I’ve tested OnLive just now. Overall, it is very impressive. The resolution is high, the picture is awesome. These guys put much effort to finally pull it off. However, the latency is a huge problem. I can fell it clearly in the GRID racing game. It is a typical case that one put money and effort to but the technology is not mature enough for their fate. Good luck to them.
In the period of 1990 to 2000, politicians around the world were all more concerned on the stabilization as a whole. The massive increase of international trading encapsulated the fascination that global trading now is way more powerful than actual war as a tool to achieve a specific politic goal. In the particular case of Iraq after the Persian Gulf War, the U.S. and the free world leaders failed to remove Saddam from his position with the hope of keeping the region’s stabilization in the Middle East. Instead of full military invasion, they used the full sanction tool and expected Saddam will eventually be removed from his position by angry people in Iraq. However, sanction failed to serve as a politic tool to topple Saddam’s regime.
The full sanction didn’t stopped Saddam’s regime from exporting oil to the global market. Wherever is a trading barrier, there is a black market. As a matter of fact, full sanction requires multi-nation cooperation. If one party plays dirty, it will destroy the merit of full sanction in seconds. In fact, behind the United Nations’ decision of full sanctions, there was disagreement among relevant countries. Oil-hungry countries such as China and South Korea publicly expressed the desire to lift the sanction and import oil from Iraq [1]. Even every nation agreed and honestly to do so, by only leaving minor military presence, U.S. / U.N. were unable to prevent Iraq’s oil trading in black market [3]. In Iraq’s reality, during the full sanction years, Saddam’s regime managed to consistently export large volume of oil to global market and made profit from it personally.
The full sanction is a two side blade. It not only worsened the Iraq economy, but also made it impossible for U.S. companies legally import oil from one major oil production country. Left Saddam ruling power survived, the U.S. has no way to protect its oil interests in Iraq. No U.S. companies could involve in the Iraq oil production or exportation because of the sanction policy. U.S. oil companies such as Total even lined up with foreign governments in seeking to enter Iraq oil production [1]. By implementing the full sanction honestly, the U.S., financially speaking, failed to meet the oil interests which drove us first into the war [4].
The full sanction worsened the human rights situation in Iraq, therefore it dramatically strengthened Saddam’s ruling power. Iraq, although has plenty of oil reservation, is a dessert country. Water, food and medical, essentially all the commodities for basic living in this country were depends on importing. The sanction made it is hard for international non-government organizations to provide any necessary aids to people in Iraq. The Saddam’s regime became the only dependable source of basic living for most Iraqis. The situation in Iraq also disappointed human right advocates around the world who were fighting hard against dictators in China, North Korea, and Cuba etc. It created a rather negative perception that in order to keep a stable world, the International community, namely the leaders of the free world were willing to let the human right situation in other countries become worse.
The full sanction measure as a specific political tools prevented the U.S. taking more aggressive yet fruitful actions. The global trading is, under the skin, just a business. It cannot and shouldn’t be used as a “continuation of politics by other means”. The naive belief that sanction can solve problem without casualty made U.S. lost its best chance to create a model democracy country in the Middle East with cheap price. Instead of full sanction, the U.S. had option to support the uprising of Shi’ya and Kurds within Iraq, and potentially, it could remove Saddam’s regime once for all. However, since Saddam and his followers found a consistent route to make profit and maintain his living standard, he could only put people against him in poverty. The tragedy actually causes later distrust between U.S. and the large part of Iraq population. It turns out that the psychological effect made people more tend to blame direct cause rather than indirect ones. Thus, rather than going through all the logical arguments and realizing Saddam’s invasion to Kuwait led the poverty in Iraq, people blame the sanctions implemented by the United States and the United Nations. It eliminated the U.S. option to ally people within Iraq in the future potential military operations.
The sanction in policy makers’ eye is an attractive resolution with minimal casualties comparing to other options such as military invasion. They were afraid that since major Iraqi Republican Guard were untouched in the Kuwait combat, the casualties for a full invasion to Iraq expected to be high. However, as [2] pointed out, sanction method if applied successfully should only be a short-term policy with other following resolutions. In Iraq situation, prolonged sanction served no good for overthrowing current regime. The following military resolution is almost inevitable. However, if the policy makers could leverage and put effort to support the Kurds and Shiya’s uprising within Iraq, the military cost should be only marginal comparing to what we get 12 years later. Besides, in the time when the terrorism was not a common scene in the Middle East, the U.S.’s intervene in Iraq may receive much more positive feedback.
