Vision Error Messages

Syntax Errors

A Syntax Error occurs when you try to execute a Vision expression that is not formulated correctly. For example, the following expression does not supply a parameter to the + message: 

  3 +
If you execute this expression, you should get the error message: 
  >>> 'syntax error' near source line 2, character 9 <<<
        3 +
  **       ^
Since Vision was expecting a value following the + message and none was provided, you are informed that you have made a syntax error. Vision tries to identify where the error occurred and provides an indicator arrow (i.e., the ^ symbol) in the area where the problem was first identified. In this case, the arrow points to the area directly after the + message. Execution is terminated as soon the first syntax error is encountered.

Several other mistakes will produce syntax errors. For example, the expression: 

  2 + 7 . print
produces the error: 
  >>> 'syntax error' near source line 1, character 12 <<<
        2 + 7 . print
  **          ^
because you cannot use the . character to terminate a binary message. A syntax error is generated if you send a literal (i.e., a number, string, block, or magic word) to another object, since literals must be the first object in an expression. For example, the expression: 
  2 2
produces the error message: 
  >>> 'syntax error' near source line 1, character 8 <<<
        2 2
  **      ^
The expression: 
  2 "xxx"
produces the error message: 
  >>> 'syntax error' near source line 1, character 8 <<<
    2 "xxx"
  **      ^
The expression: 
  2 [ ]
produces the error message: 
  >>> 'syntax error' near source line 1, character 4 <<<
    2 [ ]
  **  ^
The expression: 
  2 ^self
produces the error message: 
  >>> 'syntax error' near source line 1, character 4 <<<
    2 ^self
  **  ^
You will generate a syntax error if you execute a program that has a mismatched number of quote characters. For example, the expression: 
  "this is a string that never ends.
produces the error message: 
  >>> 'End of File encountered in String' near source line 2, character 38 <<<
    "this is a string that never ends.
   *^
  >>> 'syntax error' near source line 2, character 38 <<<
    "this is a string that never ends.
   *^
You will also generate a syntax error if you do not have the appropriate number of closing parentheses or brackets in your program. For example, the expression: 
  [ 2 + 2 ;
produces the error message: 
  >>> 'syntax error' near source line 2, character 11 <<<
    [ 2 + 2 ;
  **         ^
Since the set of magic words is fixed and internal to Vision, you will generate a syntax error if you try to use an unknown magic word. For example, the expression: 
  ^cur gm sales
produces the error message: 
  >>> 'Unrecognized magic word '^cur'' near source line 1, character 4 <<<
   ^cur gm sales
  **  ^
You will also receive a syntax error if you have a keyword message as the initial message in an expression. For example: 
  defineMethod: [ | x | "This is a method at ^current" ] ;
produces the error message: 
  >>> 'syntax error' near source line 1, character 13 <<<
   defineMethod: [ | x | "This is a method at ^current" ] ;
  **           ^
You must send binary and keyword messages to a named object or a literal (i.e., a number, string, block, or magic word).

Selector Not Found Errors

A Selector Not Found error occurs because you have asked Vision to execute a message that is not defined. For example: 

  "This is a string" + 5
This expression produces the error message: 
  >>> Selector '+' Not Found <<<
    NA
When you ask Vision to add 5 to a string, Vision complains because the addition message is not defined for strings. The Selector Not Found response identifies the specific message that Vision could not perform. In this case, the message identified is +. Execution is not terminated when a selector is undefined. The result of applying an undefined selector to an object is the value NA.

When you are using named blocks, you can generate a variation on the selector not found message if you do not provide the correct number of parameters to a block. For example: 

  !block <-
       [ | sampleP1: a  P2: b |
         "Parameter 1: " print ; a printNL ;
         "Parameter 2: " print ; b printNL ;
       ] ;
  block valueWith: 10
produces: 
  >>> Parameter 'a' Unavailable <<<
  Parameter 1:       NA 
  Parameter 2:        10
Notice that the value NA was substituted for the missing parameter and the program execution continued.

Fatal Vision Errors

A fatal Vision error is indicated by output in the form: 

  >>>  Error Trapped By Read-Eval-Print  <<<
  *    Utilities [132]
  *    'malloc' Error
  *    Private Memory Allocation Error
  Size: 3255252408, Details: Not Enough Space
When a fatal error is encountered, the current execution is aborted. Your Vision session will remain active, but you will not be able to commit any saves if your session encounters a fatal error. Depending on the nature of the error, you may be able to continue working in your session; however, it is normally best to restart your session as soon as possible.

In general, Memory Allocation and Map Segment errors indicate that your session has exceeded available system resources.

Following are examples and descriptions of some of the fatal errors you can encounter, grouped by category (displayed in the second line after Error Trapped By Read-Eval-Print in the error message):

System Faults

  • Map Segment [/localvision/network/42/35596] 'No such file or directory'
    • This error simply indicates that the segment cannot be found. This most frequently occurs when a compaction has been run since this session was started. The segment in question has either been moved to the .dsegs directory or deleted entirely. 
  • Segment '...3/76' checksum 123456 not equal to computed checksum 98765
    • On update, this error indicates that a newly created segment written to disk does not have the expected contents causing the update to abort. The problem can be the result of disk corruption. On HP-UX operating systems, this error can also occur if you have tuned the operating system to NOT force commits to happen immediately. The parameter 'fs_async' should be set to 0 so updates to disk are forced to happen. 
  • Segment Seek To Offset [0]: 'Bad file number'
    • This is due to a directory write permission problem in the /vision/network sub-directories. It is not a fatal error, but is currently reported as such.

