Green and Native Threads...
How do I find whether green / native threads are used in my VM???
Can I control whether to use green / native threads are used?
I use 2 VM's, one for win NT and one for ISeries(as/400).
Thanks in advance!
I don't think green/native threads can be used on windows, but for example on linux, native threads are running in their own process, while green threads means they all run in the same process.
You can use the flag -native and -green to specify whether it should run native or green threads (on linux at least).
Similar Messages
-
JNI and Native Threads Doesn't work
I am writing a wrapper class in C++ for a java class that publishes a message to JMS. In the C++ code I create the class, and call the one method. Everything does what it is supposed to, UNLESS more than one thread calls it. All the C++ wrapper stuff is in a DLL, and the classpath is correct for the java side, I then run an exe that is linked with the dll. The dll exposes one method that creates the java class, and calls the method. when more than one thread enters the DLL, I start getting class not found exceptions?? where as if I just call the method multiple times in a single thread, all works fine?? Please help, code included
-----------------------DLL CODE-------------------------------
extern "C"
BOOL APIENTRY DllMain(HINSTANCE hInst,DWORD reason,LPVOID reserved)
switch (reason)
case DLL_PROCESS_ATTACH:
if(!crit_init)
printf("Initializing Critical Section\n");
InitializeCriticalSection(&cs);
crit_init = true;
EnterCriticalSection(&cs);
if(jvm == NULL)
char buffer[1024];
int portNum = -1;
JavaVMInitArgs vm_args;
JNIEnv *env = NULL;
JavaVMOption options[4];
memset(buffer,0,sizeof(buffer));
strcat(buffer,"-Djava.class.path=");
strcat(buffer,getenv("CLASSPATH"));
printf("\nClassPath :\n\n%s",buffer);
printf("\n\n");
options[0].optionString = "-Djava.compiler=NONE"; // disable JIT
options[1].optionString = buffer; // user classes
options[2].optionString = "-Xms64M";
options[3].optionString = "-Xmx64M";
vm_args.version = JNI_VERSION_1_2;
vm_args.options = options;
vm_args.nOptions = 4;
vm_args.ignoreUnrecognized = 1;
printf("Creating JVM\n\n");
if(JNI_CreateJavaVM(&jvm, (void **)&env, &vm_args ) != 0)
printf("Failed to Create JVM!\n");
LeaveCriticalSection(&cs);
return false;
printf("JVM Created\n\n");
LeaveCriticalSection(&cs);
return true;
case DLL_PROCESS_DETACH:
break;
case DLL_THREAD_ATTACH:
break;
case DLL_THREAD_DETACH:
break;
/* Returns TRUE on success, FALSE on failure */
return TRUE;
DLLIMPORT char* publishAndWait(char * destination,
char* payloadFormat, char* transactionType,
char *payload, int timeoutSec)
JNIEnv* jEnv = NULL;
if(jvm->AttachCurrentThread((void**) &jEnv, NULL) || jEnv == NULL)
printf("AttachCurrentThread error\n");
return NULL;
EnterCriticalSection(&cs);
if(jmsStub == NULL)
int portNum = -1;
char buffer[10];
memset(buffer,0,sizeof(buffer));
itoa(portNum,getenv("CORBA_RESP_PORT"),10);
printf("Creating JMSStub Instance\n");
jmsStub = new JMSStub(getenv("WL_URL"),getenv("WL_CONN_FACTORY"),portNum,jEnv);
printf("JMSStub Created\n\n");
LeaveCriticalSection(&cs);
return jmsStub->publishAndWait(destination,payloadFormat,
transactionType,payload,timeoutSec,jEnv);
int retDetVal = jvm->DetachCurrentThread();
if(retDetVal)
printf("DetachCurrentThread error %d\n", retDetVal);
return NULL;
----------------------JMS STUB CLASS (IN DLL)-------------------------
JMSStub::JMSStub(string wlURL, string connectionFactory, int responsePort,JNIEnv* jEnv)
printf("Setting Local Strings\n");
this->wlURL = wlURL;
this->connectionFactory = connectionFactory;
this->responsePort = responsePort;
printf("Local Strings Set\n");
// load class
this->loadMethodIDs(jEnv);
localObject = jEnv->NewObject(jmsStubCls,stubMethodMap.find("<init>")->second,
jEnv->NewStringUTF(wlURL.c_str()),jEnv->NewStringUTF(connectionFactory.c_str()),
responsePort,false);
// create global reference so garbage collection will not take place
printf("Creating GlobalRef to JMSStub Instance\n");
globalObject = jEnv->NewGlobalRef(localObject);
void JMSStub::loadMethodIDs(JNIEnv* jEnv)
printf("Getting Hashtable Class\n");
hashTableCls = jEnv->FindClass("java/util/Hashtable" );
printf("Getting JMSStub Class\n");
jmsStubCls = jEnv->FindClass("com/pacificare/common/jms/JMSStub");
if(hashTableCls == NULL)
printf("Error Getting Hashtable information!!\n");
exit(-255);
if(jmsStubCls == NULL)
printf("Error Getting JMSStub information!!\n");
exit(-255);
printf("Getting Hashtable Methods\n");
/* Get Hashtable Constructor */
hashMethodMap.insert(MethodIDMap::value_type("<init>",
jEnv->GetMethodID(hashTableCls, "<init>","()V")));
/* get put method id */
hashMethodMap.insert(MethodIDMap::value_type("put",jEnv->GetMethodID(hashTableCls, "put",
"(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;")));
printf("Getting JMSStub Methods\n");
/* get JMSStub constructor */
stubMethodMap.insert(MethodIDMap::value_type("<init>",jEnv->GetMethodID(jmsStubCls, "<init>",
"(Ljava/lang/String;Ljava/lang/String;IZ)V" )));
/* find the publishAndWait method */
stubMethodMap.insert(MethodIDMap::value_type("publishAndWait",jEnv->GetMethodID(jmsStubCls,"publishAndWait",
"(Ljava/lang/String;Ljava/util/Hashtable;I)Ljava/lang/String;")));
bool JMSStub::hasExceptionOccurred(JNIEnv* jEnv)
jthrowable jthr = NULL;
jthr = jEnv->ExceptionOccurred();
if(jthr == NULL)
return false;
jEnv->ExceptionDescribe();
jEnv->ExceptionClear();
return true;
char* JMSStub::publishAndWait(char * destination,
char* payloadFormat, char* transactionType,
char payload, int timeoutSec,JNIEnv jEnv)
jmethodID hpMid = hashMethodMap.find("put")->second;
// Strings used in methods, constructors, ect
jstring destinationStr = jEnv->NewStringUTF(destination);
jstring payloadFormatStr = jEnv->NewStringUTF(payloadFormat);
jstring transTypeStr = jEnv->NewStringUTF(transactionType);
jstring payloadStr = jEnv->NewStringUTF(payloadFormat);
jobject localHashtable = jEnv->NewObject(hashTableCls,hashMethodMap.find("<init>")->second);
jEnv->CallObjectMethod(localHashtable,hpMid,jEnv->NewStringUTF("^^^^^payloadFormat"),payloadFormatStr);
jEnv->CallObjectMethod(localHashtable,hpMid,jEnv->NewStringUTF("^^^^^transactionType"),transTypeStr);
jEnv->CallObjectMethod(localHashtable,hpMid,jEnv->NewStringUTF("^^^^^payload"),payloadStr);
jstring retStr = (jstring)jEnv->CallObjectMethod(globalObject,
stubMethodMap.find("publishAndWait")->second,
destinationStr,localHashtable,timeoutSec);
