Java OSX MessageDigest.getInstance(“MD5”) hangs
Question
I am currently experiencing an issue with Java code deployed to OSX. According to my debug logs, this line:
m = MessageDigest.getInstance("MD5");
Sometimes just doesn't finish executing. It does not return. The application keeps consuming CPU. This is very early during the application startup, so there are no GUI windows but there already 2 threads which try to perform md5 hashing - maybe the interact somehow? The only report I am getting from our users is "the app sometimes doesn't start". It's rather random, happening 3 times out of 10 or so.
Is this some known issue? Am I initializing something the wrong way? I noticed someone mentioning the MessageDigest classes are not threadsafe, but putting the entire problematic code in a synchronized function didn't solve the issue. Any ideas?
Java 1.6.0_45 64bit, running on Mac OS X 10.6.8
EDIT: As per Oleg's idea, I grabbed stacktraces of all the process:
"Thread-4" daemon prio=5 tid=1130d6000 nid=0x1006d8000 waiting for monitor entry [00000000]
java.lang.Thread.State: BLOCKED (on object monitor)
"AWT-Shutdown" prio=5 tid=113b1c000 nid=0x11b616000 in Object.wait() [11b615000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <7e1f45168> (a java.lang.Object)
at java.lang.Object.wait(Object.java:485)
at sun.awt.AWTAutoShutdown.run(AWTAutoShutdown.java:265)
- locked <7e1f45168> (a java.lang.Object)
at java.lang.Thread.run(Thread.java:680)
"AWT-AppKit" daemon prio=5 tid=1139db000 nid=0x7fff70596cc0 waiting for monitor entry [00000000]
java.lang.Thread.State: BLOCKED (on object monitor)
"Thread-1" prio=5 tid=113962000 nid=0x11b293000 waiting for monitor entry [11b290000]
java.lang.Thread.State: BLOCKED (on object monitor)
at java.lang.Runtime.loadLibrary0(Runtime.java:815)
- waiting to lock <7e1e04f80> (a java.lang.Runtime)
at java.lang.System.loadLibrary(System.java:1045)
at sun.security.pkcs11.wrapper.PKCS11$1.run(PKCS11.java:88)
at java.security.AccessController.doPrivileged(Native Method)
at sun.security.pkcs11.wrapper.PKCS11.<clinit>(PKCS11.java:86)
at sun.security.pkcs11.SunPKCS11.<init>(SunPKCS11.java:281)
at sun.security.pkcs11.SunPKCS11.<init>(SunPKCS11.java:86)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at sun.security.jca.ProviderConfig$4.run(ProviderConfig.java:262)
at java.security.AccessController.doPrivileged(Native Method)
at sun.security.jca.ProviderConfig.doLoadProvider(ProviderConfig.java:244)
at sun.security.jca.ProviderConfig.getProvider(ProviderConfig.java:224)
- locked <7e1e3a020> (a sun.misc.Launcher$AppClassLoader)
at sun.security.jca.ProviderList.getProvider(ProviderList.java:215)
at sun.security.jca.ProviderList.getService(ProviderList.java:313)
at sun.security.jca.GetInstance.getInstance(GetInstance.java:140)
at java.security.Security.getImpl(Security.java:659)
at java.security.MessageDigest.getInstance(MessageDigest.java:129)
at pl.gizarma.starter2.util.MD5.getMD5Bytes(MD5.java:23)
- locked <7fb495f30> (a java.lang.Class for pl.gizarma.starter2.util.MD5)
at pl.gizarma.starter2.util.MD5.fromBytes(MD5.java:14)
at pl.gizarma.starter2.util.MD5.fromString(MD5.java:9)
at pl.gizarma.starter2.net.UrlCache.getUrl(UrlCache.java:69)
- locked <7e1fb2600> (a pl.gizarma.starter2.net.UrlCache)
at pl.gizarma.starter2.net.UrlCache.getUrl(UrlCache.java:61)
at pl.gizarma.starter2.net.RetryingUrlReader.readUseCache(RetryingUrlReader.java:75)
at pl.gizarma.starter2.net.RetryingUrlReader.read(RetryingUrlReader.java:60)
at pl.gizarma.starter2.net.UpdateDownloader.download(UpdateDownloader.java:29)
at pl.gizarma.starter2.job.UpdateJob.run(UpdateJob.java:20)
at pl.gizarma.starter2.Starter2Main$1.run(Starter2Main.java:51)
"Low Memory Detector" daemon prio=5 tid=113035000 nid=0x11af39000 runnable [00000000]
java.lang.Thread.State: RUNNABLE
"C2 CompilerThread1" daemon prio=9 tid=113034800 nid=0x11ae36000 waiting on condition [00000000]
java.lang.Thread.State: RUNNABLE
"C2 CompilerThread0" daemon prio=9 tid=113033800 nid=0x11ad33000 waiting on condition [00000000]
java.lang.Thread.State: RUNNABLE
"Signal Dispatcher" daemon prio=9 tid=113033000 nid=0x11ac30000 waiting on condition [00000000]
