是否有经验的一些简单的规则时使用poll与epoll在低延迟环境？epoll如果只监控少量文件描述符,则应该有更高的开销.请提供一些见解,答案"自己检查"放在别处.
我想计算A(3, 20)应该2^23 - 3 = 8388605使用的Ackermann函数(见维基百科)的值Data.MemoCombinators.我的代码是:
{-# LANGUAGE BangPatterns #-}
import Data.MemoCombinators as Memo
ack = Memo.memo2 Memo.integral Memo.integral ack'
where
ack' 0 !n = n+1
ack' !m 0 = ack (m-1) 1
ack' !m !n = ack (m-1) $! (ack m (n-1))
main = print $ ack 3 20
但它最终会出现堆栈溢出错误;-)是否可以进行调整或计算链真的那么长,即使是memoization也无济于事？
如何在Linux环境CMakeLists.txt下写入有条件地链接到系统范围的librt库？
我已经成功编译了clang的当前3.3分支.但随后任何文件的C++编译都会因错误/错误而失败.可以修复吗？
In file included from /usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7/iostream:39:
In file included from /usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7/ostream:39:
In file included from /usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7/ios:40:
In file included from /usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7/bits/char_traits.h:40:
In file included from /usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7/bits/stl_algobase.h:65:
In file included from /usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7/bits/stl_pair.h:61:
In file included from /usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7/bits/move.h:57:
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7/type_traits:256:39: error: use of
undeclared identifier '__float128'
struct __is_floating_point_helper<__float128>
^
1 error generated.
当反病毒在称为"沙盒"的虚拟环境中运行某些应用程序时,从Windows内核的角度来看,这个沙箱是如何精确工作的？
写这样的沙箱难吗？
我看不到任何alloca.h等价物Visual C 2010.如何Visual C在Windows上执行堆栈分配？我想念这个功能alloca.
如何设置(以最优雅的方式)n最不重要的位uint32_t？那就是写一个函数void setbits(uint32_t *x, int n);.函数应该处理每一个n从0到32.
尤其n==32应该处理价值.
socket.io和node.js项目之间有什么区别(目的)？
在给定void *指针的情况下,如何判断在给定地址上分配的块的大小(先前使用malloc在Linux和Windows中分配)？我希望两个系统肯定会在某处存储这种信息.也就是说,malloc_sizeOSX/Darwin上存在替代方案.如果它有帮助,使用gcc/mingw.