io.smallrye.reactive.messaging.annotations

Annotation Type Blocking

@Retention(value=RUNTIME)
 @Target(value=METHOD)
public @interface Blocking

Identifies that a particular method performs blocking operations, and as such should be executed on separate worker. When supported, the caller execution context is captured and restored after the execution of the blocking method. This means that the rest of the pipeline would run in the same context (same thread). Typically this is the case if the caller is using a Vert.x Context (event loop or worker).

Field Summary

Fields

Modifier and Type	Fields and Description
static String	DEFAULT_WORKER_POOL

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
boolean	ordered Indicates if execution of methods marked with this annotation should be sequenced and preserve the message ordering, or run concurrently with messages being emitted in the order that method executions complete.
String	value Indicates the name of the worker pool to use for execution.

Field Detail

DEFAULT_WORKER_POOL

public static final String DEFAULT_WORKER_POOL

Element Detail

value

public abstract String value

Indicates the name of the worker pool to use for execution. By default all executions will be performed on the default worker pool. The maximum concurrency of a custom worker pool can be set with the following configuration key: smallrye.messaging.worker.{pool-name}.max-concurrency

Returns:

custom worker pool name for blocking execution.

Default:

"<no-value>"

ordered

public abstract boolean ordered

Indicates if execution of methods marked with this annotation should be sequenced and preserve the message ordering, or run concurrently with messages being emitted in the order that method executions complete. By default, or when ordered is set to true, executions of a blocking method are serialized and messages are processed in order. The results are emitted in the same order, preserving the relative message order. Multiple different ordered=true methods may be active on workers at one time, but each individual such method will be active once at most. When ordered is set to false blocking method executions are run concurrently on worker threads and may finish in a different order from the order they were invoked. Results are emitted as soon as the blocking computation has finished. Message ordering, whether of input messages being observed by blocking methods running concurrently, or of output messages subsequently emitted, is not preserved.

Returns:

whether executions will be ordered.

Default:

true