Rahul.Joshi
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Posted: July 12, 2009 03:20 by Rahul.Joshi
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Hi, I wrote a simple program to see BTrace in action on Windows with JDK 1.6.0_14. Here's the program to be traced: public class DoCurrentTimeMillis { public static void main(String[] args) { while (true) { System.out.println("Hello World at " + System.currentTimeMillis()); } } } Here's the BTrace script (CurrentTimeMillis.java): import com.sun.btrace.annotations.*; import static com.sun.btrace.BTraceUtils.*; @BTrace public class CurrentTimeMillis { @OnMethod(clazz="java.lang.System", method="currentTimeMillis") public static void onCurrentTimeMillisReturn() { println("The System.currentTimeMillis() is called!"); } } On running the DoCurrentTimeMillis.java program first, then BTrace as follows, I get the following: C:\tools\btracedemo\exercises\ex0> btrace.bat 5528 CurrentTimeMillis.java DEBUG: btrace debug mode is set DEBUG: btrace unsafe mode is set DEBUG: dumpClasses flag is set DEBUG: dumpDir is . DEBUG: assuming default port 2020 DEBUG: assuming default classpath '.' DEBUG: compiling CurrentTimeMillis.java DEBUG: compiled CurrentTimeMillis.java DEBUG: attaching to 5528 DEBUG: attached to 5528 DEBUG: loading C:\tools\btrace-bin\build\btrace-agent.jar DEBUG: agent args: port=2020,debug=true,unsafe=true,dumpClasses=true,dumpDir=.,systemClassPath=C:\Progra~1\Java\jdk1.6.0_14\lib\tools.jar,probeDescPat h=. DEBUG: loaded C:\tools\btrace-bin\build\btrace-agent.jar DEBUG: registering shutdown hook DEBUG: registering signal handler for SIGINT DEBUG: submitting the BTrace program DEBUG: opening socket to 2020 DEBUG: sending instrument command DEBUG: entering into command loop DEBUG: received com.sun.btrace.comm.OkayCommand@10e3293 So, the result is that there is no output printed. Also tried location = @Location(Kind.RETURN) I also tried using the VisualVM BTrace plugin but still no output. Note that I enabled debuggin in btrace/btrace.bat Thanks, Rahul |
Tracing simple program on Windows
3 posts
Replies: 2 - Last Post: July 15, 2009 18:25
by: Rahul.Joshi
by: Rahul.Joshi
showing 1 - 3 of 3
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sundararajana
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Posted: July 13, 2009 15:05 by sundararajana
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Hi Rahul, System.currentTimeMillis() is a native method. BTrace currently does not support tracing native methods. But, it may be feasible to support tracing native methods using native method prefixing support of java.lang.instrument. (http://java.sun.com/javase/6/docs/api/java/lang/instrument/Instrumentation.html#isNativeMethodPrefixSupported%28%29). I think this is a good candidate for an RFE with BTrace. |
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Rahul.Joshi
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Posted: July 15, 2009 18:25 by Rahul.Joshi
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| Thanks Sundararajan. |
Replies: 2 - Last Post: July 15, 2009 18:25
by: Rahul.Joshi
by: Rahul.Joshi