if(hasExceptionOccurred(jEnv))
printf("Exception has occurred.\n");
return NULL;
else
if(retStr == NULL)
return NULL;
const char *utfPtr = jEnv->GetStringUTFChars(retStr,0);
int len = jEnv->GetStringUTFLength(retStr);
char returnStr = (char)malloc(len);
memset(returnStr,0,len);
memcpy(returnStr,utfPtr,len);
jEnv->ReleaseStringUTFChars(retStr,utfPtr);
return returnStr;
------------------------------EXE------------------------------------
DWORD WINAPI ThreadFunc( LPVOID lpParam )
char buffer = (char )lpParam;
const char *tst = publishAndWait("vitria.jms.authreq","XML","276",buffer,120);
if(tst == NULL)
printf("No Response\n");
else
printf("%s\n",tst);
delete tst;
tCntDone++;
_endthread();
char * readFile(char* fileName)
FILE *xmlFile = NULL;
printf("Opening File %s\n",fileName);
if((xmlFile = fopen(fileName,"r")) == NULL)
printf("Unable to open File %s\n",fileName);
exit(-256);
long fileLen = filelength(fileno(xmlFile));
char *buffer = new char[30000];
memset(buffer,0,sizeof(buffer));
fread(buffer,fileLen,1,xmlFile);
buffer[fileLen] = '\0';
fclose(xmlFile);
return buffer;
int main(int argc, char *argv[])
DWORD dwThreadId[2];
HANDLE hThread[2];
char *buffer = NULL;
if(argc < 2)
printf("You must supply the name of the xml file as an argument!!\n");
exit(-255);
buffer = readFile(argv[1]);
printf("%s\n",buffer);
for(int i = 0; i < 2; i++)
printf("Creating Thread %x\n",i);
hThread[i] = CreateThread(NULL,0,ThreadFunc,buffer,0,&dwThreadId);
Sleep(1000);
while(tCntDone < 2)
Sleep(3000);
//printf("Threads Complete %x\n",tCntDone);
CloseHandle(hThread[0]);
CloseHandle(hThread[1]);
/*for(int x = 0; x < 2;x++)
const char *tst = publishAndWait("vitria.jms.authreq","XML","276",buffer,120);
if(tst == NULL)
printf("No Response\n");
else
printf("%s\n",tst);
delete tst;
delete(buffer);Ok, I have done some more testing. It appears that two native threads cannot access the same java object, even if a global reference exist, and you call AttachCurrentThread, and using that env pointer to make calls. It always fails with some java error, like ClassNotFoundError, and only on the second native thread created. Is this a part of the spec or is it a bug, or am I having an operator malfuntion?
-
Can you mix calls to the Posix and native thread librariess?
Is it possible to mix calls to different thread libraries within the same process.
We have a shared library interface to our product which is called from a customers application. In order to provide a thread safety we need to protect global data in this library with a mutex. However we do not know which thread library (if any) will be used by the calling application.
If we used a Posix mutex in our library would it work if the calling application was implemented using non-Posix threads?
Are the Posix and Solaris thead header files different interfaces to the same underlying implementation?
What overheads are there loading the thread library when it is not needed? If for example the calling application was implemented without using threads.
Would we have to test our interface with the different thread implementations available? eg /usr/lib/lwp/libthread.so, /usr/lib/sparcv9/libthread.so as well as /usr/lib/libthread.so.I know the author of the original post wrote this long ago, but I thought I'd write a reply in case anyone else stumbles on this like I just did.
Is it possible to mix calls to different thread
libraries within the same process.Yes. Though you have to be careful about compilation and link flags, and the order of libraries specified on the link command-line (-lpthread and -lthread). For complete information, refer to the Solaris "Multithreaded Programming Guide", available at http://docs.sun.com in the the Solaris 8 (or whatever version) Software Developer Collection.
If we used a Posix mutex in our library would it work
if the calling application was implemented using
non-Posix threads?Yes.
Are the Posix and Solaris thead header files different
interfaces to the same underlying implementation?Yes, I believe so. POSIX specifies an interface. I think the Solaris threads implementation was part of the Solaris OS before pthreads were supported on it. Anyway Solaris really uses "LWPs" (Lightweight Processes) at the kernel level, and user-level threads (POSIX or Solaris threads) are mapped onto LWPs.
What overheads are there loading the thread library
when it is not needed? If for example the calling
application was implemented without using threads.You should never link to the thread library when it is not needed. It results in unnecessary overhead. This is documented in the book mentioned above.
Would we have to test our interface with the different
thread implementations available? eg
/usr/lib/lwp/libthread.so,
/usr/lib/sparcv9/libthread.so as well as
/usr/lib/libthread.so.I don't think so, but judge for yourself; I suspect if any inconsistent behavior is found it will have more to do with defects in these implementations than in your own code. On Solaris 8:
- /usr/lib/libthread.so is the default Solaris threads library that does a many-to-many mapping of user-level threads to kernel-level-lwp's
- /usr/lib/lwp/libthread.so is the "alternate" Solaris threads library that does a 1-to-1 mapping of user-level threads to kernel-level-lwp's
- /usr/lib/sparcv9/libthread.so I think is the fully 64-bit version of the default libthread
Hope this helps somebody. -
Hi everyone,
I was wondering if anyone had any problems using WLS 4.5.1 with weblogic's
oracle pool driver with a JDK1.2.2 vm running with native threads. We had
been running with green threads and we want to consider using native threads
for performance reasons. Is native threads in Solaris supported?
Thanks!
Gary Mui
[email protected]g> I was wondering if anyone had any problems using WLS 4.5.1 with
g> weblogic's oracle pool driver with a JDK1.2.2 vm running with
g> native threads.
Provided you're running a recent WLS service pack, you should be in
fine shape.
<b
Let us pray:
What a Great System.
Please Do Not Crash.
^G^IP@P6 -
Hello,
I would like to know if which version of the JRE that supports native threads under Windows 2000. We have Dell 6450 and 8450 boxes which 6 and 8 CPUs respectivly. Are there any performance gains using green threads or native threads in your java apps running on this type of hardware? We are having problems scaling our app across multiple processors, anyone have any suggestions? I have read the articles on performance tuning for GC.