java.lang.Thread.State: RUNNABLE
"Surrogate Locker Thread (Concurrent GC)" daemon prio=5 tid=113032000 nid=0x11ab2d000 waiting on condition [00000000]
java.lang.Thread.State: RUNNABLE
"Finalizer" daemon prio=8 tid=11387d000 nid=0x11aa2a000 in Object.wait() [11aa29000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <7e1e01300> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:118)
- locked <7e1e01300> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:134)
at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:171)
"Reference Handler" daemon prio=10 tid=113029000 nid=0x11a7cb000 in Object.wait() [11a7ca000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <7e1e011d8> (a java.lang.ref.Reference$Lock)
at java.lang.Object.wait(Object.java:485)
at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:116)
- locked <7e1e011d8> (a java.lang.ref.Reference$Lock)
"main" prio=5 tid=113800800 nid=0x1017fb000 runnable [1017f8000]
java.lang.Thread.State: RUNNABLE
at java.lang.ClassLoader$NativeLibrary.load(Native Method)
at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1827)
- locked <7e1e010a8> (a java.util.Vector)
- locked <7e1e01100> (a java.util.Vector)
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1724)
at java.lang.Runtime.loadLibrary0(Runtime.java:823)
- locked <7e1e04f80> (a java.lang.Runtime)
at java.lang.System.loadLibrary(System.java:1045)
at sun.security.action.LoadLibraryAction.run(LoadLibraryAction.java:50)
at java.security.AccessController.doPrivileged(Native Method)
at sun.awt.NativeLibLoader.loadLibraries(NativeLibLoader.java:38)
at sun.awt.DebugHelper.<clinit>(DebugHelper.java:29)
at java.awt.Component.<clinit>(Component.java:566)
at pl.gizarma.starter2.Starter2Main.prepareMainFrame(Starter2Main.java:23)
at pl.gizarma.starter2.Starter2Main.main(Starter2Main.java:17)
"VM Thread" prio=9 tid=113024800 nid=0x11a927000 runnable
"Gang worker#0 (Parallel GC Threads)" prio=9 tid=113802000 nid=0x112dc4000 runnable
"Gang worker#1 (Parallel GC Threads)" prio=9 tid=113802800 nid=0x112ec7000 runnable
"Concurrent Mark-Sweep GC Thread" prio=9 tid=11384d000 nid=0x11a498000 runnable
"VM Periodic Task Thread" prio=10 tid=113897000 nid=0x11b03c000 waiting on condition
"Exception Catcher Thread" prio=10 tid=113801800 nid=0x112c01000 runnable
JNI global references: 1004
Heap
par new generation total 19136K, used 3772K [7e1e00000, 7e32c0000, 7e4790000)
eden space 17024K, 22% used [7e1e00000, 7e21af1b8, 7e2ea0000)
from space 2112K, 0% used [7e2ea0000, 7e2ea0000, 7e30b0000)
to space 2112K, 0% used [7e30b0000, 7e30b0000, 7e32c0000)
concurrent mark-sweep generation total 63872K, used 0K [7e4790000, 7e85f0000, 7fae00000)
concurrent-mark-sweep perm gen total 21248K, used 7162K [7fae00000, 7fc2c0000, 800000000)
The cited MessageDigest.getInstance("MD5") results in System.loadLibrary, which is "waiting to lock <7e1e04f80>". 7e1e04f80 is locked by a different System.loadLibrary call - started from java.awt.Component., which means is more or less outside my control. The locking thread is executing the native routine $NativeLibrary.load, which seems to have hanged. I don't know what library is being loaded.
Any ideas?
1 answers
solution1
0 2014-05-02 21:46:48
From the stacktrace
"Thread-1" prio=5 tid=113962000 nid=0x11b293000 waiting for monitor entry [11b290000] java.lang.Thread.State: BLOCKED (on object monitor) at java.lang.Runtime.loadLibrary0(Runtime.java:815) - waiting to lock <7e1e04f80> (a java.lang.Runtime) at java.lang.System.loadLibrary(System.java:1045) at sun.security.pkcs11.wrapper.PKCS11$1.run(PKCS11.java:88)
PKCS#11 is a module standard that is commonly used to access SmartCards and other hardware cryptography devices. It looks like your application hangs while loading a PKCS#11 module. PKCS#11 drivers are provided by third parties and I am sorry to say, but in my experience are often buggy and unstable. I suggest disabling PKCS#11 if your application does not need access to crypto hardware.
for(Provider p: Security.getProviders())
if(p instanceof sun.security.pkcs11.SunPKCS11)
Security.removeProvider(p.getName());
See also:
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