#!/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,v 1.1.1.1 2015/09/30 22:01:09 christos Exp $ * * 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)); }