Thanks for you help,
RichieThere are a lot of GC calls. About every 2-3 secs:
[GC 2510K->2018K(2844K), 0.0083897 secs]
[GC 2530K->2066K(2844K), 0.0079910 secs]
[GC 2578K->2081K(2844K), 0.0057756 secs]
[GC 2593K->2086K(2844K), 0.0049079 secs]
[GC 2598K->2109K(2844K), 0.0045131 secs]
[GC 2621K->2111K(2844K), 0.0040606 secs]
[GC 2623K->2116K(2844K), 0.0032259 secs]
[Full GC 2429K->1891K(3732K), 0.1262438 secs]
[GC 2403K->1899K(3732K), 0.0031484 secs]
[GC 2411K->1896K(3732K), 0.0027157 secs]
[Full GC 2290K->1907K(3756K), 0.1177704 secs]
[GC 2419K->1910K(3756K), 0.0027415 secs]
[GC 2422K->1913K(3756K), 0.0027142 secs]
[GC 2425K->1920K(3756K), 0.0029628 secs]
[Full GC 2154K->1776K(3756K), 0.1736008 secs]
[GC 2288K->1779K(3756K), 0.0025489 secs]
[GC 2291K->1780K(3756K), 0.0027452 secs]
[GC 2292K->1791K(3756K), 0.0028704 secs]
[Full GC 2025K->1792K(3756K), 0.1165200 secs]
[GC 2304K->1800K(3756K), 0.0028561 secs]
[GC 2312K->1815K(3756K), 0.0033773 secs]
[Full GC 1877K->1808K(3756K), 0.1168870 secs]
[GC 2320K->1812K(3756K), 0.0026055 secs]
[GC 2324K->1813K(3756K), 0.0027891 secs]
[GC 2325K->1813K(3756K), 0.0030839 secs]
[Full GC 2082K->1824K(3756K), 0.1178141 secs]
[GC 2336K->1832K(3756K), 0.0028492 secs]
[GC 2343K->1831K(3756K), 0.0031900 secs]
[GC 2342K->1839K(3756K), 0.0028541 secs]
[Full GC 2130K->1776K(3756K), 0.1235131 secs]
[GC 2288K->1781K(3756K), 0.0027983 secs]
[GC 2293K->1793K(3756K), 0.0028564 secs]
[Full GC 2090K->1792K(3756K), 0.1179482 secs]
[GC 2304K->1798K(3756K), 0.0027652 secs]
[GC 2310K->1796K(3756K), 0.0031365 secs]
[GC 2308K->1806K(3756K), 0.0028844 secs]
[Full GC 2041K->1808K(3756K), 0.1173085 secs]
[GC 2320K->1815K(3756K), 0.0027971 secs]
After the changes you recommended, all the calls where full GCs but about every minute or so:
[Full GC 29465K->1633K(229376K), 0.1860478 secs]
[Full GC 7693K->1861K(229376K), 0.1346889 secs]
[Full GC 6788K->2378K(229376K), 0.1453195 secs]
[Full GC 4473K->2172K(229376K), 0.1886921 secs]
[Full GC 3425K->2200K(229376K), 0.1256969 secs]
[Full GC 5118K->2228K(229376K), 0.1301106 secs]
[Full GC 4778K->2257K(229376K), 0.1294866 secs]
[Full GC 4864K->2172K(229376K), 0.1394726 secs]
[Full GC 4266K->2200K(229376K), 0.1312010 secs]
[Full GC 4242K->2228K(229376K), 0.1283027 secs]
[Full GC 4391K->2249K(229376K), 0.1281122 secs]
[Full GC 4730K->2163K(229376K), 0.1425039 secs]
[Full GC 3477K->2191K(229376K), 0.1254208 secs]
[Full GC 5201K->2219K(229376K), 0.1340530 secs]
[Full GC 4763K->2246K(229376K), 0.1299836 secs]
[Full GC 4915K->2136K(229376K), 0.1432493 secs]
[Full GC 4116K->2164K(229376K), 0.1287218 secs]
[Full GC 4325K->2194K(229376K), 0.1300299 secs]
[Full GC 4324K->2221K(229376K), 0.1302815 secs]
[Full GC 4802K->2137K(229376K), 0.1434224 secs]
[Full GC 3461K->2165K(229376K), 0.1263876 secs]
[Full GC 5078K->2193K(229376K), 0.1326188 secs]
[Full GC 4795K->2221K(229376K), 0.1319525 secs]
[Full GC 4744K->2137K(229376K), 0.1306481 secs]
None of the calls are very long. So far, so good. -
Hi,
Using the version solaris 8 java 1.2.2 , the threads are native so not
controlled by the user. Having 2 threads wich interfere each others because they share the same data, i have a critical section. How can i protect my data ? Is there semaphore in Java ? Any idea ?
Thanks in advance...
OlivierOk, here a exemple of code,
----with green thread it works only if T1 is run before T2 (normal, you will say me)
----with nativ thread on solaris, it works only if i run T1 before T2, I understand that T2 has to call notify method, after that T1 calls the wait method, how to prevent the reverse to happen, it cause a thread to block ( i think this is call a dead lock). we don't know how the system will switch beetween T1 and T2,perhaps it works by hasards and one time it will block.
Thanks a lot
PS: I know how to do it with a flag and the Thread.wait() method, but i am looking for a code that is not ugly.
Also java is supposed to be portable, or that show java is NOT. How to make it protable
//the purpose of the test prog is to push on a stack (in T2 thread) and
//after to pop the stack (in T1 thread);
public static void main (String[] a) {
Block aBlock = new Block();
System.out.println ("Main thread starts executing.");
try {
System.out.println ("Initial value of stack top = " + aBlock.getTopValue() + ".");
catch (BlockException e) {
System.out.println("error : " + e.getMessage());
System.out.println ("Main thread will now fork two threads.");
AcquireBlock t1 = new AcquireBlock (aBlock);
ReleaseBlock t2 = new ReleaseBlock (aBlock);
t2.start (); // RB added to ready queue
t1.start (); // AB added to ready queue
try { // wait for termination of AB & RB
t1.join ();
t2.join ();
catch (InterruptedException e) {
System.out.println ("System terminates normally.");
try {
System.out.println ("Final value of stack top = " + aBlock.getTopValue() + ".");
catch (BlockException e) {
class AcquireBlock extends Thread {//T1
private Block aBlock;
public AcquireBlock(Block aBlock) {
this.aBlock = aBlock;
public void run () {
System.out.println ("AcquireBlock thread starts executing.");
try {
synchronized(aBlock) {
try {
aBlock.wait();
catch (InterruptedException e) {}
aBlock.pop();
catch (BlockException e) {
System.out.println("error : " + e.getMessage());
System.out.println ("AcquireBlock thread terminates.");
class ReleaseBlock extends Thread {// T2
private Block aBlock;
public ReleaseBlock (Block aBlock) {
this.aBlock = aBlock;
public void run () {
System.out.println ("ReleaseBlock thread starts executing.");
try {
synchronized(aBlock) {
aBlock.push('e');
try {
aBlock.notify();
catch (IllegalMonitorStateException e) {}
catch (BlockException e) {
System.out.println("error : " + e.getMessage());
System.out.println ("ReleaseBlock thread terminates.");
} -
Stack size for native thread attaching to JVM
All:
I have a native thread (see below, FailoverCallbackThread) that attaches to the JVM and does a Java call through JNI. The stack size for the native thread is 256KB.
