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1
8 package eworld.service;
9
10 import org.codehaus.aspectwerkz.extension.hotswap.EWorldUtil;
11 import org.codehaus.aspectwerkz.joinpoint.JoinPoint;
12 import org.codehaus.aspectwerkz.joinpoint.MethodRtti;
13 import org.codehaus.aspectwerkz.joinpoint.MemberSignature;
14 import org.codehaus.aspectwerkz.exception.WrappedRuntimeException;
15
16 import java.util.Map  ;
17 import java.util.HashMap ;
18
19
20
23 public class ComputationStandalone {
24
25 private static final int WEAVING_FREQUENCY = new Integer (
26 System
27 .getProperty("weaving.frequency")
28 ).intValue();
29
30 private static final boolean USE_CACHE = System.getProperty("cache").equals("true");
31
32 private static final boolean USE_TRACE = System.getProperty("trace").equals("true");
33
34 private static final String EXPRESSION = "execution(int eworld.service.ComputationStandalone.fib(int))";
35
36 private static final String SYSTEM_ID = "eworld/wlw/aop";
37
38 private static final String CACHE_POINTCUT = "cache";
39
40 private static final String TRACE_POINTCUT = "trace";
41
42 private static final String CACHE_ADVICE = "cache";
43
44 private static final String TRACE_ADVICE = "trace";
45
46 public static int fib(int n) {
47 if (n < 2) {
48 System.err.println(n + ".");
49 return 1;
50 } else {
51 System.err.print(n + ",");
52 return fib(n - 1) + fib(n - 2);
53 }
54 }
55
56 private static void weave() {
57 if (USE_CACHE) {
58 System.err.println("weaving in cache support");
59 EWorldUtil.activate(
60 SYSTEM_ID,
61 CacheAspect.class.getName(),
62 CACHE_ADVICE,
63 EXPRESSION,
64 CACHE_POINTCUT
65 );
66 }
67 if (USE_TRACE) {
68 System.err.println("weaving in trace support");
69 EWorldUtil.activate(
70 SYSTEM_ID,
71 TraceAspect.class.getName(),
72 TRACE_ADVICE,
73 EXPRESSION,
74 TRACE_POINTCUT
75 );
76 }
77 }
78
79 private static void unWeave() {
80 if (USE_CACHE) {
81 System.err.println("un-weaving cache support");
82 EWorldUtil.deactivate(
83 SYSTEM_ID,
84 CacheAspect.class.getName(),
85 CACHE_ADVICE,
86 CACHE_POINTCUT
87 );
88 System.err.println("** Flushing the cache...");
90 CacheAspect.s_cache.clear();
91 }
92 if (USE_TRACE) {
93 System.err.println("un-weaving trace support");
94 EWorldUtil.deactivate(
95 SYSTEM_ID,
96 TraceAspect.class.getName(),
97 TRACE_ADVICE,
98 TRACE_POINTCUT
99 );
100 }
101 }
102
103 public static void main(String [] args) {
104
105 try {
150 int iterations = new Integer (args[0]).intValue();
151 long sleep = new Long (args[1]).longValue();
152 int counter = 0;
153 boolean isWeaved = false;
154 while (true) {
155 System.out.println(
156 "TraceAspect weave status = "
157 + EWorldUtil.isWeaved(SYSTEM_ID, TraceAspect.class.getName())
158 );
159 System.out.println(
160 "CacheAspect weave status = "
161 + EWorldUtil.isWeaved(SYSTEM_ID, CacheAspect.class.getName())
162 );
163 counter++;
164 Thread.sleep(sleep);
165 System.err.println("fib(" + iterations + ") = " + fib(iterations));
166 if (USE_CACHE || USE_TRACE) {
167 if ((counter %= WEAVING_FREQUENCY) == 0) {
168 if (isWeaved) {
169 unWeave();
170 isWeaved = false;
171 } else {
172 weave();
173 isWeaved = true;
174 }
175 EWorldUtil.hotswap("eworld.service");
176 }
177 }
178 }
179 } catch (InterruptedException e) {
180 throw new WrappedRuntimeException(e);
181 }
182 }
183
184
187 public static class CacheAspect {
188
189
190 public static Map s_cache = new HashMap ();
191
192 public Object cache(final JoinPoint joinPoint) throws Throwable {
193 MethodRtti mrtti = (MethodRtti) joinPoint.getRtti();
194 Integer parameter = (Integer ) mrtti.getParameterValues()[0];
195 Integer cachedValue = (Integer ) s_cache.get(parameter);
196 if (cachedValue == null) {
197 System.err.println("not in cache");
198 Object newValue = joinPoint.proceed(); s_cache.put(parameter, newValue);
200 return newValue;
201 } else {
202 System.err.println("using cache: " + cachedValue);
203 return cachedValue; }
205 }
206 }
207
208
211 public static class TraceAspect {
212 private int m_level = 0;
213
214 public Object trace(final JoinPoint joinPoint) throws Throwable {
215 MemberSignature signature = (MemberSignature) joinPoint.getSignature();
216 indent();
217 System.out.println(
218 "--> "
219 + signature.getDeclaringType().getName()
220 + "::"
221 + signature.getName()
222 );
223 m_level++;
224 final Object result = joinPoint.proceed();
225 m_level--;
226 indent();
227 System.out.println(
228 "<-- "
229 + signature.getDeclaringType().getName()
230 + "::"
231 + signature.getName()
232 );
233 return result;
234 }
235
236 private void indent() {
237 for (int i = 0; i < m_level; i++) {
238 System.out.print(" ");
239 }
240 }
241 }
242 } |
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