Mobile OS

Mobile OS 
OS for mobile handheld devices, wireless, devices,  palm PC, pocket PCs, PDAs and phones.

Protection mechanism

Protection mechanism
A mechanism at an OS  to protect against unauthorized accesses to the resources. 

Deregistering

DeRegistering
Making it unfeasible for the RTOS to schedule like a task.

Registering a Device

Registering a Device

Making it feasible for RTOS to schedule like a task.

Linux OS

Linux OS
A powerful operating system with UNIX like features plus special device driver scheduling features and memory management features.

Fixed real time scheduling

Fixed real time scheduling
A scheduling strategy in which the time for each task is fixed.

Critical section run

Critical section run
In spite of higher priority pending, a critical section is allowed to run by a scheduler using the semaphore.

Cooperative Scheduling

Cooperative Scheduling
A waiting task lets another task run till it finishes.

Time Slicing Scheduling

Time Slicing Scheduling
A scheduling algorithm in which each task is allotted a time slice after which it is blocked and waits for its turn on the next cycle. 

Preempting scheduling

Preempting scheduling
A scheduling algorithm in which  a higher priority task is forced to block by the scheduler to let a higher priority task run. 

Round Robin or Cyclic Scheduling

Round Robin or Cyclic Scheduling 
A scheduling algorithm in which the tasks are scheduled in a sequence from a list of ready tasks. 

Real Time Operating System

Real Time Operating System
Operating system with real time task scheduling, interrupt-latency control, synchronization of tasks with IPCs, predictable timing and synchronization behavior of the system.

Operating system

Operating system
A system having kernel functions, file management functions and other functions also.

Kernel

Kernel 
A basic unit of any OS that includes the functions for processes, memory, task scheduling, inter process communication, management of devices, IOs , and interrupts and may include the file systems and network subsystem in a certain OSs.

Remote Procedure Call

Remote Procedure Call 
A method used for connecting two remotely placed methods by first using protocol for connecting the processes. It is used in the cases of distributed tasks.

Socket

Socket
It provides the logical link using a protocol between the tasks in a client-server or peer-to-peer environment.

Pipe

Pipe
A task sending the messages used by another task using these as input. A pipe can be a device like file which also a virtual device.

Mailbox

Mailbox
A message or message pointer from a task that is addressed to another task .

Message Queue

Message Queue
A task sending the multiple FIFO or priority messages into a queue for use by another task using queue messages as an input.

Deadlock Situation

Deadlock Situation

A task waiting for some semaphore the release of a semaphore from a task and another different task waiting for another semaphore release to run. None of these is able to proceed further . An operating system can take care of this is by appropriate provisions.