| Previous | Contents | Index |
On Alpha and Integrity server systems, returns the displayable pathname for a given I/O channel or device name. Can be used to return all displayable paths to an I/O device.
SYS$DEVICE_PATH_SCAN [chan] [,devnam] ,itmlst [,contxt] [,nullarg]
int sys$device_path_scan (unsigned short int chan, void *devnam, void *itmlst, unsigned int *contxt, struct_generic_64 *nullarg);
chan
OpenVMS usage: channel type: word (unsigned) access: read only mechanism: by value
Number of the I/O channel assigned to the device about which information is desired. The chan argument is a word containing this number.To identify a device to $DEVICE_PATH_SCAN, you can specify either the chan or devnam parameters, but you should not specify both. If you specify both arguments, the chan argument is used.
If you specify neither chan nor devnam, $DEVICE_PATH_SCAN uses a default value of 0 for chan.
devnam
OpenVMS usage: device_name type: character-coded text string access: read only mechanism: by descriptor--fixed-length string descriptor
The name of the device about which $DEVICE_PATH_SCAN is to return path information. The devnam argument is the address of a character string descriptor pointing to this name string.The device name string can be either a physical device name or a logical name. If the first character in the string is an underscore (_), the string is considered a physical device name; otherwise, the string is considered a logical name and logical name translation is performed until either a physical device name is found or the system default number of translations has been performed.
If the device name string contains a colon (:), the colon and the characters that follow it are ignored.
To identify a device to $DEVICE_PATH_SCAN, you can specify either the chan or devnam argument, but you should not specify both. If both arguments are specified, the chan argument is used.
If you specify neither chan nor devnam, $DEVICE_PATH_SCAN uses a default value of 0 for chan.
itmlst
OpenVMS usage: item_list_3 type: longword (unsigned) access: read only mechanism: by reference
Item list specifying which information about the device is to be returned. The itmlst argument is the address of a list of item descriptors, each of which describes an item of information. The list of item descriptors is terminated by a longword of 0. The following diagram depicts the format of a single item descriptor:
See the itmlst argument in the $GETDVI system service description for information on the meaning of these fields in the item list.
| OpenVMS usage: | longword_unsigned |
| type: | longword (unsigned) |
| access: | modify |
| mechanism: | by reference |
| OpenVMS usage: | null_arg |
| type: | quadword (unsigned) |
| access: | read only |
| mechanism: | by reference |
DPS$_MP_PATHNAME
When you specify DPS$_MP_PATHNAME, $DEVICE_PATH_SCAN returns the name of one of the Multipath I/O paths connecting to the device named in the devnam argument. When the value of the contxt argument is 0, the path name for the first established path will be returned. On subsequent calls, with a non-zero contxt value, the path names of the remaining available paths to the device will be returned.In the item code, the Buffer Address field must point to the buffer that will hold the path name to be returned by the service. The Return Length Address field must be point to the buffer that will hold the return length returned by the service.
Upon completion of the command, the buffer pointed to by the Buffer Address field will hold a string identifying the requested path name. The Return Length Address field will point to the length in bytes of the path name being returned. The bytes in the path name buffer beyond the end of the path string will remain in the state they were set by the caller of the service.
The DPSDEF macro contains this item code.
The Scan for Device Paths service returns I/O path information for a given I/O channel or device name. Each call to $DEVICE_PATH_SCAN will return information on a different I/O path connecting with the device specified in the chan or devnam arguments.If the contxt argument is handled appropriately, the service will return information on the paths in the order in which they were established. On the first call, the contxt argument should be set to zero. The contxt value will be changed by the service during this call and a new value will be written into contxt and returned to the caller. The caller must use this same value in the next call to the service. Following this convention will result in a different path name being returned on each call.
Once the service has returned information on all paths to the named device, any further calls that use the final contxt value will result in SS$_NOMOREPATH status being returned.
None
None.
$ASSIGN, $DASSGN, $DEVICE_SCAN, $GETDVI, $GETDVIW, $SET_DEVICE
SS$_NORMAL The service completed successfully. SS$_ACCVIO The device name string descriptor, device name string, or itmlst argument cannot be read; or the buffer or return length longword cannot be written. SS$_BADPARAM The item list contains an invalid item code, or the buffer length field in an item descriptor specified insufficient space for the return length information. SS$_IVCHAN You specified an invalid channel number, that is, a channel number larger than the number of channels. SS$_IVDEVNAM The device name string contains invalid characters, or neither the devnam nor chan argument was specified. SS$_NOPRIV The specified channel is not assigned or was assigned from a more privileged access mode. SS$_NOMOREPATH No more device paths exist for this device. SS$_NOSUCHDEV The specified device does not exist on the host system.
Returns the names of all devices that match a specified set of search criteria.
