Java tutorial
/******************************************************************************* * Copyright (c) 2009, 2015 Mountainminds GmbH & Co. KG and Contributors * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * Marc R. Hoffmann - initial API and implementation * *******************************************************************************/ package org.jacoco.core.runtime; import org.jacoco.core.data.AbstractExecutionDataStore; import org.jacoco.core.data.ControlFlowExecutionData; import org.jacoco.core.data.IExecutionDataVisitor; import org.jacoco.core.data.ISessionInfoVisitor; import org.jacoco.core.data.SessionInfo; import org.jacoco.core.internal.instr.InstrSupport; import org.objectweb.asm.MethodVisitor; import org.objectweb.asm.Opcodes; /** * Container for runtime execution and meta data. All access to the runtime data * is thread safe. */ public abstract class AbstractRuntimeData { /** store for execution data */ protected AbstractExecutionDataStore store; private long startTimeStamp; private String sessionId; /** * Creates a new runtime. */ public AbstractRuntimeData() { sessionId = "<none>"; startTimeStamp = System.currentTimeMillis(); } /** * Sets a session identifier for this runtime. The identifier is used when * execution data is collected. If no identifier is explicitly set a * identifier is generated from the host name and a random number. This * method can be called at any time. * * @see #collect(IExecutionDataVisitor, ISessionInfoVisitor, boolean) * @param id * new session identifier */ public void setSessionId(final String id) { sessionId = id; } /** * Get the current a session identifier for this runtime. * * @see #setSessionId(String) * @return current session identifier */ public String getSessionId() { return sessionId; } /** * Collects the current execution data and writes it to the given * {@link IExecutionDataVisitor} object. * * @param executionDataVisitor * handler to write coverage data to * @param sessionInfoVisitor * handler to write session information to * @param reset * if <code>true</code> the current coverage information is also * cleared */ public final void collect(final IExecutionDataVisitor executionDataVisitor, final ISessionInfoVisitor sessionInfoVisitor, final boolean reset) { synchronized (store) { final SessionInfo info = new SessionInfo(sessionId, startTimeStamp, System.currentTimeMillis()); sessionInfoVisitor.visitSessionInfo(info); store.accept(executionDataVisitor); if (reset) { reset(); } } } /** * Resets all coverage information. */ public final void reset() { synchronized (store) { store.reset(); startTimeStamp = System.currentTimeMillis(); } } /** * Returns the coverage data for the class with the given identifier. If * there is no data available under the given id a new entry is created. * This is a synchronized access to the underlying store. * * @param id * class identifier * @param name * VM name of the class * @param probecount * probe data length * @return execution data */ public abstract ControlFlowExecutionData getExecutionData(final Long id, final String name, final int probecount); /** * Retrieves the execution probe array for a given class. The passed * {@link Object} array instance is used for parameters and the return value * as follows. Call parameters: * * <ul> * <li>args[0]: class id ({@link Long}) * <li>args[1]: vm class name ({@link String}) * <li>args[2]: probe count ({@link Integer}) * </ul> * * Return value: * * <ul> * <li>args[0]: probe array (<code>boolean[]</code>) * </ul> * * @param args * parameter array of length 3 */ public void getProbes(final Object[] args) { final Long classid = (Long) args[0]; final String name = (String) args[1]; final int probecount = ((Integer) args[2]).intValue(); args[0] = getExecutionData(classid, name, probecount).getProbes(); } /** * In violation of the regular semantic of {@link Object#equals(Object)} * this implementation is used as the interface to the execution data store. * * @param args * the arguments as an {@link Object} array * @return has no meaning */ @Override public boolean equals(final Object args) { if (args instanceof Object[]) { getProbes((Object[]) args); } return super.equals(args); } /** * Generates code that creates the argument array for the * {@link #getProbes(Object[])} method. The array instance is left on the * operand stack. The generated code requires a stack size of 5. * * @param classid * class identifier * @param classname * VM class name * @param probecount * probe count for this class * @param mv * visitor to emit generated code */ public static void generateArgumentArray(final long classid, final String classname, final int probecount, final MethodVisitor mv) { mv.visitInsn(Opcodes.ICONST_3); mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object"); // Class Id: mv.visitInsn(Opcodes.DUP); mv.visitInsn(Opcodes.ICONST_0); mv.visitLdcInsn(Long.valueOf(classid)); mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Long", "valueOf", "(J)Ljava/lang/Long;", false); mv.visitInsn(Opcodes.AASTORE); // Class Name: mv.visitInsn(Opcodes.DUP); mv.visitInsn(Opcodes.ICONST_1); mv.visitLdcInsn(classname); mv.visitInsn(Opcodes.AASTORE); // Probe Count: mv.visitInsn(Opcodes.DUP); mv.visitInsn(Opcodes.ICONST_2); InstrSupport.push(mv, probecount); mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Integer", "valueOf", "(I)Ljava/lang/Integer;", false); mv.visitInsn(Opcodes.AASTORE); } /** * Generates the code that calls a {@link ControlFlowRuntimeData} instance through the * JRE API method {@link Object#equals(Object)}. The code pops a * {@link Object} instance from the stack and pushes the probe array of type * <code>boolean[]</code> on the operand stack. The generated code requires * a stack size of 6. * * @param classid * class identifier * @param classname * VM class name * @param probecount * probe count for this class * @param mv * visitor to emit generated code */ public static void generateAccessCall(final long classid, final String classname, final int probecount, final MethodVisitor mv) { // stack[0]: Ljava/lang/Object; generateArgumentArray(classid, classname, probecount, mv); // stack[1]: [Ljava/lang/Object; // stack[0]: Ljava/lang/Object; mv.visitInsn(Opcodes.DUP_X1); // stack[2]: [Ljava/lang/Object; // stack[1]: Ljava/lang/Object; // stack[0]: [Ljava/lang/Object; mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Object", "equals", "(Ljava/lang/Object;)Z", false); mv.visitInsn(Opcodes.POP); // stack[0]: [Ljava/lang/Object; mv.visitInsn(Opcodes.ICONST_0); mv.visitInsn(Opcodes.AALOAD); // stack[0]: [Z mv.visitTypeInsn(Opcodes.CHECKCAST, InstrSupport.DATAFIELD_DESC); } }