i would to clear a little!<br><br>the expressions are independant from each thread, <br><br>exp1 = x*y+....<br><br>exp2 = x+x+x+x...<br><br>exp3 = y+y*y+3...<br>..<br>..<br>expn = just_symbols..<br><br>no subexpressions never.<br>
<br>when i wrote point 4), i meant that the matrix is where these expressions go, each thread puts its expression in a unique cell.<br><br>its just as you first though Jens,<br><br><br><span style="color: black;"><div dir="ltr">
<div><a href="http://www.youtube.com/neoideo">Cristobal</a></div></div></span><br><br><div class="gmail_quote">On Sun, Jun 13, 2010 at 2:37 PM, Jens Vollinga <span dir="ltr"><<a href="mailto:jensv@nikhef.nl">jensv@nikhef.nl</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">Hi!<br>
<br>
Am 13.06.2010 20:05, schrieb Alexei Sheplyakov:<div class="im"><br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
4) threads access the same common matrix of expressions, but two threads<br>
will never access the same cell.<br>
</blockquote>
<br>
This does NOT guarantee that you (or GiNaC on your behalf) won't operate<br>
on a same (sub)expression from different threads. You *really* need a thread<br>
safe (or atomic) reference counting to solve this problem.<br>
</blockquote>
<br></div>
ah, now I see why we keep arguing: I misread point 4 completely!!! I thought he meant to have a clear the separation of expressions between threads (matrix and cell as tech-speak synonyms for groups of expressions, but NO, he meant really matrices and cells ..., stupid me!).<div class="im">
<br>
<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
As far as I understand GCD code is not any worse in this regard (that said,<br>
it's not any better either). I might be wrong (I'm just a human being), so<br>
I'd be grateful if someone could point out any non-reentrant code in GCD<br>
routines.<br>
</blockquote>
<br></div>
Well, someone says: you have static variables inside functions there. A thread-switch might occur during the construction, I guess.<br>
<br>
Regards,<br><font color="#888888">
Jens</font><div><div></div><div class="h5"><br>
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