#!/usr/sbin/dtrace -Zs
/*
* j_classflow.d - trace a Java class method flow using DTrace.
* Written for the Java hotspot DTrace provider.
*
* $Id: j_classflow.d 63 2007-10-04 04:34:38Z brendan $
*
* This traces activity from all Java processes on the system with hotspot
* provider support (1.6.0) and the flag "+ExtendedDTraceProbes". eg,
* java -XX:+ExtendedDTraceProbes classfile
*
* USAGE: j_classflow.d classname # hit Ctrl-C to end
*
* This watches Java method entries and returns, and indents child
* method calls.
*
* FIELDS:
* C CPU-id
* TIME(us) Time since boot, us
* PID Process ID
* CLASS.METHOD Java class and method name
*
* LEGEND:
* -> method entry
* <- method return
*
* WARNING: Watch the first column carefully, it prints the CPU-id. If it
* changes, then it is very likely that the output has been shuffled.
* Changes in TID will appear to shuffle output, as we change from one thread
* depth to the next. See Docs/Notes/ALLjavaflow.txt for additional notes.
*
* COPYRIGHT: Copyright (c) 2007 Brendan Gregg.
*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at Docs/cddl1.txt
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* CDDL HEADER END
*
* 09-Sep-2007 Brendan Gregg Created this.
*/
/* increasing bufsize can reduce drops */
#pragma D option bufsize=16m
#pragma D option quiet
#pragma D option defaultargs
#pragma D option switchrate=10
self int depth[int];
dtrace:::BEGIN
/$$1 == ""/
{
printf("USAGE: j_classflow.d classname\n");
exit(1);
}
dtrace:::BEGIN
{
printf("%3s %6s %-16s -- %s\n", "C", "PID", "TIME(us)", "CLASS.METHOD");
}
hotspot*:::method-entry,
hotspot*:::method-return
{
this->class = stringof((char *)copyin(arg1, arg2 + 1));
this->class[arg2] = '\0';
}
hotspot*:::method-entry
/this->class == $$1/
{
this->method = (char *)copyin(arg3, arg4 + 1);
this->method[arg4] = '\0';
printf("%3d %6d %-16d %*s-> %s.%s\n", cpu, pid, timestamp / 1000,
self->depth[arg0] * 2, "", stringof(this->class),
stringof(this->method));
self->depth[arg0]++;
}
hotspot*:::method-return
/this->class == $$1/
{
this->method = (char *)copyin(arg3, arg4 + 1);
this->method[arg4] = '\0';
self->depth[arg0] -= self->depth[arg0] > 0 ? 1 : 0;
printf("%3d %6d %-16d %*s<- %s.%s\n", cpu, pid, timestamp / 1000,
self->depth[arg0] * 2, "", stringof(this->class),
stringof(this->method));
}