请问一个关于 cost of pointer的问题 - 未名空间MITBBS历史存档

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请问一个关于 cost of pointer的问题

请问一个关于 cost of pointer的问题# Programming - 葵花宝典

S*n2008-06-13 07:06

1 楼

And today we got:
*CISCO: NEW ROUTER FEATURES 12X SPEED CNBC SAYS
*CISCO: AT&T ALREADY IN TRIAL WITH NEW CRS-3 ROUTER: CNBC SAYS
*CISCO UNVEILS NEW ROUTER, CNBC REPORTS
What the FUCK? Just a new router to change the Internet forever??

h*o2008-06-13 07:06

2 楼

想自已写一个 matrix class并用 valarray作成员变量存储数据
现在的问题是用指向valarray的指针好还是valarray直接作变量好
ＣＳ的同学给我建议说如果要频繁寻址，用指针的话开销会比较大
请问是这样吗？
我的另一个concern是直接作变量，放在stack 上面，是不是有大小上的限制？
那在设计 member variable的时候用指针又有什么好处？
新手问题啊，多谢指教

j*a2008-06-13 07:06

3 楼

take it easy...

【在 S******n 的大作中提到】

: And today we got:
: *CISCO: NEW ROUTER FEATURES 12X SPEED CNBC SAYS
: *CISCO: AT&T ALREADY IN TRIAL WITH NEW CRS-3 ROUTER: CNBC SAYS
: *CISCO UNVEILS NEW ROUTER, CNBC REPORTS
: What the FUCK? Just a new router to change the Internet forever??

k*f2008-06-13 07:06

4 楼

Although it is an implementation detail, the fact that size of a valarray
can be determined at runtime indicates that the underlying memory of
valarray is very likely to be allocated on heap, not on stack. So the size
of a valarry variable may not be directly related to the size of the data
inside it. So I'd say use the valarry directly. You may try to initiate a
very big valarry to see if there's any stack overflow issue. At least some
compiler will complain when it happens.
Good luck.

s*g2008-06-13 07:06

5 楼

Exactly, besides, did not Alcatel-Lucent and Juniper have 100G router
already? I was expecting Cisco would come out with something that replaces current TCP/IP.
Every time they come out with a new product, they would claim Internet will be changed forever, what the FUCK?!

【在 S******n 的大作中提到】

S*n2008-06-13 07:06

6 楼

按说思科不至于扯这种蛋来吸引眼球吧。
而且思科刚刚推出的,vendor finance,恐怕是一大败笔。当初朗讯玩这个玩得很大，给
买家低息贷款，哗啦啦出货，然后稻特康崩盘，成千上百的公司倒闭，付不起钱了，这
些用过的旧设备回到朗讯手里，卖也不值钱(电子产品通病)，那边还欠着银行的巨额贷
款，两下挤兑，挂了。
如果钱伯斯觉得经济危机已经过去，这么干提升短期业绩，的确见效快。只不过经济危
机真的过去了?

current TCP/IP.
will be changed forever, what the FUCK?!

【在 s*****g 的大作中提到】

: Exactly, besides, did not Alcatel-Lucent and Juniper have 100G router
: already? I was expecting Cisco would come out with something that replaces current TCP/IP.
: Every time they come out with a new product, they would claim Internet will be changed forever, what the FUCK?!

c*i2008-06-13 07:06

7 楼

另外juniper和verizon刚刚做了100G的field trial
http://www.lightwaveonline.com/networking/news/Verizon-Juniper-NEC-Finisar-conduct-100G-field-trial-86874052.html?cmpid=EnlDirectMarch82010

c*i2008-06-13 07:06

8 楼

另外华为的multi chassis也在field trial了.

【在 c*****i 的大作中提到】

: 另外juniper和verizon刚刚做了100G的field trial
: http://www.lightwaveonline.com/networking/news/Verizon-Juniper-NEC-Finisar-conduct-100G-field-trial-86874052.html?cmpid=EnlDirectMarch82010

Z*e2008-06-13 07:06

9 楼

it's all marketing, hehe

【在 S******n 的大作中提到】

z*r2008-06-13 07:06

10 楼

当初CRS-1出来的时候也这么说过

【在 S******n 的大作中提到】

z*r2008-06-13 07:06

11 楼

replace current tcp/ip? then it will have to be IPv6

current TCP/IP.
will be changed forever, what the FUCK?!

【在 s*****g 的大作中提到】

z*r2008-06-13 07:06

12 楼

vendor finance是比较危险，不过csco现在cash有40多个B，这么干可能是一个不错的
选择，以前lucent, nortel等都搞过这个，但是他们从来就没有过这么多cash，所以那
种情况下就可能是个双刃剑了

【在 S******n 的大作中提到】

: 按说思科不至于扯这种蛋来吸引眼球吧。
: 而且思科刚刚推出的,vendor finance,恐怕是一大败笔。当初朗讯玩这个玩得很大，给
: 买家低息贷款，哗啦啦出货，然后稻特康崩盘，成千上百的公司倒闭，付不起钱了，这
: 些用过的旧设备回到朗讯手里，卖也不值钱(电子产品通病)，那边还欠着银行的巨额贷
: 款，两下挤兑，挂了。
: 如果钱伯斯觉得经济危机已经过去，这么干提升短期业绩，的确见效快。只不过经济危
: 机真的过去了?
:
: current TCP/IP.
: will be changed forever, what the FUCK?!

z*r2008-06-13 07:06

13 楼

在哪里？国内还是欧洲？

【在 c*****i 的大作中提到】

: 另外华为的multi chassis也在field trial了.

t*r2008-06-13 07:06

14 楼

回楼上, 陕西电信

w*s2008-06-13 07:06

15 楼

还有个DCSS, 貌似内容路由和智能VPN，细节还不清楚

【在 S******n 的大作中提到】

w*s2008-06-13 07:06

16 楼

是背对背还是N+M?

【在 t*******r 的大作中提到】

: 回楼上, 陕西电信

t*r2008-06-13 07:06

17 楼

回楼上, 一拖四.

e*w2008-06-13 07:06

18 楼

I think what he means is something revolutionarily changing the networking
industry, like the L2/L3 protocol changes. After all, faster router with new
ASIC rolled out every 4 years is not something that can be exaggerated to
change
the world.
But, people, don't take marketing propaganda too seriously. No need to get
too excited or feeling fooled.

【在 z**r 的大作中提到】

: replace current tcp/ip? then it will have to be IPv6
:
: current TCP/IP.
: will be changed forever, what the FUCK?!

w*s2008-06-13 07:06

19 楼

那是仿T-Matrix阿。

【在 t*******r 的大作中提到】

: 回楼上, 一拖四.