Explain two circumstances that would cause user level threading during process execution. (4 marks)DICT MOD 1 July 2020

User level threading occurs when a program creates and manages its own threads, rather than relying on the operating system to do so. There are several circumstances that may cause a program to use user level threading during process execution:

1. The program requires a high degree of control over the threads it creates: User level threads allow a program to have more control over the scheduling and execution of its threads. This can be useful for programs that need to implement custom scheduling algorithms or that need to manage the threads in a specific way.
2. The program needs to run on a system that does not support kernel level threading: Some operating systems do not provide support for kernel level threads, which means that programs running on these systems must use user level threads if they want to use multiple threads.
3. The program needs to run on a system with limited resources: Kernel level threads require additional resources (such as system memory and processor time) to manage and schedule. If a system has limited resources, using user level threads may be more efficient.
4. The program needs to run on a system with a large number of threads: Some systems may have a large number of threads that need to be managed concurrently. In these cases, using user level threads may be more efficient than relying on the kernel to manage all of the threads.