How iOS and Android manage multitasking and memory use

Recently, I read two posts, which were written two years apart but both thoroughly explained some fascinating concepts.

One is written by Fraser Speirs on how iOS manages multitasking, aimed at busting the myth of multitasking bar. The other is written by Remias Mate on how Android manages background processes, aimed at explaining how his app works. Although they had different purposes, they each gave a very detailed, easy-to-understand explanation on how each OS handles multitasking and memory usage.

In general, if you are an Android fan, next time you can laugh at your iOS counterpart on how iOS doesn't do "real" multitasking, and how you can determine which apps to run. If you are an iOS fan, you can surely enjoy your care-free style and let your Android friends know how you trust Steve Jobs (RIP) & Co, and not to mention all the battery life you are getting from that small battery of yours.

Root Verizon Galaxy Nexus using Mac

Got me a Galaxy Nexus (FINALLY!!) the day it comes out (Dec 15th). Naturally the first thing I do is to unlock the bootloader, since all Nexus devices have similar unlocking procedure. Now I want root to use Titanium Backup to transfer all my apps without using data, although I grandfatered in my unlimited data, and where I live just got 4G coverage.

With a little look around, unsurprisingly my idols, Koush and Pete Alfonso are ahead of the curve and gave out instructions and nicely packaged files to use.

I figure I can go into more details so a wider audience can root their phone and enjoy the fight against evil :)

I also only have a Mac, so that's the instruction I am going to give. My Mac is 10.5 (Leopard), so I am expecting you to have a better one :)

A little concept and step summary (optional)

1. Unlock bootloader
A bootloader is a piece of software that loads other essential software for a phone to successfully start up. It loads all kinds of firmwares, recovery, and of course the OS (Android). A locked bootloader only loads things with a verified "signature", i.e. preinstalled ones made by Google/Samsung/Verizon. We need to unlock it to boot whatever we want, such as things below.

2. Flash a custom recovery
With a unlocked bootloader, we can now flash/install a custom recovery software, such as SPRecovery and Clockwork. Recovery enables you to install software directly on your phone without loading the OS. These software can include, but not limited to, super user application (give you root privilege on your OS), and custom ROMs/Android builds. With this custom recovery, we can start install whatever we want, more to follow.

3. Install super user or custom ROM
Now we can install everything, so if you want to use stock ROM but elevate your privilege to root, install super user application. If you want to use a custom ROM (with different themes and features etc), you just need to install that ROM, but make sure it gives you root privileges, although I can hardly imagine anybody made a non-root custom ROM.

Now the how (all commends are in bold):

1. Unlock bootloader (WARNING: this will wipe all your settings and data, so back up)

• Download Android SDK from here (this provides utility tools to unlock your bootloader)
• Unzip the SDK to a desired location. For the purpose of an easy instruction, name the unzipped folder "android-sdk" and put it in your home directory (i.e. /User/YOUR_USER_NAME/)
• Download fastboot for mac from here (this is a utility tool not included in SDK, but uses utility tools provided by SDK. We will use this to perform many necessary operations.)
• Move fastboot-mac file to android-sdk/platform-tools folder
• Open "Terminal" app under Applications -> Utilities
• Type vi ~/.bash_profile (this edit your hidden bash_profile file. I use vi, and you can surely use other text editor, such as nano)
• Press i to start editing, and add following two lines to the end of the file (add these two path to your PATH variable will make all utilities in these two directory, including fastboot-mac, accessible everywhere
• export PATH=${PATH}:~/android-sdk/tools
• export PATH=${PATH}:~/android-sdk/platform-tools
• Press esc to finish editing, and type :wq to save and quit
• Command + Q to quit your Terminal and restart it again (to load the new PATH variable we just added)
• Shut down your phone
• Press volumn up and volumn down at the same time, and while holding those two keys, press the power button until an Android with its front panel open cartoon shows up (now you entered the fastboot mode, as indicated in the red text at the lower left corner. You can see in that text block that it says your phone is currently locked)
• Connect your phone to your Mac using the USB cable
• Type fastboot-mac oem unlock
• Select "Yes" on the following screen, and it will start unlocking. Should be fairly quick. Then you are back to the Android cartoon, and now it should say unlocked in the text. You are done.