at psiUserStackBangNow+112()@0x20000000007a96d0
at psiGuessUserStackBounds+320()@0x20000000007a8940
at psiGuessStackBounds+48()@0x20000000007a8f60
at psiGetPlatformStackInfo+336()@0x20000000007a9110
at psiGetStackInfo+160()@0x20000000007a8b40
at psSetupStackInfo+48()@0x20000000007a5e00
at vmtiAttachToVMThread+208()@0x20000000007c88b0
at tsAttachCurrentThread+896()@0x20000000007ca500
at attachThread+304()@0x2000000000751940
at genericACFConnectionCallback+400(JdbcOdbc.c:4624)@0x104b1bc10
at FailoverCallbackThread+512(vocctx.cpp:688)@0x104b8ddc0
at start_thread+352()@0x20000000001457f0
at __clone2+208()@0x200000000030b9f0
This causes stack overflow in Oracle JRockit JVM. (It does not cause overflow with Oracle Sun JDK.) Is there a recommended stack size for this use case for JRockit? Is there a way to compute it roughly?
Platform Itanium 64 (linux)]
java version "1.5.0_06"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-b05)
BEA JRockit(R) (build R26.4.0-63-63688-1.5.0_06-20060626-2259-linux-ia64, )
mpHow do I found default heap size, stack size for the
thread, number of threads per jvm/process supported ?The threads is OS, OS install and jvm version specific. That information is also not useful. If you create the maximum number of threads that your application can create you will run out of memory. Threads require memory. And it is unlikely to run very well either.
The default heap size and stack size are documented in the javadocs that explain the tools that come with the sun jdk.
and how the above things will vary for each OS and how
do I found ? Threads vary by OS, and OS install. The others do not (at least not with the sun jvm.)
If I get "OutOfMemoryError: Unable to create new native thread" Most of the time it indicates a design problem in your code. At the very lease, you should consider using a thread pool instead.
I found in one forum, in linux you can create maximum
of 894 threads. Is it true ?Seems high since in linux each thread is a new process, but it could be. -
Java.lang.OutOfMemoryError: unable to create new native thread on Win2000
Dear all,
I install a java server (SAP J2EE) on the windows machine and run into the following problem: the total number of threads cannot exceed 1200 (as i see this in the task manager)
After it does reach this number no other tasks can be started. Thereafter i get java.lang.OutOfMemoryError: unable to create new native thread error .
However the other machine where the same distribution of Win2000 Server is installed can easily coupe with more than 2500 theads. The same is true when the safe mode on the first machine is on: I can generate more than 1200 threads. So it seems the problem has something to do with Windows itself.
I am really puzzled here, would really appreciate any help.
Thanks in advance,
Dimitry
Surkov Dimitry
[email protected]
+49.1632.492618well, i do not supply any options when i start jvm, but it is not the course:
it also happens with c programs. however in the safe mode it works. both for c and for java program.
so it must be either some software (however memory is ok) or ...? i am lost. In some Unix system you can set the total number of threads allowed as an option in the kernal. But i guess this is not the case with windows.
Thanks a lot for your reply,
dimitry -
Java.lang.OutOfMemoryError: unable to create new native thread
Hi All,
I have installed weblogic server 8 sp4 in production environment . I am facing problems with JVM issues .
JVM is crashing very frequently with the following errro :
####<Jun 18, 2009 10:58:22 AM IST> <Info> <Common> <IMM90K-21> <SalesCom> <ExecuteThread: '24' for queue: 'weblogic.kernel.Default'> <<anonymous>> <> <BEA-000628> <Created "1" resources for pool "PIConnectionPool", out of which "1" are available and "0" are unavailable.>
####<Jun 18, 2009 11:00:09 AM IST> <Info> <EJB> <IMM90K-21> <SalesCom> <ExecuteThread: '23' for queue: 'weblogic.kernel.Default'> <<anonymous>> <> <BEA-010051> <EJB Exception occurred during invocation from home: payoutCheck.ejb.payoutCheck_s6v3so_HomeImpl@121a735 threw exception: java.lang.OutOfMemoryError: unable to create new native thread
java.lang.OutOfMemoryError: unable to create new native thread
at java.lang.Thread.start(Native Method)
at payoutCheck.classes.MyThread2.MyThreadv(PayoutCheckBOImpl.java:249)
at payoutCheck.classes.PayoutCheckBOImpl.genSP(PayoutCheckBOImpl.java:184)
at payoutCheck.ejb.PayoutCheckSLSB.genSP(PayoutCheckSLSB.java:191)
at payoutCheck.ejb.payoutCheck_s6v3so_EOImpl.genSP(payoutCheck_s6v3so_EOImpl.java:315)
at payoutCheck.ejb.payoutCheck_s6v3so_EOImpl_CBV.genSP(Unknown Source)
at payoutCheck.deligate.PayoutCheckBD.genSP(PayoutCheckBD.java:226)
at ui.action.SearchAction.callFilter(SearchAction.java:378)
at sun.reflect.GeneratedMethodAccessor201.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:280)
at org.apache.struts.actions.DispatchAction.execute(DispatchAction.java:220)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:446)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:266)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1292)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:510)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:1006)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:419)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:315)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:6718)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121)
at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3764)
at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2644)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:219)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:178)
>
The above mentioned is coming several times , anybody please help out to get rid of this issue.
Thanks in advance ,
Krikar.This only tells you that the JVM is running out of heap space. It doesn't tell you what is causing the problem. You likely have a memory leak, but you could also try increasing the max heap size of the JVM (-Xmx command line option). It would help to watch the % mem in use statistic, but only immediately after a garbage collection cycle (you can force a GC from the admin console). If the % mem in use after the GC is increasing over time, then that likely confirms you have a memory leak. Note that looking at that statistic during the server startup probably is irrelevant. You'd need to wait until the server finishes starting up, and likely processed a few messages (to load static data).
If you get to the point of confirming that you have a memory leak, that requires doing detailed analysis with a Java profiler (JProfiler, JProbe, YourKit, etc.) to track down the source of the leak. -
Help! Unable to create new native thread
Ok I see this problem all over the web but most of the posts are many years old and still leave me a little confused. Often at random times on the same tags like CFLDAP I get the error "Unable to create new native thread". Then a few minutes later the same tag on the same page works just fine.
I have 4GB of memory in this box with 1400 MB set as the maximum Java heap size by the way.
Here are my arguments from the jvm.config file.
# Arguments to VM
java.args=-server -Xmx1400m -Dsun.io.useCanonCaches=false -XX:MaxPermSize=192m -XX:+UseParallelGC -Dcoldfusion.rootDir={application.home}/../ -Dcoldfusion.libPath={application.home}/../lib -Dcoldfusion.classPath={application.home}/../lib/updates,{application.home}/../lib,{appli cation.home}/../gateway/lib/,{application.home}/../wwwroot/WEB-INF/flex/jars,{application. home}/../wwwroot/WEB-INF/cfform/jars,"C:\\Program Files\\Apache Software Foundation\\Apache2.2\\htdocs\\InterWeb-Prod\\includes\\classes"
Here is a typical error that comes through.
struct
Browser Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/533.4 (KHTML, like Gecko) Chrome/5.0.375.70 Safari/533.4
DateTime {ts '2010-06-23 10:07:44'}
Diagnostics unable to create new native thread null <br>The error occurred on line 122.
