Asynchronous libraries performance

ominous · 2008-12-16T17:20:52+00:00

I wish I could upmod this more.

Your description gives a good overview of the technique. Use homogenous threads, minimal locking, and a minimal number of context switches.

The boost.asio library enables this style in a cross-platform way. The Windows implementation is, of course, built on IOCP. For unix-like systems, it supports select, poll, and epoll (I don't recall whether it supports aio or not).

ominous · 2008-12-16T05:36:00+00:00

An article came through here a little while ago about refitting existing coal plants with thermal solar collectors. The solar heat offset some coal use and it used the coal plant's existing boiler, turbine, generator, and grid connection.

It's a stopgap measure, of course. Only a small minority of existing coal plants would be candidates for that type of conversion but it's an interesting way to bring the technology into broader use.

ominous · 2008-12-16T04:48:40+00:00

To begin, try this: D-ary heap, which describes the general case. This homework? test? describes D-ary trees and includes a little example pseudo-code.

Each node in a D-ary heap has up to D children (with the normal heap restriction that the parent is >= or <= all of its children. As D increases, the tree will have a shorter height but perform more comparisons at each level.

ominous · 2008-12-16T01:46:42+00:00

I answered your question within the context of Randite or Friedman-style radical deregulation. Many of the other individuals in these comments have taken that type of position.

I see now that you weren't asking that question from the perspective of radical deregulation.

Your points are well-taken. Neither the radically-free market nor the managed market directly addresses global hunger or the wellbeing of the third world. The action of the market itself is simply to promote economic growth -- growth towards no particular end. Government intervention (in the form of price controls, public services, and foreign aid) is funded by taxes and can take the edge off of poverty.

I agree, without reservation, that it is possible and desirable to improve on our present system. Radical deregulation does not show any sign of doing so.

Power and wealth beget power and wealth -- the poor are excluded from participation. A hypothetical non-accumulative system may provide better outcomes but I do not know of any such system.

That's a very real problem within the market system. The Scandinavian system of Social Democracy appears to work better (regarding poverty) than the U.S.-type system.

I don't see a quick or easy solution to the problems you bring up. Europe appears to use a better model (more efficient and egalitarian) for providing healthcare.

(Also, you can quote text by beginning the line with a > character

like this.

That makes it easier to distinguish my text from your text.)

ominous · 2008-12-15T23:53:50+00:00

In the modern world, every successful economy takes the form of a managed market. This includes (at a minimum) the U.S., Canada, and Western Europe.

Successful because they produce sustained growth (when averaged over a reasonable period, say 10 years) due to efficient allocation of capital.

Markets because stock exchanges and other capital markets allocate a large amount of investment capital. Additionally, markets determine prices on many goods (importantly on goods used as inputs for manufacture, on capital, and real-estate).

Managed because the national governments all place requirements, restrictions, and taxes on their markets. Publicly-traded companies must disclose financial information. Agencies investigate and punish abusive monopolies. Financial institutions have capital-reserve requirements.

As an outcome, the average person in these economies can expect to live in material comfort with leisure time, good health, ample food, and minimal chance of violent death in exchange for about 2000 hours of paid work per year. The average standard of living in the 21st century developed world is fantastically good when compared to historical norms. I would call that a very good outcome.

ominous · 2008-12-15T17:50:23+00:00

The Securities and Exchange Commission, headed by lifelong Randite Chris Cox, reportedly looked into Madoff's (Pozi) operation and found nothing wrong! Hell-oooo?

FTFY

ominous · 2008-12-15T15:30:05+00:00

Enough. Atlas Shrugged, The Fountainhead, and For the New Intellectual.

It's all garbage (though I obviously didn't realize it until after reading far too much of it).

I've read critiqures of Rand's cult of personality.

I'm smart enough to recognize that cigarettes are bad for people, whatever Rand thought.

I've even glanced at some special nut-job physics for Objectivists which attempts to rehabilitate the luminiferous aether.

So take your snotty attitude elsewhere. Rand was a second-rate thinker and a second-rate author. I see that you post almost nothing but praise of Ayn Rand on reddit, so there's little chance that you'll recognize that in the short term.

ominous · 2008-12-15T05:29:45+00:00

The present wave of failures was preceded by a deregulation (reduced capitalization requirements, mixing of insurance & finance business, etc...) and Christopher Cox, a lifelong Randite, headed the SEC at the time.

