1 /* 2 * Copyright (C) 2010 The Android Open Source Project 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 dalvik.system.profiler; 18 19 import dalvik.system.VMStack; 20 import java.util.Arrays; 21 22 class DalvikThreadSampler implements ThreadSampler { 23 24 private int depth; 25 26 /** 27 * Reusable storage for sampling sized for the specified depth. 28 */ 29 private StackTraceElement[][] mutableStackTraceElements; 30 setDepth(int depth)31 @Override public void setDepth(int depth) { 32 this.depth = depth; 33 this.mutableStackTraceElements = new StackTraceElement[depth+1][]; 34 for (int i = 1; i < mutableStackTraceElements.length; i++) { 35 this.mutableStackTraceElements[i] = new StackTraceElement[i]; 36 } 37 } 38 getStackTrace(Thread thread)39 @Override public StackTraceElement[] getStackTrace(Thread thread) { 40 int count = VMStack.fillStackTraceElements(thread, mutableStackTraceElements[depth]); 41 if (count == 0) { 42 return null; 43 } 44 if (count < depth) { 45 System.arraycopy(mutableStackTraceElements[depth], 0, 46 mutableStackTraceElements[count], 0, 47 count); 48 } 49 return mutableStackTraceElements[count]; 50 } 51 } 52