Re: Help needed with concurrency bug

[Peter Firmstone]

The following is specific to:

com/sun/jini/test/impl/start/aggregatepolicyprovider/GetContextTest.td
I've just come across the concurrency issue (experienced randomly when 
attempting to debug any of the failing tests) in the existing River 
trunk code, after exiting the debugger, the test is in a deadlocked 
state, here's the thread dump:

In this case I've tried to print the domain (ProtectionDomain), as you 
can see two threads have arrived at the same breakpoint.

jdb -attach 8000
Set uncaught java.lang.Throwable
Set deferred uncaught java.lang.Throwable
Initializing jdb ...
>
VM Started: No frames on the current call stack

main[1] stop in com.sun.jini.start.AggregatePolicyProvider.implies
Deferring breakpoint com.sun.jini.start.AggregatePolicyProvider.implies.
It will be set after the class is loaded.
main[1] run
> Set deferred breakpoint 
com.sun.jini.start.AggregatePolicyProvider.implies

Breakpoint hit: "thread=main", 
com.sun.jini.start.AggregatePolicyProvider.implies(), line=201 bci=0

main[1] print domain

Breakpoint hit: "thread=main", 
com.sun.jini.start.AggregatePolicyProvider.implies(), line=201 bci=0

main[1] where all
Signal Dispatcher:
Finalizer:
 [1] java.lang.Object.wait (native method)
 [2] java.lang.ref.ReferenceQueue.remove (ReferenceQueue.java:118)
 [3] java.lang.ref.ReferenceQueue.remove (ReferenceQueue.java:134)
 [4] java.lang.ref.Finalizer$FinalizerThread.run (Finalizer.java:159)
Reference Handler:
 [1] java.lang.Object.wait (native method)
 [2] java.lang.Object.wait (Object.java:485)
 [3] java.lang.ref.Reference$ReferenceHandler.run (Reference.java:116)
main:
 [1] com.sun.jini.start.AggregatePolicyProvider.implies 
(AggregatePolicyProvider.java:201)
 [2] java.security.ProtectionDomain.implies (ProtectionDomain.java:224)
 [3] java.security.AccessControlContext.checkPermission 
(AccessControlContext.java:352)
 [4] java.security.AccessController.checkPermission 
(AccessController.java:546)
 [5] java.lang.SecurityManager.checkPermission (SecurityManager.java:532)
 [6] java.security.ProtectionDomain.seeAllp (ProtectionDomain.java:295)
 [7] java.security.ProtectionDomain.toString (ProtectionDomain.java:255)
 [8] com.sun.jini.start.AggregatePolicyProvider.implies 
(AggregatePolicyProvider.java:201)
 [9] java.security.ProtectionDomain.implies (ProtectionDomain.java:224)
 [10] java.security.AccessControlContext.checkPermission 
(AccessControlContext.java:352)
 [11] java.security.AccessController.checkPermission 
(AccessController.java:546)
 [12] java.lang.SecurityManager.checkPermission (SecurityManager.java:532)
 [13] java.lang.SecurityManager.checkCreateClassLoader 
(SecurityManager.java:594)
 [14] java.lang.ClassLoader.checkCreateClassLoader (ClassLoader.java:177)
 [15] java.lang.ClassLoader.<init> (ClassLoader.java:225)
 [16] java.security.SecureClassLoader.<init> (SecureClassLoader.java:93)
 [17] java.net.URLClassLoader.<init> (URLClassLoader.java:115)
 [18] 
com.sun.jini.test.impl.start.aggregatepolicyprovider.GetContextTest.run 
