CoroutineContext

CoroutineContext is a map of elements that define a coroutine’s behavior, as well as carry supporting information.

Diagram

Coroutine Diagram

graph TD;

    A[coroutineContext] -->|Has a| B("Job")
    A -->|Has a| C[Dispatcher]
    A -->|Has a| CoroutineExceptionHandler

    B -->|Parent of| J1[Child Job 1]
    B -->|Parent of| J2[Child Job 2]
    B -->|Parent of| J3[Child Job 3]

    J1 -->|Manages| D1[Coroutine 1]
    J2 -->|Manages| D2[Coroutine 2]
    J3 -->|Manages| D3[Coroutine 3]

    D1 -->|Runs| E1[Task 1]
    D2 -->|Runs| E2[Task 2]
    D3 -->|Runs| E3[Task 3]

    classDef blue fill:#3b82f6,stroke:#ffffff,stroke-width:2px;
    classDef green fill:#10b981,stroke:#ffffff,stroke-width:2px;
    classDef red fill:#ef4444,stroke:#ffffff,stroke-width:2px;

    class A blue;
    class B green;
    class D1,D2,D3 red;

References

• Job
• CoroutineContext
• Dispatcher

Link to original

Behavioral elements (affect how the coroutine runs):

• Job — controls the lifecycle of the coroutine.
• Dispatcher — defines the thread/thread-pool the work will be dispatched to.
• CoroutineExceptionHandler — handles uncaught exceptions.

Supporting information elements

• CoroutineName — Adds a name to the coroutine (useful for debugging).
• custom-CoroutineContextElement: custom elements that can be added to the context. Such as adding request id.

References

• Coroutines Part I – Grasping the Fundamentals by Victor Brandalise