-
Notifications
You must be signed in to change notification settings - Fork 467
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Add
Event<T> type that can be used to implement a WinRT event (#1705)
- Loading branch information
Showing
10 changed files
with
421 additions
and
5 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,254 @@ | ||
| use super::*; | ||
| use bindings::*; | ||
| use std::sync::*; | ||
|
|
||
| /// A type that you can use to declare and implement an event of a specified delegate type. | ||
| /// | ||
| /// The implementation is thread-safe and designed to avoid contention between events being | ||
| /// raised and delegates being added or removed. | ||
| pub struct Event<T: Interface + Clone> { | ||
| swap: Mutex<()>, | ||
| change: Mutex<()>, | ||
| delegates: Array<T>, | ||
| } | ||
|
|
||
| impl<T: Interface + Clone> Default for Event<T> { | ||
| fn default() -> Self { | ||
| Self::new() | ||
| } | ||
| } | ||
|
|
||
| impl<T: Interface + Clone> Event<T> { | ||
| /// Creates a new, empty `Event<T>`. | ||
| pub fn new() -> Self { | ||
| Self { delegates: Array::new(), swap: Mutex::default(), change: Mutex::default() } | ||
| } | ||
| /// Registers a delegate with the event object. | ||
| pub fn add(&mut self, delegate: &T) -> Result<i64> { | ||
| let mut _lock_free_drop = Array::new(); | ||
| Ok({ | ||
| let change_lock = self.change.lock().unwrap(); | ||
| let mut new_delegates = Array::with_capacity(self.delegates.len() + 1)?; | ||
| for delegate in self.delegates.as_slice() { | ||
| new_delegates.push(delegate.clone()); | ||
| } | ||
| let delegate = Delegate::new(delegate); | ||
| let token = delegate.to_token(); | ||
| new_delegates.push(delegate); | ||
|
|
||
| let swap_lock = self.swap.lock().unwrap(); | ||
| _lock_free_drop = self.delegates.swap(new_delegates); | ||
| token | ||
| }) | ||
| } | ||
| /// Revokes a delegate's registration from the event object. | ||
| pub fn remove(&mut self, token: i64) -> Result<()> { | ||
| let mut _lock_free_drop = Array::new(); | ||
| { | ||
| let change_lock = self.change.lock().unwrap(); | ||
| if self.delegates.is_empty() { | ||
| return Ok(()); | ||
| } | ||
| let mut capacity = self.delegates.len() - 1; | ||
| let mut new_delegates = Array::new(); | ||
| let mut removed = false; | ||
| if capacity == 0 { | ||
| if self.delegates.as_slice()[0].to_token() == token { | ||
| removed = true; | ||
| } | ||
| } else { | ||
| new_delegates = Array::with_capacity(capacity)?; | ||
| for delegate in self.delegates.as_slice() { | ||
| if !removed && delegate.to_token() == token { | ||
| removed = true; | ||
| continue; | ||
| } | ||
| if capacity == 0 { | ||
| debug_assert!(!removed); | ||
| break; | ||
| } | ||
| new_delegates.push(delegate.clone()); | ||
| capacity -= 1; | ||
| } | ||
| } | ||
| if removed { | ||
| let swap_lock = self.swap.lock().unwrap(); | ||
| _lock_free_drop = self.delegates.swap(new_delegates); | ||
| } | ||
| } | ||
| Ok(()) | ||
| } | ||
| /// Clears the event, removing all delegates. | ||
| pub fn clear(&mut self) { | ||
| let mut _lock_free_drop = Array::new(); | ||
| { | ||
| let change_lock = self.change.lock().unwrap(); | ||
