Operating System Basics and Processes

A program in execution is a dynamic and active entity. It is a 'living', running program, using system resources.

A static entity, a list of instructions stored in a file. It doesn't use system resources until it's loaded into memory to become a process.

An operating system function that creates a process from a program. It allows multiple programs to run concurrently.

The space in main memory (RAM) reserved for a process.

A system call informs the OS requesting an operation like creating a process, opening a file, or allocating memory. It's how programs interact with the OS.

A unique identifier assigned to each process, often represented as a number.

The creation of new processes from existing ones. A parent process can create child processes, which in turn can create their own children, forming a tree-like structure.

The process of deciding which process to run on which CPU core at any given time.

The ability to stop or terminate a process, either voluntarily by the user or involuntarily by the operating system.

The management of the computer's working memory (RAM) by the operating system, allocating memory to processes and ensuring efficient utilization.

When a program is loaded into memory to run, some memory is already assigned to it. This allocation usually follows a predefined structure, like a text segment for program instructions and a data segment for initial data.

A process where a program requests and receives memory during its execution.

Areas of memory that are allocated by a program during execution can be stored on the heap or stack, which grow towards each other.

The process of returning allocated memory to the system, indicating it is no longer needed. This frees up the memory for other programs to use.

A situation where a program constantly allocates memory but never releases it, leading to a shortage of available memory and potential program crashes.

A common problem in dynamic memory allocation where a program writes data beyond the allocated memory boundary, potentially overwriting other data and causing program errors or security vulnerabilities.

A computer security vulnerability caused by buffer overflows, allowing attackers to execute arbitrary code on a vulnerable system.

Human programmers can be prone to forgetting to release allocated memory, leading to memory leaks. This highlights the importance of proper memory management practices.

Data stored next to the allocated memory for the variable where writing data overflows.

A situation where a program tries to write more data than the allocated space allows for.

Ensuring a program checks if it has reached the allocated memory limit before writing more data.

A specially crafted message designed to exploit a vulnerability like a buffer overflow and execute malicious code.

A technique that allows an attacker to gain control of a device by manipulating its memory through a vulnerability, often a buffer overflow.

The method of loading only the required parts of a program into main memory, instead of the entire program, optimizing use of memory resources.