51.When is a system in safe state?
The set of dispatchable processes is in a safe state if there exists at least one temporal order in which all processes can be run to completion without resulting in a deadlock.
52. What is cycle stealing?
We encounter cycle stealing in the context of Direct Memory Access (DMA). Either the DMA controller can use the data bus when the CPU does not need it, or it may force the CPU to temporarily suspend operation. The latter technique is called cycle stealing. Note that cycle stealing can be done only at specific break points in an instruction cycle.
53. What is an idle thread?
The special thread a dispatcher will execute when no ready thread is found.
54. What is FtDisk?
It is a fault tolerance disk driver for Windows NT.
55.What is Dispatcher?
Dispatcher module gives control of the CPU to the process selected by the short-term scheduler; this involves: Switching context, Switching to user mode, Jumping to the proper location in the user program to restart that program, dispatch latency time it takes for the dispatcher to stop one process and start another running.
56. When does the condition ‘rendezvous’ arise?
In message passing, it is the condition in which, both, the sender and receiver are blocked until the message is delivered.
57. What is process spawning?
When the OS at the explicit request of another process creates a process, this action is called process spawning
58. What are the reasons for process suspension?
1) swapping
2) interactive user request
3) timing
4) parent process request
59. What are the sub-components of I/O manager in Windows NT?
1) Network redirector/ Server
2) Cache manager.
3) File systems
4) Network driver
5) Device driver
60. What is a drawback of MVT?
1) ability to support multiple processors
2) virtual storage
3) source level debugging