(GetContextTest.java:85)
 [19] com.sun.jini.qa.harness.MasterTest.doTest (MasterTest.java:252)
 [20] com.sun.jini.qa.harness.MasterTest.main (MasterTest.java:142)
no heart without soul:
 [1] com.sun.jini.start.AggregatePolicyProvider.implies 
(AggregatePolicyProvider.java:201)
 [2] java.security.ProtectionDomain.implies (ProtectionDomain.java:224)
 [3] java.security.AccessControlContext.checkPermission 
(AccessControlContext.java:352)
 [4] java.security.AccessController.checkPermission 
(AccessController.java:546)
 [5] java.lang.SecurityManager.checkPermission (SecurityManager.java:532)
 [6] java.lang.SecurityManager.checkRead (SecurityManager.java:871)
 [7] java.io.File.exists (File.java:731)
 [8] com.sun.jini.qa.harness.HeartOfTheMachine.hasReasonToLive 
(HeartOfTheMachine.java:56)
 [9] com.sun.jini.qa.harness.HeartOfTheMachine.ticktack 
(HeartOfTheMachine.java:62)
 [10] com.sun.jini.qa.harness.HeartOfTheMachine.access$000 
(HeartOfTheMachine.java:29)
 [11] com.sun.jini.qa.harness.HeartOfTheMachine$1.run 
(HeartOfTheMachine.java:45)
 [12] java.lang.Thread.run (Thread.java:662)
Thread-2:
 [1] java.net.PlainSocketImpl.socketAccept (native method)
 [2] java.net.PlainSocketImpl.accept (PlainSocketImpl.java:408)
 [3] java.net.ServerSocket.implAccept (ServerSocket.java:462)
 [4] java.net.ServerSocket.accept (ServerSocket.java:430)
 [5] com.sun.jini.tool.ClassServer.run (ClassServer.java:396)
Thread-3:
 [1] java.net.PlainSocketImpl.socketAccept (native method)
 [2] java.net.PlainSocketImpl.accept (PlainSocketImpl.java:408)
 [3] java.net.ServerSocket.implAccept (ServerSocket.java:462)
 [4] java.net.ServerSocket.accept (ServerSocket.java:430)
 [5] com.sun.jini.tool.ClassServer.run (ClassServer.java:396)
Thread-4:
 [1] java.net.PlainSocketImpl.socketAccept (native method)
 [2] java.net.PlainSocketImpl.accept (PlainSocketImpl.java:408)
 [3] java.net.ServerSocket.implAccept (ServerSocket.java:462)
 [4] java.net.ServerSocket.accept (ServerSocket.java:430)
 [5] com.sun.jini.tool.ClassServer.run (ClassServer.java:396)
RequestHandler:
 [1] java.io.FileInputStream.readBytes (native method)
 [2] java.io.FileInputStream.read (FileInputStream.java:220)
 [3] java.io.BufferedInputStream.fill (BufferedInputStream.java:218)
 [4] java.io.BufferedInputStream.read1 (BufferedInputStream.java:258)
 [5] java.io.BufferedInputStream.read (BufferedInputStream.java:317)
 [6] java.io.ObjectInputStream$PeekInputStream.read 
(ObjectInputStream.java:2,265)
 [7] java.io.ObjectInputStream$PeekInputStream.readFully 
(ObjectInputStream.java:2,278)
 [8] java.io.ObjectInputStream$BlockDataInputStream.readShort 
(ObjectInputStream.java:2,749)
 [9] java.io.ObjectInputStream.readStreamHeader 
(ObjectInputStream.java:779)
 [10] java.io.ObjectInputStream.<init> (ObjectInputStream.java:279)
 [11] com.sun.jini.qa.harness.MasterTest$RequestHandler.run 
(MasterTest.java:323)
 [12] java.lang.Thread.run (Thread.java:662)
main[1] monitor
main[1] step
>
Breakpoint hit: "thread=no heart without soul", 
com.sun.jini.start.AggregatePolicyProvider.implies(), line=201 bci=0

