shithub: mc

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Prettify mutex code a bit.

	The if statements at the start were a touch odd.

--- a/lib/thread/mutex+futex.myr

+++ b/lib/thread/mutex+futex.myr

@@ -60,17 +60,19 @@

 const mtxunlock = {mtx

 	/*

+	Either the lock is contended or it's uncontended. Any other

+	state is a bug.

+

 	Uncontended case: If the mutex state is not contended, and we still

 	are uncontended by the xchg() call, then it's safe to simply return;

 	nobody was waiting for us.

 	*/

-	if mtx._state == Contended

-		mtx._state = Unlocked

-	elif xchg(&mtx._state, Unlocked) == Locked

+	if xcas(&mtx._state, Locked, Unlocked) == Locked

 		-> void

 	;;

-	/* wake one thread */

+	/* Contended case: set the state to unlocked and wake one thread */

+	mtx._state = Unlocked

 	ftxwake(&mtx._state)

 }