2. Flash a custom recovery

• Download Clockwork recovery here (the only one I can find, and thank Koush for the quick post)
• For the sake of this tutorial, put this .img file to your home directory
• In Terminal, type fastboot-mac flash recovery ~/recovery-clockwork-5.5.0.4-toro.img (install this recovery mode onto your phone)
• Now you have the custom recovery, and choose 3 OR 4 to root your phone

3. Root your stock OS

• Download super user here (this will give you root privilege)
• For the sake of this tutorial, put this zip file to your home directory
• In Terminal, type adb push ~/su.zip /sdcard/ (copy su.zip to your phone)
• Once the process is done, disconnect the cable, and at the fastboot mode, press volumn down key until the "Start" at the top of the screen becomes "Recovery Mode". Press power button to enter recovery mode
• Use volumn up and down buttons to highlight install .zip file and use power button to select. Find the su.zip file on your phone, and select it to install
• Once this is done, restart your phone, and now you have root. To verify, see if you have Superuser app installed. If you do, success.

4. Install a rooted ROM

• Peter Alfonso quickly packed a rooted stock ROM for us to download here (ICL53F is the latest) 
• Rename the file to update.zip and put it to your home directory (again, for the sake of this tutorial)
• In Terminal, type adb push ~/update.zip /sdcard/
• Turn off the phone and then go into fastboot mode (vol up and down and power)
• Press volumn down key until the "Start" at the top of the screen becomes "Recovery Mode". Press power button to enter recovery mode
• Use volumn up and down button to choose install update.zip from sdcard, and once it's done, reboot your phone use the option provided by the recovery.
• Now you have root. To verify, see if you have Superuser app installed. If you do, success.

A little trouble shooting:

1. Can't mount sdcard
When I tried to install zip file from sdcard using the recovery, it gives . I restarted the phone, it stayed on the booting animation screen for a few mins, and I am not sure whether it restarted itself, or due to the fact that I was holding the power button for a while, but the second boot was successful, and I could use my phone. Then I restarted the phone and entered fastboot mode, chose recovery mode, and then chose to install .zip again in the hope that it could somehow work the second time. And low and behold, it did work. So somehow the recovery mode didn't recognize my phone's /sdcard/ partition at first, but eventually did the second time around.

Easter Eggs

It is not news now. The barrel roll of Google provided so much amusement to so many people in a very short time. Suddenly all the "Easter Eggs" planted by miserable yet creative, humorous web developers are trending now. Tilted Google, YouTube snake, Lego pegman, reverse mini cooper etc etc.

With this fun spirit, I decided to do a little Easter Egg of my own. I am obviously too afraid to do it on my project at work (or am I? ;)), so I decided to have a little fun with my blog.

So, officially now, there is an Easter Egg hidden in this blog!

The angel had to go back home

The world had been so lucky to have such a visionary, who didn't compromise on perfection. So inspiring, so creative, so charming.

As it turns out, he is not a man. He doesn't belong to this world. Our lease expired. The heaven wants him back now. The whole world is left in awe. We are using the technology started by him, perfected by him or popularized by him to spread our disbelief on his departure

Steve, if you can hear us, we are so thankful for your time here. We understand it is time for you to go home, and we are happy for you. Now, we just wait. Wait for your second coming.

Love,

Is a spinoff of iPhone coming soon?

As all rumors indicate, there will be two iPhones coming out this fall, one fancy for high-end users, one cheap for teenagers, and most Chinese.

Coincidentally, I watched a rerun of Shark Tank a few days ago, and one person was rejected pretty much because she wants to expand to low-end market while Sharks think she should stay high-end. Sharks made a lot of sense. If you are profiting beautifully from high-end market, why shrink your profit margin to go for low-end? Think LV, Hermes, PRADA etc etc (I have been shopping with my girl way too much...)

However, intuitively, it always seems to be a good idea to extend your market to the widest audience. The average profit margin may be low, but the total amount of profit is surely up.

The problem is that making your product available to general public would hurt your high end market, since people wouldn't pay as much for luxury if the same luxury name can be acquired with a much lower price (I don't think people who buy luxury care about the quality difference between 2-year lifespan and 5-year lifespan. I don't even think they can keep those stuff that long). People are competitive, but people don't want to brag and look like b&$%#. Therefore, people want their "better" stuff to be noticed in the most obvious way, brand name. Whether a product is made of the best cloth material on earth or just cotton, as long as it is not obvious to general public, i.e. friends, it is not worth the extra 200% money spent.

