1 #!/usr/sbin/dtrace -Zs 2 /* 3 * j_flow.d - snoop Java execution showing method flow using DTrace. 4 * Written for the Java hotspot DTrace provider. 5 * 6 * $Id: j_flow.d,v 1.1.1.1 2015/09/30 22:01:09 christos Exp $ 7 * 8 * This traces activity from all Java processes on the system with hotspot 9 * provider support (1.6.0) and the flag "+ExtendedDTraceProbes". eg, 10 * java -XX:+ExtendedDTraceProbes classfile 11 * 12 * USAGE: j_flow.d # hit Ctrl-C to end 13 * 14 * This watches Java method entries and returns, and indents child 15 * method calls. 16 * 17 * FIELDS: 18 * C CPU-id 19 * TIME(us) Time since boot, us 20 * PID Process ID 21 * CLASS.METHOD Java class and method name 22 * 23 * LEGEND: 24 * -> method entry 25 * <- method return 26 * 27 * WARNING: Watch the first column carefully, it prints the CPU-id. If it 28 * changes, then it is very likely that the output has been shuffled. 29 * Changes in TID will appear to shuffle output, as we change from one thread 30 * depth to the next. See Docs/Notes/ALLjavaflow.txt for additional notes. 31 * 32 * COPYRIGHT: Copyright (c) 2007 Brendan Gregg. 33 * 34 * CDDL HEADER START 35 * 36 * The contents of this file are subject to the terms of the 37 * Common Development and Distribution License, Version 1.0 only 38 * (the "License"). You may not use this file except in compliance 39 * with the License. 40 * 41 * You can obtain a copy of the license at Docs/cddl1.txt 42 * or http://www.opensolaris.org/os/licensing. 43 * See the License for the specific language governing permissions 44 * and limitations under the License. 45 * 46 * CDDL HEADER END 47 * 48 * 09-Sep-2007 Brendan Gregg Created this. 49 */ 50 51 /* increasing bufsize can reduce drops */ 52 #pragma D option bufsize=16m 53 #pragma D option quiet 54 #pragma D option switchrate=10 55 56 self int depth[int]; 57 58 dtrace:::BEGIN 59 { 60 printf("%3s %6s %-16s -- %s\n", "C", "PID", "TIME(us)", "CLASS.METHOD"); 61 } 62 63 hotspot*:::method-entry 64 { 65 this->class = (char *)copyin(arg1, arg2 + 1); 66 this->class[arg2] = '\0'; 67 this->method = (char *)copyin(arg3, arg4 + 1); 68 this->method[arg4] = '\0'; 69 70 printf("%3d %6d %-16d %*s-> %s.%s\n", cpu, pid, timestamp / 1000, 71 self->depth[arg0] * 2, "", stringof(this->class), 72 stringof(this->method)); 73 self->depth[arg0]++; 74 } 75 76 hotspot*:::method-return 77 { 78 this->class = (char *)copyin(arg1, arg2 + 1); 79 this->class[arg2] = '\0'; 80 this->method = (char *)copyin(arg3, arg4 + 1); 81 this->method[arg4] = '\0'; 82 83 self->depth[arg0] -= self->depth[arg0] > 0 ? 1 : 0; 84 printf("%3d %6d %-16d %*s<- %s.%s\n", cpu, pid, timestamp / 1000, 85 self->depth[arg0] * 2, "", stringof(this->class), 86 stringof(this->method)); 87 } 88