Add haxe.GcFinalizer with handle-based API

extra/CHANGES.txt

@@ -56,6 +56,8 @@
 	all : [std] allow setting haxe.Exception.stack (#12213)
 	all : [std] Serializer: implement reset method (#12068)
 	all : [std] use Vectors in haxe.zip (#11034)
+	all : [std] add haxe.IHandle interface (#12766)
+	all : [std] add haxe.GcFinalizer with handle-based API (#12766)
 	all : [messageReparting] pretty errors as default message reporting (#11587)
 	all : [messageReporting] add config to use absolute positions (#11439)
 	all : [display] diagnostics as json rpc (#11412)

std/cpp/_std/haxe/GcFinalizer.hx

@@ -0,0 +1,91 @@
+/*
+ * Copyright (C)2005-2019 Haxe Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+package haxe;
+
+import haxe.atomic.AtomicBool;
+
+private class Registration<T> {
+	public var heldValue:Null<T>;
+	public var callback:Null<T->Void>;
+	public var cancelled:AtomicBool;
+	public var weakTarget:cpp.vm.WeakRef<Dynamic>;
+
+	public function new(target:Dynamic, heldValue:T, callback:T->Void) {
+		this.weakTarget = new cpp.vm.WeakRef<Dynamic>(target);
+		this.heldValue = heldValue;
+		this.callback = callback;
+		this.cancelled = new AtomicBool(false);
+	}
+}
+
+private class Handle<T> implements IHandle {
+	var reg:Registration<T>;
+
+	public function new(reg:Registration<T>) {
+		this.reg = reg;
+	}
+
+	public function close():Void {
+		if (reg.cancelled.compareExchange(false, true) == false) {
+			reg.callback = null;
+			reg.heldValue = null;
+		}
+	}
+}
+
+@:coreApi
+class GcFinalizer<T> {
+	var callback:T->Void;
+	var registrations:Array<Registration<T>>;
+
+	public function new(callback:T->Void) {
+		this.callback = callback;
+		this.registrations = [];
+	}
+
+	function pollQueue():Void {
+		var i = registrations.length - 1;
+		while (i >= 0) {
+			var reg = registrations[i];
+			if (reg.weakTarget.get() == null) {
+				if (reg.cancelled.compareExchange(false, true) == false) {
+					reg.callback(reg.heldValue);
+					reg.callback = null;
+					reg.heldValue = null;
+				}
+				registrations.splice(i, 1);
+			} else if (reg.cancelled.load()) {
+				// close() already nulled fields
+				registrations.splice(i, 1);
+			}
+			i--;
+		}
+	}
+
+	public function register(target:{}, heldValue:T):IHandle {
+		pollQueue();
+		var reg = new Registration(target, heldValue, callback);
+		registrations.push(reg);
+		return new Handle(reg);
+	}
+}

std/eval/_std/haxe/GcFinalizer.hx

@@ -0,0 +1,74 @@
+/*
+ * Copyright (C)2005-2019 Haxe Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+package haxe;
+
+import haxe.atomic.AtomicBool;
+
+private class Registration<T> {
+	public var heldValue:Null<T>;
+	public var cancelled:AtomicBool;
+	public var callback:Null<T->Void>;
+
+	public function new(heldValue:T, callback:T->Void) {
+		this.heldValue = heldValue;
+		this.cancelled = new AtomicBool(false);
+		this.callback = callback;
+	}
+}
+
+private class Handle<T> implements IHandle {
+	var reg:Registration<T>;
+
+	public function new(reg:Registration<T>) {
+		this.reg = reg;
+	}
+
+	public function close():Void {
+		if (reg.cancelled.compareExchange(false, true) == false) {
+			reg.callback = null;
+			reg.heldValue = null;
+		}
+	}
+}
+
+@:coreApi
+class GcFinalizer<T> {
+	var callback:T->Void;
+
+	public function new(callback:T->Void) {
+		this.callback = callback;
+	}
+
+	public function register(target:{}, heldValue:T):IHandle {
+		var reg = new Registration(heldValue, callback);
+		eval.vm.Gc.finalise(function(_) {
+			if (reg.cancelled.compareExchange(false, true) == false) {
+				reg.callback(reg.heldValue);
+				reg.callback = null;
+				reg.heldValue = null;
+			}
+		}, target);
+
+		return new Handle(reg);
+	}
+}

