C++ 20 (2a) New Features - Lightweight Access Coordination

The video tutorial introduces counting semaphores, a synchronization primitive added in C20. It explains their initialization and operations like acquire and release, which manage thread synchronization by controlling access to shared resources. The tutorial highlights that semaphores were not available in C until C20, and current major compilers may not support them. The next video will cover latches and barriers.

What is the initial value of the semaphore in the given example?

• 1

• 0

• 5

• 10

What happens when both threads try to acquire a semaphore with a counter of zero?

• Both threads proceed without blocking

• One thread blocks while the other proceeds

• Both threads are blocked

• The semaphore counter increases

What operation increases the semaphore counter by 1?

• Block

• Initialize

• Release

• Acquire

What ensures that only one thread will be sleeping at a time?

• The semaphore counter is always positive

• The acquire operation is never called

• Both threads are always active

• The semaphore ensures only one thread can acquire it at a time

Why can't the code be compiled in any major compiler at this time?

• The semaphore is not available in any library

• The code is written in an unsupported language

• The code is too complex

• The standard library does not yet support semaphores