no heart without soul[1] where all
Signal Dispatcher:
Finalizer:
 [1] java.lang.Object.wait (native method)
 [2] java.lang.ref.ReferenceQueue.remove (ReferenceQueue.java:118)
 [3] java.lang.ref.ReferenceQueue.remove (ReferenceQueue.java:134)
 [4] java.lang.ref.Finalizer$FinalizerThread.run (Finalizer.java:159)
Reference Handler:
 [1] java.lang.Object.wait (native method)
 [2] java.lang.Object.wait (Object.java:485)
 [3] java.lang.ref.Reference$ReferenceHandler.run (Reference.java:116)
main:
 [1] com.sun.jini.start.AggregatePolicyProvider.implies 
(AggregatePolicyProvider.java:201)
 [2] java.security.ProtectionDomain.implies (ProtectionDomain.java:224)
 [3] java.security.AccessControlContext.checkPermission 
(AccessControlContext.java:352)
 [4] java.security.AccessController.checkPermission 
(AccessController.java:546)
 [5] java.lang.SecurityManager.checkPermission (SecurityManager.java:532)
 [6] java.security.ProtectionDomain.seeAllp (ProtectionDomain.java:295)
 [7] java.security.ProtectionDomain.toString (ProtectionDomain.java:255)
 [8] com.sun.jini.start.AggregatePolicyProvider.implies 
(AggregatePolicyProvider.java:201)
 [9] java.security.ProtectionDomain.implies (ProtectionDomain.java:224)
 [10] java.security.AccessControlContext.checkPermission 
(AccessControlContext.java:352)
 [11] java.security.AccessController.checkPermission 
(AccessController.java:546)
 [12] java.lang.SecurityManager.checkPermission (SecurityManager.java:532)
 [13] java.lang.SecurityManager.checkCreateClassLoader 
(SecurityManager.java:594)
 [14] java.lang.ClassLoader.checkCreateClassLoader (ClassLoader.java:177)
 [15] java.lang.ClassLoader.<init> (ClassLoader.java:225)
 [16] java.security.SecureClassLoader.<init> (SecureClassLoader.java:93)
 [17] java.net.URLClassLoader.<init> (URLClassLoader.java:115)
 [18] 
com.sun.jini.test.impl.start.aggregatepolicyprovider.GetContextTest.run 
(GetContextTest.java:85)
 [19] com.sun.jini.qa.harness.MasterTest.doTest (MasterTest.java:252)
 [20] com.sun.jini.qa.harness.MasterTest.main (MasterTest.java:142)
no heart without soul:
 [1] com.sun.jini.start.AggregatePolicyProvider.implies 
(AggregatePolicyProvider.java:201)
 [2] java.security.ProtectionDomain.implies (ProtectionDomain.java:224)
 [3] java.security.AccessControlContext.checkPermission 
(AccessControlContext.java:352)
 [4] java.security.AccessController.checkPermission 
(AccessController.java:546)
 [5] java.lang.SecurityManager.checkPermission (SecurityManager.java:532)
 [6] java.lang.SecurityManager.checkRead (SecurityManager.java:871)
 [7] java.io.File.exists (File.java:731)
 [8] com.sun.jini.qa.harness.HeartOfTheMachine.hasReasonToLive 
(HeartOfTheMachine.java:56)
 [9] com.sun.jini.qa.harness.HeartOfTheMachine.ticktack 
(HeartOfTheMachine.java:62)
 [10] com.sun.jini.qa.harness.HeartOfTheMachine.access$000 
(HeartOfTheMachine.java:29)
 [11] com.sun.jini.qa.harness.HeartOfTheMachine$1.run 
(HeartOfTheMachine.java:45)
 [12] java.lang.Thread.run (Thread.java:662)
Thread-2:
 [1] java.net.PlainSocketImpl.socketAccept (native method)
 [2] java.net.PlainSocketImpl.accept (PlainSocketImpl.java:408)
 [3] java.net.ServerSocket.implAccept (ServerSocket.java:462)
 [4] java.net.ServerSocket.accept (ServerSocket.java:430)
 [5] com.sun.jini.tool.ClassServer.run (ClassServer.java:396)
Thread-3:
 [1] java.net.PlainSocketImpl.socketAccept (native method)
 [2] java.net.PlainSocketImpl.accept (PlainSocketImpl.java:408)
 [3] java.net.ServerSocket.implAccept (ServerSocket.java:462)
 [4] java.net.ServerSocket.accept (ServerSocket.java:430)
 [5] com.sun.jini.tool.ClassServer.run (ClassServer.java:396)
Thread-4:
 [1] java.net.PlainSocketImpl.socketAccept (native method)
 [2] java.net.PlainSocketImpl.accept (PlainSocketImpl.java:408)
 [3] java.net.ServerSocket.implAccept (ServerSocket.java:462)
 [4] java.net.ServerSocket.accept (ServerSocket.java:430)
 [5] com.sun.jini.tool.ClassServer.run (ClassServer.java:396)
RequestHandler:
 [1] java.io.FileInputStream.readBytes (native method)
 [2] java.io.FileInputStream.read (FileInputStream.java:220)
 [3] java.io.BufferedInputStream.fill (BufferedInputStream.java:218)
 [4] java.io.BufferedInputStream.read1 (BufferedInputStream.java:258)
 [5] java.io.BufferedInputStream.read (BufferedInputStream.java:317)
 [6] java.io.ObjectInputStream$PeekInputStream.read 
(ObjectInputStream.java:2,265)
 [7] java.io.ObjectInputStream$PeekInputStream.readFully 
(ObjectInputStream.java:2,278)
 [8] java.io.ObjectInputStream$BlockDataInputStream.readShort 
(ObjectInputStream.java:2,749)
 [9] java.io.ObjectInputStream.readStreamHeader 
(ObjectInputStream.java:779)
 [10] java.io.ObjectInputStream.<init> (ObjectInputStream.java:279)
 [11] com.sun.jini.qa.harness.MasterTest$RequestHandler.run 
(MasterTest.java:323)
 [12] java.lang.Thread.run (Thread.java:662)
no heart without soul[1] step
>
Breakpoint hit: "thread=main", 
com.sun.jini.start.AggregatePolicyProvider.implies(), line=201 bci=0

