1 #!/usr/sbin/dtrace -Zs
2 /*
3  * Copyright (c) 2006, Oracle and/or its affiliates. All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  *   - Redistributions of source code must retain the above copyright
10  *     notice, this list of conditions and the following disclaimer.
11  *
12  *   - Redistributions in binary form must reproduce the above copyright
13  *     notice, this list of conditions and the following disclaimer in the
14  *     documentation and/or other materials provided with the distribution.
15  *
16  *   - Neither the name of Oracle nor the names of its
17  *     contributors may be used to endorse or promote products derived
18  *     from this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
21  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
22  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
24  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
26  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
27  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
28  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
29  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
30  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34 */
35 
36 /*
37  * Usage:
38  *   1. monitors.d -c "java ..."
39  *   2. monitors.d -p JAVA_PID
40  *
41  * The script traces monitor related probes.
42  *
43  * Notes:
44  *  - These probes are disabled by default since it incurs performance
45  *    overhead to the application. To trace the monitor-* probes, you need
46  *    to turn on the ExtendedDTraceProbes VM option.
47  *    You can either start the application with -XX:+ExtendedDTraceProbes
48  *    option or use the jinfo command to enable it at runtime as follows:
49  *
50  *       jinfo -flag +ExtendedDTraceProbes <java_pid>
51  *
52  */
53 
54 #pragma D option quiet
55 #pragma D option destructive
56 #pragma D option defaultargs
57 #pragma D option aggrate=100ms
58 
59 
60 self string thread_name;
61 self char* str_ptr;
62 
63 :::BEGIN
64 {
65     SAMPLE_NAME = "hotspot monitors tracing";
66 
67     printf("BEGIN %s\n\n", SAMPLE_NAME);
68 }
69 
70 /*
71  * hotspot:::thread-start, hotspot:::thread-stop probe arguments:
72  *  arg0: char*,        thread name passed as mUTF8 string
73  *  arg1: uintptr_t,    thread name length
74  *  arg2: uintptr_t,    Java thread id
75  *  arg3: uintptr_t,    native/OS thread id
76  *  arg4: uintptr_t,    is a daemon or not
77  */
78 hotspot$target:::thread-start
79 {
80     self->str_ptr = (char*) copyin(arg0, arg1+1);
81     self->str_ptr[arg1] = '\0';
82     self->thread_name = (string) self->str_ptr;
83 
84     printf("thread-start: id=%d, is_daemon=%d, name=%s, os_id=%d\n",
85             arg2, arg4, self->thread_name, arg3);
86 
87     threads[arg2] = self->thread_name;
88 }
89 
90 
91 hotspot$target:::thread-stop
92 {
93     self->str_ptr = (char*) copyin(arg0, arg1+1);
94     self->str_ptr[arg1] = '\0';
95     self->thread_name = (string) self->str_ptr;
96 
97 
98     printf("thread-stop: id=%d, is_daemon=%d, name=%s, os_id=%d\n",
99             arg2, arg4, self->thread_name, arg3);
100 }
101 
102 /*
103  *
104  * hotspot::monitor-contended-enter, hotspot::monitor-contended-entered
105  *
106  *  arg0: uintptr_t,    the Java thread identifier for the thread peforming
107  *                          the monitor operation
108  *  arg1: uintptr_t,    a unique, but opaque identifier for the specific
109  *                          monitor that the action is performed upon
110  *  arg2: char*,        a pointer to mUTF-8 string data which contains the
111  *                          name of the class of the object being acted upon
112  *  arg3: uintptr_t,    the length of the class name (in bytes)
113  */
114 
115 hotspot$target:::monitor-contended-enter
116 {
117     /* (uintptr_t thread_id, uintptr_t monitor_id,
118        char* obj_class_name, uintptr_t obj_class_name_len) */
119 
120     self->str_ptr = (char*) copyin(arg2, arg3+1);
121     self->str_ptr[arg3] = '\0';
122     self->class_name = (string) self->str_ptr;
123 
124     monitors[arg1] = self->class_name;
125 
126     monitors_enter[arg1] = arg0;
127     printf("%s: -> enter monitor (%d) %s\n",
128         threads[arg0], arg1, monitors[arg1]);
129 }
130 
131 hotspot$target:::monitor-contended-entered
132 {
133     /* (uintptr_t thread_id, uintptr_t monitor_id, char* obj_class_name,
134         uintptr_t obj_class_name_len) */
135 
136     monitors_entered[arg1] = arg0;
137     printf("%s: <- entered monitor (%d) %s\n",
138         threads[arg0], arg1, monitors[arg1]);
139 }
140 
141 
142 :::END
143 {
144     printf("\nEND of %s\n", SAMPLE_NAME);
145 }
146 
147 syscall::rexit:entry,
148 syscall::exit:entry
149 /pid == $target/
150 {
151    exit(0);
152 }
153