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When is VxWorks inappropriate, but QNX appropriate? EDIT: http://www.embeddedrelated.com/showthread/comp.arch.embedded/123841-1.php http://www.embeddedrelated.
by nchelluri 11y ago
When is VxWorks inappropriate, but QNX appropriate?
EDIT: http://www.embeddedrelated.com/showthread/comp.arch.embedded/123841-1.php http://www.embeddedrelated.com/showthread/comp.arch.embedded... says:
> the most fundamental difference between VxWorks and QNX is as you have described, QNX lends itself to a message passing architecture while VxWorks lends itself to a shared memory architecture.
>
> My personal opinion is that a message passing architecture is easier to get to grips with and as such is potentially easier to understand and debug.
> However, the majority of software engineers with experience of an embedded RTOS will be very well informed about the Shared Memory architecture.
- gte525u 11y agoI think it's less of an issue now than say 10 years ago. VxWorks 6.x added support for protection domains (MPU/MMU support) and RTPs (real time processes). VxWorks 5 everything operated in the kernel. Even with 6.x very little typically runs by default in user space on a VxWorks setup. With respect to the message passing - both support messaging. VxWorks has several types of message queues - vxworks proprietary msgQLib API, POSIX api etc. QNX has much the same MsgSend/MsgRecv which is the microkernel API and POSIX. QNX has an add-on PubSub middleware that the OP of the usenet group may be thinking of.
- saosebastiao 11y agoWould this imply no support for mmap(or similar) in qnx? Or just not very optimal to use it?
- gte525u 11y agoBoth support mmap and shared memory - that's why I found the "shared memory" usenet post a little puzzling.