Questions tagged [reference-cycle]
15 questions
6
votes
2 answers
how to properly implement Observer in python when the observer is [should be] destroyed
I'm implementing an observer-observable pattern in python:
This is the Observable class:
class Observable(object):
def __init__(self, value):
self.value = value
self.observers = []
def set(self, value):
old =…
fferri
- 18,285
- 5
- 46
- 95
4
votes
2 answers
Strong, weak or unowned in reference cycle with Timer
I have a UIViewController that has a reference to a Timer object that is calling a closure repeatedly. The Timer object captures self in its block. As far as I understand this leads to a retains cycle between the View Controller and the block. There…
surToTheW
- 772
- 2
- 10
- 34
3
votes
0 answers
Reference cycles when using inspect module
The documentation says:
Note Keeping references to frame objects, as found in the first element of the frame records these functions return, can cause your program to create reference cycles. Once a reference cycle has been created, the lifespan of…
x-yuri
- 16,722
- 15
- 114
- 161
3
votes
2 answers
Why does adding a closure capture list prevent my instance from being deallocated?
class Name {
var name: String
init(name: String) {
self.name = name
}
deinit {
print("\(name) deinit")
}
}
var x: Name? = Name(name: "abc")
var someClosure = {
print("\(x?.name)")
}
someClosure()
x =…
李茂琦
- 43
- 3
3
votes
1 answer
How to remove strong reference cycle from closure from method?
Here I have some examples for closure strong reference cycles.
If I assign a closure to a stored property, I can use a closure capture list to make the captured reference unowned/weak.
But if I assign a method to a stored property closure or assign…
Binarian
- 12,296
- 8
- 53
- 84
1
vote
0 answers
Deleting object's reference itself inside a function of object in JavaScript
I want to remove object itself by function of it from a object collection. If I code like below does it course to reference cycle or any other error.
const obj_collec={};
function Obj(id){
this.id=id;
this.remove=function(){
…
Chamod
- 587
- 2
- 6
- 17
1
vote
2 answers
Is it possible to keep track of an object from its finalizer, to detect accidental resurrection of the object by a different object's finalizer?
One of the many issues with finalize methods in Java is the "object resurrection" issue (explained in this question): if an object is finalized, and it saves a copy of this somewhere globally reachable, the reference to the object "escapes" and you…
smithaiw
- 107
- 6
1
vote
1 answer
Using a [weak self] for a HTTP Request
I have a question regarding the need of using [weak self] in closures and HTTP requests.
As example we have a HTTP request who triggers a closure on completion:
func saveBla() {
blaManager.saveBla(bla) { error in
self.pay5euro()
…
R Pelzer
- 1,188
- 14
- 34
1
vote
1 answer
Does @synchronized(self) in a block lead to a retain cycle?
Let's say I want to do @synchronized(self) within a block. I suppose this will lead to a retain cycle, so normally we would re-write it like this:
-(void)myMethod
{
__weak TheClass * weakSelf = self;
…
yano
- 4,095
- 3
- 35
- 68
0
votes
0 answers
publishing value of NSObject by KeyPath using AsyncStream - reference cycle problem
I'm plaing with concurrency features of Swift. I've created helper function which returns AsyncStream with values published by NSOBject implementations. Sort of code below.
func asyncStreamFor (_ root: Root, keyPath:…
jactmp
- 36
- 3
0
votes
1 answer
Is there an annotation that triggers a warning if an object is passed that captures enclosing ‘this’?
I have a Kotlin function with this signature:
fun registerDisposer(obj: Any, disposer: Closeable)
What the function does is attach disposer to a phantom reference and arrange it to be closed when obj is garbage-collected (i.e. when the phantom…
user3840170
- 26,597
- 4
- 30
- 62
0
votes
2 answers
Vala closure reference cycle
I'm writing a class in Vala where I bind two of the same object's properties together, with a closure to transform one to the other.
class Foo : Object
{
public int num { get; set; }
public int scale = 2;
public int result { get; set;…
Albert Tomanek
- 387
- 4
- 13
0
votes
1 answer
Callback strong Reference Cycle
Is the following creating a strong reference cycle? I have a feeling it is because I'm referencing self within callback.
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
[picker…
AnonProgrammer
- 239
- 1
- 11
0
votes
0 answers
nodejs - does forEach create a reference cycle?
I am a newbie in NodeJS, my background is Swift.
When facing forEach, I wonder if it would create a reference cycle?
const array = [1, 3, 2, 4]
arrach.forEach(function(element) {
doSomething(element)
})
function doSomething(number) {
//…
quanguyen
- 1,443
- 3
- 17
- 29
0
votes
2 answers
Does assigning a weak pointer to a strong pointer copy the object?
The common pattern to avoid capturing self within a Block is to create a weak self outside the Block and use this to create a "locally strong" version of self within the Block (inner self).
__weak ClassX *weakSelf = self;
[someOtherObject…
Smart Home
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