HP OpenVMS I/O User's Reference Manual

Control Connection Routines

PDT$CANCEL Cancel Queued Request

PDT$DELETE Delete a Pseudoterminal

PDT$CREATE -- Createa Pseudoterminal  

Format 

PDT$CREATE chan [,acmode] [,charbuff] [,bufflen] [,astadr] [,astprm]            [,ast_acmode], inadr

Returns 

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

Arguments 

chan 

OpenVMS usage:
		channel
type :		word (unsigned)
access:		write only
mechanism:		by value

Number of the channel that is assigned to the new pseudoterminal.This argument is the address of a word into which PTD$CREATE writesthe channel number. This channel is only intended to be used forPTD$XXX operations.

acmode 

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

Access mode to be associated with the channel. The most privilegedaccess mode is the access mode of the caller. I/O operations onthe channel can be performed only from equal and more privilegedaccess modes.

charbuff 

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

Address of buffer containing the device characteristics. Thisinformation is used to set up the pseudoterminal's initial characteristics.This buffer can be 12, 16, or 20 bytes long.

Device Characteristics Buffer shows the formatof this buffer:  

Figure 1  Device Characteristics Buffer

bufflen 

OpenVMS usage:
		word_unsigned
type :		word (unsigned)
access:		read only
mechanism:		by value

Length of the characteristics buffer (either 12, 16, or 20bytes). This argument is required if you supply the charbuff argument.

astadr 

OpenVMS usage:
		ast_procedure
type :		procedure value
access:		call without stack unwinding
mechanism:		by reference

AST service routine to be executed when the terminal connectiondeassigns the last channel to the pseudoterminal. This argumentis the procedure value of this routine. This is a repeating ASTand is active until the control connection deletes the pseudoterminal.

astprm 

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

AST parameter to be passed to the AST service routine specifiedby astadr.

ast_acmode 

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

Access mode for which the AST is to be declared. The mostprivileged access mode is the access mode of the caller. The resultingmode is the access mode at which the AST is declared.

inadr 

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

Address of a two-longword array containing the starting andending virtual addresses in the virtual address space of the process(either P0 or P1 regions) to be used as I/O buffers. The array contains,in order, the starting and ending virtual addresses. The addressessupplied to inadr must expressan integral number of CPU-specific pages. The lower address mustbe on a CPU-specific page boundary, and the higher address mustbe one less than a CPU-specific page boundary. Together these addressesform a range from lowest to highest bytes. The pages must alreadyexist and must be fully contained in either P0 or P1 space. Allpages in the range must:

• Have identical page protection



• Be writable in the mode of the caller



• Be owned by the same access mode



• Be owned in a mode equal to or less privileged thanthe caller



• Be of the same page type (process or global)

Description 

PTD$CREATE creates a new pseudoterminal with a unique devicename. This device name is in the form FTAn:,where n is the unit number.

When a pseudoterminal is created, it inherits the currentsystem terminal default attributes unless you specify an alternateset of characteristics.

ReturnValues 

SS$_NORMAL	Normal successful completion.
SS$_ACCVIO	Unable to read one of the arguments.
SS$_BADPARAM	Bad Parameter Value.
SS$_EXBYTLM	Insufficient BYTLM to create device or map buffers.
SS$_EXQUOTA	Insufficient quota to create device.
SS$_EXASTLM	Insufficient AST quota for notification AST.
SS$_INSFMEM	Insufficient memory to create device.
SS$_INSFWSL	Insufficient working set limit to map buffers.
SS$_IVSECFLG	Invalid process or global section flags.
SS$_NOPRIV	No privilege for attempted operation.
SS$_PAGPNWNVIO	Page owner violation.
SS$_VA_IN_USE	Virtual address already in use.

PDT$CANCEL Cancel Queued Request

PDT$DELETE Delete a Pseudoterminal