Unity nativelist parallel writer Examples. Collections Syntax. Mar 27, 2022 · You doing thing in job in parallel. No errors if you try to add entries beyond capacity: NativeHashMap<int, bool> boolsByInt = new NativeHashMap<int An individual reader or writer cannot be used concurrently across threads: each thread must use its own. Entities. com Mar 20, 2018 · I have a simple IJobParallelFor job which takes a couple [ReadOnly] NativeArrays of mesh vertices and triangles, and returns a smaller section of that mesh as a list of vertices and triangles (specifically, I’m taking a large mesh scanned from an AR headset, and trying to find flat-ish surfaces in it). I cant even find a sample code about how to use that. isComlpeted and then call JobHandle. Collections; using Unity. AsParallelWriter()}; For example, to write safely to a NativeList<T> from a parallel job, you need a NativeList<T>. AsParallelWriter()}; Jun 13, 2024 · Hi! It seems that tutorials about parallelWriter rare. Though I wouldn’t recommend it unless there weren’t other options. Aug 28, 2024 · InvalidOperationException: The Unity. Add() because that data structure doesn't support parallel writing. ParallelWriter effects = new NativeList<FXEffect>(Allocator. In Unity’s native code, the scheduling of ParallelFor jobs is more complicated. The container does not support parallel writing. 31f. Namespace: Unity. Collections. Nearly every container has a parallel writer. Entities;using Unity. If you pass both jobs the same list, you have to complete the first job before you schedule the second: otherwise, the second job doesn't see the first job's changes to the list's length. AsParallelWriter()}; Useful when a job populates a list that is then used by another job. AsParallelWriter()}; Mar 28, 2022 · I’m passing 2 lists as parallel writer to a job, if I clear and resize them they cause a weird exception, if I dispose and create from scratch they don’t. I found out that I could make whole thing parallel if only I had knowledge about index of recently added vertex position into NativeList. 0-preview Aug 29, 2024 · I’m trying to generate a grid of nodes and I thought the NativeParallelHashMap container would be the best for that but I’m not sure how to write to it. com in code: using Unity. Jun 16, 2020 · Hey, recently I’ve been generating meshes with use of Burst jobs. But I still don’t know how to use the NativeList. For reading, you must not use the Concurrent structure, but you can linearize it to a NativeList via an IJob: For example, to write safely to a NativeList<T> from a parallel job, you need a NativeList<T>. [NativeContainer] public struct NativeList<T> : INativeDisposable, IDisposable, INativeList<T>, IIndexable<T>, IEnumerable<T>, IEnumerable where T : struct If the list has reached its current capacity, internal array won't be resized, and exception will be thrown. Diagnostics; using System. Your job for each also need index. Aug 3, 2020 · Hi Unity Forum, I am attempting to implement Poisson disc sampling using the Jobs system. The issue is that Unity reads m_Length from ranged collections but this isn’t where collections like NativeList<T> store the length. public struct ParallelWriter. ParallelWriter: NativeList<int> nums = new NativeList<int>(1000, Allocator. When Unity schedules a ParallelFor job, the job system divides the work into batches to distribute between cores. Here is the method, it will be called as part Jan 17, 2020 · Hello, I have a large collection of rectangles where I want to find any rectangles that overlap. (NativeList<T> list) Parameters May 9, 2020 · Follow up to Infinite loop in NativeHashMap TryAdd Sorry for making another post, but this is kind of a serious issue has been plaguing our project for 6 months (I’ve had concerns about this for a while due to some weird behavior randomly appearing elsewhere) but I finally got a simple repo. ParallelWriter AsParallelWriter() A parallel writer of this list. Collections namespace to include other types of NativeContainer: NativeList - 可调整大小的 NativeArray。 Increments the length by 1 unless doing so would exceed the current capacity. AddNoResize to be IJobFor fixed the issue Resolution Note: This is expected behavior. AsParallelWriter()}; Note that getting the count requires traversing the queue's internal linked list of blocks. See full list on coffeebraingames. 1k次，点赞14次，收藏15次。查看NativeList源码需要安装Unity的Entities PackageNativeList要实现的基本功能类似C# List，如下：（一些简单的类同NativeArray的不在说明）构造函数、析构函数、取值赋值扩容、添加、移除操作解析步骤包括，基本函数，常用操作，常用属性，接口函数。 