Real Time OS

[mikeshn]

Can someone explain to me what Real Time OS means?
Thanks a lot

 

[Nothinman]

It's means processes are guaranteed real-time scheduler time.

In an OS like Windows or Linux (without the RT patches) a process can be suspended indefinately for whatever reason, usually some form of I/O.

In a RT OS like QNX (I believe) or Linux with the RT patches a real-time process is guaranteed X amount of CPU time every Y milliseconds, no matter what.

 

[freebsddude]

RTOS (Real Time OS) are OS'es whose response is predictable/deterministic under various loads
and responds based on preset requirements.

Many people think (I did that myself!) of RTOS as an operating system that responds immediately to an action. This is not true.

A fighter jet may have an RTOS that fires weapons or moves wing flaps quickly. Your gas level indicator in your car can also be thought of as an RTOS. Its response is not instantaneous but gradual and dampened, i.e. the gas tank reading is based on information collected over a period of time. Think what would happen if your car was negotiating a bumpy road. If the requirement was to instantaneously and accurately give you a gas tank reading, then the needle would flip all over the place (since gas will keep moving and shifting in your gas tank on bumpy roads).

Real Time OS'es are not necessarily confined to OSes in the standard software terminology but could be anything. Our home heating dial/control can also be viewed as having one.

Best Wishes!