Change lock to use time.After (#190)

Author: lredlin

testdata/examples/channel/channel.gold.v

@@ -1668,39 +1668,19 @@ Definition Lock__LockWithTimeoutⁱᵐᵖˡ {ext : ffi_syntax} {go_gctx : GoGlob
     (if: Convert go.untyped_bool go.bool ((![time.Duration] "d") ≤⟨time.Duration⟩ #(W64 0))
     then return: (#false)
     else do:  #());;;
-    let: "done" := (GoAlloc (go.ChannelType go.sendrecv (go.StructType [
-
-    ])) (GoZeroVal (go.ChannelType go.sendrecv (go.StructType [
-
-    ])) #())) in
-    let: "$r0" := ((FuncResolve go.make1 [go.ChannelType go.sendrecv (go.StructType [
-
-     ])] #()) #()) in
-    do:  ("done" <-[go.ChannelType go.sendrecv (go.StructType [
-
-    ])] "$r0");;;
-    let: "$go" := (λ: <>,
-      exception_do (do:  (let: "$a0" := (![time.Duration] "d") in
-      (FuncResolve time.Sleep [] #()) "$a0");;;
-      do:  (let: "$a0" := (![go.ChannelType go.sendrecv (go.StructType [
-
-      ])] "done") in
-      (FuncResolve go.close [go.ChannelType go.sendrecv (go.StructType [
-
-       ])] #()) "$a0");;;
-      return: #())
-      ) in
-    do:  (Fork ("$go" #()));;;
-    return: (let: "$a0" := (Convert (go.ChannelType go.sendrecv (go.StructType [
+    let: "$v0" := (CompositeLiteral (go.StructType [
 
-     ])) (go.ChannelType go.recvonly (go.StructType [
+    ]) (LiteralValue [])) in
+    let: "$ch0" := (![go.ChannelType go.sendrecv (go.StructType [
 
-     ])) (![go.ChannelType go.sendrecv (go.StructType [
+    ])] (StructFieldRef Lock "ch"%go (![go.PointerType Lock] "l"))) in
+    let: "$ch1" := (let: "$a0" := (![time.Duration] "d") in
+    (FuncResolve time.After [] #()) "$a0") in
+    SelectStmt (SelectStmtClauses None [(CommClause (SendCase (go.StructType [
 
-     ])] "done")) in
-     (MethodResolve (go.PointerType Lock) "LockIfNotCancelled"%go (![go.PointerType Lock] "l")) "$a0")).
+    ]) "$ch0" "$v0") (return: (#true))); (CommClause (RecvCase time.Time "$ch1") (return: (#false)))])).
 
-(* go: lock.go:69:16 *)
+(* go: lock.go:70:16 *)
 Definition Lock__LockWithDeadlineⁱᵐᵖˡ {ext : ffi_syntax} {go_gctx : GoGlobalContext} : val :=
   λ: "l" "deadline",
     exception_do (let: "l" := (GoAlloc (go.PointerType Lock) "l") in

testdata/examples/channel/lock.go

@@ -58,12 +58,13 @@ func (l *Lock) LockWithTimeout(d time.Duration) bool {
 	if d <= 0 {
 		return false
 	}
-	done := make(chan struct{})
-	go func() {
-		time.Sleep(d)
-		close(done)
-	}()
-	return l.LockIfNotCancelled(done)
+
+	select {
+	case l.ch <- struct{}{}:
+		return true
+	case <-time.After(d):
+		return false
+	}
 }
 
 func (l *Lock) LockWithDeadline(deadline time.Time) bool {