| use crate::sys::rwlock as imp; |
| |
| /// An OS-based reader-writer lock. |
| /// |
| /// This structure is entirely unsafe and serves as the lowest layer of a |
| /// cross-platform binding of system rwlocks. It is recommended to use the |
| /// safer types at the top level of this crate instead of this type. |
| pub struct RWLock(imp::RWLock); |
| |
| impl RWLock { |
| /// Creates a new reader-writer lock for use. |
| /// |
| /// Behavior is undefined if the reader-writer lock is moved after it is |
| /// first used with any of the functions below. |
| pub const fn new() -> RWLock { |
| RWLock(imp::RWLock::new()) |
| } |
| |
| /// Acquires shared access to the underlying lock, blocking the current |
| /// thread to do so. |
| /// |
| /// Behavior is undefined if the rwlock has been moved between this and any |
| /// previous method call. |
| #[inline] |
| pub unsafe fn read(&self) { |
| self.0.read() |
| } |
| |
| /// Attempts to acquire shared access to this lock, returning whether it |
| /// succeeded or not. |
| /// |
| /// This function does not block the current thread. |
| /// |
| /// Behavior is undefined if the rwlock has been moved between this and any |
| /// previous method call. |
| #[inline] |
| pub unsafe fn try_read(&self) -> bool { |
| self.0.try_read() |
| } |
| |
| /// Acquires write access to the underlying lock, blocking the current thread |
| /// to do so. |
| /// |
| /// Behavior is undefined if the rwlock has been moved between this and any |
| /// previous method call. |
| #[inline] |
| pub unsafe fn write(&self) { |
| self.0.write() |
| } |
| |
| /// Attempts to acquire exclusive access to this lock, returning whether it |
| /// succeeded or not. |
| /// |
| /// This function does not block the current thread. |
| /// |
| /// Behavior is undefined if the rwlock has been moved between this and any |
| /// previous method call. |
| #[inline] |
| pub unsafe fn try_write(&self) -> bool { |
| self.0.try_write() |
| } |
| |
| /// Unlocks previously acquired shared access to this lock. |
| /// |
| /// Behavior is undefined if the current thread does not have shared access. |
| #[inline] |
| pub unsafe fn read_unlock(&self) { |
| self.0.read_unlock() |
| } |
| |
| /// Unlocks previously acquired exclusive access to this lock. |
| /// |
| /// Behavior is undefined if the current thread does not currently have |
| /// exclusive access. |
| #[inline] |
| pub unsafe fn write_unlock(&self) { |
| self.0.write_unlock() |
| } |
| |
| /// Destroys OS-related resources with this RWLock. |
| /// |
| /// Behavior is undefined if there are any currently active users of this |
| /// lock. |
| #[inline] |
| pub unsafe fn destroy(&self) { |
| self.0.destroy() |
| } |
| } |