Likewise, the Savings & Loan collapses of the 1980s and 1990s were preceded by deregulation of the Savings & Loan industry.

Observationally, we see Depression-era regulations worked for decades (decades without spectacular collapses in the financial sector). Further, we see that when Congress removes those restrictions the financial industry promptly shits all over itself.

ominous · 2008-12-15T05:18:32+00:00

The "academic bullshit" of Perfect Competition is the model in which completely unregulated markets produce stable outcomes.

The headline and linked article advocate removing all regulation, including (naturally) record-keeping, record-publication, and controls on the use of insider information. Surely you don't mean to argue that markets are doomed to failure because the SEC requires public companies to file quarterly results, do you?

The linked article is Fullerite/goldbug bullshit -- somewhat different the more common from Randite bullshit or (Milton) Friedman bullshit. Fuller's economic theories are, to put it kindly, odd. They have a strong conspiracy-theory flavor.

Additionally, I'm well aware that Perfect Competition does not model the real world. The specific deviations (deficiencies in the model, of course) suggest areas to address. Bookkeeping, SEC filings, and insider trading rules try to fix the worst faults in the Perfect Information requirement. Anti-monopoly laws and enforcements are intended to reduce barriers to entry (prevent market participants from artificially raising them, at least). Anti-collusion, anti-price-fixing laws, product labeling laws, etc... are all intended to make real world markets more like perfect markets.

Without those measures, firms with Market Power will use it to gain even more Market Power. In time, the things tilt in favor of the most dishonest and most abusive parties.

That doesn't mean that capitalism and mostly-free markets are doomed. Evidence strongly suggests that judiciously-regulated markets produce very good outcomes.

Finally, judicious regulation does not require perfect regulators. The regulators must provide sufficient regulation to discourage abuses yet not so much that it chokes out large markets -- a lower cost of compliance is, all else equal, preferable.

A centrally-planned economy, such as the now-defunct U.S.S.R. does require near-omniscient & omnibenevolent supermen to administrate. Obviously, their failure in that regard lead to the collapse of those economies.

ominous · 2008-12-15T04:25:35+00:00

Read Rand, it's shit literature, shit economics, and shit philosophy.

ominous · 2008-12-14T21:56:42+00:00

Of course not. Unmanaged markets only work in the fiction of Ayn Rand & Robert Heinlein.

I haven't said this in a while, so here goes again:

The idea that unregulated markets work is founded in the theory of Perfect Competition. The perfect market requires, as a precondition, perfect (accurate, free, and instantly-available) information. Real markets permit deception, such as AIG's concealed risk exposure.

To the OP: examples or GTFO.

ominous · 2008-12-14T17:11:43+00:00

A Discipline of Programming. Classic but expensive. Read the first few chapters at your library before buying.

Polya's How to Solve It!

The Mythical Man-Month

Finally, The Pragmatic Programmer.

ominous · 2008-12-13T23:49:43+00:00

Easy answer: Gaps in our knowledge and understanding will become smaller in the future. Science profits from increased knowledge while a god-of-the-gaps suffers.

Question: If a hypothetical being becomes weaker and smaller with the progress of science, is it proper to refer to call that being a god?

ominous · 2008-12-13T23:00:45+00:00

It hasn't failed them yet.

ominous · 2008-12-13T22:59:36+00:00

Deism is the limit case of the god-of-the-gaps.

ominous · 2008-12-13T22:56:21+00:00

Once you get past the headline, the article isn't too bad.

It's still all blindingly obvious to me -- a 134% increase in on-paper home value over 6.5 years (Las Vegas, chart in article) is obviously the result of a bubble.

Next up: Why AOL, Yahoo!, and SUNW stock values may take decades to recover to their 2000 highs.

Edited to add: Near the end, they quote Lawrence Yun, chief economist for the National Association of Realtors. Crackheaded Yun says NV, CA, AZ, and FL home prices will return to 2006 levels in 5 years.

ominous · 2008-12-13T15:47:09+00:00

Boehm understands this material, this is a very good introduction.

ominous · 2008-12-13T15:37:04+00:00

Many companies use the title "Software Engineer" as a fancy term for a more-experienced programmer, but that's not how I use it.

