HP OpenVMS Systems Documentation

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, return_length_64, and return_prot arguments.

If a condition value other than SS$_ACCVIO is returned, the returned address and returned length indicate the pages that were successfully changed before the error occurred. If no pages were changed, 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.

Required Privileges

None

Required Quota

If a process changes the protection for any pages in a private section from read-only to read/write, $SETPRT_64 uses the paging file (PGFLQUOTA) quota of the process.

Related Services

$CRETVA_64, $CRMPSC_FILE_64, $CRMPSC_GFILE_64, $CRMPSC_GPFILE_64, $EXPREG_64, $MGBLSC_64

Condition Values Returned

SS$_NORMAL	The service completed successfully.
SS$_ACCVIO	The return_va_64 or the return_length_64 argument cannot be written by the caller.
SS$_EXPGFLQUOTA	The process exceeded its paging file quota while changing a page in a read-only private section to a read/write page.
SS$_IVPROTECT	The specified protection code has a numeric value of 1 or is greater than 15.
SS$_LENVIO	A page in the specified range is not in process private address space.
SS$_NOSUCHPAG	An attempt was made to change the protection on a nonexistent page.
SS$_PAGNOTINREG	A page in the specified range is not within the specified region.
SS$_PAGTYPVIO	A page in the specified range is not in process private address space.
SS$_PAGOWNVIO	The process attempted to change the protection on a page owned by a more privileged access mode.

Enables or disables specified privileges for the calling process.

Format

SYS$SETPRV [enbflg] ,[prvadr] ,[prmflg] ,[prvprv]

C Prototype

int sys$setprv (char enbflg, struct _generic_64 *prvadr, char prmflg, struct _generic_64 *prvprv);

Arguments

enbflg

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

Indicator specifying whether the specified privileges are to be enabled or disabled. The enbflg argument is a longword value. The value 1 indicates that the privileges specified in the prvadr argument are to be enabled. The value 0 (the default) indicates that the privileges are to be disabled.

prvadr

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

Privileges to be enabled or disabled for the calling process. The prvadr argument is the address of a quadword bit vector wherein each bit corresponds to a privilege that is to be enabled or disabled.

Each bit has a symbolic name. The $PRVDEF macro defines these names. You form the bit vector by specifying the symbolic name of each desired privilege in a logical OR operation. The following table provides the symbolic name and description of each privilege:

User Privilege	Symbolic Name	Description
ACNT	PRV$M_ACNT	Create processes for which no accounting is done
ALLSPOOL	PRV$M_ALLSPOOL	Allocate a spooled device
ALTPRI	PRV$M_ALTPRI	Set (alter) any process priority
AUDIT	PRV$V_AUDIT	Generate audit records
BUGCHK	PRV$M_BUGCHK	Make bugcheck error log entries
BYPASS	PRV$M_BYPASS	Bypass all protection
CMEXEC	PRV$M_CMEXEC	Change mode to executive
CMKRNL	PRV$M_CMKRNL	Change mode to kernel
DIAGNOSE	PRV$M_DIAGNOSE	Can diagnose devices
DOWNGRADE	PRV$V_DOWNGRADE	Can downgrade classification
EXQUOTA	PRV$M_EXQUOTA	Can exceed quotas
GROUP	PRV$M_GROUP	Group process control
GRPNAM	PRV$M_GRPNAM	Place name in group logical name table
GRPPRV	PRV$V_GRPPRV	Group access by means of system protection field
IMPERSONATE	PRV$M_IMPERSONATE	Create detached processes under another UIC
IMPORT	PRV$V_IMPORT	Mount a nonlabeled tape volume
LOG_IO	PRV$M_LOG_IO	Perform logical I/O operations
MOUNT	PRV$M_MOUNT	Issue mount volume QIO
NETMBX	PRV$M_NETMBX	Create a network device
OPER	PRV$M_OPER	All operator privileges
PFNMAP	PRV$M_PFNMAP	Map to section by physical page frame number
PHY_IO	PRV$M_PHY_IO	Perform physical I/O operations
PRMCEB	PRV$M_PRMCEB	Create permanent common event flag clusters
PRMGBL	PRV$M_PRMGBL	Create permanent global sections
PRMMBX	PRV$M_PRMMBX	Create permanent mailboxes
PSWAPM	PRV$M_PSWAPM	Change process swap mode
READALL	PRV$V_READALL	Possess read access to everything
SECURITY	PRV$V_SECURITY	Can perform security functions
SETPRV	PRV$M_SETPRV	Set any process privileges
SHARE	PRV$M_SHARE	Can assign a channel to a nonshared device
SHMEM	PRV$M_SHMEM	Allocate structures in memory shared by multiple processors
SYSGBL	PRV$M_SYSGBL	Create system global sections
SYSLCK	PRV$M_SYSLCK	Queue systemwide locks
SYSNAM	PRV$M_SYSNAM	Place name in system logical name table
SYSPRV	PRV$M_SYSPRV	Access files and other resources as if you have a system UIC
TMPMBX	PRV$M_TMPMBX	Create temporary mailboxes
UPGRADE	PRV$V_UPGRADE	Can upgrade classification
VOLPRO	PRV$M_VOLPRO	Override volume protection
WORLD	PRV$M_WORLD	World process control

