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1
5 package com.terracotta.session;
6
7 import java.io.File  ;
8 import java.io.IOException ;
9 import java.io.InputStream ;
10 import java.util.ArrayList ;
11 import java.util.Collections ;
12 import java.util.IdentityHashMap ;
13 import java.util.List ;
14 import java.util.Map ;
15 import java.util.TreeMap ;
16 import java.util.Map.Entry;
17
18 import javax.servlet.http.HttpServletRequest ;
19 import javax.servlet.http.HttpSession ;
20
21 public class StuckRequestTracker implements RequestTracker {
22
23 private final Map requests = Collections.synchronizedMap(new IdentityHashMap ());
24 private final Monitor monitor;
25
26 StuckRequestTracker(long sleepTime, long stuckThreshold, boolean dump) {
27 monitor = new Monitor(sleepTime, stuckThreshold, dump);
28 }
29
30 void start() {
31 monitor.start();
32 }
33
34 public void begin(HttpServletRequest request) {
35 getRequestDetail(true).begin(request);
36 }
37
38 public void recordSessionId(TerracottaRequest tr) {
39 getRequestDetail(false).recordSessionId(tr);
40 }
41
42 public boolean end() {
43 boolean done = getRequestDetail(false).end();
44 if (done) {
45 requests.remove(Thread.currentThread());
46 }
47 return done;
48 }
49
50 private RequestDetail getRequestDetail(boolean create) {
51 Thread t = Thread.currentThread();
52 RequestDetail rd = (RequestDetail) requests.get(t);
53 if (rd == null) {
54 if (!create) { throw new AssertionError ("missing request detail"); }
55 rd = new RequestDetail(t);
56 requests.put(t, rd);
57 }
58
59 return rd;
60 }
61
62 private static class RequestDetail implements RequestTracker {
63 private final Thread thread;
64 private final List requests = new ArrayList ();
65 private final long start = System.currentTimeMillis();
66 private String sid;
67 private int count;
68
69 RequestDetail(Thread thread) {
70 this.thread = thread;
71 }
72
73 public synchronized String toString() {
74 return "[" + thread.getName() + "], session " + sid + ", request(s) " + requests;
75 }
76
77 public synchronized void begin(HttpServletRequest req) {
78 count++;
79
80 StringBuffer buf = new StringBuffer (req.getRequestURI());
81
82 String query = req.getQueryString();
83 if (query != null && query.length() > 0) {
84 buf.append('?').append(query);
85 }
86
87 requests.add(buf.toString());
88 }
89
90 public synchronized boolean end() {
91 count--;
92 return count == 0;
93 }
94
95 public synchronized void recordSessionId(TerracottaRequest tr) {
96 if (sid == null) {
97 HttpSession s = tr.getSession(false);
98 if (s != null) {
99 sid = s.getId();
100 }
101 }
102 }
103 }
104
105 private static class ThreadDump {
106 private static final String [] CMD;
107 private static final boolean hasKillAll;
108
109 static {
110 String killall = findKillAll();
111
112 if (killall == null) {
113 hasKillAll = false;
114 CMD = null;
115 } else {
116 hasKillAll = true;
117 CMD = new String [] { killall, "-3", "java" };
118 }
119 }
120
121 private static String findKillAll() {
122 String [] variants = new String [] { "/usr/bin/killall", "/usr/sbin/killall", "/sbin/killall", "/bin/killall" };
123 for (int i = 0; i < variants.length; i++) {
124 String path = variants[i];
125 File f = new File (path);
126 if (f.exists()) { return path; }
127 }
128 return null;
129 }
130
131 static void dumpThreads() {
132 if (hasKillAll) {
133 try {
134 Process proc = Runtime.getRuntime().exec(CMD);
135 proc.getOutputStream().close();
136 consume(proc.getInputStream());
137 consume(proc.getErrorStream());
138 proc.waitFor();
139 } catch (Exception e) {
140 e.printStackTrace();
141 }
142 }
143 }
144
145 private static final byte[] buf = new byte[128];
146
147 private static void consume(InputStream is) throws IOException {
148 while (is.read(buf, 0, 128) >= 0) {
149 }
151 }
152
153 }
154
155 private class Monitor extends Thread {
156
157 private final long stuckThreshold;
158 private final long sleepTime;
159 private final boolean dump;
160
161 Monitor(long sleepTime, long stuckThreshold, boolean dump) {
162 this.sleepTime = sleepTime;
163 this.stuckThreshold = stuckThreshold;
164 this.dump = dump;
165 setDaemon(true);
166 setName("Session Stuck Thread Monitor");
167 }
168
169 public void run() {
170 while (true) {
171 try {
172 sleep(sleepTime);
173 } catch (InterruptedException e) {
174 continue;
175 }
176
177 long now = System.currentTimeMillis();
178 Map stuck = new TreeMap ();
179 Object [] currentRequests = StuckRequestTracker.this.requests.values().toArray();
180 for (int i = 0, n = currentRequests.length; i < n; i++) {
181 RequestDetail rd = (RequestDetail) currentRequests[i];
182
183 long time = now - rd.start;
184 if (time > stuckThreshold) {
185 stuck.put(new Long (time), rd);
186 }
187 }
188
189 if (stuck.size() > 0) {
190 StringBuffer message = new StringBuffer ("Stuck Threads (").append(stuck.size()).append(")\n");
191 Object [] stuckRequests = stuck.entrySet().toArray();
192 for (int i = stuckRequests.length - 1; i >= 0; i--) {
193 Map.Entry entry = (Entry) stuckRequests[i];
194 RequestDetail t = (RequestDetail) entry.getValue();
195 long time = ((Long ) entry.getKey()).longValue();
196 message.append(" ").append(time).append(" ").append(t).append("\n");
197 }
198
199 System.err.println(message);
200 System.err.flush();
201 if (dump) {
202 ThreadDump.dumpThreads();
203 }
204 }
205 }
206 }
207 }
208
209 } |
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