In most problem analyses the question of memory ownership or use will arise. For example:
To which module does this instruction belong?
Which process executed this module?
Who allocated this storage?
Who passed these parameters?
What control block does this address point to?
In fact the frequency with which this question is asked makes it a fundamental aspect of analytical technique.
For hang analysis this is no less true:
In the case of loops, analysis proceeds in a similar manner to that of traps.
In the case of waits, a key piece of information is the BlockId. In many cases this is an address of a system control block that relates closely to the reason for waiting. Discovery of the owner of storage pointed to by a BlockId is therefore of prime interest.
We start by reviewing memory management in OS/2 and in particular memory ownership.