Unusual Error in Threaded Environment

Question

I get a weird error when running my application on a threaded mode. This error however occurs not always but once in a while and that too when I have around 20+ threads. When I have lesser number of threads this error does not occur at all or i could say very very rarely.
any idea guys
I am using 11g instant client and 10g database. and this is how my error message goes.
*** glibc detected *** /home/bala/workspace/OracleTester/OracleTest/Debug/OracleTest: corrupted double-linked list: 0x0845a390 ***
======= Backtrace: =========
/lib/tls/i686/cmov/libc.so.6[0xb61cc3f4]
/lib/tls/i686/cmov/libc.so.6[0xb61ce207]
/lib/tls/i686/cmov/libc.so.6(cfree+0x96)[0xb61ce456]
/opt/oracle/instantclient/instantclient_11_1/libclntsh.so.11.1(sltsmxd+0x34)[0xb68d16b0]
/opt/oracle/instantclient/instantclient_11_1/libclntsh.so.11.1(ltsmxd+0x37)[0xb6904633]
/opt/oracle/instantclient/instantclient_11_1/libclntsh.so.11.1[0xb65e46a1]
/opt/oracle/instantclient/instantclient_11_1/libclntsh.so.11.1(kpufhndl0+0x32a)[0xb65df82a]
/opt/oracle/instantclient/instantclient_11_1/libclntsh.so.11.1(kpufhndl+0x20)[0xb65df4f6]
/opt/oracle/instantclient/instantclient_11_1/libclntsh.so.11.1(kpuspsessionrelease+0x111d)[0xb6eed9e5]
/opt/oracle/instantclient/instantclient_11_1/libclntsh.so.11.1(OCISessionRelease+0xa2)[0xb6d84086]
and here is my code
Environment* Genv1; // OCCI environment
Connection* Gcon1; // OCCI connection
int const MAX = 50;
void openConcurrentConnections(void _tgtObject);
int main(){
int iRetVal;
pthread_t thread[MAX];
pthread_attr_t attr;
void *status;
Genv1 = Environment::createEnvironment(Environment::THREADED_MUTEXED);
/* Initialize and set thread detached attribute */
pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
for(int i =0 ;i<MAX;i++){
iRetVal = pthread_create(&thread, &attr, openConcurrentConnections, (void *)i);
if (iRetVal) {
printf("ERROR; return code from pthread_create()is %d\n", iRetVal);
exit(-1);
/* Free attribute and wait for the other threads */
pthread_attr_destroy(&attr);
for(unsigned short int t=0; t< MAX; t++) {
iRetVal = pthread_join(thread[t], &status);
// delete all filereader pointers and set the variable to NULL
if (iRetVal) {
printf("ERROR; return code from pthread_join()is %d\n", iRetVal);
exit(-1);
printf("Main: completed join with thread %d having a status of %ld\n",t,(long)status);
Genv1->terminateEnvironment(Genv1);
printf("Main: program completed. Exiting.\n");
pthread_exit(NULL);
void openConcurrentConnections(void _tgtObject){
Gcon1 = Genv1->createConnection("Ecologital","123","//192.168.1.11:1521/Neurologik");
cout << "oracle connection OPENED" << endl;
Genv1->terminateConnection(Gcon1);
cout << "oracle connection CLOSED" << endl;
pthread_exit((void*) _tgtObject);

Answer 1

Hi,
Have you tried running something like valgrind against this?
Regards,
Mark