class ProcessInfoIterator

Collects details from all threads of all attached processes. The exact

details that are yielded from the iterator are controlled via

ThreadDetailsInterest passed to |GetProcessInfo|. The iterator will yield an

empty vector after all attached process' threads have been iterated. It is

an error if there are no processes supplied to this iterator, which could be

from too restrictive of a filter passed to |GetProcessInfo| or DebugAgent is

not attached to anything.

This iteration is inherently racy, there is no way for DebugAgent to prevent

other system entities from causing a process or thread to disappear while we

are traversing them, so it's possible for this iterator to return errors

when those threads or processes have been destroyed. These are not fatal

errors, but can happen multiple times in one iteration.

For example, take this process structure, and assume DebugAgent is attached

to everything:

pr: "process-1" 1234

t: "pr1234-t1" 1

t: "pr1234-t2" 2

pr: "process-2" 2345

t: "pr2345-t1" 3

If "process-1" is killed after "pr1234-t1" is yielded, but before

"pr1234-t2" is yielded, a THREAD_GONE error will be returned on the next

|GetNext| call. Calling |GetNext| again will yield "pr2345-t1".