On Tuesday, 22 January 2013 at 10:27:58 UTC, bearophile wrote:
I have modified a little the code on RosettaCode (no changes in
the logic).
monarch_dodra:
Avoids deadlock.
imagine 2 threads:
a: from 2 to 5.
b: from 5 to 2.
If both threads acquire their first lock, then you have a dead
lock, and your program is basically dead.
By always locking low first, you avoid the deadlock in a
rather simple but elegant way.
The Go language has four different solutions, one of them is:
http://rosettacode.org/wiki/Atomic_updates#Lock-free
[SNIP]
Bye,
bearophile
That's a good point, and I'm sure we could also have a version of
D that could also do it that way. D has attomic swap operations
too, AFAIK.
But I was really just answering the original question of "if you
need 2 locks, why do it that way?".