Segmentation Faults, Interrupts, and Container Framing Errors

  • Segmentation Violation Signal
    • This a serious error that indicates that the underlying batchvision program attempted to access memory that was not part of its address space. There can be many causes for this. If a rollback has been done, and new segments have been created since the rollback, any sessions that started before the rollback would be likely to get this error. A corrupt segment could cause the error. An unidentified bug in the C code implementing batchvision can cause this error. 
  • Bus Error Signal
    • This error is very similar to the Segmentation Violation. The main difference is the value of the illegal address being accessed. 
  • Container Framing Error
Specifics: MA:017A2700, POP:[0:551], RT:[12], S:[835316604/126891290]
    • The causes of this error are similar to Segmentation violations and Bus Errors. The difference is that the bad address that was used was within the process's address space, and data structures were corrupted.

Malloc Errors

  • Private Memory Re-Allocation Error
Address: 7DC69130, Size: 26009624, Details: Not enough space
    • This error indicates that the process does not have a contiguous set of addresses in its address space which is large enough to honor the request to grow the size of a private data structure. A couple of approaches could be taken to avoid this error:

      - the tuning parameter VisionMappingLimit could be lowered; that will raise the probability that enough space will remain in the private data area of the process

      - the second approach would be to examine and optimize the vision code

    If the Details: section reads "Resource temporarily unavailable" instead of "Not enough space", then a system resource has been exhausted; typically the resource is swap space. 

  • Private Memory Allocation Error
Size: 258856460, Details: Not enough space
    • This is similar to the Re-allocation error described above. The difference is that this refers to the creation of a new data structure rather than the growth of an existing one.

Internal Inconsistencies

  • rtPTOKEN_IsntCurrent: R-Type Error: RTYPE_C_Link Found, RTYPE_C_PToken Expected.
    • This error could be a "domino-effect" error following an allocation error or a segmentation violation. It could be the result of a rollback, or it could be caused by a bug in batchvision's C code. 
  • M_GetSpecificCPD: R-Type Error: RTYPE_C_MethodD Found, RTYPE_C_PToken Expected.
    • This Internal Inconsistency could have the same causes as the above. 
  • rtPTOKEN_BaseElementCount: R-Type Error: RTYPE_C_Undefined Found, RTYPE_C_PToken Expected.
    • This is similar to the previous Internal Inconsistencies. 
  • Unknown Descriptor Pointer Type '0' Found By 'DSC_InitPointerFromPointerCPD'
    • This is similar to the previous Internal Inconsistencies except that it would not be caused by a rollback. 
  • rtPTOKEN_NewBasePToken: Invalid Element Count -2085841084
    • This error occurs when vision code tries to create a collection with more than 2 billion elements. This usually occurs with time series operations or within nested list operations. 
  • DSC_InitCorrespondenceDescriptor: P-Token Size Difference
    • This error indicates that the positional state of an object was changed while the object was being used. The typical way of causing this would be via a delete operation from within a list iteration, and then trying to use the collection which had elements deleted from within that same list iteration.

    For example, if an Entity instance was deleted and Security instanceList was then accessed in a list operation, you would get the error. To avoid the error, after the deletion run a cleanSpace for the Entity class object space and that will align all subclasses in that space. 

  • rtVECTOR_Save: Transient store in vector set
    • This error occurs when an IndexedList is being updated with an indexing object from a transient store (non-permanent residence in object space 0). Instances from new classes created in the current session or existing objects with extensions reside in transient stores.

    In releases prior to 6.1.1 the only alternative is to save the newly created class prior to the IndexedList update. In release 6.1.1 and above you are able to establish a forward residency of the new class upon creation and therefore avoid the transient store error. Please see Vision Release 6.1.1 Notes for more information on establishing residency for new classes.

    In most cases, an extended object used as an index is a mistake. You should strip all extensions prior to the IndexedList update by sending the message asSelf, otherwise the index lookup will fail (i.e. return NA).

Memory Manager Errors

  • M_FreeCPD: CPD not in use
    • This is typically a "domino-effect" error which occurs when batchvision tries to clean up following another error. 
  • No More Room In Container Table (space:0)
    • This is typically due to an infinitely recursive block execution. Each block execution creates some number of containers, and those containers normally get garbage collected when the block exits. If there is non-bounded recursion, more containers get created and none get freed - this continues until you get a malloc error or this error. In the days before plentiful memory, you would run out of memory before running out of container table entries.

    For persistent spaces (not 0) this means that, over time, containers have accumulated in the space. This may be because cleanup/garbage collection is not being run in a timely fashion or it may be that updates to data are very poorly clustered.

Unknown UVector RType Errors

  • DSC_InitScalarWithUVElement: Unsupported R-Type RTYPE_C_Undefined
    • or 
  • DSC_InitScalarWithUVElement: Unsupported R-Type RTYPE_C_ValueStore
    • These errors indicate that batchvision is confused internally - it may be due to a corrupted segment, an IO error or an unidentified bug. A check of all segments should be done to verify they all belong to the expected network.

Usage Errors

  • !!!!!  Primitive # 196637 Not Implemented In This Version  !!!!!
    • This error means that a primitive method has been incorrectly defined and typically happens if code meant for a new release is used with an earlier version of batchvision. The primitive index value, if not in the range 1-600, can be obtained via   nnnn mod: 65536   .. in the example above, the primitive index is 29.