std/haxe/GcFinalizer.hx

@@ -0,0 +1,55 @@
+/*
+ * Copyright (C)2005-2019 Haxe Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+package haxe;
+
+/**
+	A GC finalizer registry that invokes a callback when a watched object
+	is garbage-collected. Modeled after JavaScript's `FinalizationRegistry`.
+
+	The callback receives a held value (not the collected object itself),
+	which is safe because the object may already be in an invalid state.
+
+	Not all targets support GC finalizers. On unsupported targets, the
+	constructor throws `NotImplementedException`.
+**/
+class GcFinalizer<T> {
+	/**
+		Creates a new `GcFinalizer` with the given cleanup `callback`.
+		The callback will be invoked with the held value when a registered
+		target object is garbage-collected.
+	**/
+	public function new(callback:T->Void) {
+		throw new haxe.exceptions.NotImplementedException("Not implemented for this platform");
+	}
+
+	/**
+		Registers `target` for clean-up. When `target` is garbage-collected,
+		the callback will be invoked with `heldValue`.
+
+		Returns an `IHandle` handle. Calling `close()` on the handle
+		cancels the registration, preventing the callback from firing.
+	**/
+	public function register(target:{}, heldValue:T):IHandle {
+		return null;
+	}
+}

std/haxe/IHandle.hx

@@ -0,0 +1,33 @@
+/*
+ * Copyright (C)2005-2019 Haxe Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+package haxe;
+
+/**
+	A general-purpose interface for handles that can be released
+	by calling `close()`. Used by `GcFinalizer` to return cancellation
+	handles, and intended for thread callback handles, coroutine
+	scheduler handles, and similar patterns.
+**/
+interface IHandle {
+	function close():Void;
+}

std/js/_std/haxe/GcFinalizer.hx

@@ -0,0 +1,38 @@
+/*
+ * Copyright (C)2005-2019 Haxe Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+package haxe;
+
+@:coreApi
+class GcFinalizer<T> {
+	var h:js.lib.FinalizationRegistry<T>;
+
+	public inline function new(callback:T->Void) {
+		h = new js.lib.FinalizationRegistry(callback);
+	}
+
+	public inline function register(target:{}, heldValue:T):IHandle {
+		var token = {};
+		h.register(target, heldValue, token);
+		return cast {close: function() h.unregister(token)};
+	}
+}

std/js/lib/FinalizationRegistry.hx

@@ -0,0 +1,49 @@
+package js.lib;
+/*
+ * Copyright (C)2005-2019 Haxe Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+	A `FinalizationRegistry` object lets you request a callback when a value is garbage-collected.
+
+	Documentation [FinalizationRegistry](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/FinalizationRegistry) by
+	[Mozilla Contributors](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/FinalizationRegistry/contributors.txt),
+	licensed under [CC-BY-SA 2.5](https://creativecommons.org/licenses/by-sa/2.5/).
+**/
+@:native("FinalizationRegistry")
+extern class FinalizationRegistry<T> {
+	/**
+		Creates a new `FinalizationRegistry` with the given cleanup callback.
+	**/
+	function new(cleanupCallback:T->Void);
+
+	/**
+		Registers a target object with the registry, associating it with a held value
+		and an optional unregister token.
+	**/
+	function register(target:{}, heldValue:T, ?unregisterToken:{}):Void;
+
+	/**
+		Unregisters any registrations associated with the given unregister token.
+		Returns `true` if at least one registration was removed.
+	**/
+	function unregister(unregisterToken:{}):Bool;
+}