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BTrace: A safe, dynamic tracing tool for the Java platform
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
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 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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import org.openjdk.btrace.core.annotations.BTrace;
import org.openjdk.btrace.core.annotations.Kind;
import org.openjdk.btrace.core.annotations.Location;
import org.openjdk.btrace.core.annotations.OnMethod;
import org.openjdk.btrace.core.annotations.Self;
import org.openjdk.btrace.core.annotations.TLS;

import static org.openjdk.btrace.core.BTraceUtils.Threads;
import static org.openjdk.btrace.core.BTraceUtils.println;

/**
 * This example demonstrates printing stack trace
 * of an exception and thread local variables. This
 * trace script prints exception stack trace whenever
 * java.lang.Throwable's constructor returns. This way
 * you can trace all exceptions that may be caught and
 * "eaten" silently by the traced program. Note that the
 * assumption is that the exceptions are thrown soon after
 * creation [like in "throw new FooException();"] rather
 * that be stored and thrown later.
 */
@BTrace
public class OnThrow {
    // store current exception in a thread local
    // variable (@TLS annotation). Note that we can't
    // store it in a global variable!
    @TLS
    static Throwable currentException;

    // introduce probe into every constructor of java.lang.Throwable
    // class and store "this" in the thread local variable.
    @OnMethod(
            clazz = "java.lang.Throwable",
            method = ""
    )
    public static void onthrow(@Self Throwable self) {
        currentException = self;
    }

    @OnMethod(
            clazz = "java.lang.Throwable",
            method = ""
    )
    public static void onthrow1(@Self Throwable self, String s) {
        currentException = self;
    }

    @OnMethod(
            clazz = "java.lang.Throwable",
            method = ""
    )
    public static void onthrow1(@Self Throwable self, String s, Throwable cause) {
        currentException = self;
    }

    @OnMethod(
            clazz = "java.lang.Throwable",
            method = ""
    )
    public static void onthrow2(@Self Throwable self, Throwable cause) {
        currentException = self;
    }

    // when any constructor of java.lang.Throwable returns
    // print the currentException's stack trace.
    @OnMethod(
            clazz = "java.lang.Throwable",
            method = "",
            location = @Location(Kind.RETURN)
    )
    public static void onthrowreturn() {
        if (currentException != null) {
            Threads.jstack(currentException);
            println("=====================");
            currentException = null;
        }
    }
}