People in car industry had the right idea, spin-offs. Everybody feels it is worth the money to spend much more than they should for a Luxus / Lincoln / Acura / Cadillac, but not for a Toyota / Ford / Honda / Chevrolet. As a result, everyone is happy. Rich people distinguished themselves by spending tons more for a different logo, rich people's average Joe friends settled with good quality bargains, and the company squeezed every last penny from everyone.

Other industries have similar things as well, MiuMiu and PRADA, Marc and Marc Jacobs, dENiZEN and Levi's (Levi's IS high-end in China), etc etc (again, been shopping with my girl too much).

When I watched that Shark Tank, I was wondering why nobody proposed the idea of dividing the company. It might be because Sharks only focus on make small businesses take off rather than consider long-term strategies, or it might be because Sharks won't say that to a person who is obviously not interested in others' opinion.

In the case of Apple, however, I believe it is very possible that either 1) all high-end iPhones in the future are going to look radically different from low-end ones, or 2) there will be a name spin-off for all entry-level iPhones, so Apple can perform the old trick of price discrimination to maximize total profit. Apple is big enough to go after markets with smaller profit margins, and Apple is famous enough as well.

I don't think the price of a phone will go up by much, since people have a certain budget for things they are very certain will be changed in two years (people change purses more frequent than that, but a purse *looks like* can be used forever). However, the cost of producing a phone will be reduced while the price won't. Hence, the entry-level iPhones can go ahead and compete in the price war, while the high-end ones stay on top.

Maybe I should start a rumor about Apple like everyone else... mmm...

Take full advantage of the current situation

People complain about their current situation. Big deal. However, when you constantly hear people talk about how they miss being a kid, miss being in (Chinese hard-core) high school, it becomes irritating.

Two possibilities: 1) their lives do suck more as grown-ups than being in a high school with incredible amount of course workload. 2) They simply only see what they don't have as adults but did have in high school, and not see the other side.

If 1), well, karma is a bitch. You enjoyed too much in high school, college, you suck at real life. Blame yourself. Sure, go ahead and blame your parents too.

If 2), which I believe is a more common case, I feel it is important to switch perspective and realize how people would envy your current situation.

Back to the first scenario, people want to go back to high school times, and feel high school kids don't realize how easy it is to be in high school.

Feeling mature? think again. Back in high school, (Chinese) students are forced to obey / listen to parents, teachers. Kids have minimum liberty, make up lies after lies just to go out with a "person of interest". Privacy and relationships are almost impossible, if not immoral. Then it is all those course works that you do without pay. It is difficult to make fully aware adults to learn new things just because new things *could be* good for the future, let alone high school kids.

Of course, vice versa. Adults need to take more responsibilities etc etc (whiners talked a lot of that, and high schoolers never really say adults get it easier)

Everyone knows long distance relationship sucks. However, instead of complaining about it and telling couples that they don't realize how fortunate they are, people who are in long distance relationship should really take advantage of the situation (of course, if they really want this relationship to work. Otherwise, just break up already).

There are a lot of good things about being in a long distance relationship. Having a stable relationship requires no need to constantly improve the dating game, or make strategies etc etc. There is no need to pretend to be somebody else. Caring each other to maintain this relationship is definitely easier. There is no need to go back home right after work for family and kids. Hitting the gym while nobody is there is absolutely a great perk. Enjoy the maximum utility to improve health and shape. There is also the extra free time, which could be quite beneficial if used on reading, learning and career-related things.

Without a doubt, I'd love to give up a healthy body and shape and even some career security for being together with my other half, so we can travel, go outside, do stuff, or just cuddle. However, since the long distance is a given, why not try to fully utilize all the advantages of this situation rather than envying others? Why not make others envy your healthy body and shape and career security? Otherwise, you would have nothing regardless what situation you are in.

Stop saying how high schoolers don't realize how fortunate they are, and start thinking how fortunate you are to be at where you are. Take full advantage of the current situation, especially when it is a given. Otherwise, you are no different from people who just blame the unchangeable for their own failure.

Chromebook, continued

Find one thing I miss a lot about my MacBook pro: the easiness to create a PDF out of ... well, anything, especially a web page.

