Rollup merge of rust-lang#53311 - RalfJung:windows-mutex, r=retep998

kennytm · web-flow · commit ab5a71b0347b · 2018-08-24T16:44:30.000+08:00
Window Mutex: Document that we properly initialize the SRWLock See rust-lang#35836
diff --git a/src/libstd/sys/windows/mutex.rs b/src/libstd/sys/windows/mutex.rs
@@ -58,6 +58,8 @@ pub unsafe fn raw(m: &Mutex) -> c::PSRWLOCK {
 impl Mutex {
     pub const fn new() -> Mutex {
         Mutex {
+            // This works because SRWLOCK_INIT is 0 (wrapped in a struct), so we are also properly
+            // initializing an SRWLOCK here.
             lock: AtomicUsize::new(0),
             held: UnsafeCell::new(false),
         }

Original file line number	Diff line number	Diff line change
`@@ -58,6 +58,8 @@ pub unsafe fn raw(m: &Mutex) -> c::PSRWLOCK {`
`58`	`58`	`impl Mutex {`
`59`	`59`	`pub const fn new() -> Mutex {`
`60`	`60`	`Mutex {`
	`61`	`+ // This works because SRWLOCK_INIT is 0 (wrapped in a struct), so we are also properly`
	`62`	`+ // initializing an SRWLOCK here.`
`61`	`63`	`lock: AtomicUsize::new(0),`
`62`	`64`	`held: UnsafeCell::new(false),`
`63`	`65`	`}`