Unraveling Life's Mysteries...

Posted by The Modern Buddha , Tuesday, October 11 19:08

As I sat on an easy-chair staring at the sky from the porch on a lazy evening, a string of new thought process set into motion in my grey cells...
I ponder upon the words "Life moves on...no matter what", "what the heck does it even mean?". A voice inside my head answered " Life moves on...no matter what...no matter who dies or who is born...no matter who does what...there is only one direction where life and time move and that is FORWARD". "So, depressing to hear it", I thought. "Is this the truth. So, there is no purpose to life, eh?". Again the voice " No. You Idiot. Can't you think straight? The purpose of LIFE is LIFE itself. To Live it out." I thought "Uh! OK....Whatever that meant...."
Silence For sometime as I ponder about this.....
I recalled a story of a wise man who once said to a disciple seeking the same question "The purpose of life is to observe all the wonders while still carrying a spoon filled with oil without spilling it." This really had an impression on me....What kind i don't know but it sure did. The voice "Silent for so long? What is it that's on your mind?" I ask "Why then is Life for? What purpose does it serve to the one who created it?" The voice "Hey hey kiddo!! Slow down. You move too fast....Two questions and you are already upon the Creator of Life!! Phew!!"."He he" I laughed, "I take it as a compliment then." The Voice said then, " Lemme ask you a question now." I am all excited now, "Shoot right away!!". It said "If you cook something with all your heart and soul, would you not want to test it to see how well it's been?" I said "Well, Yes!" The Voice "Then there's the answer to your question. The Great Lord created LIFE and wanted to know how well he had done. So he tests us." I thought "Ohhk!! Give me a Break!! Weird! Huh!" "But, Somehow this answer seems to be right in a way, as I have nothing to contradict it." I sighed. 

"I think God made the sky blue in order to give hope and peace to those who seek it. All one has to do is look up". And pondering upon all these I sign-out. See ya later!!

P.S : By the way Blue is color associated with hope and peace since times unknown. Science says that Blue color is the most effective in calming nerves.

Google Chrome : A multi-process Architecture

Posted by The Modern Buddha , Monday, August 15 19:26

Unlike most current web browsers, Google Chrome uses many operating system processes to keep web sites separate from each other and from the rest of your computer.  In this blog post, I'll explain why using a multi-process architecture can be a big win for browsers on today's web.  I'll also talk about which parts of the browser belong in each process and in which situations Google Chrome creates new processes.

1. Why use multiple processes in a browser?

In the days when most current browsers were designed, web pages were simple and had little or no active code in them.  It made sense for the browser to render all the pages you visited in the same process, to keep resource usage low.

Today, however, we've seen a major shift towards active web content, ranging from pages with lots of JavaScript and Flash to full-blown "web apps" like Gmail.  Large parts of these apps run inside the browser, just like normal applications run on an operating system.  Just like an operating system, the browser must keep these apps separate from each other.

On top of this, the parts of the browser that render HTML, JavaScript, and CSS have become extraordinarily complex over time.  These rendering engines frequently have bugs as they continue to evolve, and some of these bugs may cause the rendering engine to occasionally crash.  Also, rendering engines routinely face untrusted and even malicious code from the web, which may try to exploit these bugs to install malware on your computer.

In this world, browsers that put everything in one process face real challenges for robustness, responsiveness, and security.  If one web app causes a crash in the rendering engine, it will take the rest of the browser with it, including any other web apps that are open.  Web apps often have to compete with each other for CPU time on a single thread, sometimes causing the entire browser to become unresponsive.  Security is also a concern, because a web page that exploits a vulnerability in the rendering engine can often take over your entire computer.

It doesn't have to be this way, though.  Web apps are designed to be run independently of each other in your browser, and they could be run in parallel.  They don't need much access to your disk or devices, either.  The security policy used throughout the web ensures this, so that you can visit most web pages without worrying about your data or your computer's safety.  This means that it's possible to more completely isolate web apps from each other in the browser without breaking them.  The same is true of browser plug-ins like Flash, which are loosely coupled with the browser and can be separated from it without much trouble.

