAGFIL Pages form a global page-file section. SEC$M_PAGFIL also implies SEC$M_WRT and SEC$M_DZRO. By default, this flag is always present in this service and cannot be disabled.
SEC$M_PERM Global section is permanent. By default, this flag is always present in this service and cannot be disabled.
SEC$M_SYSGBL Pages form a system global section. By default, pages form a group global section.
SEC$M_WRT Pages form a read/write section. By default, this flag is always present in this service and cannot be disabled.

All other bits in the flags argument are reserved for future use by Compaq and should be specified as 0. The condition value SS$_IVSECFLG is returned if any undefined bits are set.


Description

The Create Permanent Global Page File Section service allows a process to create a permanent global page file section. Global page file sections contain demand-zero allocation pages that are writable and backed up by the system page file. All pages in the global page file section are shared by all processes that map to the global section.

Required Privileges

In order to create a permanent global page file section, the process must have the following privileges:

Required Quota

The systemwide number of global page file pages is limited by the system parameter GBLPAGFIL.

Related Services

$CRMPSC, $CRMPSC_GPFILE_64, $DGBLSC, $MGBLSC, $MGBLSC_64


Condition Values Returned

SS$_CREATED The service completed successfully. The specified global section did not previously exist and has been created.
SS$_ACCVIO The gs_name_64 descriptor cannot be read by the caller.
SS$_DUPLNAM A global section of the same name already exists; a new global section was not created.
SS$_GPTFULL There is no more room in the system global page table to set up page table entries for the section.
SS$_GSDFULL There is no more room in the system space allocated to maintain control information for global sections.
SS$_IVLOGNAM The specified global section name has a length of 0 or has more than 43 characters.
SS$_IVSECFLG An invalid flag, a reserved flag, or an invalid combination of flags was specified.
SS$_IVSECIDCTL The match control field of the global section identification is invalid.
SS$_LEN_NOTPAGMULT The length_64 argument is not a multiple of CPU-specific pages or was specified as 0.
SS$_NOPRMGBL The process does not have the privileges to create or delete a permanent group global section (PRMGBL).
SS$_NOSYSGBL The process does not have the privileges to create or delete a system global section (SYSGBL).
SS$_SECTBLFUL There are no entries available in the system global section table.
SS$_TOOMANYLNAM The logical name translation of the gs_name_64 argument exceeded the allowed depth of 10.

$CREATE_GPFN (Alpha Only)

On Alpha systems, creates a permanent page frame section to which processes can map.

This service accepts 64-bit addresses.


Format

SYS$CREATE_GPFN gs_name_64 ,ident_64 ,prot ,start_pfn ,page_count ,acmode ,flags


C Prototype

int sys$create_gpfn (void *gs_name_64, struct _secid *ident_64, unsigned int prot, unsigned int start_pfn, unsigned int page_count, unsigned int acmode, unsigned int flags);


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- 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.

prot


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

Protection to be applied to the global page frame section.

The mask contains four 4-bit fields. Bits are read from right to left in each field. The following diagram depicts the mask:


Cleared bits indicate that read, write, execute, and delete access, in that order, are granted to the particular category of user. Only read, write, and execute access are meaningful for section protection. Delete access bits are ignored. Read access also grants execute access for those situations where execute access applies. If zero is specified, read access and write access are granted to all users.

start_pfn


OpenVMS usage: page frame number
type: longword (unsigned)
access: read only
mechanism: by value

The CPU-specific page frame number where the section begins in memory.

page_count


OpenVMS usage: CPU-specific page count
type: longword (unsigned)
access: read only
mechanism: by value

Length of the page frame section in CPU-specific pages.

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. 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

flags


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

Flag mask specifying the characteristics of the page frame section to be created. The flags argument is a longword bit vector in which each bit corresponds to a flag. The $SECDEF macro and the SECDEF.H file define a symbolic name for each flag. You construct the flags argument by performing a logical OR operation on the symbol names for all desired flags. The following table describes the flags that are valid for the $CREATE_GPFN service:
Flag Description
SEC$M_GBL Pages form a global section. By default, this flag is always present in this service and cannot be disabled.
SEC$M_PERM Global section is permanent. By default, this flag is always present in this service and cannot be disabled.
SEC$M_PFNMAP Pages form a page frame section. By default, this flag is always present in this service and cannot be disabled.
SEC$M_SYSGBL Pages form a system global page frame section. By default, pages form a group global page frame section.
SEC$M_WRT Pages form a read/write section. By default, pages form a read-only section.

All other bits in the flags argument are reserved for future use by Compaq and should be specified as 0. The condition value SS$_IVSECFLG is returned if any undefined bits are set or if an illegal combination of flags is set.


Description

The Create Permanent Global Page Frame Section service allows a process to create a global page frame section. All global page frame sections are permanent. Pages mapped to a global page frame section are not included in or charged against the process's working set; they are always valid. Do not lock these pages in the working set by using $LKWSET_64; this can result in a machine check if they are in I/O space.

Required Privileges

To create a permanent global page frame section, the process must have the following privileges:


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