A very good tool (chrome extension) I found is iWeb2x, which reads the current URL and makes a pdf out of it.

There is a deadly and unfortunately unchangeable imperfection to this approach. It cannot handle log-in sessions. For example, if you want to save your Facebook front page, iWeb2x will load that URL (http://www.facebook.com) itself without any log-in info, i.e. session cookies, so you will just get the log in page of Facebook.

Solution: if you need to make a pdf out of a private webpage (one that you can only see after logging in), save the webpage use Ctrl + S to your inferior file system, and go to http://pdfcrowd.com/#convert_by_upload to upload the html file you just saved.

However, pdfcrowd adds a (rather insignificant) logo watermark at the corner. Additionally, Chromebook doesn't save the "entire webpage", which means many images "might be" lost during the save (strangely not losing all images, which could be good news).

I tried many other websites, and although many of them don't add watermarks or even allow you to add your own watermarks, they either require you to give an email address to send the resulting file to or give you a zip file, which Chromebook doesn't handle very well, or just does a poor job in converting (probably because those sites have a poor html parsing tool).

pdfcrowd also makes an extension, called "Save as PDF", which works very much like iWeb2x, and as the website, it adds a small logo watermark at the corner.

If you wants to upload the PDF directly to Google Docs, use "Send to Google Docs". This extension works the same way as the other two, and in fact, it actually uses pdfcrowd's service to create the PDF, and then just directly sends the result to Google Docs. Of course, it also has the pdfcrowd watermark.

Speaking of all the files Chromebook doesn't play, I decide to keep a list of video and audio format that I managed to play on my Chromebook, and of course those that don't.

Working video format:
- Some .mp4 (yes, some .mp4 files don't work...)
- Some .mov

Non-working video format:
- .avi
- .wmv

Working audio format:
- .mp3

Non-working audio format:
- .aac (rumor)
- .wma (rumor)

All lists are continuously updated, of course.

Cheers!

Update July/10/2011
If you are a heavy keyboard user, i.e. use key shortcuts more than mouse click, you may see the Ctrl + Alt + / combo tip I talked about here.

If you use a Mac, you know how bad it is to go from "command" key to "ctrl" key due to their different locations. Well, sad no more! Settings -> System -> Language -> Modifier Keys.

When I first saw this, I was confused why would somebody wants to press "ctrl" to have "alt"'s behaviors. Now I know. "Alt" is in the same position as "Command" in a Mac keyboard, and by altering the behavior, Mac users wouldn't get frustrated when switching between Chromebooks and MacBook. Genius!

Update Oct/21/2011
Finally got my butt around and rooted my chromebook.

Took quite a few tries, but the result of integrating two articles leads to success.

First one: http://goo.gl/f9JFS < this one would be sufficient, unless you are a Mac user, which I am. If using Mac to burn the recovery image to USB, then you need to reference the second link for completing Step one in this link

Second: http://www.google.com/support/chromeos/bin/answer.py?answer=183098 < Only the step 2 in this link is useful

Also, I used a 2GB USB, and it was sufficient, so...

A brief review (and perhaps tricks) of Chromebook (not Cr-48)

My chromebook finally got here right before the 4th of July weekend (about time!) Like a 16-year old boy seeing his girlfriend naked for the first time, I pretty much jumped on it right away. The only difference is, my play time lasted the entire weekend :)

Enough with the useless, let me just get right into it.

It is very much what you would expect from a "cloud terminal". Fast, clean, right to the point, because there isn't much else. A few things I find very useful.

1. Key shortcuts
The best thing about Chromebook is, you only need to remember one combo: Ctrl + Alt + /

This gives you all the key shortcuts on a map. Yes, a map. A virtual keyboard shows up, and as you press Ctrl, Alt, Shift or any combo of these three, the virtual keyboard highlights all keys associated with them (and of course description of what those shortcuts do).

2. Move files
This may sound insane, but as a terminal to the cloud, the last thing Google wants to do is to encourage you to use the file system. Therefore, it is a little different to manage files stored on your chromebook from what you are used to do.

As the key shortcut map can tell you, press Ctrl + m brings you to the file manager, but this manager only allows you to rename, delete, upload (if applicable) and view (a very limited set of file types).