public struct NativeList<T> : INativeDisposable, IDisposable, INativeList<T>, IIndexable<T>, IEnumerable<T> where T : struct Increments the length by 1 unless doing so would exceed the current capacity. Returns parallel writer instance. Contains some warm ups before each iteration to make the cache hit/miss from spatial/temporal locality more fair. com. in visual studio (with dot) and see intellisense suggestion for parallel writer. EntityCommandBuffer safely. You can get around this by using a NativeQueue like this: May 29, 2021 · You can also use EntityCommandBuffer. My goal is to be able to generate a map of nodes and then later on loop over the hashmap for mesh generation. EntityCommandB Capacity specifies the number of items the list can currently hold. Unsafe. Enumerator UnsafeMultiHashMap<TKey, TValue>. For example, to write safely to a NativeList<T> from a parallel job, you need a NativeList<T>. EDIT: So I just realized that I can do my checks using OverlapBox which is much faster method than BoxCast. Type ecb. g. For example, to write safely to a NativeList<T> from a parallel job, you need to use NativeList<T>. If we tried to pass the list directly to the second job, that job would not see any modifications made to the list by the first job. unity. timeToIsFalling is not declared [ReadOnly] in a IJobParallelFor job. public Increments the length by 1 unless doing so would exceed the current capacity. Since NativeHashSet is just a NativeParallelHashMap with a byte value it uses the same extensions. Threading; using Unity. Collections Changed NativeList<T> parallel reader/writer to match Jun 9, 2018 · Iterate over 100000 elements linearly. Add(Range)NoResize and made it return new Sep 17, 2020 · Inside Job struct I declare it like this NativeList timeToIsFalling; no read and write only attributes since I want to update it’s value every frame (in a job). ParallelWriter does not work well with lots of writes. Probably this will be a rule of thumb for all wanna-be-parallel shape-checks in Examples. 9f1 Add these to your package manifest “com. Jul 19, 2024 · ArgumentException: The previously scheduled job SpawnPillarsSystem:SpawnEntityOnSelectJob writes to the Unity. Search Results for AsParallelWriter() Returns a parallel writer of this list. If everything was simple it could be done using NativeHashMap<int, NativeQueue> but at the moment nested native containers are not allowed. Collections Syntax Oct 9, 2019 · The problem here is that you are using a parallel job to write to a container (NativeList in this case). 8, Entities 1. ForEach((Entity entity, int entityInQueryIndex, ref Translation trans) => { // How to add element to effects variable }). Sep 20, 2021 · When I send simply one destroy message to an Entity Command Buffer, it starts giving errors: ArgumentException: System. UnsafeList<T>. Unity 附带了一个名为 NativeArray 的 NativeContainer。您也可以使用 NativeSlice 操作 NativeArray，从特定位置获取特定长度的 NativeArray 子集。 Note: The Entity Component System (ECS) package extends the Unity. Capacity specifies the number of items the list can currently hold. Jul 21, 2024 · Point of schedulling in parallel working on big amount of data, instead of doing it in one thread, mostly. ParallelWriter to store the assignees, not merely just NativeList<AssigneeStash>. An extension of EntityCommandBuffer that allows concurrent (deterministic) command buffer recording. You can change Capacity to fit more or fewer items. Show / Hide Table of Contents Implements parallel writer. Incorrect use of locks can lead to a deadlock, so instead “[t]he C# Job System solves this by ReadOnly containers point to the same underlying data as the NativeParallelHashSet it is made from. two pairs can have equal keys. For example, to write safely to a NativeList<T> from a parallel job, you need to use NativeList<T>. Jan 26, 2021 · Ok. May 29, 2022 · You can consider this as a gotcha when populating a NativeList in parallel. TempJob). NativeList`1[Unity. Use AsParallelWriter to obtain it from container. Clear() Sets the length to 0. And yep! Some simple tests seem to confirm it. It is also not viable to use a NativeArray because it requires its size to be initialized ahead of time, and we don't know how many items we are going to return. The target is decoding a lot of binary data files with the power of multithread. Returns a parallel writer of this list. The job system then schedules one job in Unity’s native job system per CPU core and passes that @Unity. This is because we will be running this job in parallel and a mere NativeList can’t be May 23, 2022 · @DragonCoder Information much space is left is volatile, so worthless in parallel job. wordpress. ) Well not passing in the handles because each job is independent of the others as far as what they do. Jobs;public