GeneratedContent
HTTPReferer http://--------------------/index.cfm?FuseAction=HR.main
Mailto interweb@---------------------
Message unable to create new native thread
QueryString fuseaction=ManagedLists.MailSubscriptions
RemoteAddress 192.168.250.124
RootCause struct
Message unable to create new native thread
StackTrace java.lang.OutOfMemoryError: unable to create new native thread at java.lang.Thread.start0(Native Method) at java.lang.Thread.start(Thread.java:597) at com.sun.jndi.ldap.Connection.<init>(Connection.java:208) at com.sun.jndi.ldap.LdapClient.<init>(LdapClient.java:112) at com.sun.jndi.ldap.LdapCtx.connect(LdapCtx.java:2504) at com.sun.jndi.ldap.LdapCtx.<init>(LdapCtx.java:263) at com.sun.jndi.ldap.LdapCtxFactory.getInitialContext(LdapCtxFactory.java:76) at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:667) at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:288) at javax.naming.InitialContext.init(InitialContext.java:223) at javax.naming.InitialContext.<init>(InitialContext.java:197) at javax.naming.directory.InitialDirContext.<init>(InitialDirContext.java:82) at coldfusion.tagext.net.LdapTag.do_ActionQuery(LdapTag.java:839) at coldfusion.tagext.net.LdapTag.doStartTag(LdapTag.java:616) at coldfusion.runtime.CfJspPage._emptyTcfTag(CfJspPage.java:2661) at cfadfunctions2ecfm1473603830$funcADLOOKUPUSERNAME.runFunction(C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\InterWeb-Prod\includes\adfunctions.cfm:122) at coldfusion.runtime.UDFMethod.invoke(UDFMethod.java:418) at coldfusion.runtime.UDFMethod$ArgumentCollectionFilter.invoke(UDFMethod.java:324) at coldfusion.filter.FunctionAccessFilter.invoke(FunctionAccessFilter.java:59) at coldfusion.runtime.UDFMethod.runFilterChain(UDFMethod.java:277) at coldfusion.runtime.UDFMethod.invoke(UDFMethod.java:192) at coldfusion.runtime.CfJspPage._invokeUDF(CfJspPage.java:2471) at cfadfunctions2ecfm1473603830$funcADLOOKUPMULTIPLEUSERNAMES.runFunction(C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\InterWeb-Prod\includes\adfunctions.cfm:54) at coldfusion.runtime.UDFMethod.invoke(UDFMethod.java:418) at coldfusion.runtime.UDFMethod$ArgumentCollectionFilter.invoke(UDFMethod.java:324) at coldfusion.filter.FunctionAccessFilter.invoke(FunctionAccessFilter.java:59) at coldfusion.runtime.UDFMethod.runFilterChain(UDFMethod.java:277) at coldfusion.runtime.UDFMethod.invoke(UDFMethod.java:192) at coldfusion.runtime.CfJspPage._invokeUDF(CfJspPage.java:2471) at cfdsp_managedlists2ecfm55598920.runPage(C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\InterWeb-Prod\hr\managedlists\dsp_managedlists.cfm:232) at coldfusion.runtime.CfJspPage.invoke(CfJspPage.java:196) at coldfusion.tagext.lang.IncludeTag.doStartTag(IncludeTag.java:370) at coldfusion.runtime.CfJspPage._emptyTcfTag(CfJspPage.java:2661) at cffbx_switch2ecfm2121232114.runPage(C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\InterWeb-Prod\hr\managedlists\fbx_switch.cfm:23) at coldfusion.runtime.CfJspPage.invoke(CfJspPage.java:196) at coldfusion.tagext.lang.IncludeTag.doStartTag(IncludeTag.java:370) at coldfusion.runtime.CfJspPage._emptyTcfTag(CfJspPage.java:2661) at cffbx_fusebox30_cf502ecfm1180471387._factor4(C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\InterWeb-Prod\fbx_fusebox30_cf50.cfm:241) at cffbx_fusebox30_cf502ecfm1180471387._factor5(C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\InterWeb-Prod\fbx_fusebox30_cf50.cfm:1) at cffbx_fusebox30_cf502ecfm1180471387.runPage(C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\InterWeb-Prod\fbx_fusebox30_cf50.cfm:1) at coldfusion.runtime.CfJspPage.invoke(CfJspPage.java:196) at coldfusion.tagext.lang.IncludeTag.doStartTag(IncludeTag.java:370) at coldfusion.runtime.CfJspPage._emptyTcfTag(CfJspPage.java:2661) at cfindex2ecfm749274359.runPage(C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\InterWeb-Prod\index.cfm:23) at coldfusion.runtime.CfJspPage.invoke(CfJspPage.java:196) at coldfusion.tagext.lang.IncludeTag.doStartTag(IncludeTag.java:370) at coldfusion.filter.CfincludeFilter.invoke(CfincludeFilter.java:65) at coldfusion.filter.ApplicationFilter.invoke(ApplicationFilter.java:273) at coldfusion.filter.RequestMonitorFilter.invoke(RequestMonitorFilter.java:48) at coldfusion.filter.MonitoringFilter.invoke(MonitoringFilter.java:40) at coldfusion.filter.PathFilter.invoke(PathFilter.java:86) at coldfusion.filter.ExceptionFilter.invoke(ExceptionFilter.java:70) at coldfusion.filter.ClientScopePersistenceFilter.invoke(ClientScopePersistenceFilter.java:2 8) at coldfusion.filter.BrowserFilter.invoke(BrowserFilter.java:38) at coldfusion.filter.NoCacheFilter.invoke(NoCacheFilter.java:46) at coldfusion.filter.GlobalsFilter.invoke(GlobalsFilter.java:38) at coldfusion.filter.DatasourceFilter.invoke(DatasourceFilter.java:22) at coldfusion.CfmServlet.service(CfmServlet.java:175) at coldfusion.bootstrap.BootstrapServlet.service(BootstrapServlet.java:89) at jrun.servlet.FilterChain.doFilter(FilterChain.java:86) at coldfusion.monitor.event.MonitoringServletFilter.doFilter(MonitoringServletFilter.java:42 ) at coldfusion.bootstrap.BootstrapFilter.doFilter(BootstrapFilter.java:46) at jrun.servlet.FilterChain.doFilter(FilterChain.java:94) at jrun.servlet.FilterChain.service(FilterChain.java:101) at jrun.servlet.ServletInvoker.invoke(ServletInvoker.java:106) at jrun.servlet.JRunInvokerChain.invokeNext(JRunInvokerChain.java:42) at jrun.servlet.JRunRequestDispatcher.invoke(JRunRequestDispatcher.java:286) at jrun.servlet.ServletEngineService.dispatch(ServletEngineService.java:543) at jrun.servlet.jrpp.JRunProxyService.invokeRunnable(JRunProxyService.java:203) at jrunx.scheduler.ThreadPool$DownstreamMetrics.invokeRunnable(ThreadPool.java:320) at jrunx.scheduler.ThreadPool$ThreadThrottle.invokeRunnable(ThreadPool.java:428) at jrunx.scheduler.ThreadPool$UpstreamMetrics.invokeRunnable(ThreadPool.java:266) at jrunx.scheduler.WorkerThread.run(WorkerThread.java:66)
I could really use some help figuring this out. We are getting random errors a few times a day and usually in places where we are using CFLDAP.
