Issue 1-8, January 31, 1996

Be Engineering Insights: The Be OS from a UNIX Perspective!

By Dominic Giampaolo

If you come from a heavy UNIX background like I do, you may be wondering just what the Be OS looks like under the hood and how it compares to the legendary heavy-weight of big-boy operating systems.

As a starting point, let me say right off the bat: The Be OS is not UNIX nor is it intended to be a UNIX clone. That's not to say that there is no UNIX compatibility, as we do have a Posix library that's intended to make it easy to port UNIX application code (and release 1.1d7 will offer a big leap forward in that area). However, the fundamental abstractions provided by UNIX and the Be OS are different.

Let's begin with the model of a program. Both the Be OS and UNIX offer separate address spaces for each "team" ("process" in UNIX-speak). Each program runs in its own 2-gigabyte memory space and can use as much or as little of that space as it needs, since the Be OS (like UNIX) offers virtual memory. Separate address spaces of course mean that each program is isolated and cannot accidentally rampage through memory.

Unlike most versions of UNIX, the Be OS offers multiple threads of execution within each team (address space). To create a thread, the Be OS provides spawn_thread(). To create a new team, there's the function load_executable() (which also creates a default thread to run in that team). The Be OS has no concept of fork() or exec(), they're instead implemented in our Posix library.

System calls from a user program are made in the traditional UNIX way of trapping into the kernel and then jumping to the real code. Since the only way a user program can get into the kernel is via a trap, our kernel is more robust because an errant or malicious program can't just jump into random kernel code and cause damage. The overhead to make a simple system call is quite low, coming in at just over three microseconds.

The mechanism for IPC in UNIX is traditionally through a pipe or the System V shared memory and message routines. The main mechanism for IPC under the Be OS is through named message ports that have a queue for incoming messages. Be message ports are unidirectional, and the incoming queue is limited in size to prevent run-away processes from gobbling all of system memory. We also support shared memory through the create_area() and clone_area() system calls, which allow one process to create an area and another to obtain a mapping to that area. The higher-level library code uses both message ports and shared memory to enable communication between threads in different teams.

Another area that the Be OS differs significantly from the traditional UNIX model is in how it handles files. The Be OS attempts to avoid the issue of handling path names of arbitrary length by presenting a concept of a file "ref". A file ref is a unique reference to a file on a given volume and is independent of the file's path. This avoids dealing with arbitrarily long pathname and eliminates hard- coded constants, such as PATH_MAX, that limit how long a file path can be. Of course the standard C library and Posix server cooperate to provide a standard pathname-style interface, so existing code doesn't have to be aware of this.

There are other differences between the Be OS and UNIX, but these are a few of the highlights. The Be OS is different from UNIX, but that doesn't imply incompatibility, since our Posix library works to cover the differences. The features that the Be OS does provide offer a rich base for building new applications that use multithreading and messaging in a real SMP<title>Symmetric Multi-Processing</title> environment.

There are still many areas we're working on in the Be OS, and we plan on enhancing it significantly over time. Release 1.1d7 will contain a number of enhancements and we'll continue to improve the Be OS as we get more feedback from developers as to what they need to write even better, more sophisticated applications.

Market Outlook: Who the Heck Wants a New Platform?

By Mark Gonzales

Here, at Be, we talk to people every day about the Be System—the BeBox and the Be OS. These people include developers, customers, press, and resellers, all interested in the potential of the Be System. They have plenty of questions, and we provide lots of answers. But simmering just below the surface is always one question: "Are you guys crazy? Who the heck wants a new computing platform?"

Well, let's get this one out in the open. Conventional wisdom in the computing industry says that the world has moved towards a few standards on a limited number platforms (read: one). No company can stand against the tide, it's a better strategy to ride with it—and that means being 100 percent compatible. To suggest something different is to create astonishment in your audience. Be was called "renegade" in one recent article.

If the question is "Who wants a new computing platform?", I'll concede right now that conventional wisdom is absolutely correct. The answer to this question is "No one wants a new platform." But before you e-mail me in agreement or disgust (, please allow me to place another thought on the table: "Is this the right question to be asking?"

Jean-Louis is fond of saying that the source of product gold mines is user frustration. And frustration with today's personal computer systems is growing—among both users and developers. This isn't surprising since current computer architectures are well over a decade old, and many of the capabilities users and developers are demanding today simply weren't considered when these architectures were designed. Further, many changes have occurred in the industry since these legacy systems first appeared. A few examples:

A growing class of personal computer users are reaching, and often surpassing, the limits of today's personal computer architectures. They're purchasing high-end PCs and then equipping them with expensive high-performance graphics cards, video I/O cards, accelerators, and other add-ons, in order to achieve minimally acceptable performance. In essence, these users are paying extra because of the overhead created by legacy system design, while receiving systems that are underpowered for the same reason. These users would purchase high-end workstations if they could afford them, but most can't. All of this leads to an understandable level of frustration.

