Use Drop instead of destroy() for locks.

Author: m-ou-se

library/std/src/sys/hermit/condvar.rs

@@ -70,9 +70,13 @@ impl Condvar {
         mutex.lock();
         res == 0
     }
+}
 
-    pub unsafe fn destroy(&self) {
-        let _ = abi::sem_destroy(self.sem1);
-        let _ = abi::sem_destroy(self.sem2);
+impl Drop for Condvar {
+    fn drop(&mut self) {
+        unsafe {
+            let _ = abi::sem_destroy(self.sem1);
+            let _ = abi::sem_destroy(self.sem2);
+        }
     }
 }

library/std/src/sys/hermit/mutex.rs

@@ -215,7 +215,4 @@ impl Mutex {
         }
         guard.locked
     }
-
-    #[inline]
-    pub unsafe fn destroy(&self) {}
 }

library/std/src/sys/hermit/rwlock.rs

@@ -84,12 +84,6 @@ impl RwLock {
         // FIXME: should only wake up one of these some of the time
         self.cond.notify_all();
     }
-
-    #[inline]
-    pub unsafe fn destroy(&self) {
-        self.lock.destroy();
-        self.cond.destroy();
-    }
 }
 
 impl State {

library/std/src/sys/itron/condvar.rs

@@ -117,8 +117,6 @@ impl Condvar {
         unsafe { mutex.lock() };
         success
     }
-
-    pub unsafe fn destroy(&self) {}
 }
 
 mod waiter_queue {

library/std/src/sys/itron/mutex.rs

@@ -64,8 +64,10 @@ impl Mutex {
             }
         }
     }
+}
 
-    pub unsafe fn destroy(&self) {
+impl Drop for Mutex {
+    fn drop(&mut self) {
         if let Some(mtx) = self.mtx.get().map(|x| x.0) {
             expect_success_aborting(unsafe { abi::del_mtx(mtx) }, &"del_mtx");
         }

library/std/src/sys/sgx/condvar.rs

@@ -38,7 +38,4 @@ impl Condvar {
         unsafe { mutex.lock() };
         success
     }
-
-    #[inline]
-    pub unsafe fn destroy(&self) {}
 }

library/std/src/sys/sgx/mutex.rs

@@ -52,7 +52,4 @@ impl Mutex {
             true
         }
     }
-
-    #[inline]
-    pub unsafe fn destroy(&self) {}
 }

library/std/src/sys/sgx/rwlock.rs

@@ -168,9 +168,6 @@ impl RwLock {
             unsafe { self.__read_unlock(rguard, wguard) };
         }
     }
-
-    #[inline]
-    pub unsafe fn destroy(&self) {}
 }
 
 // The following functions are needed by libunwind. These symbols are named

library/std/src/sys/solid/rwlock.rs

@@ -82,9 +82,11 @@ impl RwLock {
         let rwl = self.raw();
         expect_success_aborting(unsafe { abi::rwl_unl_rwl(rwl) }, &"rwl_unl_rwl");
     }
+}
 
+impl Drop for RwLock {
     #[inline]
-    pub unsafe fn destroy(&self) {
+    fn drop(&mut self) {
         if let Some(rwl) = self.rwl.get().map(|x| x.0) {
             expect_success_aborting(unsafe { abi::rwl_del_rwl(rwl) }, &"rwl_del_rwl");
         }

library/std/src/sys/unix/locks/futex.rs

@@ -24,9 +24,6 @@ impl Mutex {
     #[inline]
     pub unsafe fn init(&mut self) {}
 
-    #[inline]
-    pub unsafe fn destroy(&self) {}
-
     #[inline]
     pub unsafe fn try_lock(&self) -> bool {
         self.futex.compare_exchange(0, 1, Acquire, Relaxed).is_ok()
@@ -121,9 +118,6 @@ impl Condvar {
     #[inline]
     pub unsafe fn init(&mut self) {}
 
-    #[inline]
-    pub unsafe fn destroy(&self) {}
-
     // All the memory orderings here are `Relaxed`,
     // because synchronization is done by unlocking and locking the mutex.
 

library/std/src/sys/unix/locks/futex_rwlock.rs

@@ -63,9 +63,6 @@ impl RwLock {
         Self { state: AtomicU32::new(0), writer_notify: AtomicU32::new(0) }
     }
 
-    #[inline]
-    pub unsafe fn destroy(&self) {}
-
     #[inline]
     pub unsafe fn try_read(&self) -> bool {
         self.state

library/std/src/sys/unix/locks/pthread_condvar.rs

@@ -179,14 +179,14 @@ impl Condvar {
 
     #[inline]
     #[cfg(not(target_os = "dragonfly"))]
-    pub unsafe fn destroy(&self) {
+    unsafe fn destroy(&mut self) {
         let r = libc::pthread_cond_destroy(self.inner.get());
         debug_assert_eq!(r, 0);
     }
 
