lean4-htt/tests/lean/run/sync_mutex.lean
Henrik Böving 1b5a52a5e9
feat: Std.BaseMutex.tryLock and Mutex.tryAtomically (#7751)
This PR adds `Std.BaseMutex.tryLock` and `Std.Mutex.tryAtomically` as
well as unit tests for our locking and condition variable primitives.

---------

Co-authored-by: Markus Himmel <markus@lean-fro.org>
2025-03-31 12:19:09 +00:00

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2.4 KiB
Text

import Std.Sync.Mutex
def countIt (mutex : Std.Mutex Nat) : IO Unit := do
for _ in [0:1000] do
mutex.atomically do
modify fun s => s + 1
def atomically : IO Unit := do
let mutex ← Std.Mutex.new 0
let t1 ← IO.asTask (prio := .dedicated) (countIt mutex)
let t2 ← IO.asTask (prio := .dedicated) (countIt mutex)
let t3 ← IO.asTask (prio := .dedicated) (countIt mutex)
let t4 ← IO.asTask (prio := .dedicated) (countIt mutex)
IO.ofExcept t1.get
IO.ofExcept t2.get
IO.ofExcept t3.get
IO.ofExcept t4.get
mutex.atomically do
let val ← get
if val != 4000 then
throw <| .userError s!"Should be 4000 but was {val}"
def holdIt (mutex : Std.Mutex Nat) (ref : IO.Ref Nat) : IO Unit := do
mutex.atomically do
ref.set 1
modify fun s => s + 1
while (← ref.get) == 1 do
IO.sleep 1
def tryIt (mutex : Std.Mutex Nat) (ref : IO.Ref Nat) : IO Unit := do
while (← ref.get) == 0 do
IO.sleep 1
let success ← mutex.tryAtomically (modify fun s => s + 1)
if success.isSome then throw <| .userError s!"lock succeeded but shouldn't"
ref.set 2
mutex.atomically (modify fun s => s + 1)
let success ← mutex.tryAtomically (modify fun s => s + 1)
if success.isNone then throw <| .userError s!"lock didn't succeed but should"
def tryAtomically : IO Unit := do
let mutex ← Std.Mutex.new 0
let ref ← IO.mkRef 0
let t1 ← IO.asTask (prio := .dedicated) (holdIt mutex ref)
let t2 ← IO.asTask (prio := .dedicated) (tryIt mutex ref)
IO.ofExcept t1.get
IO.ofExcept t2.get
mutex.atomically do
let val ← get
if val != 3 then
throw <| .userError s!"Should be 3 but was {val}"
def workIt (mutex : Std.Mutex Nat) (cond : Std.Condvar) : IO Unit := do
for _ in [0:1000] do
mutex.atomically do (modify fun s => s + 1)
cond.notifyAll
def finishIt (mutex : Std.Mutex Nat) (cond : Std.Condvar) : IO Unit := do
mutex.atomicallyOnce cond (do return (← get) == 1000) do
modify fun s => s + 41000
def condVar : IO Unit := do
let mutex ← Std.Mutex.new 0
let cond ← Std.Condvar.new
let t1 ← IO.asTask (prio := .dedicated) (workIt mutex cond)
let t2 ← IO.asTask (prio := .dedicated) (finishIt mutex cond)
IO.ofExcept t1.get
IO.ofExcept t2.get
mutex.atomically do
let val ← get
if val != 42000 then
throw <| .userError s!"Should be 42000 but was {val}"
#eval atomically
#eval tryAtomically
#eval condVar