main[1] where all
Signal Dispatcher:
Finalizer:
 [1] java.lang.Object.wait (native method)
 [2] java.lang.ref.ReferenceQueue.remove (ReferenceQueue.java:118)
 [3] java.lang.ref.ReferenceQueue.remove (ReferenceQueue.java:134)
 [4] java.lang.ref.Finalizer$FinalizerThread.run (Finalizer.java:159)
Reference Handler:
 [1] java.lang.Object.wait (native method)
 [2] java.lang.Object.wait (Object.java:485)
 [3] java.lang.ref.Reference$ReferenceHandler.run (Reference.java:116)
main:
 [1] com.sun.jini.start.AggregatePolicyProvider.implies 
(AggregatePolicyProvider.java:201)
 [2] java.security.ProtectionDomain.implies (ProtectionDomain.java:224)
 [3] java.security.AccessControlContext.checkPermission 
(AccessControlContext.java:352)
 [4] java.security.AccessController.checkPermission 
(AccessController.java:546)
 [5] java.lang.SecurityManager.checkPermission (SecurityManager.java:532)
 [6] java.security.ProtectionDomain.seeAllp (ProtectionDomain.java:295)
 [7] java.security.ProtectionDomain.toString (ProtectionDomain.java:255)
 [8] com.sun.jini.start.AggregatePolicyProvider.implies 
(AggregatePolicyProvider.java:201)
 [9] java.security.ProtectionDomain.implies (ProtectionDomain.java:224)
 [10] java.security.AccessControlContext.checkPermission 
(AccessControlContext.java:352)
 [11] java.security.AccessController.checkPermission 
(AccessController.java:546)
 [12] java.lang.SecurityManager.checkPermission (SecurityManager.java:532)
 [13] java.lang.SecurityManager.checkCreateClassLoader 
(SecurityManager.java:594)
 [14] java.lang.ClassLoader.checkCreateClassLoader (ClassLoader.java:177)
 [15] java.lang.ClassLoader.<init> (ClassLoader.java:225)
 [16] java.security.SecureClassLoader.<init> (SecureClassLoader.java:93)
 [17] java.net.URLClassLoader.<init> (URLClassLoader.java:115)
 [18] 
com.sun.jini.test.impl.start.aggregatepolicyprovider.GetContextTest.run 
(GetContextTest.java:85)
 [19] com.sun.jini.qa.harness.MasterTest.doTest (MasterTest.java:252)
 [20] com.sun.jini.qa.harness.MasterTest.main (MasterTest.java:142)
no heart without soul:
 [1] java.lang.SecurityManager.checkRead (SecurityManager.java:873)
 [2] java.io.File.exists (File.java:731)
 [3] com.sun.jini.qa.harness.HeartOfTheMachine.hasReasonToLive 
(HeartOfTheMachine.java:56)
 [4] com.sun.jini.qa.harness.HeartOfTheMachine.ticktack 
(HeartOfTheMachine.java:62)
 [5] com.sun.jini.qa.harness.HeartOfTheMachine.access$000 
(HeartOfTheMachine.java:29)
 [6] com.sun.jini.qa.harness.HeartOfTheMachine$1.run 
(HeartOfTheMachine.java:45)
 [7] java.lang.Thread.run (Thread.java:662)
Thread-2:
 [1] java.net.PlainSocketImpl.socketAccept (native method)
