Guardian Procedure Calls Reference Manual

The array has this form:
+----------------------------------------+
descriptors[0] | number of items to be checkpointed |
|----------------------------------------|
[n] |----------------------------------------|
|-------- descriptors pairs -------------|
[n+1] |----------------------------------------|
. .
. .
If the first word of the pair contains -1, the pair describes a file synchronization block item for
the file whose file number is in the second word of the pair.
|----------------------------------------|
descriptors[n] | -1=file sync block item for file |
|----------------------------------------|
[n+1] | file's filenum |
|----------------------------------------|
. .
. .
Otherwise, the pair of words describes a data block to be checkpointed: the first word contains
the word address of the data block, and the second word contains the length, in words, of the
data block:
|----------------------------------------|
descriptors[n] | word address of the data block |
|----------------------------------------|
[n+1] | length in words of the data block |
|----------------------------------------|
. .
. .
The size, in words, of the descriptors array must be at least
1 + 2 * descriptors[0]
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; 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
Error in word [n-2] (see Considerations).n > 1
146 Guardian Procedure Calls (C)