该项目已移至https://github.com/Adrninistrator/java-callgraph2

使用说明

编译命令：

gradlew jar

执行参数：

VM options: 用于指定输出文件路径

-Doutput.file=a.txt

Program arguments:用于指定需要解析的jar包路径列表

build/libs/a.jar build/libs/b.jar

增加调用关系类型及调用者代码行号

增强后的java-callgraph输出的方法调用关系的格式与原始java-callgraph基本一致，如下所示：

M:class1:<method1>(arg_types) (typeofcall)class2:<method2>(arg_types) line_number jar_number

原始java-callgraph支持的调用类型arg_types如下：

• M for invokevirtual calls
• I for invokeinterface calls
• O for invokespecial calls
• S for invokestatic calls
• D for invokedynamic calls

增强后的java-callgraph增加的调用类型arg_types如下：

typeofcall	含义
ITF	接口与实现类方法
RIR	Runnable实现类线程调用
CIC	Callable实现类线程调用
TSR	Thread子类线程调用
LM	lambda表达式（含线程调用等）
SCC	父类调用子类的实现方法
CCS	子类调用父类的实现方法

• line_number

为当前调用者方法源代码对应行号

• jar_number

jar包序号，从1开始

增加jar包文件路径

增强后的java-callgraph会输出当前jar包文件路径，如下所示：

J:jar_number jar_file_path

• jar_number

jar包序号，从1开始

• jar_file_path

jar包文件路径

原始java-callgraph调用关系缺失的场景

原始java-callgraph在多数场景下能够获取到Java方法调用关系，但以下场景的调用关系会缺失：

• 接口与实现类方法

假如存在接口Interface1，及其实现类Impl1，若在某个类Class1中引入了接口Interface1，实际为实现类Impl1的实例（使用Spring时的常见场景），在其方法Class1.func1()中调用了Interface1.fi()方法；

原始java-callgraph生成的方法调用关系中，只包含Class1.func1()调用Interface1.fi()的关系，Class1.func1()调用Impl1.fi()，及Impl1.fi()向下调用的关系会缺失。

• Runnable实现类线程调用

假如f1()方法中使用内部匿名类形式的Runnable实现类在线程中执行操作，在线程中执行了f2()方法，如下所示：

private void f1() {
    new Thread(new Runnable() {
        @Override
        public void run() {
            f2();
        }
    }).start();
}

原始java-callgraph生成的方法调用关系中，f1()调用f2()，及f2()向下调用的关系会缺失；

对于使用命名类形式的Runnable实现类在线程中执行操作的情况，存在相同的问题，原方法调用线程中执行的方法，及继续向下的调用关系会缺失。

• Callable实现类线程调用

与Runnable实现类线程调用情况类似，略。

• Thread子类线程调用

与Runnable实现类线程调用情况类似，略。

• lambda表达式（含线程调用等）

假如f1()方法中使用lambda表达式的形式在线程中执行操作，在线程中执行了f2()方法，如下所示：

private void f1() {
    new Thread(() -> f2()).start();
}

原始java-callgraph生成的方法调用关系中，f1()调用f2()，及f2()向下调用的关系会缺失；

对于其他使用lambda表达式的情况，存在相同的问题，原方法调用lambda表达式中执行的方法，及继续向下的调用关系会缺失。

• 父类调用子类的实现方法

假如存在抽象父类Abstract1，及其非抽象子类ChildImpl1，若在某个类Class1中引入了抽象父类Abstract1，实际为子类ChildImpl1的实例（使用Spring时的常见场景），在其方法Class1.func1()中调用了Abstract1.fa()方法；

原始java-callgraph生成的方法调用关系中，只包含Class1.func1()调用Abstract1.fa()的关系，Class1.func1()调用ChildImpl1.fa()的关系会缺失。

• 子类调用父类的实现方法

假如存在抽象父类Abstract1，及其非抽象子类ChildImpl1，若在ChildImpl1.fc1()方法中调用了父类Abstract1实现的方法fi()；

原始java-callgraph生成的方法调用关系中，ChildImpl1.fc1()调用Abstract1.fi()的关系会缺失。

针对以上问题，增强后的java-callgraph都进行了优化，能够生成缺失的调用关系。

增强后的java-callgraph地址为#github#

对于更复杂的情况，例如存在接口Interface1，及其抽象实现类Abstract1，及其子类ChildImpl1，若在某个类中引入了抽象实现类Abstract1并调用其方法的情况，生成的方法调用关系中也不会出现缺失。

原始文档

java-callgraph: Java Call Graph Utilities

A suite of programs for generating static and dynamic call graphs in Java.