SYS$DEVICE_SCAN return_devnam ,retlen ,[search_devnam] ,[itmlst] ,[contxt]
int sys$device_scan (void *return_devnam, unsigned short int *retlen, void *search_devnam, void *itmlst, struct _generic_64 *contxt);
return_devnam
OpenVMS usage: char_string type: character-coded text string access: write only mechanism: by descriptor--fixed-length string descriptor
Buffer to receive the device name. The return_devnam argument is the address of a character string descriptor pointing to a buffer into which $DEVICE_SCAN writes the name of the first or next device that matches the specified search criteria. The maximum size of any device name is 64 bytes.retlen
OpenVMS usage: word_unsigned type: word (unsigned) access: write only mechanism: by reference
Length of the device name string returned by $DEVICE_SCAN. The retlen argument is the address of a word into which $DEVICE_SCAN writes the length of the device name string.search_devnam
OpenVMS usage: device_name type: character-coded text string access: read only mechanism: by descriptor--fixed-length string descriptor
Name of the device for which $DEVICE_SCAN is to search. The search_devnam argument accepts the standard wildcard characters, the asterisk (*), which matches any sequence of characters, and the percent sign (%), which matches any one character. If the search_devnam argument does not include a wildcard character, an exact match is used for comparison. For example, to match all unit 0 DU devices on any controller, specify *DU%0. This string is compared to the most complete device name (DVI$_ALLDEVNAM). Only uppercase characters are accepted.
itmlst
OpenVMS usage: item_list_3 type: longword_unsigned access: read only mechanism: by reference
Item list specifying search criteria used to identify the device names for return by $DEVICE_SCAN. The itmlst argument is the address of a list of item descriptors, each of which describes one search criterion. The list of item descriptors is terminated by a longword of 0.The following diagram depicts the format of a single item descriptor:
The following table defines the item descriptor fields:
| Descriptor Field | Definition |
|---|---|
| Buffer length | A word containing a user-supplied integer specifying the length (in bytes) of the longword from which $DEVICE_SCAN is to read the information. The length of the buffer needed depends on the item code specified in the item code field of the item descriptor. |
| Item code | A word containing a user-specified symbolic code specifying the item of information that $DEVICE_SCAN is to return. The $DVSDEF macro defines these codes. Each item code is described in the Item Codes section. |
| Buffer address | A longword containing the address of a longword value that contains item code information. Examples include DC$_DISK and DC$_MAILBOX. |
| Return length address |
A longword containing the address of a word to receive the length (in
bytes) of information returned for the output value item code.
For the input value item code, this field is not used. HP recommends the placeholder value be 0. |
| OpenVMS usage: | quadword_unsigned |
| type: | quadword (unsigned) |
| access: | modify |
| mechanism: | by reference |
DVS$_DEVCLASS
An input value item code that specifies, as an unsigned longword, the device class being searched. The $DCDEF macro defines these classes.The DVS$_DEVCLASS argument is a longword containing this number; however, DVS$_DEVCLASS uses only the low-order byte of the longword.
DVS$_DEVTYPE
An input value item code that specifies, as an unsigned longword, the device type for which $DEVICE_SCAN is going to search. The $DCDEF macro defines these types.The DVS$_DEVTYPE argument is a longword containing this number; however, DVS$_DEVTYPE uses only the low-order byte of the longword. DVS$_DEVTYPE should be used in conjunction with DVS$_DEVCLASS to specify the device type being searched for.
The Scan for Devices system service returns the names of all devices that match a specified set of search criteria. The names returned by $DEVICE_SCAN can then be passed to another service; for example, $GETDVI or $MOUNT.The device names are returned for one process per call. A context value is used to continue multiple calls to $DEVICE_SCAN.
$DEVICE_SCAN allows wildcard searches based on device names, device classes, and device types. It also provides the ability to perform a wildcard search on other device-related services.
$DEVICE_SCAN makes it possible to combine search criteria. For example, to find only RA82 devices, use the following selection criteria:
DVS$_DEVCLASS = DC$_DISK and DVS$_DEVTYPE = DT$_RA82To find all mailboxes with MB as part of the device name (excluding mailboxes such as NLA0), use the following selection criteria:
DVS$_DEVCLASS = DC$_MAILBOX and DEVNAM = *MB*None
None
$ALLOC, $ASSIGN, $BRKTHRU, $BRKTHRUW, $CANCEL, $CREMBX, $DALLOC, $DASSGN, $DELMBX, $DISMOU, $GETDVI, $GETDVIW, $GETMSG, $GETQUI, $GETQUIW, $INIT_VOL, $MOUNT, $PUTMSG, $QIO, $QIOW, $SNDERR, $SNDJBC, $SNDJBCW, $SNDOPR
SS$_NORMAL The service completed successfully. SS$_ACCVIO The search_devnam, itmlst, or contxt argument cannot be read by the caller, or the retlen, return_devnam, or contxt argument cannot be written by the caller. SS$_BADPARAM The contxt argument contains an invalid value, or the item list contains an invalid item code. SS$_NOMOREDEV No more devices match the specified search criteria. SS$_NOSUCHDEV The specified device does not exist on the host system.
