In what way is Google's chrome close to being an OS kernel? Is it handling device drivers, or scheduling, or address space management, or file system I/O?
It's running JavaScript apps which brings up a lot of these issues. Read a little about the history of Firefox and it's memory management and security issues and you can see why they built Chrome. Chrome can gracefully handle a buggy JavaScript application without failing vs. the Firefox issue of one tab locking all of the rest of them. etc.
PS: I don't think browsers are a true kernel but they are getting a lot closer. I am going to wait a few months for chrome to work the major bugs out and then try it.
That is exactly what Chrome is not. It's not a monolithic process, with a large pool of green threads being scheduled to run on native threads using runtime trickery.
Instead it's just a bunch of shared-nothing exec-ed processes that are scheduled by the OS kernel, have their mallocs handled directly by the OS libc, and have their address space mapped and reclaimed by the OS kernel's VMM.
In my own work, when I fork threads that are run and executed by the kernel, I still make decisions outside the kernel about how those threads run. I may tell threads to go to sleep, wait for another thread to finish something, or prefer a certain thread to run over others.
Yes, they are still scheduled by the OS kernel, but they are also being controlled by my own scheduling algorithms. I call this scheduling, because it's the same problem as OS level scheduling. And if I have to do it, I imagine Chrome has to do it. In this scenario, if you want to understand the runtime behavior of the threads, you must consider both OS kernel level decisions and my scheduling decisions.
I would also be surprised if there was no Chrome memory management inbetween malloc and the OS kernel.
"Web content has evolved to contain significant amounts of active code that run within the browser, making many web sites more like applications than documents. This evolution has changed the role of the browser into an operating system rather than a simple document renderer. Unlike current browsers, Chromium is built like an operating system to run these applications in a safe and robust way, using multiple OS processes to isolate web sites from each other and from the browser itself."