• javacg-static: Reads classes from a jar file, walks down the method bodies and prints a table of caller-caller relationships.
• javacg-dynamic: Runs as a Java agent and instruments the methods of a user-defined set of classes in order to track their invocations. At JVM exit, prints a table of caller-callee relationships, along with a number of calls

Compile

The java-callgraph package is build with maven. Install maven and do:

mvn install

This will produce a target directory with the following three jars:

• javacg-0.1-SNAPSHOT.jar: This is the standard maven packaged jar with static and dynamic call graph generator classes
• javacg-0.1-SNAPSHOT-static.jar: This is an executable jar which includes the static call graph generator
• javacg-0.1-SNAPSHOT-dycg-agent.jar: This is an executable jar which includes the dynamic call graph generator

Run

Instructions for running the callgraph generators

Static

javacg-static accepts as arguments the jars to analyze.

java -jar javacg-0.1-SNAPSHOT-static.jar lib1.jar lib2.jar...

javacg-static produces combined output in the following format:

For methods

  M:class1:<method1>(arg_types) (typeofcall)class2:<method2>(arg_types)

The line means that method1 of class1 called method2 of class2. The type of call can have one of the following values (refer to the JVM specification for the meaning of the calls):

• M for invokevirtual calls
• I for invokeinterface calls
• O for invokespecial calls
• S for invokestatic calls
• D for invokedynamic calls

For invokedynamic calls, it is not possible to infer the argument types.

For classes

  C:class1 class2

This means that some method(s) in class1 called some method(s) in class2.

Dynamic

javacg-dynamic uses javassist to insert probes at method entry and exit points. To be able to analyze a class javassist must resolve all dependent classes at instrumentation time. To do so, it reads classes from the JVM's boot classloader. By default, the JVM sets the boot classpath to use Java's default classpath implementation (rt.jar on Win/Linux, classes.jar on the Mac). The boot classpath can be extended using the -Xbootclasspath option, which works the same as the traditional -classpath option. It is advisable for javacg-dynamic to work as expected, to set the boot classpath to the same, or an appropriate subset, entries as the normal application classpath.

Moreover, since instrumenting all methods will produce huge callgraphs which are not necessarily helpful (e.g. it will include Java's default classpath entries), javacg-dynamic includes support for restricting the set of classes to be instrumented through include and exclude statements. The options are appended to the -javaagent argument and has the following format

-javaagent:javacg-dycg-agent.jar="incl=mylib.*,mylib2.*,java.nio.*;excl=java.nio.charset.*"

The example above will instrument all classes under the the mylib, mylib2 and java.nio namespaces, except those that fall under the java.nio.charset namespace.

java
-Xbootclasspath:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Classes/classes.jar:mylib.jar
-javaagent:javacg-0.1-SNAPSHOT-dycg-agent.jar="incl=mylib.*;"
-classpath mylib.jar mylib.Mainclass

javacg-dynamic produces two kinds of output. On the standard output, it writes method call pairs as shown below:

class1:method1 class2:method2 numcalls

It also produces a file named calltrace.txt in which it writes the entry and exit timestamps for methods, thereby turning javacg-dynamic into a poor man's profiler. The format is the following:

<>[stack_depth][thread_id]fqdn.class:method=timestamp_nanos

The output line starts with a < or > depending on whether it is a method entry or exit. It then writes the stack depth, thread id and the class and method name, followed by a timestamp. The provided process_trace.rb script processes the callgraph output to generate total time per method information.