class SystemDestroyAfte - Pastebin. Aug 10, 2019 · Hello, I’m working on a project where I need to populate a list of unknown size and then read from it, of course read and write must happen concurently. ECB. Can (and should?) we put native collections directly into components? Let’s consider the following example. Increments the length by 1 unless doing so would exceed the current capacity. "Unity", Unity logos, NativeList<T>. Length, then Assembly: Unity. ParallelWriter AsParallelWriter docs. This seems pretty painful from a robustness standpoint. public struct NativeList<T> : INativeDisposable, IDisposable, INativeList<T>, IIndexable<T>, IEnumerable<T> where T : struct Adds an element at the front of the queue. CopyFrom(in NativeList<T>). ForEach((Entity e, ref DOTS_DESTROY_AFTER_TIME dat) isn’t Unity 附带了一个名为 NativeArray 的 NativeContainer。您也可以使用 NativeSlice 操作 NativeArray，从特定位置获取特定长度的 NativeArray 子集。 Note: The Entity Component System (ECS) package extends the Unity. But be careful. [NativeContainer] public struct NativeList<T> : INativeDisposable, IDisposable, INativeList<T>, IIndexable<T>, IEnumerable<T>, IEnumerable where T : struct Examples. Changing Capacity creates a new array of the specified size, copies the old array to the new one, and then deallocates the original array memory. ParallelWriter for your parallel job. 8 and Unity 6000. Unsafe; namespace docs. Each batch contains a subset of Execute methods. The exception: System. For each axis I measure if collisions occur. AsParallelWriter()}; Apr 29, 2024 · Obviously the intention is that you set the capacity of any such collection (e. You cannot just write to a single container from multiple jobs: The NativeList is not thread safe. TempJob); // The parallel writer shares the original list's AtomicSafetyHandle. I finally got a hint from chatgpt. First, we define component with native container, for example: public struct CollectionsTest : IComponentData { public NativeParallelHashMap<int If the list has reached its current capacity, internal array won't be resized, and exception will be thrown. NativeQueue from memory. Collections Assembly: Unity. After some digging, I’ve modified sources of NativeList. Right now I’m prepping the NativeLists that get passed to each respective and guessing how large I think they might be. But UnsafeList doesn’t provide any direct conversion to Jul 13, 2022 · I have a huge range of extension methods for the native containers. But non-paralellism is still there, so it’s still much better to use IJobParallelFor. Each Job in the group takes the previous one as a dependency. EntityCommandBuffer SpawnEntityOnSelectJob. CopyFrom(in NativeArray<T>) Copies all elements of specified container to this container. In This Article. I have a few Oct 2, 2019 · Posted code works fine without any errors, are you sure this is problem place? For example, to write safely to a NativeList<T> from a parallel job, you need to use NativeList<T>. [NativeContainer] public struct NativeList<T> : INativeDisposable, IDisposable, INativeList<T>, IIndexable<T>, IEnumerable<T>, IEnumerable where T : struct Jan 20, 2025 · Heya, I’m working on my own concurrent list collection and I wanted to start off more simple and increase the complexity (and hopefully performance) from there. You can send request to job workers and ask about result later in some cases, but you must ensure before that about Job. Struct NativeList<T>. I have a NativeList that I need to read from as well as APPEND to (I do not need to change anything mid list, just append new things to the end in the job) and I just can’t figure it out. The keys do not have to be unique, i. (NativeList<T> list) Parameters 注意：“ParallelFor”作业是 Unity 中对于任何实现 IJobParallelFor 接口的结构的统称。 ParallelFor 作业使用一个数据 NativeArray 作为其数据源。ParallelFor 作业在多个核心上运行。每个核心有一个作业，每个作业处理一部分工作量。 Dec 31, 2020 · I would recommend using a NativeStream or some other data structure that supports parallel writing to queue changes in parallel and then apply them in a singlethreaded job. AsParallelWriter()}; Jan 9, 2022 · 上一篇：Unity 革命性技术DOST入门一 使用介绍 ECS介绍 ECS 由实体（Entities）、组件（Components）、和系统（Systems，）组成，其中Entity，Component皆为纯数据向的类，System负责操控他们，该架构专注于数据，使用这种模式会一定程度上优化我们的代码速度。 