Therefore, if you want to move files between folders or simply get files from a external storage, such as an USB drive, you need to open a new tab and put the following in the omnibox (URL bar / address bar)

- Move files from external storage:
file:///media

- Move files within Chromebook (File Shelf)
file:///home/chronos/user/Downloads/

In there, it is the good ol' tree / directory view of your file system. You just need to navigate to the file of interest and right click. Ta-da!

3. Some geeky stuff
If you really feel like it, you can of course check out the task manager (Shift + Esc), and test features ("About Chrome OS" -> "More Info" -> Change "Channel" to Beta or Dev -> put "about:flags" in omnibox) at your own risk.


I will add more tricks in the future (if there are some essential ones left to be known)

Now it's the review part.

Compare to laptops:

- Pros
a. Incredibly energy efficient. One charge lasts me all day (that's what sh...)
b. Incredibly fast on start-up and shutdown, <= 8 secs and <= 4 secs, respectively.
c. Internet-optimized keyboard (one button press for back, forward, refresh, full screen, switch windows, brightness, and volume http://goo.gl/5m71i)
d. Light weight (both literally and technically)
e. SD card slot
f. Apps are updated automatically on "the cloud", so no more pop-ups for updates
g. Files are stored on "the cloud", so you don't need to worry about losing files when you dropped chromebook in a keg, and you can access all of them anywhere there is an internet connection and a (modern) browser (yeah, I am talking to you, IE6)

- Cons
a. Although threats are everywhere, cloud is still more dangerous than your hard-drive, so no sensitive content (unless you feel very adventurous and trusting)
b. It is almost (not entirely) useless when there is no internet, because there is no native apps you can run, and only few offline apps (nice work, Scratchpad and Angry Birds)
c. Can't do any technical work, such as professional video / photo editing, coding etc.
d. Not much layout customization (Firefox is doing a much better job on this)
e. The extension and app store needs some improvement (selection wise)

Compare to tablets:

- Pros
a. The screen and keyboard are separate, so you don't need to angle your hands to make your head more comfortable
b. Full keyboard, so you don't need to cramp your hands and give up the most efficient way to type
c. Full internet (not tablet web browser, but full web browser, and support Adobe Flash, unlike some)
d. SD card slot, two USB port, and one video output (WITH cable)

- Cons
a. Similar to the comparison with laptops, no native apps (but most native apps on tablets require internet connection too, and often times features they provide can be done through web apps as well. The lack of these apps makes the whole web experience quicker and smoother as well)
b. Heavier (about 1~2 pounds heavier)
c. Not many games, which is part of the no native / offline apps issue (I am personally not a big gamer, so, not a big deal for me)
d. Similar to the comparison with laptops, the file system cannot do much locally, and the most painful thing is decompression. I tried wobzip but never really made it working.

In general, after three straight days, I find myself surprisingly comfortable with living on the cloud. I did need to adjust and give myself an orientation at first, but now I feel completely comfortable to migrate my entertainment and casual life to the cloud and enjoy all the pros I stated above. That is when I realize how little I do on my MacBook Pro besides opening up a browser. Even among those few things, I realize how little I cannot do or am not willing to do on the cloud.

Bottom line: If you often don't have internet connection where you want to use a portable device (laptop / tablet), don't consider chromebooks. Otherwise, it could be a very good fit for you. You may be surprised to find how boring all portable devices are without internet (remember not wanting to take your laptop out from your bag in the airport with expensive wifi and long layover?).

Happy 4th of July!

iPad, the new Louis Vuitton

This title sounds a little odd, doesn't it? Well, this idea suddenly hit me while I was driving home the other day. I was impatiently waiting for an update on my Chromebook order from Amazon, and thinking about all the terrible things that can happen to this order.

One thing that occurred to me was they would ask me whether a white one would be good (I ordered the black Titan Silver one), if I want it now rather than a month later. I felt grossed out by this idea alone, a white Chromebook? Ewww... I would never want that, and I would rather not use a Chromebook at all.

Wait a second, aren't they both Chromebooks? Same specs, same OS, and the only difference is the color? I would rather have none than the white one? And I call myself a practical person?

I suddenly realize why I want Chromebook at the first place. Sure, the whole living on the cloud thing is cool and all. I got one despite of all those security concerns because I want to be seen with it! I like the idea of trying out new stuff that I think is the future (without "too much" sacrifice to my personal security and privacy).