Thanks,
DavidAbsolutely unbelievable that this has been going on for 4 YEARS and there are still NO definitive answers from Adobe!!
There's no definite answer from Adobe, because there's no definitive single question. These errors come up because - for any number of possible reasons - the JVM becomes overloaded. And it's almost always down to an issue with the application code being run, and nothing to do with CF, per-se. So what's Adobe supposed to do? Come and fix your application for you? There are plenty of diagnostic tools out there - some built into CF itself - which you could use to sort the problem out. Or you could hire someone like Mike Brunt to come and have a look at your set up. All it takes to fix these things is to actually do something about fixing it, rather than slamming one's fist on the desk saying "why doesn't Adobe do something!"
I thought - and my knowledge in the area isn't expansive - the inability to allocate threads was down to the app being choked up: threads are a finite commodity, and if requests are queuing up faster than the JVM can clear them, you're gonna get errors eventually. What causes this sort of thing? More traffic than the server can process. This could be because of server kit, or it could be due to code that doesn't scale to the requirement. Usually the latter. Basically one cannot polish a turd.
I have a 24x7 production server that services 180,000 clients in 300 countries around the clock that cannot afford to be down for more than a few minutes at a time.
I'm running Windows 2008 32-bit with 4GB of RAM because I have some graphics software that cannot tolerate a 64-bit OS. Everything has been running fine for the past few months, but now it's starting to crash more and more frequently. I have CF 8.0.1.195765 and Java 1.6.0_04
How many concurrent requests for 180000 clients generate? The number of clients matters less than how heavily the site is used. But, to be honest, I get the impression the implication is "it's a busy site", in which case I think your hardware is a bit on the lean side. Also, if it's a mission-critical app, running it on a single server is probably ill-advised, just from a fault-tolerance perspective even before one starts thinking about performance.
If I was in your situation, I'd consider the following options:
* upgrade your JVM to the most recent version (1.6.0_21?)
* put more RAM in the box, and run a second CF instance on it.
* get another box.
* refactor the environment so the graphics software runs on a different box, upgrading the CF server to 64-bit (again, with more RAM)
* run some diagnostics on the server, seeing what's taking up threads and where any bottlenecks might be
* get an expert in to do the analysis side of things.
* stop expecting Adode to fix "something".
One of my other symptoms I have noticed is that any work done using RDP starts getting really really bogged down. Opening Windows Explorer and searching for files can take minutes. Restarting the CF service will sometimes fail to complete, and you have to wait a few minutes before the manual Start option appears in the dropdown. Maybe coincidentally, the Performance Monitor will fail to add any of the ColdFusion metrics, for example Running Requests and Queued Requests, and the Event Monitor shows an error relating to an 8-byte boundary not being maintained.
You don't, by any chance, store your client variables in the registry do you? The only time I've seen this happen is when the CF box is munging the OS environment, and the only way I can think this could happen if it was clogging the registry. Never store client variables in the registry.
Adam -
Unable to create native thread in Normal Condition
I am trying to analyze the "OOM unable to create native thread" error that occurred in our application. I wrote a sample program which has to creates 5000 threads and monitored it using JConsole.
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
* ThreadJvmMemory.java
* Created on June 1, 2007, 9:49 AM
* To change this template, choose Tools | Template Manager
* and open the template in the editor.
* @author Administrator
public class ThreadJvmMemory extends Thread{
/** Creates a new instance of ThreadJvmMemory */
BufferedReader in = null;
public ThreadJvmMemory() {
public static void main(String args[]){
ThreadJvmMemory dummy = new ThreadJvmMemory();
dummy.waitTillEnter();
for(int i=0;i<5000;i++){
if(i%1000==0){
System.out.println(i);
dummy.waitTillEnter();
ThreadJvmMemory dummy1 = new ThreadJvmMemory();
dummy1.start();
public void run(){
//System.out.println("Here");
Object dummyObject = new Object();
try {
in = new BufferedReader(new InputStreamReader(System.in));
in.readLine();
} catch (IOException ex) {
ex.printStackTrace();
System.out.println("Came out of the thread");
public void waitTillEnter(){
try {
if(in==null)
in = new BufferedReader(new InputStreamReader(System.in));
in.readLine();
} catch (IOException ex) {
ex.printStackTrace();
I started the program using the following command line option..
"c:\Program Files\Java\jdk1.5.0_09\bin\java.exe" -Dcom.sun.management.jmxremote.port=9979 -Xmx512m -Xminf0.1 -Xmaxf0.1 -XX:MaxPermSize=256m -XX:PermSize=256m -XX:+<GCTYPE> -XX:+PrintGCDetails
where GCType will be UseTrainGC or UseSerialGC or UseParallelGC or
What i observe in all the cases, there are no more than 1000 threads getting created . After completion of 1000 threads garbage collector keeps running and no more threads get created. Since i have configured heapsize to be 512m, PermGenSpace to be 256 and default value for process sapece is 2gb, JVM would be able to create only 1000 threads as per the formula "NoOfThreads = Process space - (Heap + permGen+some for VM initialization)/Stack Size" (correct me if i am wrong). But why i am not getting OutOfMemoryError while creating native thread. Moreover i can observer non-heap (Perm Gen) space keep growing overtime. But there is enough space in all other spaces.So my doubts are
1. Actually when we will get OOM error saying unable to create Native thread. To be more specific when which space occupied i will get this error.
2. Is there any way to configure process space. IMO No ?? Confirm ??
3. Does any one tried using a a tool that analyzes verboseGC output of SUN JVM. If so can you give any pointer. I have read through GCPortal, but i havent fully deployed it.
Java version is 1.5.0
OS Windows 2k3
Snippet of GC Output
[GC [DefNew: 5208K->38K(5824K), 0.0072564 secs] 32049K->26879K(34636K), 0.0080451 secs]
[GC [DefNew: 5222K->24K(5824K), 0.0070320 secs] 32063K->26868K(34636K), 0.0078097 secs]
[GC [DefNew: 5208K->39K(5824K), 0.0082161 secs] 32052K->26883K(34636K), 0.0090173 secs]
[GC [DefNew: 5223K->27K(5824K), 0.0080766 secs] 32067K->26874K(34636K), 0.0089273 secs]
[GC [DefNew: 5211K->39K(5824K), 0.0071186 secs] 32058K->26886K(34636K), 0.0078970 secs]
[GC [DefNew: 5223K->25K(5824K), 0.0070952 secs] 32070K->26875K(34636K), 0.0078766 secs]
[GC [DefNew: 5209K->21K(5824K), 0.0069871 secs] 32059K->26872K(34636K), 0.0077657 secs]I am trying to analyze the "OOM unable to create native thread" error that occurred in our application. I wrote a sample program which has to creates 5000 threads and monitored it using JConsole.