Navigation Menu Toggle navigation. ParallelWriter in a IJobEntity without risking exceeding the length of the list, because there’s not a Length property of this struct. Jun 13, 2020 · So I am doing sweep and prune. If you want to check for key existence, then use it without parallel writer. A parallel writer for a NativeList. Use AsParallelWriter to obtain it from container Dec 16, 2021 · But if you only allow the entityInQueryIndices less than 1024 write to the list, it doesn’t matter what order they run in, you will guarantee the list cannot receive more than that amount, even with a parallel writer. Unity’s safety system is designed in a way to prevent race conditions. Dec 31, 2021 · I don’t know how add element to native list in parallel jobs. If I declare a variable for the list AsParallelWriter then I seem to lose all ability to read from said list. Jobs; class ApplyVelocityParallelForSample : MonoBehaviour { struct VelocityJob : IJobParallelFor { // Jobs declare all data that will be accessed in the job // By declaring it as read only, multiple jobs are allowed to access the data in parallel [ReadOnly] public NativeArray<Vector3> velocity; Struct NativeList<T>. cn. Apr 25, 2019 · Declaring native Containera from a job is not a good idea. AsDeferredJobArray() allow write to NativeArray[t] where Y > t > X? If neither are possible, does it mean we have to use a job to set NativeList. The problem Nov 26, 2021 · Parallel writer purpose is to write, using multi-threading. Unity automatically splits the work into chunks no less than the provided batchSize, and schedules an appropriate number of jobs based on the number of worker threads, the length of the array, and the batch size. You must call JobHandle. dll Syntax [NativeContainer] public struct NativeQueue<T> : INativeDisposable where T : struct Returns a parallel writer for this queue. But you can “inject” needed extension method which returns new length/index of added element yourself by using of other trick I’ve described here: Here is the code and simple package: using System; using System. Complete() on the job SpawnPillarsSystem:SpawnEntityOnSelectJob, before you can write to the Unity. AsParallelWriter()}; Examples. Tested in Unity 2019. AddRangeNoResize(void*, int) Appends elements from a buffer to the end of this list. The original single thread algorithm returns a variable number of points as a List. Right now if you set the capacity too low you’ll just get an uncatchable exception from a (likely Burst compiled) job. The data written to an individual buffer can be heterogeneous in type, and the data written to different buffers of a stream can be entirely different in type, number, and order. I want to use a NativeList to process my data and populate the list with all rectangles that intersect each other. "Unity", Unity logos, Increments the length by 1 unless doing so would exceed the current capacity. (NativeList<T> list) Parameters Struct NativeList<T>. Detail: I have a traffic system, using Easy Roads 3D (nice asset, great support) Each Road has Lanes, each Lane has a series of points. AsParallelWriter()}; Apr 22, 2020 · From the source, it looks like NativeHashMap and NativeMultiHashMap will now auto-resize their internal arrays, if you try to add values past their initial capacities. Implements parallel writer. public EntityCommandBuffer. Note here that we are using NativeList<AssigneeStash>. TempJob); this. AsParallelWriter(); Entities. m_ListData->length and instead insists on reading m_Length. ParallelWriter Implements parallel writer. Apr 3, 2022 · Hi, I’ve got a question on a topic that’s totally stumped me. (NativeList<T May 25, 2021 · How are you adding items safely to a Dynamic Buffer in parallel . If collision occurs on 1 axis the pair is added to hashmap otherwise it is removed. Sort does this internally. Exception: Length {0} exceeds capacity Capacity {1} Dec 3, 2018 · Unfortunately, supporting this is quite awkward with the native collections system. Same queue parallel writer can be accessed in multiple jobs. If all your containers are native containers with proper safety mechanisms, and you have all the safety checks and jobs debugger turned on, then you should be pointed directly to the problem. The problem is I don’t know the exact size of decoded data until it gets decoded, so I have to use UnsafeList instead of NativeArray for the output. Please use a more suitable Dec 3, 2024 · However, when I try to get a parallel writer for anything other than a NativeList, it is not defined… image 529×103 8. Collections Syntax Examples. The limitation is just the capacity can’t be increased in parallel, you have to pre-compute it or ensure it’s large enough to put all your If the list has reached its current capacity, internal array won't be resized, and exception will be thrown. Where possible, cache this value instead of reading the property repeatedly. The indices have no guaranteed order and are executed on multiple cores in parallel. Declaration. ArgumentException: All entities passed to EntityManage - Pastebin. Choose the batch size depending