     #[inline]
     #[cfg(target_os = "dragonfly")]
-    pub unsafe fn destroy(&self) {
+    unsafe fn destroy(&mut self) {
         let r = libc::pthread_cond_destroy(self.inner.get());
         // On DragonFly pthread_cond_destroy() returns EINVAL if called on
         // a condvar that was just initialized with
@@ -195,3 +195,10 @@ impl Condvar {
         debug_assert!(r == 0 || r == libc::EINVAL);
     }
 }
+
+impl Drop for Condvar {
+    #[inline]
+    fn drop(&mut self) {
+        unsafe { self.destroy() };
+    }
+}

library/std/src/sys/unix/locks/pthread_mutex.rs

@@ -73,13 +73,13 @@ impl Mutex {
     }
     #[inline]
     #[cfg(not(target_os = "dragonfly"))]
-    pub unsafe fn destroy(&self) {
+    unsafe fn destroy(&mut self) {
         let r = libc::pthread_mutex_destroy(self.inner.get());
         debug_assert_eq!(r, 0);
     }
     #[inline]
     #[cfg(target_os = "dragonfly")]
-    pub unsafe fn destroy(&self) {
+    unsafe fn destroy(&mut self) {
         let r = libc::pthread_mutex_destroy(self.inner.get());
         // On DragonFly pthread_mutex_destroy() returns EINVAL if called on a
         // mutex that was just initialized with libc::PTHREAD_MUTEX_INITIALIZER.
@@ -89,6 +89,13 @@ impl Mutex {
     }
 }
 
+impl Drop for Mutex {
+    #[inline]
+    fn drop(&mut self) {
+        unsafe { self.destroy() };
+    }
+}
+
 pub(super) struct PthreadMutexAttr<'a>(pub &'a mut MaybeUninit<libc::pthread_mutexattr_t>);
 
 impl Drop for PthreadMutexAttr<'_> {

library/std/src/sys/unix/locks/pthread_rwlock.rs

@@ -128,7 +128,7 @@ impl RwLock {
         self.raw_unlock();
     }
     #[inline]
-    pub unsafe fn destroy(&self) {
+    unsafe fn destroy(&mut self) {
         let r = libc::pthread_rwlock_destroy(self.inner.get());
         // On DragonFly pthread_rwlock_destroy() returns EINVAL if called on a
         // rwlock that was just initialized with
@@ -141,3 +141,10 @@ impl RwLock {
         }
     }
 }
+
+impl Drop for RwLock {
+    #[inline]
+    fn drop(&mut self) {
+        unsafe { self.destroy() };
+    }
+}

library/std/src/sys/unsupported/locks/condvar.rs

@@ -26,7 +26,4 @@ impl Condvar {
     pub unsafe fn wait_timeout(&self, _mutex: &Mutex, _dur: Duration) -> bool {
         panic!("condvar wait not supported");
     }
-
-    #[inline]
-    pub unsafe fn destroy(&self) {}
 }

library/std/src/sys/unsupported/locks/mutex.rs

@@ -32,7 +32,4 @@ impl Mutex {
     pub unsafe fn try_lock(&self) -> bool {
         self.locked.replace(true) == false
     }
-
-    #[inline]
-    pub unsafe fn destroy(&self) {}
 }

library/std/src/sys/unsupported/locks/rwlock.rs

@@ -62,7 +62,4 @@ impl RwLock {
     pub unsafe fn write_unlock(&self) {
         assert_eq!(self.mode.replace(0), -1);
     }
-
-    #[inline]
-    pub unsafe fn destroy(&self) {}
 }

library/std/src/sys/windows/locks/condvar.rs

@@ -51,8 +51,4 @@ impl Condvar {
     pub unsafe fn notify_all(&self) {
         c::WakeAllConditionVariable(self.inner.get())
     }
-
-    pub unsafe fn destroy(&self) {
-        // ...
-    }
 }

library/std/src/sys/windows/locks/mutex.rs

@@ -53,9 +53,4 @@ impl Mutex {
     pub unsafe fn unlock(&self) {
         c::ReleaseSRWLockExclusive(raw(self));
     }
-
-    #[inline]
-    pub unsafe fn destroy(&self) {
-        // SRWLock does not need to be destroyed.
-    }
 }

library/std/src/sys/windows/locks/rwlock.rs

@@ -38,9 +38,4 @@ impl RwLock {
     pub unsafe fn write_unlock(&self) {
         c::ReleaseSRWLockExclusive(self.inner.get())
     }
-
-    #[inline]
-    pub unsafe fn destroy(&self) {
-        // ...
-    }
 }

library/std/src/sys_common/condvar.rs

@@ -55,9 +55,3 @@ impl Condvar {
         self.inner.wait_timeout(mutex.raw(), dur)
     }
 }
-
-impl Drop for Condvar {
-    fn drop(&mut self) {
-        unsafe { self.inner.destroy() };
-    }
-}

library/std/src/sys_common/mutex.rs

@@ -92,9 +92,3 @@ impl MovableMutex {
         self.0.unlock()
     }
 }
-
-impl Drop for MovableMutex {
-    fn drop(&mut self) {
-        unsafe { self.0.destroy() };
-    }
-}

library/std/src/sys_common/remutex.rs

@@ -168,13 +168,6 @@ impl<T> ReentrantMutex<T> {
     }
 }
 
-impl<T> Drop for ReentrantMutex<T> {
-    fn drop(&mut self) {
-        // Safety: We're the unique owner of this mutex and not going to use it afterwards.
-        unsafe { self.mutex.destroy() }
-    }
-}
-
 impl<T> Deref for ReentrantMutexGuard<'_, T> {
     type Target = T;
 

library/std/src/sys_common/rwlock.rs

@@ -126,9 +126,3 @@ impl MovableRwLock {
         self.0.write_unlock()
     }
 }
-
-impl Drop for MovableRwLock {
-    fn drop(&mut self) {
-        unsafe { self.0.destroy() };
-    }
-}