Am Monday 18 January 2010 16:18:22 schrieb Peter Petrov:
Greetings Frank, boosters,
Currently using a signal with a boost::signals2:dummy_mutex works well only in single-threaded programs. I'm wondering if it can be made a little more useful.
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Because using a real mutex will significantly degrade both performance and concurrency, I'm wondering if this assertion is really necessary. In this case it should be safe to continue even if the uniqueness is violated, because the connection list is never modified. And I think my use case is quite common :)
not a direct answer to your question, but if signals2 is posing performance problems to you, you might want to check out my alternate signal/slot implementation: http://www.chaoticmind.net/~hcb/projects/libtscb/ It provides the same interface as "signals2", but... - it is always thread-safe (no dummy-mutex mode because there is simply no need to ever do that) - it is three(!) times as fast as thread-unsafe "signals" - it is five(!) times as fast as "signals2" with a real mutex It makes extensive use of atomic operations to achieve that -- for your use-case, it adds an overhead of exactly one pair of atomic inc/dec operations for every notification through the signal over an "open-coded" linked list of boost::function objects. Additionally, it can support a "wait-free" mode where you can activate the signal from an interrupt or similar context (e.g. unix signal handler). Regards, Helge