If you do not specify prvadr or assign it the value 0, the privileges are not altered.

prmflg

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

Indicator specifying whether the privileges are to be affected permanently or temporarily. The prmflg argument is a longword value. The value 1 specifies that the privileges are to be affected permanently, that is, until you change them again by using $SETPRV or until the process is deleted. The value 0 (the default) specifies that the privileges are to be affected temporarily, that is, until the current image exits (at which time the permanently enabled privileges of the process will be restored).

Setting the prmflg argument to nonzero changes privilege bits in both the CURPRIV mask and the PROCPRIV mask.

prvprv

OpenVMS usage:	mask_privileges
type:	quadword (unsigned)
access:	write only
mechanism:	by reference

Privileges previously possessed by the calling process. The prvprv argument is the address of a quadword bit vector wherein each bit corresponds to a privilege that was previously either enabled or disabled. If you do not specify prvprv or assign it the value 0, the previous privilege mask is not returned.

Description

The Set Privileges service enables or disables specified privileges for the calling process.

The operating system maintains four separate privilege masks for each process:

• AUTHPRIV---Privileges that the process is authorized to enable, as designated by the system manager or the process creator. The AUTHPRIV mask never changes during the life of the process.
• PROCPRIV---Privileges that are designated as permanently enabled for the process. The PROCPRIV mask can be modified by $SETPRV.
• IMAGPRIV---Privileges with which the current image is installed.
• CURPRIV---Privileges that are currently enabled. The CURPRIV mask can be modified by $SETPRV.

When a process is created, its AUTHPRIV, PROCPRIV, and CURPRIV masks have the same contents. Whenever a system service (other than $SETPRV) must check the process privileges, that service checks the CURPRIV mask.

When a process runs an installed image, the privileges with which that image was installed are enabled in the CURPRIV mask. When the installed image exits, the PROCPRIV mask is copied to the CURPRIV mask.

The $SETPRV service can set bits only in the CURPRIV and PROCPRIV mask, but $SETPRV checks the AUTHPRIV mask to see whether a process can set specified privilege bits in the CURPRIV or PROCPRIV masks. Consequently, a process can give itself the SETPRV privilege only if this privilege is enabled in the AUTHPRIV mask.

You can obtain each of a process's four privilege masks by calling the $GETJPI (Get Job/Process Information) service and specifying the desired privilege mask or masks as item codes in the itmlst argument. You construct the item code for a privilege mask by prefixing the name of the privilege mask with the characters JPI$_ (for example, JPI$_CURPRIV is the item code for the current privilege mask).

The DCL command SET PROCESS/PRIVILEGES also enables or disables specified privileges; refer to the HP OpenVMS DCL Dictionary for details.

Required Access or Privileges

To set a privilege permanently, the calling process must be authorized to set the specified privilege, or the process must be executing in kernel or executive mode.

To set a privilege temporarily, one of the following three conditions must be true:

• The calling process must be authorized to set the specified privilege.
• The calling process must be executing in kernel or executive mode.
• The image currently executing must be one that was installed with the specified privilege.

Required Quota

None

Related Services

$CANEXH, $CMKRNL, $CREPRC, $DCLEXH, $DELPRC, $EXIT, $FORCEX, $GETJPI, $GETJPIW, $HIBER, $PROCESS_SCAN, $RESUME, $SETPRI, $SETPRN, $SETRWM, $SUSPND, $WAKE

Condition Values Returned

SS$_NORMAL	The service completed successfully. All privileges were enabled or disabled as specified.
SS$_NOTALLPRIV	The service completed successfully. Not all specified privileges were enabled; see the Description section for details.
SS$_ACCVIO	The privilege mask cannot be read or the previous privilege mask cannot be written by the caller.
SS$_IVSTSFLG	You specified a value other than 1 or 0 in either the prmflg argument or the enblfg argument.

Allows a process to specify what action system services should take when system resources required for their execution are unavailable.

Caution Disabling resource waiting should be performed with caution, as doing so can have unexpected effects on constituent sharable images and runtime libraries.

