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1
19
20 package edu.umd.cs.findbugs.detect;
21
22
23 import edu.umd.cs.findbugs.*;
24 import org.apache.bcel.classfile.Code;
25
26 public class WaitInLoop extends BytecodeScanningDetector implements StatelessDetector {
27
28 boolean sawWait = false;
29 boolean sawAwait = false;
30 boolean waitHasTimeout = false;
31 boolean sawNotify = false;
32 int notifyPC;
33 int earliestJump = 0;
34 int waitAt = 0;
35 private BugReporter bugReporter;
36
37 public WaitInLoop(BugReporter bugReporter) {
38 this.bugReporter = bugReporter;
39 }
40
41
42
43 @Override 
44 public void visit(Code obj) {
45 sawWait = false;
46 sawAwait = false;
47 waitHasTimeout = false;
48 sawNotify = false;
49 earliestJump = 9999999;
50 super.visit(obj);
51 if ((sawWait || sawAwait) && waitAt < earliestJump) {
52 String bugType = sawWait ? "WA_NOT_IN_LOOP" : "WA_AWAIT_NOT_IN_LOOP";
53 bugReporter.reportBug(new BugInstance(this, bugType, waitHasTimeout ? LOW_PRIORITY : NORMAL_PRIORITY)
54 .addClassAndMethod(this)
55 .addSourceLine(this, waitAt));
56 }
57 if (sawNotify)
58 bugReporter.reportBug(new BugInstance(this, "NO_NOTIFY_NOT_NOTIFYALL", LOW_PRIORITY)
59 .addClassAndMethod(this)
60 .addSourceLine(this, notifyPC));
61 }
62
63 @Override
64 public void sawOpcode(int seen) {
65
66 if ((seen == INVOKEVIRTUAL || seen == INVOKEINTERFACE)
67 && getNameConstantOperand().equals("notify")
68 && getSigConstantOperand().equals("()V")) {
69 sawNotify = true;
70 notifyPC = getPC();
71 }
72 if (!(sawWait || sawAwait)
73 && (seen == INVOKEVIRTUAL || seen == INVOKEINTERFACE)
74 && (isMonitorWait() || isConditionAwait())) {
75
76 if (getNameConstantOperand().equals("wait")) {
77 sawWait = true;
78 } else {
79 sawAwait = true;
80 }
81 waitHasTimeout = !getSigConstantOperand().equals("()V");
82 waitAt = getPC();
83 earliestJump = getPC() + 1;
84 return;
85 }
86 if (seen >= IFEQ && seen <= GOTO
87 || seen >= IFNULL && seen <= GOTO_W)
88 earliestJump = Math.min(earliestJump, getBranchTarget());
89 }
90
91 private boolean isConditionAwait() {
92 String className = getClassConstantOperand();
93 String name = getNameConstantOperand();
94 String sig = getSigConstantOperand();
95
96 if (!className.equals("java/util/concurrent/locks/Condition")) return false;
97
98 if (!name.startsWith("await")) return false;
99
100 if (
101 name.equals("await") &&
102 (sig.equals("()V") || sig.equals("(JLjava/util/concurrent/TimeUnit;)V")))
103 return true;
104 if (name.equals("awaitNanos") && sig.equals("(J)V"))
105 return true;
106 if (name.equals("awaitUninterruptibly") && sig.equals("()V"))
107 return true;
108 if (name.equals("awaitUntil") && sig.equals("(Ljava/util/Date;)V"))
109 return true;
110
111 return false;
112 }
113
114 private boolean isMonitorWait() {
115 String name = getNameConstantOperand();
116 String sig = getSigConstantOperand();
117
118 return name.equals("wait")
119 && (sig.equals("()V") || sig.equals("(J)V") || sig.equals("(JI)V"));
120 }
121
122
123 }
124 |
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