Question about process enumeration and _pinfo structure

Chris January chris@atomice.net
Tue May 28 14:21:00 GMT 2002


I want to add a member to the _pinfo structure which contains the command
line originally passed to the process. At the moment, when the Cygwin DLL
needs a list of the current Cygwin processes it uses winpids to enumerate
the processes and the _pinfo structures for each Cygwin process are copied
from a named file mapping. So to store the command line I either need to:
i) make the command line an in-line array, e.g. char cmdline[1024];
or
ii) make the member a pointer to a string allocated on the cygwin heap.
The first would work, but would set a limit on the size of command line. (I
believe there are several other, conflicting, limits elsewhere so this
shouldn't be a problem).
The second would also work, but would tie the _pinfo structure to a specific
instance of the Cygwin DLL.
Now I know there's supposed to be only one instance of the DLL running on
the system anyway, which leads me to the following question:
Why are the processes enumerated in this fashion rather than an array or
linked list of _pinfo's stored in the shared_info structure? Is this just
historical (i.e. noone got round to changing it) or is there some reasoning
behind it?

Chris




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