Guardian Procedure Calls Reference Manual

descriptors
input
INT .EXT:ref:*
is an array that describes the items (data blocks or file synchronization blocks) to be
checkpointed. The first word of the array, descriptors[0], contains the number of items to
be checkpointed. The rest of the array consists of sets of words, with each set containing five
words and describing one item.
The array has this form:
Contains the number of items to be checkpointed. Each item consists of a set of five words.[0]
If the item is a file:
Equals -1D.[0:1]
Is the file number.[2]
(Is reserved.)[3]
(Is reserved.)[4]
If the item is a data area:
Is the length in bytes.[0:1]
Is the segment ID. (If it is -1, the address is in the stack or current segment.)[2]
Is the extended address.[3:4]
See Considerations (page 151) for more information about checkpointing data areas.
Returned Value
INT
A status word of this form:
No error.<0:7> = 0
No backup process or unable to communicate with backup process; then <8:15> = file-system error
number.
<0:7> = 1
Takeover from primary process; then <8:15> =<0:7> = 2
Primary process stopped.0
Primary process abnormally ended.1
Primarys process processor failed.2
Primary process called CHECKSWITCH.3
Invalid parameter; then <8:15> =<0:7> = 3
Error in stack-origin parameter.1
Bounds error on descriptors.2
Error in specified descriptor. If bits <8:15> = 3 then the first descriptor is in error. If <8:15>
= 4 then the second descriptor is in error, and so on.
>2
150 Guardian Procedure Calls (C)