[LUGSB] Multithreading or Light-weight processes ?

[Arjun G. Menon]

Hi LUGSB,

I guess most of you must have worked with threads at some point and
are familiar with the difficulty involved in writing complex
applications that use them. I think the best way to overcome this
"thread problem"
(http://www.eecs.berkeley.edu/Pubs/TechRpts/2006/EECS-2006-1.pdf) is
by using light-weight processes.

I personally feel using light-weight processes for intra-application
multitasking is far more superior than having concurrently running
threads that share the same block of memory. Light-weight processes
are far more secure than threads in the sense they don't share memory
and thus avoid a whole host of problems associated with it. IMO, they
are also easier to work with (while programming); I find the
message-passing IPC model simpler and more manageable.

Additionally when it comes to parallel computing; even there
light-weight processes are a win-win scenario. There's no need for
complex algorithms that manage shared memory between CPUs when each
CPU can be assigned 1/more L.W.-processes and they all interact by
message passing. I think on a well designed OS, L.W.-procs should be
as efficient as threads.

Some applications like Google Chrome already use L.W.-procs (for each
tab the user opens a seperate process is launched). It surprises me
that a lot more people don't use it already, given its many
advantages. Which model of multitasking do you think is better?
(especially in terms of programmer efficiency)