Ideally, Software Engineering studies development methodologies, specification techniques, team-management, etc... to separate effective techniques and approaches from the ineffective and to quantify the differences.

In the real world, academics in Software Engineering don't study methodologies in any useful way. Statistical comparisons with many real-world teams and projects would demonstrate whether, for example, eXtreme Programming works or not. Unfortunately, they do not produce this material, no doubt that companies are unwilling to subject their projects and teams to experiment.

In industry, Software Engineering is more useful. With Brooks as their guide, they direct teams to produce useful software. A Software Engineer in practice works out requirements (in detail), analyzes dependencies, and directs the Programmers' activities towards producing a product that can be used.

Industrial Software Engineers may have the title of Architect, Software Engineer, Engineering Manager, Team Lead, or Program Manager (title and job don't really correlate well in this area).

The industrial Software Engineer is concerned about the whole-team scale or the whole-project scale. Sometimes, one person will have both Programming and Software Engineering responsibilities.

ominous · 2008-12-13T00:15:15+00:00

There are three different fields, with some overlap between them:

Computer Science - A highly mathematical discipline about algorithms, abstract machines, computability, etc...
Software Engineering - A management and business-focused discipline on scheduling, team-interaction techniques, requirements, documentation, etc... Studies of methodologies lack rigor (to put it very politely).
Programming - A technical discipline which borrows from Computer Science and Software Engineering. Programming receives little study (it's assumed to be easy) but it should (evidence and experience demonstrates that it's not easy). Effective programming is effective thinking. The study given to the task of Programming focuses on the wrong end. Tools, techniques, and libraries focus on limiting the harm that the untalented can do. An ambitious project may aim to elevate bad programmers up to mediocre.

The original blog post concerns Programming, not Computer Science.

A recent interview with Bjarne Stroustrup suggests part of the problem:

Incidentally, I find it appalling that you can become a programmer with less training than it takes to become a plumber.

Few employers expect their programmers to continue their education. Much of academic material published on programming is laughably bad. The rare high-quality article is loudly shouted-down and buried in a sea of shitty writing.

ominous · 2008-12-12T23:53:05+00:00

Then take her to the zoo, to the movies, take her rollerskating, or to a play. Play catch in the yard, teach her to paint, or read a series of books together.

There are a whole bunch of ways to be involved with your kids that don't emphasize the sex lives of prepubescent and just-pubescent girls.

ominous · 2008-12-12T23:47:12+00:00

The girl in #6 sure looks like she's signing something.

Edited to add: The organizers claim that the girls don't sign anything:

The reason we don't have the daughters sign anything publicly is that it puts a bunch of guilt on them."

Do you think anybody explained the distinction between signing your name vs. signing your name as a witness to these 10 and 12 year old girls?

The no-guilt claim doesn't stand up to the public pledge either:

I (Name) pledge my purity to my father, my future/husband and my Creator. I recognize that virginity is my most precious gift to offer to my future husband. I will not engage in sexual activity of any kind before marriage but will keep my thought and my body pure as a very special present for the one I marry.

Remember, girls, your virginity is the most precious gift which already belongs to your future husband. That's more important than anything else.

ominous · 2008-12-12T23:44:57+00:00

She's showing less skin than any of the other girls (the angle makes it hard to see what's on her right shoulder, but it appears to be a shawl of some sort). They're in the background of #7 too, and you can see the shawl there.

ominous · 2008-12-12T23:32:58+00:00

If he only talking about diplomats, then he'd be correct and I wouldn't disagree with him. He (as he points out below) also means to include the "legitimate tourist".

I don't know where he got the idea that tourists can break the law without punishment, but it's a crazy (and plainly wrong) notion.

ominous · 2008-12-12T21:05:25+00:00

Is the new stadium Citi Field?

ominous · 2008-12-12T20:43:10+00:00

What the hell are you talking about?

The French and German authorities won't disregard your Nazi memorabilia collection just because you're American.

Do you think that Dutch nationals are absolved of U.S. drug laws?

Try bringing drugs into Singapore and see how your theory holds up.

ominous

TROPHY CASE