 [2] java.net.PlainSocketImpl.accept (PlainSocketImpl.java:408)
 [3] java.net.ServerSocket.implAccept (ServerSocket.java:462)
 [4] java.net.ServerSocket.accept (ServerSocket.java:430)
 [5] com.sun.jini.tool.ClassServer.run (ClassServer.java:396)
Thread-3:
 [1] java.net.PlainSocketImpl.socketAccept (native method)
 [2] java.net.PlainSocketImpl.accept (PlainSocketImpl.java:408)
 [3] java.net.ServerSocket.implAccept (ServerSocket.java:462)
 [4] java.net.ServerSocket.accept (ServerSocket.java:430)
 [5] com.sun.jini.tool.ClassServer.run (ClassServer.java:396)
Thread-4:
 [1] java.net.PlainSocketImpl.socketAccept (native method)
 [2] java.net.PlainSocketImpl.accept (PlainSocketImpl.java:408)
 [3] java.net.ServerSocket.implAccept (ServerSocket.java:462)
 [4] java.net.ServerSocket.accept (ServerSocket.java:430)
 [5] com.sun.jini.tool.ClassServer.run (ClassServer.java:396)
RequestHandler:
 [1] java.io.FileInputStream.readBytes (native method)
 [2] java.io.FileInputStream.read (FileInputStream.java:220)
 [3] java.io.BufferedInputStream.fill (BufferedInputStream.java:218)
 [4] java.io.BufferedInputStream.read1 (BufferedInputStream.java:258)
 [5] java.io.BufferedInputStream.read (BufferedInputStream.java:317)
 [6] java.io.ObjectInputStream$PeekInputStream.read 
(ObjectInputStream.java:2,265)
 [7] java.io.ObjectInputStream$PeekInputStream.readFully 
(ObjectInputStream.java:2,278)
 [8] java.io.ObjectInputStream$BlockDataInputStream.readShort 
(ObjectInputStream.java:2,749)
 [9] java.io.ObjectInputStream.readStreamHeader 
(ObjectInputStream.java:779)
 [10] java.io.ObjectInputStream.<init> (ObjectInputStream.java:279)
 [11] com.sun.jini.qa.harness.MasterTest$RequestHandler.run 
(MasterTest.java:323)
 [12] java.lang.Thread.run (Thread.java:662)
main[1] dump this
this = {
   mainPolicyClassProperty: 
"com.sun.jini.start.AggregatePolicyProvider.mainPolicyClass"
   defaultMainPolicyClass: "net.jini.security.policy.DynamicPolicyProvider"
   trustGetCCL: instance of java.util.WeakHashMap(id=962)
   myDomain: instance of java.security.ProtectionDomain(id=963)
   subPolicies: instance of com.sun.jini.collection.WeakIdentityMap(id=964)
   subPolicyCache: instance of 
com.sun.jini.collection.WeakIdentityMap(id=965)
   mainPolicy: instance of 
net.jini.security.policy.DynamicPolicyProvider(id=966)
   $assertionsDisabled: true
   java.security.Policy.UNSUPPORTED_EMPTY_COLLECTION: instance of 
java.security.Policy$UnsupportedEmptyCollection(id=967)
   java.security.Policy.policy: instance of 
com.sun.jini.start.AggregatePolicyProvider(id=959)
   java.security.Policy.debug: null
   java.security.Policy.pdMapping: instance of 
java.util.WeakHashMap(id=968)
}
main[1] exit