The failure of full sanction which had worsened the situation in Iraq taught us an uneasy lesson. By all means, global trading is business; it cannot be manipulated as a certain extension to politics. The full sanction only worsen general population’s situation. It is an uneducated and rude policy which just like in middle Ages people punish servant for their master’s mistake. Therefore, the U.S. foreign policy should never use them. Instead, a wider and more generic support to people from other nations who fight against dictatorship should be an important aspect of U.S. foreign policy in the hope of creating a more open and dynamic world.
[1] Fareed Mohamedi, Roger Diwan, Political Economy: The Saudis, the French and the Embargo, Middle East Report, No. 193, The Iraq Sanctions Dilemma. (Mar. - Apr., 1995), pp. 24-25.
[2] Gary Clyde Hufbauer, Jeffrey J. Schott, Economic Sanctions and U. S. Foreign Policy, PS, Vol. 18, No. 4. (Autumn, 1985), pp. 727-735.
[3] Sarah Graham Brown, Chris Toensing, A Backgrounder on Inspections and Sanctions.
[4] Richard Haass, Orial History on the Gulf War, PBS Frontline: http://www.pbs.org/wgbh/pages/frontline/gulf/oral/haass/1.html.
finally see around 20% speed up over the 8-thread i7 860 CPU impl. The opencl version is really hard to get it right. Hoping a total 110% speed up by using both CPU and GPU.
it is still worth to read: http://www.vanadac.com/~dajhorn/novelties/ESR%20-%20Curse%20Of%20The%20Gifted.html
8 hours all night for 600 lines of high quality c code. When last time I do this, it is 1500 lines in two days …
It worth a separate post to explain why I argue that Google’s action by putting server in Hong Kong is still illegal in terms of Chinese domestic law.
Today’s news in China went further by claiming GoDaddy.com, the domain registration agency is violating Chinese domestic law: http://tech.163.com/10/0324/06/62H6QH81000915BF.html. In Google case, the ministry of industry and information in China claims “every company should comply the domestic law when doing business here.” So, the question is, which law or if there are any law provide legal justification to block Facebook, Twitter, Blogger, Youtube and partially block Wikipedia, Google etc.
It turns out that there really is a domestic law for doing that: the Internet Information Services Management Approach (http://www.cnnic.net.cn/html/Dir/2000/09/25/0652.htm). How the domestic law extends across border? Checkout the second line (automatic translated by Google Translate):
“Second: in the PRC engaged in Internet information service activities, must comply with these measures.
“The term Internet information services, refer to Internet users through the Internet to provide information services activities.”
Yes, I know the machine translation is absurd, but I don’t want to lose any precision by translating this myself. It provides a definition of the entities to which this law applies to. It is: anyone who provides information services through Internet to the Chinese user. Further more, it explained what is “Internet information services in PRC”: any activities that Internet users in China can engage in.
It is a confusing law because the definition is not complete by itself alone. It can be arbitrary services if the user in China can have access to. That essentially means, every website on the Internet should comply this domestic law.
Well, it is the classic Chinese approach: making everyone guilty, so that you can put anyone in jail as you wish.
发件人： chinese_s@google.com 发送时间： 2002年9月7日 2:33:18 收件人： Thanks for your note about problems accessing Google. We have been notified by several users that our site has been blocked in the People’s Republic of China. We’re working with Chinese authorities to resolve the issue. We appreciate your concern and your taking the time to write to us.
There have been recent reports that we provide dyanamic IP addresses to users who email us. This information is incorrect. We apologize for any inconvenience this false report may have caused you. We appreciate your interest in using Google and look forward to helping you with your search needs in the future.
Regards, The Google Team
看样子就快有dynamic IP addresses to users who email us了……
们总觉得这个世界没有真假对错，因此什么都无所谓了，看这里的这些评论：http://www.infzm.com/content/39771，这世界当然有正邪，真假，对错之分了！
Since I started the ccv project (http://github.com/liuliu/ccv) a few weeks ago, one motivation is to write a pure-c (C99 standard) library for computer vision. The trouble is, for a computer vision library, we deal with 4 types of matrix, unsigned char, integer, single precision, double precision. BLAS has separate functions to do calculation on the 4 types. But I found it is easier for user to just have one matrix structure with a flag to label types.
It is convenient unless you choose to play around with raw data (as the library writer did). And it did impose a problem to library writer, do I need to maintain 4 copies of code just with slight change of data type? That is one of the few times you miss the good part of C++, I mean, the template. However, with very abusive usage of macro, you can still get the candies off the shelf with the price of more compilation time.
