REQUEST=GETSHARED option of IARV64

The requirements for the caller are:

None

This macro supports multiple versions. Some keywords are unique to certain versions. See PLISTVER parameter description.

Before issuing the IARV64 macro, the caller does not have to place any information into any register unless using it in register notation for a particular parameter, or using it as a base register.

Some callers depend on register contents remaining the same before and after issuing a service. If the system changes the contents of registers on which the caller depends, the caller must save them before issuing the service, and restore them after the system returns control.

None

The REQUEST=GETSHARED option of the IARV64 macro is written as follows:

The parameters are explained as follows:

name

An optional symbol, starting in column 1, that is the name on the IARV64 macro invocation. The name must conform to the rules for an ordinary assembler language symbol.

REQUEST=GETSHARED

REQUEST=GETSHARED requests that a memory object be created. The memory object is allowed to be shared upon return (through SHAREMEMOBJ). Successful completion of this service creates system interest in the memory object, which must be removed (through DETACH AFFINITY=SYSTEM) before the memory object is freed. Addressability to the memory object is not provided by GETSHARED. Instead, use SHAREMEMOBJ to enable the virtual storage to be referenced. A memory object created through GETSHARED is not eligible for PAGEFIX or PAGEUNFIX.

,COND=NO

,COND=YES

An optional keyword input that specifies whether the request is unconditional or conditional. When you code COND=YES and there is insufficient storage to satisfy the request, instead of the request being abnormally ended the request will complete but a return code will be set to indicate that the request could not be completed successfully. In all cases the request will be abnormally ended for invalid requests, including violation of environmental restrictions. The default is COND=NO.

,COND=NO

The request is unconditional. The request will be abnormally ended when the request cannot be satisfied.

,COND=YES

The request is conditional. The request will not be abnormally ended for resource unavailability.

,SEGMENTS=segments

A required input parameter that specifies the size of storage requested in megabytes. This must be a non-zero value.

The amount of storage requested is not charged against the MEMLIMIT.

To code: Specify the RS-type address, or address in register (2)-(12), of a required doubleword field.

,KEY=key

,KEY=CALLERKEY

An optional input parameter that specifies the storage key to be assigned to the memory object. The key must be in bits 0-3 of the specified byte. Bits 4-7 are ignored.

If the key is not specified, the storage key of the memory object is the same as the caller's PSW key. The default is KEY=CALLERKEY.

To code: Specify the RS-type address, or address in register (2)-(12), of a one-byte field.

,FPROT=YES

,FPROT=NO

An optional parameter that specifies whether the memory object should be fetch protected. The default is FPROT=YES.

,FPROT=YES

The entire memory object will be fetch protected. A program must have a PSW key that matches the storage key of the memory object (or have PSW key 0) to reference data in the memory object.

,FPROT=NO

The memory object will not be fetch protected.

,USERTKN=usertkn

This parameter is the name (RS-type), or address in register (2)-(12), of a required doubleword input that identifies the user token to be associated with the shared memory object. This can be used on a later DETACH invocation to affect all memory objects associated with this value. A single shared memory object may be associated with multiple user tokens via GETSHARED and SHAREMEMOBJ.

,CHANGEACCESS=LOCAL

,CHANGEACCESS=GLOBAL

An optional parameter that specifies whether the subsequent CHANGEACCESS requests are treated as local or global. The default is CHANGEACCESS=LOCAL.

,CHANGEACCESS=LOCAL

The CHANGEACCESS for this memory object will have local scope. Subsequent CHANGEACCESS requests will change access only for the address space specified by CHANGEACCESS.

,CHANGEACCESS=GLOBAL

The CHANGEACCESS for this memory object will have global scope. Subsequent CHANGEACCESS requests will change access for all address spaces sharing the memory object and any new address spaces that will subsequently share it.

Note: Use of GLOBAL may reduce system resources needed to manage the memory object and is encouraged when all spaces will be using the same view.

,ALETVALUE=aletvalue

,ALETVALUE=0

This parameter is the name of an optional fullword integer input that indicates the ALET of the address space which will be used to create the memory object.

