测量和限制在算术子求解器中花费的时间 [英] Measure and bound time spent in arithmetic sub-solvers

问题描述

Q1:是否可以查询Z3在不同子求解器中花费的时间?

Q1: Is it possible to query the times Z3 spent in different sub-solvers?

调用 (get-info :all-statistics) 给出了 Z3 的整体运行时间，但我想将其分解为单独的子求解器.

Calling (get-info :all-statistics) gives the overall run time of Z3, but I would like to break it down into individual sub-solvers.

我对花在算术相关的子求解器上的时间特别感兴趣，更准确地说，是那些产生统计 grobner 和 nonlinear-horner 的时间.

I am particularly interested in the time spent in arithmetic-related sub-solver, more precisely, in those that give rise to the statistics grobner and nonlinear-horner.

Q2:此外，是否可以在 sub-solver 上设置超时?

Q2: Furthermore, is it possible to put a timeout on sub-solver?

我可以想象一些事情，比如为每个 check-sat 和 sub-solver 定义一个超时，它限制了 Z3 可以在该 sub-solver 中花费的时间.Z3会反复调用n个不同的子求解器，如果达到其中一个的时间限制，它会继续，但只使用剩余的n-1个子求解器.

I could imagine something like defining a timeout per check-sat and sub-solver that bounds the time Z3 can spent in that sub-solver. Z3 would repeatedly call n different sub-solvers, and if the time bound of one of them is reached it continues, but only uses the remaining n-1 sub-solvers.

我阅读了战术教程，并得到了这样的印象:这实际上可能是通过类似的方式实现的

I read the tactics tutorial and got the impression that this might actually be possible by something along the lines of

(repeat
  (par-or
    (try-for <arithmetic-solvers> 500)
    <all-other-solvers>))

但我不知道要使用哪些求解器.

but I couldn't figure out which solvers to use.

推荐答案

对于 Q1:不，您必须在其上添加自己的计时器，我希望这不是微不足道的，因为不清楚究竟应该和应该做什么不算.

For Q1: No, you'd have to add your own timers on that and I would expect this to be nontrivial as it's not clear what exactly should and shouldn't be counted.

Q2:是的，您可以构建自己的自定义策略/战术.请注意， par-or 意味着 parallel 或者，即，它将尝试并行运行提供的策略.并非我们称为求解器"的所有东西都有自己的策略，因此这可能需要一些摆弄.请注意，此上下文中的求解器"不一定与称为求解器"的 Z3 C++ 对象相同.一些求解器"也是 SMT 内核的组成部分.

Q2: Yes, you can build your own custom strategies/tactics. Note that par-or means parallel or, i.e., it will try to run the provided tactics in parallel. Not everything we call a "solver" has it's own tactic, so this might require some fiddling. Note that "solver" in this context is not necessarily the same as the Z3 C++ object called "solver". Some "solvers" are also integral parts of the SMT kernel.

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