| if self.delegates.is_empty() { | ||
| return; | ||
| } | ||
| let swap_lock = self.swap.lock().unwrap(); | ||
| _lock_free_drop = self.delegates.swap(Array::new()); | ||
| } | ||
| } | ||
| /// Invokes all of the event object's registered delegates with the provided callback. | ||
| pub fn call<F: FnMut(&T) -> Result<()>>(&mut self, mut callback: F) -> Result<()> { | ||
| let lock_free_calls = { | ||
| let swap_lock = self.swap.lock().unwrap(); | ||
| self.delegates.clone() | ||
| }; | ||
| for delegate in lock_free_calls.as_slice() { | ||
| if let Err(error) = delegate.call(&mut callback) { | ||
| const RPC_E_SERVER_UNAVAILABLE: HRESULT = HRESULT(-2147023174); // HRESULT_FROM_WIN32(RPC_S_SERVER_UNAVAILABLE) | ||
| if matches!(error.code(), RPC_E_DISCONNECTED | JSCRIPT_E_CANTEXECUTE | RPC_E_SERVER_UNAVAILABLE) { | ||
| self.remove(delegate.to_token())?; | ||
| } | ||
| } | ||
| } | ||
| Ok(()) | ||
| } | ||
| } | ||
|
|
||
| /// A thread-safe reference-counted array of delegates. | ||
| struct Array<T: Interface + Clone> { | ||
| buffer: *mut Buffer, | ||
| len: usize, | ||
| _phantom: std::marker::PhantomData<T>, | ||
| } | ||
|
|
||
| impl<T: Interface + Clone> Default for Array<T> { | ||
| fn default() -> Self { | ||
| Self::new() | ||
| } | ||
| } | ||
|
|
||
| impl<T: Interface + Clone> Array<T> { | ||
| /// Creates a new, empty `Array<T>` with no capacity. | ||
| fn new() -> Self { | ||
| Self { buffer: std::ptr::null_mut(), len: 0, _phantom: std::marker::PhantomData } | ||
| } | ||
| /// Creates a new, empty `Array<T>` with the specified capacity. | ||
| fn with_capacity(capacity: usize) -> Result<Self> { | ||
| Ok(Self { buffer: Buffer::new(capacity * std::mem::size_of::<Delegate<T>>())?, len: 0, _phantom: std::marker::PhantomData }) | ||
| } | ||
| /// Swaps the contents of two `Array<T>` objects. | ||
| fn swap(&mut self, mut other: Self) -> Self { | ||
| unsafe { std::ptr::swap(&mut self.buffer, &mut other.buffer) }; | ||
| std::mem::swap(&mut self.len, &mut other.len); | ||
| other | ||
| } | ||
| /// Returns `true` if the array contains no delegates. | ||
| fn is_empty(&self) -> bool { | ||
| self.len == 0 | ||
| } | ||
| /// Returns the number of delegates in the array. | ||
| fn len(&self) -> usize { | ||
| self.len | ||
| } | ||
| /// Appends a delegate to the back of the array. | ||
| fn push(&mut self, delegate: Delegate<T>) { | ||
| unsafe { | ||
| std::ptr::write((*self.buffer).as_mut_ptr::<Delegate<T>>().add(self.len) as _, delegate); | ||
| self.len += 1; | ||
| } | ||
| } | ||
| /// Returns a slice containing of all delegates. | ||
| fn as_slice(&self) -> &[Delegate<T>] { | ||
| if self.is_empty() { | ||
| &[] | ||
| } else { | ||
| unsafe { std::slice::from_raw_parts((*self.buffer).as_ptr::<Delegate<T>>() as _, self.len) } | ||
| } | ||
| } | ||
| /// Returns a mutable slice of all delegates. | ||
| fn as_mut_slice(&mut self) -> &mut [Delegate<T>] { | ||
| if self.is_empty() { | ||
| &mut [] | ||
| } else { | ||
| unsafe { std::slice::from_raw_parts_mut((*self.buffer).as_mut_ptr::<Delegate<T>>() as _, self.len) } | ||
| } | ||
| } | ||
| } | ||
|
|
||
| impl<T: Interface + Clone> Clone for Array<T> { | ||