Examples

The following examples instrument the Dacapo benchmark suite to produce dynamic call graphs. The Dacapo benchmarks come in a single big jar archive that contains all dependency libraries. To build the boot class path required for the javacg-dyn program, extract the dacapo.jar to a directory: all the required libraries can be found in the jar directory.

Running the batik Dacapo benchmark:

java -Xbootclasspath:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Classes/classes.jar:jar/batik-all.jar:jar/xml-apis-ext.jar -javaagent:target/javacg-0.1-SNAPSHOT-dycg-agent.jar="incl=org.apache.batik.*,org.w3c.*;" -jar dacapo-9.12-bach.jar batik -s small |tail -n 10

[...]
org.apache.batik.dom.AbstractParentNode:appendChild org.apache.batik.dom.AbstractParentNode:fireDOMNodeInsertedEvent 6270<br/>
org.apache.batik.dom.AbstractParentNode:fireDOMNodeInsertedEvent org.apache.batik.dom.AbstractDocument:getEventsEnabled 6280<br/>
org.apache.batik.dom.AbstractParentNode:checkAndRemove org.apache.batik.dom.AbstractNode:getOwnerDocument 6280<br/>
org.apache.batik.dom.util.DoublyIndexedTable:put org.apache.batik.dom.util.DoublyIndexedTable$Entry:DoublyIndexedTable$Entry 6682<br/>
org.apache.batik.dom.util.DoublyIndexedTable:put org.apache.batik.dom.util.DoublyIndexedTable:hashCode 6693<br/>
org.apache.batik.dom.AbstractElement:invalidateElementsByTagName org.apache.batik.dom.AbstractElement:getNodeType 7198<br/>
org.apache.batik.dom.AbstractElement:invalidateElementsByTagName org.apache.batik.dom.AbstractDocument:getElementsByTagName 14396<br/>
org.apache.batik.dom.AbstractElement:invalidateElementsByTagName org.apache.batik.dom.AbstractDocument:getElementsByTagNameNS 28792<br/>

Running the lucene Dacapo benchmark:

java -Xbootclasspath:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Classes/classes.jar:jar/lucene-core-2.4.jar:jar/luindex.jar -javaagent:target/javacg-0.1-SNAPSHOT-dycg-agent.jar="incl=org.apache.lucene.*;" -jar dacapo-9.12-bach.jar luindex -s small |tail -n 10

[...]
org.apache.lucene.analysis.Token:setTermBuffer org.apache.lucene.analysis.Token:growTermBuffer 43449<br/>
org.apache.lucene.analysis.CharArraySet:getSlot org.apache.lucene.analysis.CharArraySet:getHashCode 43472<br/>
org.apache.lucene.analysis.CharArraySet:getSlot org.apache.lucene.analysis.CharArraySet:equals 46107<br/>
org.apache.lucene.index.FreqProxTermsWriter:appendPostings org.apache.lucene.store.IndexOutput:writeVInt 46507<br/>
org.apache.lucene.store.IndexInput:readVInt org.apache.lucene.index.ByteSliceReader:readByte 63927<br/>
org.apache.lucene.index.TermsHashPerField:writeVInt org.apache.lucene.index.TermsHashPerField:writeByte 63927<br/>
org.apache.lucene.store.IndexOutput:writeVInt org.apache.lucene.store.BufferedIndexOutput:writeByte 94239<br/>
org.apache.lucene.index.TermsHashPerField:quickSort org.apache.lucene.index.TermsHashPerField:comparePostings 107343<br/>
org.apache.lucene.analysis.Token:termBuffer org.apache.lucene.analysis.Token:initTermBuffer 162115<br/>
org.apache.lucene.analysis.Token:termLength org.apache.lucene.analysis.Token:initTermBuffer 205554<br/>

Known Restrictions

• The static call graph generator does not account for methods invoked via reflection.
• The dynamic call graph generator will not work reliably (or at all) for multithreaded programs
• The dynamic call graph generator does not handle exceptions very well, so some methods might appear as having never returned

Author

Georgios Gousios gousiosg@gmail.com

License

2-clause BSD