For an industry that has always applauded itself for delivering ever-increasing processor power, it can be a sobering conclusion: A growing portion of the personal computing audience is consuming processing power faster than it's being introduced into the market.

Dataquest estimates that 68 million personal computers will be sold in 1996, in addition to roughly 1 million workstations. And growing at 4.5 times the rate of the overall market is a class of machines Dataquest calls "PC workstations." These personal computers—delivering workstation performance at PC prices—will be flying out the door at a 6-million-unit annual click within the next few years. This class of PC will have tremendous influence on the entire computing market -- impacting workstation design as well as the look and feel of the average PC.

What will a PC workstation look like? Without a doubt it will implement a level of processing power above what can be obtained by straight-lining today's uniprocessor designs. Most analysts project that these machines will need to be based on multiprocessor designs. The PC workstation will innately handle high-bandwidth media types such as video and audio and will be at home on the Internet. In order to maximize the capability and performance of these systems, many analysts concede that the overhead within today's legacy operating systems and applications will need to be reduced. Tomorrow's operating systems will be significantly different than today's, whether the products have familiar brand names or not. And these PC workstations will have simplified, modern, object-oriented programming models allowing developers to concentrate more on their value added than on system interfaces.

Sound familiar? It should—we've just described the Be System.

Will these PC workstations quickly appear on every user's desk? Not immediately. Let's be frank, content consumers—including most in the office automation markets—are not the ones pushing the architectural limits of PCs today. It's the content creators who are running into performance barriers. And they're the users to whom performance matters most—where getting a job done in an hour rather than a day translates directly into improvement in the bottom line. How many of these people are out there? Literally millions. We'll talk about some of these types of customers in future Be Newsletters, but you can probably already guess some of the potential groups.

Who wants a new platform? No one. But this is an industry-oriented question. We must think in terms customers' desires and expectations. Customers think in terms of capabilities, of interactivity, of getting the job done in the best way possible—as fast as possible. It's better to ask, "Are there customers whose desires currently exceed the maximum potential of today's PCs?" and "Do these customers want to wait for today's PCs to slowly evolve these desired capabilities?" These questions are more customer-focused, and the answers are more straightforward.

Conventional wisdom states that no company can stand against the tide. That tide is made up of customer desires and expectations, not product specs. Where customers demand, companies must go. We at Be don't intend to stand against the tide, we plan to ride with it. Because riding with the tide, conventional wisdom tells us, is the best strategy.

Be Developer Profile: Acorde Corporation

To some developers, the BeBox's business potential is still kind of murky. That comes as no surprise for a platform that's only a few months old. But other developers look at the BeBox's multiprocessor architecture and the features of its operating system and find it hard to resist.

Acorde Corporation of Provo, Utah, is an example. Acorde is working on Apple's CyberDog product—a version of Open Doc for the Internet. They're also interested in graphics and presentation applications.

But when Acorde looks at the Mac and other operating systems, they see the past. Indeed, Apple is promising multitasking, multithreading operating systems with Copland and Gershwin, but they're not here yet. Be has already delivered.

"We know that the capabilities of the other machines out there are being stretched," says Stephen Humphrey, Acorde's president. "The Mac is in a transition to a more modern operating system for the future. But Be gives us a chance to prototype and work with a platform that has those capabilities now. And if Be takes off as a multimedia platform, then we'll be there early."

Humphrey says he and his two associates at Acorde are considering a port of Open Doc to the Be OS, because the current lack of a component architecture is a hole in Be's offering. But he's also impressed with Be's multimedia and Internet capabilities. He considers the Internet to be the next great publishing platform, and he thinks that Be's hefty graphics and sound capabilities will present a good opportunity there.

Humphrey started Acorde last October after working on Open Doc at Novell. He's committed to the idea of a "cottage" company, where people can work together over the Internet from remote locations.

"The key is that we want to design for the future, rather than the past, and this is the only way to do it," he says. "It's an opportunity to architect applications from the ground up that take advantage of threading capabilities. The more advantage we can get by being on a cutting-edge OS like Be, the better off we'll be."

Humphrey says he's hoping he can start playing with a BeBox in the near future and have a prototype product ready by the end of the year. Then he'll look to see whether there's a market for it.

The Electronic Newsletter

More and more people want to know about Be Inc. and the BeBox. Every day we receive new subscription requests. We're really glad to see this enthusiasm and interest. In order to please everybody—and because of our weekly schedule—we have had to find a way to save time, paper, and money and to be more flexible in updating our subscription database.

Therefore, starting with the next issue, we're going to send the weekly Be Newsletter electronically—this issue is the last paper one.

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