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
* ThreadJvmMemory.java
* Created on June 1, 2007, 9:49 AM
* To change this template, choose Tools | Template Manager
* and open the template in the editor.
* @author Administrator
public class ThreadJvmMemory extends Thread{
/** Creates a new instance of ThreadJvmMemory */
BufferedReader in = null;
public ThreadJvmMemory() {
public static void main(String args[]){
ThreadJvmMemory dummy = new ThreadJvmMemory();
dummy.waitTillEnter();
for(int i=0;i<5000;i++){
if(i%1000==0){
System.out.println(i);
dummy.waitTillEnter();
ThreadJvmMemory dummy1 = new ThreadJvmMemory();
dummy1.start();
public void run(){
//System.out.println("Here");
Object dummyObject = new Object();
try {
in = new BufferedReader(new InputStreamReader(System.in));
in.readLine();
} catch (IOException ex) {
ex.printStackTrace();
System.out.println("Came out of the thread");
public void waitTillEnter(){
try {
if(in==null)
in = new BufferedReader(new InputStreamReader(System.in));
in.readLine();
} catch (IOException ex) {
ex.printStackTrace();
I started the program using the following command line option..
"c:\Program Files\Java\jdk1.5.0_09\bin\java.exe" -Dcom.sun.management.jmxremote.port=9979 -Xmx512m -Xminf0.1 -Xmaxf0.1 -XX:MaxPermSize=256m -XX:PermSize=256m -XX:+<GCTYPE> -XX:+PrintGCDetails
where GCType will be UseTrainGC or UseSerialGC or UseParallelGC or
What i observe in all the cases, there are no more than 1000 threads getting created . After completion of 1000 threads garbage collector keeps running and no more threads get created. Since i have configured heapsize to be 512m, PermGenSpace to be 256 and default value for process sapece is 2gb, JVM would be able to create only 1000 threads as per the formula "NoOfThreads = Process space - (Heap + permGen+some for VM initialization)/Stack Size" (correct me if i am wrong). But why i am not getting OutOfMemoryError while creating native thread. Moreover i can observer non-heap (Perm Gen) space keep growing overtime. But there is enough space in all other spaces.So my doubts are
1. Actually when we will get OOM error saying unable to create Native thread. To be more specific when which space occupied i will get this error.
2. Is there any way to configure process space. IMO No ?? Confirm ??
3. Does any one tried using a a tool that analyzes verboseGC output of SUN JVM. If so can you give any pointer. I have read through GCPortal, but i havent fully deployed it.
Java version is 1.5.0
OS Windows 2k3
Snippet of GC Output
[GC [DefNew: 5208K->38K(5824K), 0.0072564 secs] 32049K->26879K(34636K), 0.0080451 secs]
[GC [DefNew: 5222K->24K(5824K), 0.0070320 secs] 32063K->26868K(34636K), 0.0078097 secs]
[GC [DefNew: 5208K->39K(5824K), 0.0082161 secs] 32052K->26883K(34636K), 0.0090173 secs]
[GC [DefNew: 5223K->27K(5824K), 0.0080766 secs] 32067K->26874K(34636K), 0.0089273 secs]
[GC [DefNew: 5211K->39K(5824K), 0.0071186 secs] 32058K->26886K(34636K), 0.0078970 secs]
[GC [DefNew: 5223K->25K(5824K), 0.0070952 secs] 32070K->26875K(34636K), 0.0078766 secs]
[GC [DefNew: 5209K->21K(5824K), 0.0069871 secs] 32059K->26872K(34636K), 0.0077657 secs] -
AP 1142 Rapidly cycling through blue, green, and red
Hello
After the upgrade of the WLC 5508 to version 7.4 the 1142 access-points LED blinking rapidly cycling through blue, green, and red. I found the followinung information to this behavior: "Access point location command invoked"
The configuration didn't change. What exactly means that? How can I switch this function?
regards
PascalConsole into the AP and see what's going on. The output will tell you what is happening. If you can't determine the issues from the output, please attach it on this thread. Makes sure you get the whole process from boot up.
Sent from Cisco Technical Support iPhone App -
Aggregate Storage And Multi-Threading/Multi-Core Systems
Please pardon if this question has been asked before, but the Forum search is not returning any relevant results.
We are in the process of purchasing hardware for an 11.1.2 Essbase environment. We are going 64-bit, on Windows 2008, with either 32 GB or 64 GB of system RAM. The debate we are having is the number of CPUs and cores per CPU. We have not built any ASO databases as of yet, but we plan to launch a major BSO to ASO conversion project once 11.1.2 is off the ground here.
Historically, with BSO, we did not see performance improvements significant enough to justify the cost of additional CPUs when we ran calcs on multi-CPU systems vs. single or dual CPU systems, even when the settings and design should have taken the most advantage of BSO's multi-threading capabilities. However, it would seem that ASO's design may be able to make better use of multi-core systems.
I know that there are a lot of factors behind any system's performance, but in general, is ASO in 11.1.2 written well enough to make it worthwhile to consider, say, a four CPU, total 16 core system vs. a 2 CPU, total four core system?Grand central dispatch - infancy, not really doing its job, and I don't think apps have to be specifically written for HT, but they do have to not do things that they use to - prevent threads from going to sleep! or be parked.
high usage is not necessarily high efficiency. often the opposite.
Windows 7 seems to be optimized for multi-core thanks to a lot of reworking. Intel wants and knows it isn't possible to hand code, that the hardware has to be smarter, too. But the OS has a job, and right now I don't think it does it properly. Or handle memory.
Gulftown's 12MB cache will help, and over all should be 20% more efficient doing its work.
With dual processors, and it doesn't look like there are two quick path bridges, data shuffling has led to memory thrashing. Use to be page thrashing with not enough memory. Then core thrashing but having the cores, but not integrated (2008 is often touted as being greatest design so far, but it was FOUR dual-cores, 2009 was the first with a processor that really was new design and (native) 4-core.
One core should be owned by the OS so it is always available for its own work and housekeeping.
The iTunes audio bug last year showed how damaging and not to implement code and how a thread could usurp processing and add a high cpu temperature while basically doing nothing, sort of a denial of service attack on the processor - those 80*C temps people had.
All those new technology features under development and not like OpenCL, GCD and even OpenGL are tested, mature but rather 1.0 foundation for the future. A year ahead of readiness. -
OutOfMemoryError: unable to create native thread
Why do I get OutOfMemory exceptions even if there is plently of Memory.
JVM settings are -Xms256M and -Xmx1024M.
Debug at runtime (Runtime.totalMemory()) shows that it never got above 260M. Why does the JVM not grab some more memory -instead of throwing OutOfMemory exception.