Google Chrome takes advantage of these properties and puts web apps and plug-ins in separate processes from the browser itself.  This means that a rendering engine crash in one web app won't affect the browser or other web apps.  It means the OS can run web apps in parallel to increase their responsiveness, and it means the browser itself won't lock up if a particular web app or plug-in stops responding.  It also means we can run the rendering engine processes in a restrictive sandbox that helps limit the damage if an exploit does occur.

Interestingly, using multiple processes means Google Chrome can have its own Task Manager (shown below), which you can get to by right clicking on the browser's title bar.  This Task Manager lets you track resource usage for each web app and plug-in, rather than for the entire browser.  It also lets you kill any web apps or plug-ins that have stopped responding, without having to restart the entire browser.

For all of these reasons, Google Chrome's multi-process architecture can help it be more robust, responsive, and secure than single process browsers.

2. What goes in each process?

Google Chrome creates three different types of processes: browser, renderers, and plug-ins.

Browser.  There's only one browser process, which manages the tabs, windows, and "chrome" of the browser.  This process also handles all interactions with the disk, network, user input, and display, but it makes no attempt to parse or render any content from the web.

Renderers.  The browser process creates many renderer processes, each responsible for rendering web pages.  The renderer processes contain all the complex logic for handling HTML, JavaScript, CSS, images, and so on.  We achieve this using the open source WebKit rendering engine, which is also used by Apple's Safari web browser.  Each renderer process is run in a sandbox, which means it has almost no direct access to your disk, network, or display.  All interactions with web apps, including user input events and screen painting, must go through the browser process.  This lets the browser process monitor the renderers for suspicious activity, killing them if it suspects an exploit has occurred.

Plug-ins.  The browser process also creates one process for each type of plug-in that is in use, such as Flash, Quicktime, or Adobe Reader.  These processes just contain the plug-ins themselves, along with some glue code to let them interact with the browser and renderers.

3. When should the browser create processes?

Once Google Chrome has created its browser process, it will generally create one renderer process for each instance of a web site you visit.  This approach aims to keep pages from different web sites isolated from each other.

You can think of this as using a different process for each tab in the browser, but allowing two tabs to share a process if they are related to each other and are showing the same site.  For example, if one tab opens another tab using JavaScript, or if you open a link to the same site in a new tab, the tabs will share a renderer process.  This lets the pages in these tabs communicate via JavaScript and share cached objects.  Conversely, if you type the URL of a different site into the location bar of a tab,  a new renderer process is swapped for the tab.

Compatibility with existing web pages is important.  For this reason, a web site is defined as a registered domain name, like google.com or bbc.co.uk.  This means sub-domains like mail.google.com and maps.google.com areconsidered as part of the same site.  This is necessary because there are cases where tabs from different sub-domains may try to communicate with each other via JavaScript, so they are kept  in the same renderer process.

There are a few caveats to this basic approach, however.  Your computer would start to slow down if it created too many processes, so a limit is placed on the number of renderer processes that are created (20 in most cases).  Once this limit is hit, chrome will start re-using the existing renderer processes for new tabs.  Thus, it's possible that the same renderer process could be used for more than one web site. Chrome doesn't yet put cross-site frames in their own processes, and don't yet swap a tab's renderer process for all types of cross-site navigations.  So far, they only swap a tab's process for navigations via the browser's "chrome," like the location bar or bookmarks.  Despite these caveats, Google Chrome will generally keep instances of different web sites isolated from each other in common usage.

For each type of plug-in, Google Chrome will create a plug-in process when you first visit a page that uses it. A short time after you close all pages using a particular plug-in, chrome will destroy its process.

 So, Folks enjoy the chrome's unique architecture that gives a rich user experience and boosts performance in todays web.