70 lines
2.1 KiB
Text
70 lines
2.1 KiB
Text
import Std.Sync.RecursiveMutex
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def countIt (mutex : Std.RecursiveMutex Nat) : IO Unit := do
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for _ in [0:1000] do
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mutex.atomically do
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modify fun s => s + 1
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def atomically : IO Unit := do
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let mutex ← Std.RecursiveMutex.new 0
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let t1 ← IO.asTask (prio := .dedicated) (countIt mutex)
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let t2 ← IO.asTask (prio := .dedicated) (countIt mutex)
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let t3 ← IO.asTask (prio := .dedicated) (countIt mutex)
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let t4 ← IO.asTask (prio := .dedicated) (countIt mutex)
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IO.ofExcept t1.get
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IO.ofExcept t2.get
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IO.ofExcept t3.get
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IO.ofExcept t4.get
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mutex.atomically do
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let val ← get
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if val != 4000 then
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throw <| .userError s!"Should be 4000 but was {val}"
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def holdIt (mutex : Std.RecursiveMutex Nat) (ref : IO.Ref Nat) : IO Unit := do
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mutex.atomically do
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ref.set 1
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modify fun s => s + 1
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while (← ref.get) == 1 do
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IO.sleep 1
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def tryIt (mutex : Std.RecursiveMutex Nat) (ref : IO.Ref Nat) : IO Unit := do
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while (← ref.get) == 0 do
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IO.sleep 1
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let success ← mutex.tryAtomically (modify fun s => s + 1)
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if success.isSome then throw <| .userError s!"lock succeeded but shouldn't"
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ref.set 2
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mutex.atomically (modify fun s => s + 1)
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let success ← mutex.tryAtomically (modify fun s => s + 1)
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if success.isNone then throw <| .userError s!"lock didn't succeed but should"
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def tryAtomically : IO Unit := do
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let mutex ← Std.RecursiveMutex.new 0
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let ref ← IO.mkRef 0
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let t1 ← IO.asTask (prio := .dedicated) (holdIt mutex ref)
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let t2 ← IO.asTask (prio := .dedicated) (tryIt mutex ref)
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IO.ofExcept t1.get
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IO.ofExcept t2.get
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mutex.atomically do
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let val ← get
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if val != 3 then
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throw <| .userError s!"Should be 3 but was {val}"
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def recursive : IO Unit := do
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let mutex ← Std.RecursiveMutex.new 0
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mutex.atomically do
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mutex.atomically do
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modify fun s => s + 1
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mutex.atomically do
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discard <| mutex.tryAtomically do
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modify fun s => s + 1
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mutex.atomically do
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let val ← get
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if val != 2 then
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throw <| .userError s!"Should be 2 but was {val}"
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#eval atomically
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#eval tryAtomically
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#eval recursive
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