Execution Contexts

Tracking execution progress, checking for cancellations, and switching between different execution contexts.

The IntelliJ Platform provides APIs that allow tracking the progress of background processes and canceling their execution when they are canceled by a user, or they become obsolete due to some changes in the data model.

Available execution contexts differ depending on the IntelliJ Platform version. For the details, select the required tab below.

Background processes can be executed in two contexts:

— available since 2024.2

— obsolete since 2024.1

Currently, the Progress Indicator context is the most widely used approach in the IntelliJ Platform. As the platform's execution model moves towards coroutines, this approach can be considered obsolete.

Starting with 2024.2, it is recommended to execute new code in the Job context.

The following sections explain the contexts and provide information about process cancellation, progress tracking, and switching between contexts.

Suspending and Blocking contexts available in 2024.1 have been unified into the Job context. See the Reconsider blockingContext issue for more details.

Code executed in Kotlin coroutines is executed in the Job context. Since 2024.2, coroutines are recommended for executing background tasks to maximize CPU utilization. Note that executing code in coroutines is possible only with Kotlin.

While code executed in the Job context should use suspending functions, sometimes it is required to call non-suspending/blocking APIs that use methods such as ProgressManager.checkCanceled() or ModalityState.defaultModalityState(). Since 2024.2, these methods work as expected without the need to switch to the blocking context.

The "Job" word in the name refers to the Job class, which is used for task cancellation in suspending and non-suspending functions.

Inspection Plugin DevKit | Code | Forbidden in suspend context method usage reports calling blocking code from suspending context. While this is not an error, it is recommended to use suspending counterparts if they exist.

Background processes can be executed in three contexts:

— available since 2024.1

— obsolete since 2024.1

Starting with 2024.1, it is recommended to execute new code in the suspending context.

The following sections explain the contexts and provide information about process cancellation, progress tracking, and switching between contexts.

Code executed in Kotlin coroutines is executed in a suspending context. Since 2024.1, this context is recommended for executing background tasks to maximize CPU utilization. Note that executing code in coroutines is possible only with Kotlin.

In a suspending context, methods such as ProgressManager.checkCanceled() or ModalityState.defaultModalityState() won't have any effect. Therefore, if their behavior is required, switch to a blocking context.

Inspection Plugin DevKit | Code | Forbidden in suspend context method usage reports calling blocking code from suspending context.

Executing tasks in a blocking context means executing them on a thread without access to the coroutine context (basically, in non-suspending functions) and not under a progress indicator. Such tasks can still be canceled, but they can't report progress.

Plugins should not execute new code in the blocking context. Always prefer executing tasks in the suspending context or under the progress indicator if a plugin cannot use Kotlin.

Functions which schedule execution via Application.executeOnPooledThread() and similar methods, and which rely on ProgressManager.checkCanceled() should be annotated with @RequiresBlockingContext to inform clients about the required switch to a blocking context.

Inspection Plugin DevKit | Code | Calling method should be annotated with @RequiresBlockingContext reports missing annotations.

Code executed via the Progress API (ProgressManager, ProgressIndicator, etc.) is executed in a progress indicator context. See the section for details.

Executing code under the progress indicator is obsolete since 2024.1. It is advised to use Kotlin coroutines in new code.

Please note that obsolete status does not mean deprecation. Executing code using the Progress API is still allowed, but coroutines are recommended as a more performant solution.

The following table presents APIs to use for checking whether a task was canceled in different execution contexts.

See Background Processes: Cancellation for general cancellation mechanism explanation.

Job Context	`checkCanceled()` `ProgressManager.checkCanceled()`
Progress Indicator	`ProgressIndicator.checkCanceled()` `ProgressManager.checkCanceled()`

Suspending Context	`ensureActive()` from Kotlin coroutine's API Note that `ProgressManager.checkCanceled()` does not work in the suspending context. To enable it, switch to `blockingContext()`, if it is not possible to change the code.
Blocking Context	`ProgressManager.checkCanceled()`
Progress Indicator	`ProgressIndicator.checkCanceled()` `ProgressManager.checkCanceled()`

The following table presents the possibilities and APIs to use for reporting progress in different execution contexts.

Job Context

ProgressStep - a step-based progress reporting (see its KDoc for details)

RawProgressReporter - a raw text, details, and fraction reporting (invoked via reportRawProgress())

Any report*Progress() function must be used inside withBackgroundProgress(), withModalProgress(), or runWithModalProgressBlocking() from tasks.kt . Otherwise, if there is no reporter in the context, using report*Progress() will have no effect. Example:

withBackgroundProgress(...) { // or other // ... reportProgress { reporter -> // or another report*Progress // do tasks and report progress } // ... }

Progress Indicator

ProgressIndicator's or ProgressManager's methods

See Background Processes: Tracking Progress for details.

Suspending Context	`ProgressStep` - a step-based progress reporting (see its KDoc for details) `RawProgressReporter` - a raw text, details, and fraction reporting (invoked via `reportRawProgress()`) Any `reportProgress()` function must be used inside `withBackgroundProgress()`, `withModalProgress()`, or `runWithModalProgressBlocking()` from tasks.kt . Otherwise, if there is no reporter in the context, using `reportProgress()` will have no effect. Example: withBackgroundProgress(...) { // or other // ... reportProgress { reporter -> // or another report*Progress // do tasks and report progress } // ... }
Blocking Context	unavailable
Progress Indicator	`ProgressIndicator`'s or `ProgressManager`'s methods See Background Processes: Tracking Progress for details.

The following table presents the possibilities and APIs to use for switching between different execution contexts.

	To Job Context	To Progress Indicator
From Job Context	-	`coroutineToIndicator()` ¹
From Progress Indicator	`runBlockingCancellable()`	-
¹ `coroutineToIndicator()` is an experimental API, which was originally internal and created to aid platform migration. It is not recommended to switch from the Job context to the progress indicator. Use it only if there is no other option.

	To Suspending Context	To Blocking Context	To Progress Indicator
From Suspending Context	-	`blockingContext()` ¹	unavailable ³
From Blocking Context	`runBlockingCancellable()` ²	-	unavailable ⁴
From Progress Indicator	`runBlockingCancellable()` ²	unavailable	-
¹ `blockingContext()` enables `ProgressManager.checkCanceled()`, forwards modality state, etc. It has an opposite behavior to `runBlockingCancellable()`. Since 2024.2, it is a no-operation function, as the blocking context was unified with the suspending context into the Job context. ² `runBlockingCancellable()` has an opposite behavior to `blockingContext()` ³ `coroutineToIndicator()` is an internal API to aid platform migration ⁴ `blockingContextToIndicator()` is an internal API to aid platform migration

It is only possible to:

switch from the blocking context or progress indicator to the suspending context

switch from the suspending context to the blocking context

The lack of an API for switching from suspending and blocking contexts to progress indicator is intentional. Cancellable and trackable tasks should be run in coroutines as the progress indicator is obsolete since 2024.1.