delegate-to-thread

Uses AspectJ to make certain methods delegate their execution to dedicated threads per defined lifecycles.

Define lifecycle

Dedicated threads will be stood up for this duration, such as while handling an HTTP request.

delegateThreadLifecycle.start();

// multithreaded work that calls restricted methods

delegateThreadLifecycle.stop();

Annotate methods with @DelegateToThread to restrict execution

Execution is intercepted and submitted to the thread specified by @DelegateToThread's parameter.

class RestrictedService {

    @DelegateToThread("workA")
    public int workA() {
        // ...
    }

    @DelegateToThread("workB")
    public int workB() {
        // ...
    }
}

Restricted methods can be called within asynchronous flows

Useful when a certain task must always be performed by a single thread within an asynchronous environment.

    @Async
    public CompletableFuture<Integer> workA() {
        int result = restrictedService.workA();
        return CompletableFuture.completedFuture(result);
    }

    @Async
    public CompletableFuture<Integer> workB() {
        int result = restrictedService.workB();
        return CompletableFuture.completedFuture(result);
    }

Threads wait after entering @DelegateToThread methods

Calling threads submit their task and wait for execution to be performed on the dedicated thread.

2018-10-07 02:39:37.369 --- [ SimpleAsyncTaskExecutor-3] : producer thread [SimpleAsyncTaskExecutor-3] submitting task [workB]
2018-10-07 02:39:37.369 --- [ SimpleAsyncTaskExecutor-4] : producer thread [SimpleAsyncTaskExecutor-4] submitting task [workB]
2018-10-07 02:39:37.369 --- [ SimpleAsyncTaskExecutor-1] : producer thread [SimpleAsyncTaskExecutor-1] submitting task [workA]
2018-10-07 02:39:37.369 --- [http-nio-8080-exec-4-workA] : consumer thread running task [workA] for [SimpleAsyncTaskExecutor-1]
2018-10-07 02:39:37.369 --- [ SimpleAsyncTaskExecutor-2] : producer thread [SimpleAsyncTaskExecutor-2] submitting task [workA]
2018-10-07 02:39:37.369 --- [http-nio-8080-exec-4-workB] : consumer thread running task [workB] for [SimpleAsyncTaskExecutor-3]
2018-10-07 02:39:38.369 --- [http-nio-8080-exec-4-workA] : consumer thread completing task [workA] for [SimpleAsyncTaskExecutor-1]
2018-10-07 02:39:38.369 --- [http-nio-8080-exec-4-workB] : consumer thread completing task [workB] for [SimpleAsyncTaskExecutor-3]
2018-10-07 02:39:38.369 --- [http-nio-8080-exec-4-workA] : consumer thread running task [workA] for [SimpleAsyncTaskExecutor-2]
2018-10-07 02:39:38.369 --- [http-nio-8080-exec-4-workB] : consumer thread running task [workB] for [SimpleAsyncTaskExecutor-4]
2018-10-07 02:39:38.369 --- [ SimpleAsyncTaskExecutor-1] : producer thread [SimpleAsyncTaskExecutor-1] resumed
2018-10-07 02:39:38.369 --- [ SimpleAsyncTaskExecutor-3] : producer thread [SimpleAsyncTaskExecutor-3] resumed
2018-10-07 02:39:39.372 --- [http-nio-8080-exec-4-workA] : consumer thread completing task [workA] for [SimpleAsyncTaskExecutor-2]
2018-10-07 02:39:39.372 --- [http-nio-8080-exec-4-workB] : consumer thread completing task [workB] for [SimpleAsyncTaskExecutor-4]
2018-10-07 02:39:39.372 --- [ SimpleAsyncTaskExecutor-2] : producer thread [SimpleAsyncTaskExecutor-2] resumed
2018-10-07 02:39:39.372 --- [ SimpleAsyncTaskExecutor-4] : producer thread [SimpleAsyncTaskExecutor-4] resumed