The only supported values are 0 (primary) and 2 (home). The default value is 0.

,ORIGIN=origin

A required output parameter that contains the lowest address of the memory object.

To code: Specify the RS-type address, or address in register (2)-(12), of an eight-byte pointer field.

,RETCODE=retcode

An optional output parameter into which the return code is to be copied from GPR 15.

To code: Specify the RS-type address of a fullword field, or register (2)-(12).

,RSNCODE=rsncode

An optional output parameter into which the reason code is to be copied from GPR 0.

To code: Specify the RS-type address of a fullword field, or register (2)-(12).

,PLISTVER=IMPLIED_VERSION

,PLISTVER=MAX

,PLISTVER=0, 1, 2, 3 or 4

An optional input parameter that specifies the version of the macro. PLISTVER determines which parameter list the system generates. PLISTVER is an optional input parameter on all forms of the macro, including the list form. When using PLISTVER, specify it on all macro forms used for a request and with the same value on all of the macro forms. The values are:

• IMPLIED_VERSION, which is the lowest version that allows all parameters specified on the request to be processed. If you omit the PLISTVER parameter, IMPLIED_VERSION is the default.
• MAX, if you want the parameter list to be the largest size currently possible. This size might grow from release to release and affect the amount of storage that your program needs.

  If you can tolerate the size change, IBM® recommends that you always specify PLISTVER=MAX on the list form of the macro. Specifying MAX ensures that the list-form parameter list is always long enough to hold all the parameters you might specify on the execute form, when both are assembled with the same level of the system. In this way, MAX ensures that the parameter list does not overwrite nearby storage.

• 0, supports all parameters except those specifically referenced in higher versions.
• 1, supports both the following parameters and parameters from version 0:
  • CONVERTSIZE64
  • CONVERTSTART
  • GUARDSIZE64
  • V64SHARED
• 2, supports both the following parameters and parameters from version 0 and 1:
  • AMOUNTSIZE
  • DETACHFIXED
  • DOAUTHCHECKS
  • DUMP
  • DUMPPRIORITY
  • DUMPPROTOCOL
  • LOCALSYSAREA
  • MEMLIMIT
  • OPTIONVALUE
  • ORDER
  • OWNERASID
  • OWNERCOM
  • TYPE
  • UNLOCKED
  • USERTOKEN
  • V64COMMON
• 3, supports both the following parameters and parameters from versions 0, 1, 2:
  • ATTRIBUTE
  • OWNERJOBNAME
  • TRACKINFO
• 4, supports both the following parameter and parameters from versions 0, 1, 2, 3:
  • DMAPAGETABLE

To code: Specify one of the following:

• IMPLIED_VERSION
• MAX
• A decimal value of 0, 1, 2, 3 or 4

,MF=S

,MF=(L,list addr)

,MF=(L,list addr,attr)

,MF=(L,list addr,0D)

,MF=(E,list addr)

,MF=(E,list addr,COMPLETE)

An optional input parameter that specifies the macro form.

Use MF=S to specify the standard form of the macro, which builds an inline parameter list and generates the macro invocation to transfer control to the service. MF=S is the default.

Use MF=L to specify the list form of the macro. Use the list form together with the execute form of the macro for applications that require reentrant code. The list form defines an area of storage that the execute form uses to store the parameters. Only the PLISTVER parameter may be coded with the list form of the macro.

Use MF=E to specify the execute form of the macro. Use the execute form together with the list form of the macro for applications that require reentrant code. The execute form of the macro stores the parameters into the storage area defined by the list form, and generates the macro invocation to transfer control to the service.

,list addr

The name of a storage area to contain the parameters. For MF=S and MF=E, this can be an RS-type address or an address in register (1)-(12).

,attr

An optional 1- to 60-character input string that you use to force boundary alignment of the parameter list. Use a value of 0F to force the parameter list to a word boundary, or 0D to force the parameter list to a doubleword boundary. If you do not code attr, the system provides a value of 0D.

,COMPLETE

Specifies that the system is to check for required parameters and supply defaults for omitted optional parameters.