/*
* FindBugs - Find bugs in Java programs
* Copyright (C) 2005, University of Maryland
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package edu.umd.cs.findbugs.detect;
import java.util.BitSet;
import java.util.Iterator;
import org.apache.bcel.Constants;
import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.classfile.Method;
import org.apache.bcel.generic.ConstantPoolGen;
import org.apache.bcel.generic.INVOKESTATIC;
import org.apache.bcel.generic.Instruction;
import edu.umd.cs.findbugs.BugAccumulator;
import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.Detector;
import edu.umd.cs.findbugs.ba.CFG;
import edu.umd.cs.findbugs.ba.CFGBuilderException;
import edu.umd.cs.findbugs.ba.ClassContext;
import edu.umd.cs.findbugs.ba.DataflowAnalysisException;
import edu.umd.cs.findbugs.ba.Location;
import edu.umd.cs.findbugs.ba.LockDataflow;
import edu.umd.cs.findbugs.ba.LockSet;
/**
* Find calls to Thread.sleep() made with a lock held.
*
* @author David Hovemeyer
*/
public class FindSleepWithLockHeld implements Detector {
private final BugReporter bugReporter;
private final BugAccumulator bugAccumulator;
public FindSleepWithLockHeld(BugReporter bugReporter) {
this.bugReporter = bugReporter;
this.bugAccumulator = new BugAccumulator(bugReporter);
}
@Override
public void visitClassContext(ClassContext classContext) {
JavaClass javaClass = classContext.getJavaClass();
Method[] methodList = javaClass.getMethods();
for (Method method : methodList) {
if (method.getCode() == null) {
continue;
}
if (!prescreen(classContext, method)) {
continue;
}
try {
analyzeMethod(classContext, method);
} catch (CFGBuilderException e) {
bugReporter.logError("FindSleepWithLockHeld caught exception", e);
} catch (DataflowAnalysisException e) {
bugReporter.logError("FindSleepWithLockHeld caught exception", e);
}
}
}
private boolean prescreen(ClassContext classContext, Method method) {
BitSet bytecodeSet = classContext.getBytecodeSet(method);
if (bytecodeSet == null) {
return false;
}
// method must acquire a lock
if (!bytecodeSet.get(Constants.MONITORENTER) && !method.isSynchronized()) {
return false;
}
// and contain a static method invocation
if (!bytecodeSet.get(Constants.INVOKESTATIC)) {
return false;
}
return true;
}
private void analyzeMethod(ClassContext classContext, Method method) throws CFGBuilderException, DataflowAnalysisException {
// System.out.println("Checking " + method);
CFG cfg = classContext.getCFG(method);
LockDataflow lockDataflow = classContext.getLockDataflow(method);
for (Iterator<Location> i = cfg.locationIterator(); i.hasNext();) {
Location location = i.next();
Instruction ins = location.getHandle().getInstruction();
if (!(ins instanceof INVOKESTATIC)) {
continue;
}
if (!isSleep((INVOKESTATIC) ins, classContext.getConstantPoolGen())) {
continue;
}
// System.out.println("Found sleep at " + location.getHandle());
LockSet lockSet = lockDataflow.getFactAtLocation(location);
if (lockSet.getNumLockedObjects() > 0) {
bugAccumulator.accumulateBug(
new BugInstance(this, "SWL_SLEEP_WITH_LOCK_HELD", NORMAL_PRIORITY).addClassAndMethod(
classContext.getJavaClass(), method), classContext, method, location);
}
}
bugAccumulator.reportAccumulatedBugs();
}
private boolean isSleep(INVOKESTATIC ins, ConstantPoolGen cpg) {
String className = ins.getClassName(cpg);
if (!className.equals("java.lang.Thread")) {
return false;
}
String methodName = ins.getMethodName(cpg);
String signature = ins.getSignature(cpg);
return methodName.equals("sleep") && (signature.equals("(J)V") || signature.equals("(JI)V"));
}
@Override
public void report() {
}
}