Mozilla talks up multi-process work

Mozilla has been talking up work it is undertaking to bring multi-process content support to Firefox.

The web software developer said the work would help to prioritise as well as measure when it might be ready to ship a version of its browser that uses a multi-process model.

The details, outlined in a blog posting late last week, have led to observations that Mozilla is following a similar multi-process architecture development path to the one Google took for its Chrome browser.

The Chrome architecture uses a procedure known as 'process isolation' to separate processes allocated to each site instance and plugin.

The blog of Chris Blizzard, Mozilla web platform director, said the company realised it was going to have to invest in a multi-process model.

While multi-process development was not a panacea for further development work on performance, as well as multi-core and memory behaviour areas, "it does give us a leg up on some of the more systemic problems," he wrote.

Although Blizzard stood by the most recent release of Firefox 5 as a "great browser from a responsiveness standpoint."

"We know that if we want to separate chrome and content concerns that we're going to have to go to multi-process," he added.

The posting cited ongoing development work to use separate processes to display the browser user interface (UI), web content, and plugins in project Electrolysis as key to improving levels of responsiveness.

It also pointed to the importance of support for multi-core processors in desktops, laptops and increasingly mobile devices, as an important reason for also moving away from requiring content to have single-threaded domain object model (DOM).

"One of the easiest ways to take advantage of multiple processors is to have each DOM assigned to its own processor, and the easiest way to do that is to have a few processes that can each be assigned to their own CPU," Blizzard wrote.

Mozilla also said it was investing in longer-horizon projects to examine what a multi-threaded DOM and layout engine might look like.

In security terms, Blizzard admitted that having the ability to talk to the "more privileged" chrome process could still result in exploits that have raised permissions.

He admitted it wouldn't protect one website from another malicious website.

"But it is a positive step forward, and is well worth the investment," he added.