de.hdu.pvs.crashfinder.instrument.MethodTracer Maven / Gradle / Ivy

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package de.hdu.pvs.crashfinder.instrument;

import java.io.File;
import java.io.IOException;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Stack;

import de.hdu.pvs.crashfinder.util.Files;
import de.hdu.pvs.crashfinder.util.Globals;

/**
 * An instrumentation class
 * */
public class MethodTracer {

	private static String CONTEXT_SEP = "%%CONTEXT%%";

	public static int context_length = 0;
	public static MethodTracer tracer = new MethodTracer();

	private MethodTracer() {
		Runtime.getRuntime().addShutdownHook(new Thread() {
			@Override
			public void run() {
				System.out.println("----------dumping traces to files-------");
				synchronized (traceMap) {
					StringBuilder sb = new StringBuilder();
					for (String key : traceMap.keySet()) {
						sb.append(key + AbstractInstrumenter.SEP
								+ traceMap.get(key));
						sb.append(Globals.lineSep);
					}
					try {
						long time = System.currentTimeMillis();
						System.out.println("At: " + time);
						String fileName = "./trace_dump_" + time + ".txt";
						File f = new File(fileName);
						System.out.println("write to file: "
								+ f.getAbsolutePath());

						Files.writeToFile(sb.toString(), fileName);
					} catch (IOException e) {
						e.printStackTrace();
					}
				}
			}
		});
	}

	Map traceMap = new LinkedHashMap();
	Stack methodOnStack = new Stack();

	// push a method call to the stack
	public void pushEntry(String input) {
		synchronized (this.methodOnStack) {
			methodOnStack.push(input);
		}
		// System.out.println("push " + input + ":" +
		// this.methodOnStack.toString());
	}

	// pop the method on the stack
	public void popExit(String input) {
		synchronized (this.methodOnStack) {
			if (methodOnStack.isEmpty()) {
				return;
			}
			String topMethod = methodOnStack.peek();
			if (topMethod.equals(input)) {
				methodOnStack.pop();
			} else {
				System.err
						.println("Wrong in instrumentation, method not in stack: "
								+ input);
				while (!methodOnStack.isEmpty()) {
					String top = methodOnStack.pop();
					if (top.equals(input)) {
						break;
					}
				}
			}
		}
		// System.out.println("leave " + input + ":" +
		// this.methodOnStack.toString());
	}

	public void popExceptionExit(String input) {
		this.popExit(input);
	}

	public void trace(String input) {
		// System.out.println(input);
		synchronized (traceMap) {
			// the format of line: PRE (or POST), config name, method as context
			// we should record the call context, e.g, stacktrace

			String line = input;
			if (context_length > 0) {
				line = input + CONTEXT_SEP
				// + ExecutionContext.getCurrentContextAsString(context_length)
						+ this.getTopContexts(context_length);
				;
			}

			if (traceMap.containsKey(line)) {
				traceMap.put(line, traceMap.get(line) + 1);
			} else {
				traceMap.put(line, 1L);
			}
		}
	}

	private String getTopContexts(int length) {
		synchronized (this.methodOnStack) {
			if (this.methodOnStack.size() < length) {
				return this.methodOnStack.toString();
			} else {
				return this.methodOnStack.subList(
						this.methodOnStack.size() - length,
						this.methodOnStack.size()).toString();
			}
		}
	}
}