I am creating quite a lot of threads 800+ within a few minutes
Any ideas?I googled a bit and one thing i came across was
"In those hypothetical configurations, the error java.lang.OutOfMemoryError: unable to create new native thread would begin to saturate the JRun logs. To clarify the error text, the error message means that no more native, or OS, threads can be created for the JVM process, causing the JVM to throw an exception. The exception type is java.lang.outOfMemoryError, but I find that to be rather misleading since the resource limitation on the OS thread count, not memory usage. "
So it looks like you're looking for OS specific settings rather than anything pure java.
Note that a thread per socket is not necessary, even when not using NIO:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
public class ForumQuestion {
// i'm assuming character based input
static final List<Reader> readers = new LinkedList<Reader>();
static final Map<Reader,StringBuffer> buffers = new HashMap<Reader,StringBuffer>();
static final Map<Reader,Socket> sockets = new HashMap<Reader,Socket>();
public static void main( String[] args ) throws IOException {
// using single thread (for simplicity) to handle all sockets
// the main trick is making sure that your thread(s) doing the reading
// don't sit and "spin" around the inputStreams when they have nothing
// at all waiting... wasting CPU. Here i just make the worker sleep
// for 1000 nanos between attempts where it hasn't read anything. I'm
// sure you can do better!
Executors.newScheduledThreadPool( 1 ).scheduleWithFixedDelay( new Runnable() {
public void run() {
checkStreams();
}, 1000, 1000, TimeUnit.NANOSECONDS );
// create server socket and use main thread to block waiting for connections
ServerSocket serverSock = new ServerSocket( 1138 );
System.out.println( "Accepting connections on port 1138" );
while( true ) {
Socket s = serverSock.accept();
synchronized( readers ) {
Reader r = new BufferedReader( new InputStreamReader( s.getInputStream() ) );
readers.add( r );
buffers.put( r, new StringBuffer() );
sockets.put( r, s );
System.out.printf( "Connection: %s%n", s );
private static void checkStreams() {
// i've been lazy (over zealous) with the synchronization for simplicity. you'd want to
// Do something cleverer than blocking accepts() while work is being done
synchronized( readers ) {
if ( readers.size() == 0 ) {
return;
// carry on until no work was done for any incoming sockets
while( true ) {
boolean workDone = false;
for( Reader r : readers ) {
try {
StringBuffer buff = buffers.get( r );
while( r.ready() ) {
char c = (char)r.read();
buff.append( c );
checkBuffer( r, buff, c );
workDone = true;
} catch( IOException e ) {
// do something here, client prob dead
// if no work done (no sockets had anything) then rest the thread
if ( !workDone ) break;
private static void checkBuffer( Reader r, StringBuffer buff, char last ) {
if ( last == '\n' ) {
System.out.printf( "Read \"%s\" from %s%n", buff.toString().trim(), sockets.get( r ) );
buff.delete( 0, buff.length() );
Accepting connections on port 1138
Connection: Socket[addr=/127.0.0.1,port=1776,localport=1138]
Connection: Socket[addr=/127.0.0.1,port=1777,localport=1138]
Read "hello" from Socket[addr=/127.0.0.1,port=1776,localport=1138]
Read "hi" from Socket[addr=/127.0.0.1,port=1777,localport=1138]
Read "we're two sockets, but only using one thread to read from both of us!!" from Socket[addr=/127.0.0.1,port=1776,localport=1138]
Read "Oh! YAY!!!!" from Socket[addr=/127.0.0.1,port=1777,localport=1138]It's massively inferior to using NIO, but better than having thousands of dedicated threads -
Problem extracting red, green and blue from ColorModel
Hi everyone,
I'm attempting to write a piece of code to extract the red, green and blue components from an image using the ColorModel class. When I attempt to run my code below, I get the following error: Exception in thread "main" java.lang.IllegalArgumentException: More than one component per pixel. Does anyone know how to extract an integer representation of the red in a pixel in order to solve the problem? Here's the code snippet:
public void getRGBValues()
String imageFilename = new String("C:\\Documents and Settings\\David\\My Documents\\My Pictures\\blue hills1.jpg");
PlanarImage image = JAI.create("fileload", imageFilename);
//Get the color model for that particular image
ColorModel imageColorModel = image.getColorModel();
//ints to store the appropriate values for each colour component
int totalRed = 0;
int totalGreen = 0;
int totalBlue = 0;
int averageRed = 0;
int averageGreen = 0;
int averageBlue = 0;
int pixelNumber = 0;
int pixelCount = 0;
//Loop to extract the colour values out of each pixel in an image passed into the class
for(int i = 0; i < image.getWidth(); i++)
for (int j = 0; j < image.getHeight(); j++)
totalRed += imageColorModel.getRed(pixelNumber);
totalGreen += imageColorModel.getGreen(pixelNumber);
totalBlue += imageColorModel.getBlue(pixelNumber);
pixelCount++;
pixelNumber++;
pixelCount++;
pixelNumber++;
averageRed = Math.round(totalRed / pixelCount);
averageGreen = Math.round(totalGreen / pixelCount);
averageBlue = Math.round(totalBlue / pixelCount);
System.out.println("Average red is " + averageRed);
System.out.println("Average green is " + averageGreen);
System.out.println("Average blue is " + averageBlue);
}You are misunderstanding the ColorModel methods. The color model can translate between colors and pixels, but it doesn't know or hold pixel data.
I don't know the JAI, but if you use J2SE classes like BufferedImage, this is easy to do:
BufferedImage im = ImageIO.read(input);
int argb = im.getRGB(x, y);
int r = 0xff & (argb>>16);
int g = 0xff & (argb >>8);
int b = 0xff & argb;
Maybe you are looking for
-
OBIEE Report Export from Dashboard to Excel doesn't suppress the columns as
OBIEE Report Export from Dashboard to Excel doesn't suppress the columns as expected even after the properties are set to Suppress in the report. In Dashboard it is suppressed Properly but in the excel export it is not suppressed and values for the c
-
HP Officejet Pro 8500 Wireless (DUPLEXER MISSINN)
Hi, can anbody help me please?? I just bought a 2nd hand printer HP Officejet Pro 8500 Wireless. The printer doesnt feed the paper (it does not pick it up). However, the paper goes pass by the printer and leaves through the back. There is no duplexe
-
In Third Party sales order processing how we come to know that the customer
Hi SAP SD Gurus, In Third Party sales order processing how we come to know that the customer is recived the Goods from the vendor? Thanks & Regards, Sreenivas.P
-
Tree grid not expanding in SharePoint 2013.
I have written a code using TB.Web.UI.TreeGrid.dll to represent data in tree grid in ShaarePoint 2010. and we have moved to 2013 with same code tree grid stop expanding giving me following Javascript error.Please suggest. TypeError: tr.style is undef
-
i just update my iPhone which was previously jailbreaked when i update it after downloading all the file it start to show the apple logo for a moment and it went and completely turned off i tried to connect through iTunes but it doesn't show any iPho