Marks an existing permanent global section for deletion. The actual deletion of the global section takes place when all processes that have mapped the global section have deleted the mapped pages.On Alpha and Integrity server systems, this service accepts 64-bit addresses.
SYS$DGBLSC [flags] ,gsdnam ,[ident]
int sys$dgblsc (unsigned int flags, void *gsdnam, struct _secid *ident);
flags
OpenVMS usage: mask_longword type: longword (unsigned) access: read only mechanism: by value
Mask indicating global section characteristics. The flags argument is a longword value. A value of 0 (the default) specifies a group global section; a value of SEC$M_SYSGBL specifies a system global section; a value of SEC$M_SHMGS on an OpenVMS Galaxy system creates a shared-memory global section.gsdnam
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 to be deleted. 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.
You can specify any name from 1 to 43 characters. All processes mapping to the same global section must specify the same name. Note that the name is case sensitive.
Use of characters valid in logical names is strongly encouraged. Valid values include alphanumeric characters, the dollar sign ($), and the underscore (_). If the name string begins with an underscore (_), the underscore is stripped and the resultant string is considered to be the actual name. Use of the colon (:) is not permitted.
Names are first subject to a logical name translation, after the application of the prefix GBL$ to the name. If the result translates, it is used as the name of the section. If the resulting name does not translate, the name specified by the caller is used as the name of the section.
Additional information on logical name translations and on section name processing is available in the HP OpenVMS Programming Concepts Manual.
ident
OpenVMS usage: section_id type: quadword (unsigned) access: read only mechanism: by 32- or 64-bit reference
Identification value specifying the version number of the global section to be deleted and the matching criteria to be applied. The ident argument is the 32- or 64-bit address of a quadword structure containing three fields.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. Values for these fields can be assigned by installation convention to differentiate versions of global sections. If you specify no version number when creating a section, processes that specify a version number when mapping cannot access the global section.
The first longword specifies, in its low-order 3 bits, the matching criteria. The valid values, the symbolic names by which they can be specified, and their meanings are listed in the following table:
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$K_MATLEQ Match if the major identifications are equal and the minor identification of the mapper is less than or equal to the minor identification of the global section. If you specify no address or specify it as 0 (the default), the version number and match control fields default to 0.
The Delete Global Section service marks an existing permanent global section for deletion. The actual deletion of the global section takes place when all processes that have mapped the global section have deleted the mapped pages.After a global section has been marked for deletion, any process that attempts to map it receives the warning return status code SS$_NOSUCHSEC.
Temporary global sections are automatically deleted when the count of processes using the section goes to 0.
Depending on the operation, the calling process might need one or more of the following privileges:
- SYSGBL privilege to delete a system global section
- PRMGBL privilege to delete a permanent global section
- PFNMAP privilege to delete a page frame section
- SHMEM privilege to delete a global section located in memory shared by multiple processors
None
$ADJSTK, $ADJWSL, $CRETVA, $CRMPSC, $DELTVA, $EXPREG, $LCKPAG, $LKWSET, $MGBLSC, $PURGWS, $SETPRT, $SETSTK, $SETSWM, $ULKPAG, $ULWSET, $UPDSEC, $UPDSECW
The $DGBLSC service does not unmap a global section from a process's virtual address space. To do this, the process should call the Delete Virtual Address Space ($DELTVA or $DELTVA_64) service, which deletes the pages to which the section is mapped.
SS$_NORMAL The service completed successfully. SS$_ACCVIO The global section name or name descriptor or the section identification field cannot be read by the caller. SS$_INTERLOCK The bit map lock for allocating global sections from the specified shared memory is locked by another process. SS$_IVLOGNAM The global section name has a length of 0 or has more than 15 characters. SS$_IVSECFLG You set an invalid flag, reserved flag, or flag requiring a user privilege. SS$_IVSECIDCTL The section identification match control field is invalid. SS$_NOPRIV The caller does not have the privilege to delete a system global section, does not have read/write access to a group global section, or does not have the privilege to delete a global section located in memory that is shared by multiple processors. SS$_NOSUCHSEC The specified global section does not exist, or the identifications do not match. SS$_NOTCREATOR The section is in memory shared by multiple processors and was created by a process on another processor. SS$_TOOMANYLNAM The logical name translation of the gsdnam string exceeded the allowed depth of 10.
| Previous | Next | Contents | Index |