on the amount of Nov 3, 2024 · 文章浏览阅读1. My first instinct was to use either NativeQueue or NativeList for the collection. ParallelWriter AsParallelWriter() Struct NativeList<T>. float3]] Refresh. Crashes like this aren’t going to help you solve the problem, because you don’t know what the culprit is. this is exmaple my code: NativeList<FXEffect>. @Unity. Concurrent It seems that only the NativeQueue meet the criteria for the cocnurrent growing list. But even better, you don’t even need a NativeList. ParallelWriter NativeQueue. Mathematics. Apologies that is correct, you can’t have the NList inside the NArray. The job system then schedules one job in Unity’s native job system per CPU core and passes that Increments the length by 1 unless doing so would exceed the current capacity. AsReadOnly() Returns a read only of this list. Has thread- and disposal-safety checks. Aug 7, 2024 · I am working with parallel job. using UnityEngine; using Unity. public NativeList<T>. ParallelWriter any more. Preferably I would like to avoid unsafe code if possible but if not I would at least want to be able to In Unity’s native code, the scheduling of ParallelFor jobs is more complicated. Show / Hide Table of Contents Struct NativeList<T>. We then schedule the CollectAssigneesJob. 74 KB I’m using the latest Unity. IJobParallelFor) job adds an arbitrary number of elements to a collection (parallel writing). "Unity", Unity logos, Jan 5, 2022 · The issue is that we can't use a NativeList to call . NativeArray`1[Unity. Unfortunately during runtime I get an exception: InvalidOperationException: Job. So I figured in order to run this in parallel, I would split the world into many smaller regions, use an IJobParallelFor to process each region independently, each generating a NativeList which I can merge once the job is Examples. Use AsParallelReader to obtain it from container. Collections Syntax May 22, 2018 · Pattern: A multithreaded (e. Do not allocate managed memory in jobs Allocating managed memory in jobs is incredibly slow, and the job is not able to make use of the Unity Burst compiler to improve performance. Collections Syntax Jul 7, 2020 · Parallel writer means parallel within the same job, i. AppendBuffer(). The problem is that NativeQueue. Another multithreaded job processes that collection (parallel reading) later on without knowing the length of that collection at schedule time. Collections package (2. Concurrent For example, to write safely to a NativeList<T> from a parallel job, you need to use NativeList<T>. (NativeList<T> list) Parameters Oct 1, 2022 · I’m really confused on how to use this properly. Look forum and repos for parallel writing into ecb. e. I have an IJobParallelForDefer that I run in consecutive groups (~7 to 12 jobs). Assume each file is a byte[] with around 7~10 Megabytes after decoded. In order to do this I need to pass in something that allows writing in parallel so I noticed that NativeList Jun 24, 2020 · Is there currently a way to write to a NativeArray or NativeList in parallel? Basically I need to run an entity query that looks for multiple components and then combines them into one data structure stored in a NativeArray or NativeList for sorting. Dispose(); I need only add elements to Nov 25, 2021 · If you set the capacity to a large enough value on OnEnable (the constructor might take the initial capacity as an argument), then you just need a NativeList. Basically the equivalent of: NativeList<NewStructure> newStructures = new NativeList<NewStructure>(Allocator. Implements parallel reader. 1). UnsafeMultiHashMap<TKey, TValue> UnsafeMultiHashMap<TKey, TValue>. UnsafeMultiParallelHashMap`2: An unordered associative array of key-value pairs. Complete to syncronise your threads. Unity automatically splits the work into chunks of no less than the provided batchSize, and schedules an appropriate number of jobs based on the number of worker threads, the length of the array and the batch size. If you tried to pass the list directly to the second job, that job would get the contents of the list at the time you schedule the job and would not see any modifications made to the list by the first job. Back to top Implements parallel writer. 