1 files changed, 126 insertions, 0 deletions
diff --git a/vendor/fd-lock/src/rw_lock.rs b/vendor/fd-lock/src/rw_lock.rs
new file mode 100644
index 000000000..77f9d2231
--- /dev/null
+++ b/vendor/fd-lock/src/rw_lock.rs
@@ -0,0 +1,126 @@
+use crate::read_guard::RwLockReadGuard;
+use crate::sys;
+use crate::write_guard::RwLockWriteGuard;
+use std::io;
+
+/// Advisory reader-writer lock for files.
+///
+/// This type of lock allows a number of readers or at most one writer at any point
+/// in time. The write portion of this lock typically allows modification of the
+/// underlying data (exclusive access) and the read portion of this lock typically
+/// allows for read-only access (shared access).
+#[derive(Debug)]
+pub struct RwLock<T: sys::AsRaw> {
+    lock: sys::RwLock<T>,
+}
+
+impl<T: sys::AsRaw> RwLock<T> {
+    /// Create a new instance.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use fd_lock::RwLock;
+    /// use std::fs::File;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let mut f = RwLock::new(File::open("foo.txt")?);
+    ///     Ok(())
+    /// }
+    /// ```
+    #[inline]
+    pub fn new(inner: T) -> Self {
+        Self {
+            lock: sys::RwLock::new(inner),
+        }
+    }
+
+    /// Locks this lock with shared read access, blocking the current thread
+    /// until it can be acquired.
+    ///
+    /// The calling thread will be blocked until there are no more writers which
+    /// hold the lock. There may be other readers currently inside the lock when
+    /// this method returns. This method does not provide any guarantees with
+    /// respect to the ordering of whether contentious readers or writers will
+    /// acquire the lock first.
+    ///
+    /// Returns an RAII guard which will release this thread's shared access
+    /// once it is dropped.
+    ///
+    /// # Errors
+    ///
+    /// On Unix this may return an `ErrorKind::Interrupted` if the operation was
+    /// interrupted by a signal handler.
+    #[inline]
+    pub fn read(&self) -> io::Result<RwLockReadGuard<'_, T>> {
+        let guard = self.lock.read()?;
+        Ok(RwLockReadGuard::new(guard))
+    }
+
+    /// Attempts to acquire this lock with shared read access.
+    ///
+    /// If the access could not be granted at this time, then `Err` is returned.
+    /// Otherwise, an RAII guard is returned which will release the shared access
+    /// when it is dropped.
+    ///
+    /// This function does not block.
+    ///
+    /// This function does not provide any guarantees with respect to the ordering
+    /// of whether contentious readers or writers will acquire the lock first.
+    ///
+    /// # Errors
+    ///
+    /// If the lock is already held and `ErrorKind::WouldBlock` error is returned.
+    /// On Unix this may return an `ErrorKind::Interrupted` if the operation was
+    /// interrupted by a signal handler.
+    #[inline]
+    pub fn try_read(&self) -> io::Result<RwLockReadGuard<'_, T>> {
+        let guard = self.lock.try_read()?;
+        Ok(RwLockReadGuard::new(guard))
+    }
+
+    /// Locks this lock with exclusive write access, blocking the current thread
+    /// until it can be acquired.
+    ///
+    /// This function will not return while other writers or other readers
+    /// currently have access to the lock.
+    ///
+    /// Returns an RAII guard which will drop the write access of this rwlock
+    /// when dropped.
+    ///
+    /// # Errors
+    ///
+    /// On Unix this may return an `ErrorKind::Interrupted` if the operation was
+    /// interrupted by a signal handler.
+    #[inline]
+    pub fn write(&mut self) -> io::Result<RwLockWriteGuard<'_, T>> {
+        let guard = self.lock.write()?;
+        Ok(RwLockWriteGuard::new(guard))
+    }
+
+    /// Attempts to lock this lock with exclusive write access.
+    ///
+    /// If the lock could not be acquired at this time, then `Err` is returned.
+    /// Otherwise, an RAII guard is returned which will release the lock when
+    /// it is dropped.
+    ///
+    /// # Errors
+    ///
+    /// If the lock is already held and `ErrorKind::WouldBlock` error is returned.
+    /// On Unix this may return an `ErrorKind::Interrupted` if the operation was
+    /// interrupted by a signal handler.
+    #[inline]
+    pub fn try_write(&mut self) -> io::Result<RwLockWriteGuard<'_, T>> {
+        let guard = self.lock.try_write()?;
+        Ok(RwLockWriteGuard::new(guard))
+    }
+
+    /// Consumes this `RwLock`, returning the underlying data.
+    #[inline]
+    pub fn into_inner(self) -> T
+    where
+        T: Sized,
+    {
+        self.lock.into_inner()
+    }
+}