1e41f4b71Sopenharmony_ci# ArkCompiler Subsystem Changelog
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3e41f4b71Sopenharmony_ci## cl.arkcompiler.1 Repair of the Sendable Class Assignment Check in Hotspot Functions
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5e41f4b71Sopenharmony_ci**Reason for Change**
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7e41f4b71Sopenharmony_ciThis change is made to fix the Sendable class assignment check issues in hotspot functions.
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9e41f4b71Sopenharmony_ci**Change Impact**
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11e41f4b71Sopenharmony_ciThis change is non-compatible.
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13e41f4b71Sopenharmony_ci- Sendable data is used to address performance issues with cross-thread data transfer. For an introduction to its use, see [Sendable Development](../../../application-dev/arkts-utils/arkts-sendable.md).
14e41f4b71Sopenharmony_ci- Some constraints were not checked in hotspot functions. As a result, these constraints may be bypassed.
15e41f4b71Sopenharmony_ci- The following are the constraints bypassed in this change.
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17e41f4b71Sopenharmony_ci    | \@Sendable Class Decorator         | Description                                                                   |
18e41f4b71Sopenharmony_ci    | ------------------------- | ---------------------------------------------------------------------- |
19e41f4b71Sopenharmony_ci    | Property type restrictions for decorated objects | 1. The following types are supported: string, number, boolean, bigint, null, undefined, Sendable class, collections.Array, collections.Map, and collections.Set.<br/>2. Closure variables are not allowed.<br/>3. Private properties must be defined using **private**, rather than the number sign (#).<br/>4. Computed properties are not supported. |
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21e41f4b71Sopenharmony_ci- For violations of the **property type restrictions**:
22e41f4b71Sopenharmony_ci    - Before change: The program runs normally without errors.
23e41f4b71Sopenharmony_ci    - After change: The program throws an exception at the point of constraint violation, indicating that the assignment type does not match. You need to adapt according to the requirements of **property type restrictions** in [Sendable Development](../../../application-dev/arkts-utils/arkts-sendable.md).
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25e41f4b71Sopenharmony_ci**API Level**
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29e41f4b71Sopenharmony_ci**Change Since**
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31e41f4b71Sopenharmony_ciOpenHarmony_4.1.6.5
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33e41f4b71Sopenharmony_ci**Key API/Component Changes**
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35e41f4b71Sopenharmony_ci@Sendable decorator
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37e41f4b71Sopenharmony_ci**Adaptation Guide**
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39e41f4b71Sopenharmony_ciAfter this change, if a type mismatch exception occurs at runtime, it may violate the usage constraints, and it is necessary to check the assignment types. For detailed instructions, see [Sendable Development](../../../application-dev/arkts-utils/arkts-sendable.md).
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