Re: snapshot 20050114 race (on list)

[Christopher Faylor <me at cgf dot cx>]

On Mon, Jan 17, 2005 at 11:31:01AM -0500, Pierre A. Humblet wrote:
>Christopher Faylor wrote:
>>Thanks.  That script unearthed at least two races in the proc_waiter
>>code.  One was a "how in the world could it ever work" type.  I was
>>inadvertently relying on the fact that the last process created would
>>be the first process to exit.  It's amazing that this passed the test
>>suite.  I guess I need to beef up that aspect of it.
>
>I had never noticed that procs was an array of pinfo's, and not an
>array of pointers to pinfos, and that pinfo's were being copied when
>processes terminate and in proc_waiter.
>
>But pinfo's contain a CRITICAL_SECTION and according to
><http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/base/initializecriticalsection.asp>:
>A critical section object cannot be moved or copied.  The process must
>also not modify the object, but must treat it as logically opaque.  Use
>only the critical section functions to manage critical section objects.
>When you have finished using the critical section, call the
>DeleteCriticalSection function.

The CRITICAL_SECTION is only used for "myself" currently.  I added it to
pinfo a while ago because I thought I could use it for other stuff but I
never did.  The only way I could see this being a problem is if the
process had execed and then tried to use the lock in another thread,
which is extremely unlikely to occur.

However, I probably should pull it out of pinfo because there's no
reason for it to be there, taking up space in every pinfo, just for the
case of locking myself.

cgf