Then I realize why there are so many tablets out there that have so much more to offer than an iPad (more free apps, better hardwares, comparable OS, comparable types of apps, to name a few), but nobody is even close to catching up iPad, not even the sum of them. In fact, 97% of the tablet web traffic came from the iPad, and web browsing is actually more complete on Android devices, since the whole Adobe Flash thing.

People want to be seen with an iPad, not just a tablet, THE iPad.

When you have an iPad, it is not about what it can do, or not even what you can do with it. It is about the willingness of taking it out from your backpack during that 30 mins layover in Atlanta.

It is like Louis Vuitton. It may provide the same (or less) set of features or functionality or beauty as competitors, but people want to be seen with LV rather than some ... well, bag (btw, for once, the Chinese beat-up version actually came out first, in fact, decades earlier than the luxury).

Some may say they are completely different, because LV is a luxurious brand of handbags, while iPad is some technologically advanced, yet affordable device. They cost different, they are in different categories, and they will surely have different future.

Well, if you think carefully, both products probably have the same lifespan in your household (a new one every two three years), and their eventual costs are probably similar (don't forget about all those songs and apps you spent money on because of this magical device). As many of you may already know, it is almost impossible to buy a finite set of apps and be good with them. There are always new games, new productivity tools, and new fads (farts, vuvuzela, colorful flashlights), let alone all the endless possibilities brought by future advance in hardware. Therefore, even if you can transfer all apps from old iPad to new iPad, you will still buy apps at a very similar rate. There is no doubt about it.

LV is also not going out anytime soon either. As long as it keeps being selective, (and of course, not making absolutely terrible ideas too often), it will still be every girl's dream, and as a result, guys will pay anything for it, even if those bags are sometimes not really within some guys' financial means.

All in all, iPad is the Louis Vuitton for guys, and the second Louis Vuitton for girls. Android devices, you already one-upped iPad in technology, now step your cool game up! Otherwise, you will always be the right choice, which will only be made by geeks. You know, there aren't so many of us.

Gaddafi not stepping down is our fault

First of all, I wanna say, it is spelled Gaddafi, or al-Gaddafi in English, and al-Qaḏḏāfī in Arabic. Not Gadhafi, Qadhafi, Gaddhafi, Qaddhafi or even Kadhafi, like many blogger, journalists alike think

Nonetheless, he is a pain in the rear end without a question. Members of UN Security Council have unanimously decided that. While Gaddafi refuses to back down, we may have to ask one question: is his personality (being a jackass) the determining factor for this persistence, or we are partially to blame?

Let's step into Gaddafi's shoes for a second (assuming he is a sane person, i.e., do things that are good for him). He obviously has two choices, fight till the end, or surrender to protesters/"justice".

The breakdown:
1. Fight!
a. Protesters are scared, and supporters prevail - I enjoy my lavish life till death do us apart, and possibly find some more Ukraine nurses. Win!
b. I lose all my supports, and surrounded by protesters - Commit suicide or eat hundreds of bullets. Die.

2. Surrender
Now this gets interesting. My good ol' friend Mubarak just did that. Let's see how he is hangin'. Mmm... It doesn't look so bad. He doesn't seem to be killed or executed. Not like he got beaten up by thousands of pissed Egyptians.

Wait a sec, let's see what is on the news. Foreign assets are frozen, traveling is banned, and family funds are seized etc etc. How is that better than being dead with a few Ukraine nurses in my arms, especially after enjoying an extravagant life?

Alright then, I am winning either way if I fight till the end. I shall do the worst then!
- the end -

The way we deal with Mubarak while trying to convince Gaddafi to do the same is absolutely retarded. It only makes the whole Gaddafi situation worse. Mubarak stepped down because he didn't know how he would be treated, and he had that last bit of naive thought in the bottom of his mind. For Gaddafi though, we pretty much let him know that he is better off to keep fighting us. You can't just heavily guard Mubarak without actually doing anything for now? Just to give Gaddafi some illusion is too hard?

Well, whom can I blame, those people surely have never heard about the history of Chu-Han contention, and how the difference between Liu Bang and Xiao Yu's approaches of treating surrenders lead to the huge difference in how easy it was to seize cities in later battles.