D686 Exam Questions with 100% Correct
Answers
A thread represents a
fundamental unit of CPU utilization within a process,
A thread has essential components such as
a thread ID, program counter, register set, and stack.
Threads within the same process share
code, data, and operating system resources like files and signals.
If a process has multiple threads, it can do
multiple tasks at once. This has several benefits: it keeps applications responsive, allows easy
resource sharing, saves memory and time, and takes advantage of multiple processors to run
tasks faster
In multithreading models, the diverse approaches to managing threads within OS
distinguish between
user-level threads (threads that operate exclusively in user mode) and kernel-level threads
(threads that operate in kernel mode)
There are three primary threading models:
the many-to-one
one-to-one
many-to-many
Each threading model influences
,concurrency and system performance differently
an operating system is a
resource allocator
A control program manages the
execution of user programs to prevent errors and improper use of the computer, especially
with the operation and control of I/O devices
CPU hardware has a wire called the _____________ that the CPU senses after executing
every instruction
interrupt-request line
When the CPU detects that a controller has asserted a signal on the interrupt-request
line, it reads the interrupt number and jumps to the _________________ by using that
interrupt number as an index into the interrupt vector
interrupt-handler routine
Most CPUs have two
interrupt request lines
The ____________ interrupt, is reserved for events such as unrecoverable memory
errors
nonmaskable
The second interrupt line is _________, it can be turned off by the CPU before the
execution of critical instruction sequences that must not be interrupted
, maskable
The maskable interrupt is used by device controllers to request service
the purpose of a _______________________ is to reduce the need for a single interrupt
handler to search all possible sources of interrupts to determine which one needs service
vectored interrupt mechanism
A mechanism by which each element in an interrupt vector points to the head of a list of
interrupt handlers, which are called individually until one is found to service the
interrupt request
interrupt chaining
A typical instruction-execution cycle, as executed on a system with a von Neumann
architecture, first fetches
an instruction from memory and stores that instruction in the instruction register.
storage that is slow enough and large enough that it is used only for special purposes is
called
tertiary storage
User mode refers to the CPU operating mode that
restricts certain instructions from executing user processes
kernel mode refers to a CPU operating mode where
all instructions are accessible
At system boot time, the hardware starts in
kernel mode
Answers
A thread represents a
fundamental unit of CPU utilization within a process,
A thread has essential components such as
a thread ID, program counter, register set, and stack.
Threads within the same process share
code, data, and operating system resources like files and signals.
If a process has multiple threads, it can do
multiple tasks at once. This has several benefits: it keeps applications responsive, allows easy
resource sharing, saves memory and time, and takes advantage of multiple processors to run
tasks faster
In multithreading models, the diverse approaches to managing threads within OS
distinguish between
user-level threads (threads that operate exclusively in user mode) and kernel-level threads
(threads that operate in kernel mode)
There are three primary threading models:
the many-to-one
one-to-one
many-to-many
Each threading model influences
,concurrency and system performance differently
an operating system is a
resource allocator
A control program manages the
execution of user programs to prevent errors and improper use of the computer, especially
with the operation and control of I/O devices
CPU hardware has a wire called the _____________ that the CPU senses after executing
every instruction
interrupt-request line
When the CPU detects that a controller has asserted a signal on the interrupt-request
line, it reads the interrupt number and jumps to the _________________ by using that
interrupt number as an index into the interrupt vector
interrupt-handler routine
Most CPUs have two
interrupt request lines
The ____________ interrupt, is reserved for events such as unrecoverable memory
errors
nonmaskable
The second interrupt line is _________, it can be turned off by the CPU before the
execution of critical instruction sequences that must not be interrupted
, maskable
The maskable interrupt is used by device controllers to request service
the purpose of a _______________________ is to reduce the need for a single interrupt
handler to search all possible sources of interrupts to determine which one needs service
vectored interrupt mechanism
A mechanism by which each element in an interrupt vector points to the head of a list of
interrupt handlers, which are called individually until one is found to service the
interrupt request
interrupt chaining
A typical instruction-execution cycle, as executed on a system with a von Neumann
architecture, first fetches
an instruction from memory and stores that instruction in the instruction register.
storage that is slow enough and large enough that it is used only for special purposes is
called
tertiary storage
User mode refers to the CPU operating mode that
restricts certain instructions from executing user processes
kernel mode refers to a CPU operating mode where
all instructions are accessible
At system boot time, the hardware starts in
kernel mode