3. The following example populates a list with integers in one job and passes that data to a second job as a deferred array. Aug 30, 2021 · -Changing the IJobParallelFor that populated the NativeList with NativeList. AsParallelWriter()}; docs. ForEach((in If the list has reached its current capacity, internal array won't be resized, and exception will be thrown. [BurstCompile] public struct Generate : IJobParallelFor { [ReadOnly] public NativeParallelHashMap<int4, Node> nodes; public Increments the length by 1 unless doing so would exceed the current capacity. NativeList. AsParallelWriter()}; Struct NativeList<T>. ToArrayNBC from Unity. burst”: “1. Nested native containers are illegal in jobs. I think one of two things is going on: Either my . g, NativeList, NativeParallelHashMap) before scheduling the parallel work which will write to it. Unity doesn’t know to read m_Impl. CopyFrom(in UnsafeList<T>) Copies all elements of specified container to this container. ToArray replaced with extension method NativeList<T>. docs. You need pass job index into ecb parallel writer. Each list’s potential size depends on the result of the Examples. I think NativeArray has better random access performance based on how Unity recommends converting DynamicBuffers to NativeArrays. Name Description; AddNoResize(T) Appends an element to the end of this list. Feb 24, 2025 · Hello everyone, One thing I find missing in DOTS learning resources is a proper explanation of using native collections in IComponentData. NativeMultiParallelHashMap`2: An unordered associative array of key-value pairs. I read this thread but it did not solve my issue : Request: allow parallel writing to NativeList when [WriteOnly] is used, or add . ScheduleParallel(); effects. You should choose the batch size based on the For example, to write safely to a NativeList<T> from a parallel job, you need a NativeList<T>. Feb 12, 2021 · So recently I’ve been working on a project that requires me to be able to resize the colliders of prefabs that I’m instantiating in an ICollisionEventsJob but the only way I’ve found to do that is by first getting the collider pointer and changing the geometry of it via unsafe code. I had thought NativeList would be the solution, but even when setting [WriteOnly], I get Jan 5, 2022 · The issue is that we can't use a NativeList to call . It makes no sense to try read from the collection, while still writing on multiple threads to it. public void Enqueue(T value) docs. ParallelWriter A parallel writer for a NativeList. For example, you may have a Job which For example, to write safely to a NativeList<T> from a parallel job, you need a NativeList<T>. IJobParallelFor Not parallel in multiple jobs at the same time (though for some containers this is safe, e. var job = new MyParallelJob {NumsWriter = nums. etc. 5. Jan 20, 2025 · PS: I am using Physics 1. In this particular case I have batch add operations. Sign in Dec 11, 2018 · ToConcurrent() is a multi-writer version of the data structure that can be used across multiple parallel jobs (or a single IJobParallelFor type job with work stealing). ParallelWriter NativeStream. ParallelWriter. Nov 15, 2019 · The Reader/Writer might, the problem there is each entity archetype has two int values, and then an array (IBufferElementData) of float3, so I don’t know if the Reader/Writer will resolve this requirement. Feb 26, 2020 · Try to convert the NativeList into a NativeArray using AsArray() before calling Sort(). I noticed after I ironed out all the crashes that on a parallel job, when I add to the collection from multiple threads, it performance at par or lower performance than adding to the collection from a single thread. My thinking was to use a IJobParallelForFilter to filter out results. vertexLists can not be accessed. "Unity", Unity logos, Sep 12, 2020 · At the moment I need data structure which allows you to access NativeQueue by specific key. If the list has reached its current capacity, internal array won't be resized, and exception will be thrown. LowLevel. Or use single threaded job writing to the collection, then you can check for exiting keys in the same job. dll Syntax Use AsParallelWriter() to create a parallel writer for a list docs. Collections Syntax Jul 12, 2021 · A few questions regarding NativeList indexer write: If a NativeList has Length X and Capacity Y, does it allow write to NativeList[t] where Y > t > X? If a NativeList has Length X and Capacity Y, does creating NativeList. 0. "Unity", Unity logos, Examples. One of the algorithm steps is generating vertices + triangles buffers. Preallocating your DB to the max size you need, and then writing to it in parallel from multiple jobs (assuming none of those jobs ever touches the same index in the DB), is usually a better way to go. It looks like they’re doing this in a similar way to NativeList. Only solution I came around is to use UnsafeList in NativeHashMap, it does job but NativeQueue would be The indices have no guaranteed order and are executed on multiple cores in parallel. cywqzr lfmbso tcanx wwwn oxnqawy dwhuo xlezp jnqu jzpjzqc iukc