| fn clone(&self) -> Self { | ||
| if !self.is_empty() { | ||
| unsafe { (*self.buffer).0.add_ref() }; | ||
| } | ||
| Self { buffer: self.buffer, len: self.len, _phantom: std::marker::PhantomData } | ||
| } | ||
| } | ||
|
|
||
| impl<T: Interface + Clone> Drop for Array<T> { | ||
| fn drop(&mut self) { | ||
| unsafe { | ||
| if !self.is_empty() && (*self.buffer).0.release() == 0 { | ||
| std::ptr::drop_in_place(self.as_mut_slice()); | ||
| heap_free(self.buffer as _) | ||
| } | ||
| } | ||
| } | ||
| } | ||
|
|
||
| /// A reference-counted buffer. | ||
| #[repr(C)] | ||
| struct Buffer(RefCount); | ||
|
|
||
| impl Buffer { | ||
| /// Creates a new `Buffer` with the specified size in bytes. | ||
| fn new(size: usize) -> Result<*mut Buffer> { | ||
| if size == 0 { | ||
| Ok(std::ptr::null_mut()) | ||
| } else { | ||
| let alloc_size = std::mem::size_of::<Buffer>() + size; | ||
| let header = heap_alloc(alloc_size)? as *mut Buffer; | ||
| unsafe { | ||
| (*header).0 = RefCount::new(1); | ||
| } | ||
| Ok(header) | ||
| } | ||
| } | ||
| /// Returns a raw pointer to the buffer's contents. | ||
| fn as_ptr<T>(&self) -> *const T { | ||
| unsafe { (self as *const Self).add(1) as *const _ } | ||
| } | ||
| /// Returns a raw mutable pointer to the buffer's contents. | ||
| fn as_mut_ptr<T>(&mut self) -> *mut T { | ||
| unsafe { (self as *mut Self).add(1) as *mut _ } | ||
| } | ||
| } | ||
|
|
||
| /// Holds either a direct or indirect reference to a delegate. A direct reference is typically | ||
| /// agile while an indirect reference is an agile wrapper. | ||
| #[derive(Clone)] | ||
| enum Delegate<T: Interface + Clone> { | ||
| Direct(T), | ||
| Indirect(AgileReference<T>), | ||
| } | ||
|
|
||
| impl<T: Interface + Clone> Delegate<T> { | ||
| /// Creates a new `Delegate<T>`, containing a suitable reference to the specified delegate. | ||
| fn new(delegate: &T) -> Self { | ||
| if delegate.cast::<IAgileObject>().is_err() { | ||
| if let Ok(delegate) = AgileReference::new(delegate) { | ||
| return Self::Indirect(delegate); | ||
| } | ||
| } | ||
| Self::Direct(delegate.clone()) | ||
| } | ||
| /// Returns an encoded token to identify the delegate. | ||
| fn to_token(&self) -> i64 { | ||
| unsafe { | ||
| match self { | ||
| Self::Direct(delegate) => EncodePointer(std::mem::transmute_copy(delegate)) as _, | ||
| Self::Indirect(delegate) => EncodePointer(std::mem::transmute_copy(delegate)) as _, | ||
| } | ||
| } | ||
| } | ||
| /// Invokes the delegates with the provided callback. | ||
| fn call<F: FnMut(&T) -> Result<()>>(&self, mut callback: F) -> Result<()> { | ||
| match self { | ||
| Self::Direct(delegate) => callback(delegate), | ||
| Self::Indirect(delegate) => callback(&delegate.resolve()?), | ||
| } | ||
| } | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,12 @@ | ||
| [package] | ||
| name = "test_event" | ||
| version = "0.0.0" | ||
| authors = ["Microsoft"] | ||
| edition = "2021" | ||
|
|
||
| [dependencies.windows] | ||
| path = "../../libs/windows" | ||
| features = [ | ||
| "Foundation", | ||
| "Win32_System_WinRT", | ||
| ] |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1 @@ | ||
|
|
Oops, something went wrong.