Semaphore

A fork of golang/x/sync/semaphore that is also resizable.

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This fork adds the ability to resize the semaphore in a concurrent-safe way.

• Use semaphore.Resize(N) to resize the semaphore to a new absolute value N

• Example

  sem := semaphore.NewWeighted(5)     // Semaphore size = 5
  result1 := sem.TryAcquire(10)       // returns false.
  sem.Resize(15)                      // Semaphore size now = 10
  result2 := sem.TryAcquire(10)       // returns true.
  fmt.Println(result1,result2)        // prints false \n true  

• Added resize functionality has no impact on the semaphore performance according to benchmarks.
• Tests for the newly added Resize() was also added.