co.elastic.apm.agent.tracer.Scope Maven / Gradle / Ivy
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* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch B.V. licenses this file to you under
* the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package co.elastic.apm.agent.tracer;
/**
* Within a scope, a {@link AbstractSpan} is active on the current thread.
* Calling {@link #close()} detaches them from the active thread.
* In a scope, you can get the currently active {@link AbstractSpan} via
* {@link Tracer#getActive()}.
*
* During the duration of a {@link AbstractSpan},
* it can be active multiple times on multiple threads.
* In applications with a single thread per request model,
* there is typically one scope which lasts for the lifetime of the {@link AbstractSpan}.
* In reactive applications, this model does not work, as a request is handled in multiple threads.
* These types of application still might find it useful to scope a {@link AbstractSpan} on the currently processing thread.
* For example, an instrumentation for {@link java.util.concurrent.ExecutorService} might want to propagate the currently
* active {@link AbstractSpan} to thread which runs {@link java.util.concurrent.ExecutorService#execute(Runnable)},
* so that {@link Tracer#getActive()} returns the expected {@link AbstractSpan}.
*
*
* Note: {@link #close() closing} a scope does not {@link AbstractSpan#end() end} it's active
* {@link AbstractSpan}.
*
*/
public interface Scope extends AutoCloseable {
@Override
void close();
}