Mercurial > hg > blitz_stable

comparison src/org/dancres/blitz/StatsDumper.java @ 0:3dc0c5604566

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Initial checkin of blitz 2.0 fcs - no installer yet.
author Dan Creswell <dan.creswell@gmail.com>
date Sat, 21 Mar 2009 11:00:06 +0000
parents
children
comparison
equal deleted inserted replaced
-1:000000000000 0:3dc0c5604566
1 package org.dancres.blitz;
2
3 import java.net.*;
4
5 import java.util.logging.Level;
6
7 import org.dancres.blitz.disk.Disk;
8
9 import org.dancres.blitz.stats.StatsBoard;
10 import org.dancres.blitz.stats.Stat;
11
12 /**
13 <p>This class implements a remote access feature which allows a programmer
14 to trigger dumping of useful debug information. It is triggered by
15 <code>telnet</code>'ing to the debug port. StatsDumper detects the connection,
16 closes it and dumps relevant output to console.</p>
17
18 <p>For example, if Blitz were suffering from a deadlock, one could arrange
19 for a connection on the debug port, to dump lock information, the default
20 implementation (note that it requires a tweak to Db for it to provide the
21 right information, contact dan@dancres.org, for information).</p>
22
23 <p>If the port number is non-zero, the StatsDumper is enabled otherwise it's
24 disabled. See <code>debugPort</code> in the configuration file.</p>
25
26 @todo Find a nice way to handle the stack tracing stuff - only works on
27 JDK 1.5
28 */
29 class StatsDumper implements Runnable, ActiveObject {
30
31 private static StatsDumper theStatsDumper;
32
33 private Thread theDebugThread;
34 private boolean stopDebugging;
35 private long theCycleTime;
36
37 static void start(long aPause) {
38 try {
39 if (aPause == 0)
40 return;
41
42 System.err.println("Starting Stats Dumper: " + aPause);
43
44 theStatsDumper = new StatsDumper(aPause);
45 } catch (Exception anE) {
46 System.err.println("StatsDumper didn't start!");
47 anE.printStackTrace(System.err);
48 }
49 }
50
51 private StatsDumper(long aPause) throws Exception {
52 theCycleTime = aPause;
53 ActiveObjectRegistry.add(this);
54 }
55
56 public void begin() {
57 theDebugThread = new Thread(this, "StatsDumper");
58 theDebugThread.start();
59 }
60
61 public void halt() {
62 synchronized(this) {
63 stopDebugging = true;
64 }
65
66 theDebugThread.interrupt();
67
68 try {
69 theDebugThread.join();
70 theDebugThread = null;
71 } catch (InterruptedException anIE) {
72 SpaceImpl.theLogger.log(Level.SEVERE,
73 "Failed to wait for StatsDumper",
74 anIE);
75 }
76 }
77
78 public void run() {
79 synchronized(this) {
80 while(!stopDebugging) {
81 try {
82
83 wait(theCycleTime);
84
85 if (stopDebugging) {
86 continue;
87 }
88
89 Stat[] myStats = StatsBoard.get().getStats();
90 for (int i = 0; i < myStats.length; i++) {
91 System.err.println(myStats[i]);
92 }
93
94 /*
95 Only works on JDK 1.5!!!!!!!!
96
97
98 Map myTraces = Thread.getAllStackTraces();
99
100 Iterator myThreads = myTraces.keySet().iterator();
101 while (myThreads.hasNext()) {
102 Thread myThread = (Thread) myThreads.next();
103 StackTraceElement[] myTrace =
104 (StackTraceElement[]) myTraces.get(myThread);
105
106 System.err.println();
107 System.err.println(myThread);
108 System.err.println();
109 for (int i = 0; i < myTrace.length; i++) {
110 System.err.println(" " + myTrace[i]);
111 }
112 }
113
114 */
115 } catch (InterruptedException anIE) {
116 SpaceImpl.theLogger.log(Level.SEVERE, "StatsDumper interrupted");
117 } catch (Exception anE) {
118 System.err.println("Whoops couldn't do dump stats");
119 }
120 }
121 }
122 }
123 }