The classic education of code optimization told everyone to put if branch outside of a deep for-loop, and everyone takes it as a common sense. However, behind the scene, compiler does a lot in such scenario and it does well. Let me show you an example (ccv.h file can be found here):
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#include "ccv.h"
void copy_data_to_float(ccv_dense_matrix_t* x, float* out)
{
float* out_ptr = out;
unsigned char* m_ptr = x->data.ptr;
int i, j;
for (i = 0; i < x->rows; i++)
{
for (j = 0; j < x->cols; j++)
out_ptr[j] = ccv_get_value(x->type, m_ptr, i);
out_ptr += x->cols;
m_ptr += x->step;
}
}
int main(int argc, char** argv)
{
ccv_dense_matrix_t* x = ccv_dense_matrix_new(100, 100, CCV_8U | CCV_C1, NULL, NULL);
float* out = (float*)malloc(sizeof(float) * 100 * 100);
copy_data_to_float(x, out);
free(out);
ccv_matrix_free(x);
ccv_gabarge_collect();
return 0;
}
When compile the code with gcc and -O3 flag, you can get some nice assembly that put the inner switch statement (hided by the ccv_get_value macro) outside the for loop. More officially, here we use the -funswitch-loop flag to optimize performance. It is a trick, but gives C some ability that template has (and cons: generating larger binary). In the end of the day, we do have a clearer C code with reasonable performance.
If the compiler is so clever every time, the world will be free of wars, hunger and disease. The problem is, you can never be certain that compiler will do the smart thing. For example, if in a case you have several switches, most of the time, compiler will fail to unswitch them. It is just too much mutations (even for no-nested switches, when you unswitch them, the mutations should be first switch cases * second switch cases * … * n-th switch cases, in other word, exponential). Even that is the case, we do want to unswitch them all (4 switches, and each switch has 4 cases will result 256 different for-loops, still manageable on modern computers). How to do that semi-automatically?
First thought is to define these for-loops as macro, and somehow expanded them. It should look like some kind of:
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#define get_value(x, i) (int*)(x)[i]
#define for_block \
for (i = 0; i < 100; i++) \
y[i] = get_value(x, i);
If only we can define different get_value for different x types, the for_block can be expanded. One way to do it is to use .def file. However, #include instruction cannot be implemented inside a macro, that means we cannot wrap our solution into one nice macro.
Another thought comes to mind is: instead of define a macro first, just pass the macro as parameter. The following code did this:
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#define for_block(for_get) \
for (i = 0; i < 100; i++) \
y[i] = for_get(x, i);
#define get_int_value(x, i) ((int*)(x))[i]
#define get_float_value(x, i) ((float*)(x))[i]
switch (type)
{
case INT:
for_block(get_int_value);
break;
case FLOAT:
for_block(get_float_value);
break;
}
It is very close to the final goal, I can even imagine a nice wrapper around the method:
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#define getter(type, block) switch (type) { \
case INT: \
block(get_int_value); \
break; \
case FLOAT: \
block(get_float_value); \
break; \
}
getter(type, for_block);
We can write out our getter, the setter for our matrix operation for loop immediately, hurrah. Except one thing, you cannot use them conjunctively. Then, what’s the point of having one switch out? I want do something like set(y, i, get(x, i)), and how?
A nice feature in C99 standard is the support of variadic macros. Variadic macro, just like the name suggests, can take variable length of arguments. It is a good start point to write our joinable getter and setter. The code is:
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#define getter(type, block, rest...) switch (type) { \
case INT: \
block(rest, get_int_value); \
break; \
case FLOAT: \
block(rest, get_float_value); \
break; \
}
getter(type, for_block);
The rest part makes all different, now you can do something like: setter(type_a, getter, type_b, for_block); and the for_block will take two arguments: (set, get) in the same order you call it. The thought process is left for readers, but there is one pitfall: for one getter case, the for_block will take the first argument as dummy (because of the rest argument inserted before the real get macro).
For multiple getter, it is trickier. Because all macros are not recursive, you have to define several getters that has the exact same code but different name in order to use multiple getter. And yes, like all the macros, it is hard to debug (in this case, worse, since one mistake can generate tens or hundreds compile-time errors).
Finally, I will show you some code in action (for pairwise addition of matrix a, b to c):
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#include "ccv.h"
unsigned char* a_ptr = a->data.ptr;
unsigned char* b_ptr = b->data.ptr;
unsigned char* c_ptr = c->data.ptr;
#define for_block(__for_get_a, __for_get_b, __for_set) \
for (i = 0; i < a->rows; i++) \
{ \
for (j = 0; j < a->cols; j++) \
{ \
__for_set(c_ptr, j, __for_get_a(a_ptr, j) + __for_get_b(b_ptr, j)); \
} \
a_ptr += a->step; \
b_ptr += b->step; \
c_ptr += c->step; \
}
ccv_matrix_getter_a(a->type, ccv_matrix_getter_b, b->type, ccv_matrix_setter, c->type, for_block);
#undef for_block
If you want to use plain old C way and unswitch for-loop, you have to write 64 for-loops to cover all the cases.