1 /* 2 * Copyright 2019 Google LLC 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package io.perfmark; 18 19 import com.google.errorprone.annotations.DoNotCall; 20 21 /** 22 * A link represents a linkage between asynchronous tasks. A link is created inside of a started 23 * task. The resulting {@link Link} object can then be passed to other asynchronous tasks to 24 * associate them with the original task. 25 * 26 * <p>A source task may have multiple outbound links pointing to other tasks. However, calling 27 * {@code PerfMark.linkIn(Link)} only work if it is the first such call. Subsequent calls have no 28 * effect. 29 */ 30 public final class Link { 31 32 final long linkId; 33 Link(long linkId)34 Link(long linkId) { 35 this.linkId = linkId; 36 } 37 38 /** DO NOT CALL, no longer implemented. Use {@link PerfMark#linkIn} instead. */ 39 @Deprecated 40 @DoNotCall link()41 public void link() {} 42 } 43