CODEWITHSUNDEEP
multithreadingkernelscheduling
Luv
Luv

Reputation: 5451

Context switch between threads in a process

For Kernel-Level-Threads when one thread blocks for some I/O another thread is free to run, but in User-Level-Threads what happens if one thread is blocked?

Will that process remain blocked i.e. no other thread will execute or another thread will be scheduled to run. What happens exactly?

Upvotes: 2

Views: 1866

Answers (1)

Hristo Iliev
Hristo Iliev

Reputation: 74365

User-level threads are pieces of user code that execute in sequential fashion - one thread runs for a while then transfers the control to another thread and so on. If one of those threads make a syscall that blocks then the process as a whole blocks. User-level threading looks like a single threaded process to the kernel. No concurrent scheduling on multiple CPUs is possible.

The main advantage of kernel-level threads is that they run independently from one another and can be scheduled on different CPUs. If one blocks, others continue to execute.

Upvotes: 3

Related Questions