Lecture 3 -Process Description and Control

Allocates I/O channels and devices to processes.

Moving part or all of a process from main memory to disk.

Waiting for I/O operations to complete.

The operating system (OS).

Space for the process.

The operating system.

A more-privileged mode also referred to as control mode or kernel mode.

By opening new tabs or child windows.

A program in execution.

It is moved to a disk into a suspend queue.

Assigns a unique process identifier to the new process.

The attributes of the process.

A less-privileged mode where user programs typically execute.

When none of the processes in main memory is in the Ready state.

Memory, I/O, and files, directly or indirectly.

The kernel is involved through a system call.

Resource allocation at one snapshot in time.

The process control block.

It can be interrupted and later resumed as if the interruption had not occurred.

Process Description and Control.

An explicit request to call an operating system function.

An asynchronous external event.

It helps manage system load and optimize performance.

To maintain and use information related to files.

It handles system calls made by applications.

It enables better utilization of CPU and system resources.

From user mode to kernel mode.

It is waiting for an event and has been swapped to secondary storage.

Executable instructions.

The occurrence of the event it was waiting for.

The context that existed at the time the selected process was last switched out.

A process is a program in execution, which includes the program code, its current activity, and the resources allocated to it.

The process has waited longer than a specified maximum for a certain event to occur.

The operator or the operating system has terminated the process, such as in a deadlock situation.

To keep track of both main (real) and secondary (virtual) memory.

Eighth Edition.

Input/Output.

Memory management.

The location and attributes of the process.

The program to be executed.

The processor proceeds to the fetch stage and fetches the next instruction of the current program in the current process.

The process has to wait a long time if many inputs are given.

To provide dynamically allocated memory to a process during runtime.

It has been released from the pool of executable processes by the OS, either because it halted or aborted.

It could damage the blocks and destroy the system’s ability to manage affected processes.

It refers to memory that can be accessed by multiple processes.

Process scheduling and dispatching.

System calls or interrupts that require kernel-level access.

Kernel mode is a privileged mode of operation that allows the execution of any CPU instruction and access to any memory address, enabling full control over the system.

Process switching, or context switching, is the procedure of storing the state of a currently running process and loading the state of another process, allowing multiple processes to share the CPU effectively.

An I/O device may be available or assigned to a particular process.

A means to indicate its completion.

To execute a program.

To manage and allocate system resources efficiently.

Saving a file, writing to the terminal, or opening a TCP connection.

They represent different processes in the system.

Existence of files, location on secondary memory, current status, and other attributes.

New, Ready, Blocked, Running, Exit.

To manage processes that are swapped out of main memory and placed onto external storage.

The process can be activated and moved to the Ready state.

Suspend wait and suspend blocked.

The process has completed its execution.

To switch the CPU from one process to another.

The process requires more memory than the system can provide.

Buffer management.

The states include new (process is being created), ready (waiting to be assigned to a processor), running (currently being executed), suspend (temporarily inactive), block (waiting for an event), and exit (finished execution).

An error occurs during input or output, such as inability to find a file.

Observing system performance and resource usage.

The operating system may automatically terminate all of the offspring of that parent.

It is considered passive.

Using some sort of virtual memory or simple swapping mechanism.

A data structure that contains information about a process.

Resources are made available to multiple applications.

The processor is switched among multiple applications so all will appear to be progressing.

Processes are created in response to user requests for services.

They manage much of the detail of file management themselves.

It allows multiple child processes to run in parallel, completing tasks quickly.

Temporary data such as function parameters, return addresses, and local variables.

The process control block (PCB).

Protection, not access.

The process control block (PCB) of the selected process.

Process creation and termination.

Mode switch is generally faster than process switch.

The process attempts to use a resource it is not allowed to use or tries to use it improperly.

A parent process typically has the authority to terminate any of its offspring.

To manage the I/O devices and channels of the computer system.

An error or an exception condition associated with the execution of the current instruction.

A HALT instruction or an explicit OS service call.

Through user actions like logging off or quitting an application.

User Data, which may include program data, a user stack area, and modifiable programs.

It allows efficient use of the processor and I/O devices.

Running.

The Process Control Block (PCB).

It waits for an event to occur.

To store process identification and control information.

Another process for execution.

Waiting for an event.

A transition between user mode and kernel mode in an operating system.

Allocation of address space to processes.

Accounting.

The process attempts to use an instruction reserved for the operating system.

Interrupt.

To free up memory for other processes.

Processes may be suspended to allocate resources to higher-priority tasks.

A function call from an app into the kernel.

Main Memory and Virtual Memory.

The appropriate linkages.

Other data structures.

A process that cannot execute until some event occurs, such as the completion of an I/O operation.

Blocks are read and/or modified by virtually every module in the OS.

It is moved to the appropriate queue.

The user stack contains temporary data such as function parameters, return addresses, and local variables.

It may go to suspend ready.

The act of switching the CPU from one process to another.

User mode is a restricted mode of operation for running user applications, where the access to hardware and system resources is limited to prevent interference with the kernel.

Process control blocks.

Moving processes between main memory and disk.

Interrupt handling.

A piece of data is of the wrong type or is not initialized.

Process tables.

Where the process is located.

State, priority, program counter, memory pointers, context data, I/O status information, and accounting information.

The process of giving a game character new life or creating a copy of the parent.

Creating new guns that are similar to previous guns.

The kernel of the operating system.

Data needed by the OS to control the process.

It has just been created but has not yet been admitted to the pool of executable processes by the OS.

Global variables.

When it is brought back into main memory.

It holds the programs and data specific to a user process.

The need for the CPU to allocate time to a different process, often due to scheduling.

To allow user applications to safely access system resources.

Process creation occurs when a new process is initiated, termination happens when a process completes its execution, and suspension refers to temporarily halting a process without losing its state.

The process tries a prohibited computation, such as division by zero.

The process attempts to execute a nonexistent instruction.

Yes, processes can be suspended to facilitate debugging.

It allows multiple processes to run concurrently.

It is prepared to execute when given the opportunity.

All information about a process needed by the OS.

To temporarily halt a process without terminating it.

Processor state information includes the current state of the CPU registers.

It could affect a number of modules in the OS.

Each process is assigned a unique process identifier (PID).

Interprocess communication.

A Process Control Block is a data structure used by the operating system to store all the information about a process, including its state, program counter, CPU registers, and memory management information.

To manage CPU time among multiple processes efficiently.

To store parameters and calling addresses for procedure and system calls.

Little or no knowledge of files.

To allow the interrupt processing code to include privileged instructions.

It is swapped out of main memory and placed onto external storage by the scheduler.

The current activity of the process.

Memory management data structures.

Make substantial changes in its environment.

The process executes an OS service call to indicate that it has completed running.

The process has run longer than the specified total time limit.

The process tries to access a memory location that it is not allowed to access.

The processor sets the program counter to the starting address of an interrupt handler program.

Save the context of the processor.

The state of the OS.

'Ready' means the process is ready to run, while 'Ready/Suspend' indicates it is ready but temporarily suspended.

To allocate CPU time to a process in the Ready state.

The process is in user domain, as these are applications running in a restricted mode to interact with the system.