Format

SYS$SETRWM [watflg]

C Prototype

int sys$setrwm ( char watflg);

Argument

watflg

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

Indicator specifying whether system services should wait for required resources. The watflg argument is a longword value. The value 0 (the default) specifies that system services should wait until resources needed for their execution become available. The value 1 specifies that system services should return failure status immediately when resources needed for their execution are unavailable.

The operating system enables resource wait mode for all processes. You can disable resource wait mode only by calling $SETRWM.

If resource wait mode is disabled, it remains disabled until it is explicitly reenabled or until the process is deleted.

Description

The Set Resource Wait Mode service allows a process to specify what action system services should take when system resources required for their execution are unavailable.

When resource wait mode is enabled, system services wait for the required system resources to become available and then continue execution. When resource wait mode is disabled, system services return to the caller when required system resources are unavailable. The condition value returned by $SETRWM indicates whether resource wait mode was previously enabled or previously disabled.

The following system resources and process quotas are affected by resource wait mode:

• System dynamic memory: nonpaged pool, lock manager dynamic memory¹
• UNIBUS adapter map registers
• Direct I/O limit (DIOLM) quota
• Buffered I/O limit (BIOLM) quota
• Buffered I/O byte count limit (BYTLM) quota
• Timer queue quota
• Mailbox buffer quota
• Insufficient pipe quota

Caution Due to the process-wide implications of resource waiting, disabling resource waiting should be performed with caution. Disabling resource wait mode can have unexpected effects on libraries or shareable images upon which your application may be directly or indirectly dependent. If resource waiting is disabled, these constituent libraries or shareable images may not perform as expected. It is possible that these constituent components are coded to assume resource waiting is enabled; therefore, they may not be coded to receive various quota-related errors such as SS$_EXQUOTA. Note that you should have full control over the entire program context down to the system calls before disabling resource wait mode.

Required Access or Privileges

None

Required Quota

None

Related Services

$CANEXH, $CREPRC, $DCLEXH, $DELPRC, $EXIT, $FORCEX, $GETJPI, $GETJPIW, $HIBER, $PROCESS_SCAN, $RESUME, $SETPRI, $SETPRN, $SETPRV, $SUSPND, $WAKE

Condition Values Returned

SS$_WASCLR	The service completed successfully. Resource wait mode was previously enabled.
SS$_WASSET	The service completed successfully. Resource wait mode was previously disabled.

$SETSHLV

Controls whether a process automatically unshelves files.

Format

SYS$SETSHLV [pidadr] ,[prcnam] ,[shlvflg]

C Prototype

int sys$setshlv (unsigned int *pidadr, void *prcnam, unsigned int shlvflg);

Arguments

pidadr

OpenVMS usage:	process_id
type:	longword (unsigned)
access:	modify
mechanism:	by reference

Process identification (PID) of the process. The pidadr argument is the address of the PID. The pidadr argument can only refer to a process running on the local node. You cannot modify a process on a remote node.

You must specify the pidadr argument to modify a process whose UIC group number is different from that of the calling process.

prcnam

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

Process name of the process. The prcnam argument is the address of a character string descriptor pointing to the process name. You identify a process with a 1- to 15-character string.

You can only use the prcnam argument to modify a process in the same UIC group as the calling process. To modify a process in another UIC group, you must specify the pidadr argument.

shlvflg

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

Value specifying whether automatic unshelving is to be turned on or off. The shlvflg argument is a longword containing this value. The value 0 turns automatic unshelving on. The value 1 turns automatic unshelving off.

Description

The Set Automatic Unshelving service controls whether a process automatically unshelves files.

The pidadr and prcnam default to the current process. If the longword at address pidadr is 0, the PID of the target process is returned.

The setting for automatic unshelving is inherited by subprocesses.

The DCL command SET PROCESS/[NO]AUTOUNSHELVE also controls automatic unshelving for a process; for details, see the HP OpenVMS DCL Dictionary.

Required Access or Privileges

Depending on the operation, the calling process might need one of the following privileges to use $SETSHLV:

• GROUP privilege to modify a process in the same group, unless the target process has the same UIC as the calling process.
• WORLD privilege to modify any process in the system.

Required Quota

None

Related Services

$GETJPI

Condition Values Returned

SS$_WASCLR	The service completed successfully. Automatic unshelving was previously on.
SS$_WASSET	The service completed successfully. Automatic unshelving was previously off.
SS$_ACCVIO	An argument was not accessible by the caller.
SS$_BADPARAM	The shlvflg argument was invalid.
SS$_IVLOGNAM	The prcnam argument was invalid. The process name string had either 0 characters or more than 15 characters.
SS$_NONEXPR	The specified process did not exist, or the specified process identification was invalid.
SS$_NOPRIV	The caller did not have the privilege to modify other processes.
SS$_REMOTE_PROC	The specified process was not on the local node. The service cannot modify a process on a remote node.