Re: Fw: Some questions on reentrancy, __DYNAMIC_REENT__ and _impure_ptr
Dave Nadler <[email protected]>
| Newsgroups | gmane.comp.lib.newlib |
|---|---|
| Message-ID | <[email protected]> |
Sorry if I was not clear: If you use one memory location for _impure_ptr, and you have two processors running two threads, this does not work. Instead an alternate mechanism (ie thread-local storage for this ptr) is needed, to support each concurrent thread with a separate reentrancy structure. Hope I was clear this time! Thanks, Best Regards, Dve On 4/2/2021 12:51 PM, C Howland via Newlib wrote: >> ------------------------------ >> *From:* Newlib <[email protected]> on behalf of Dave Nadler < >> [email protected]> >> *Sent:* Friday, April 2, 2021 7:34 AM >> *To:* Nick <[email protected]> >> *Cc:* [email protected] <[email protected]> >> *Subject:* Re: Some questions on reentrancy, __DYNAMIC_REENT__ and >> _impure_ptr >> >> >> Thanks Jeff also for answering the mutex question I missed. >> One other issue I should have mentioned that becomes more important daily: >> If there are multiple processors the simple _impure_ptr mechanism won't >> work... >> > Well, if you ignore the fact you have multiple processors and do nothing > about it, then, sure, you'll have problems. But if you manage it (e.g. > treating each processor as its own thread, or as independent of each other, > etc.), then multiple processors can work fine. (I have such systems > working.) > Craig -- Dave Nadler, USA East Coast voice (978) 263-0097, [email protected], Skype Dave.Nadler1