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