.NET 4 SpinLock
- by Jon Harrop
The following test code (F#) is not returning the result I'd expect:
let safeCount() =
let n = 1000000
let counter = ref 0
let spinlock = ref <| SpinLock(false)
let run i0 i1 () =
for i=i0 to i1-1 do
let locked = ref false
try
(!spinlock).Enter locked
if !locked then
counter := !counter + 1
finally
if !locked then
(!spinlock).Exit()
let thread = System.Threading.Thread(run 0 (n/2))
thread.Start()
run (n/2) n ()
thread.Join()
!counter
I'd expect the SpinLock to mutually exclude the counter and, therefore, for it to return counts of 1,000,000 but, instead, it returns smaller values as if no mutual exclusion is occurring.
Any ideas what's wrong?
