Dbms_alert package under C++ Daemon

Question

Hi,
I have created a C++ Daemon whihc is using dbms_alert package.
When Daemon runs it makes a call
dbms_alert.waitone("ALERTNAME","MESSAGE", STATUS);
well this is a blocking call as i don;t want to use timeout as 0.
Now when i want to stop my Daemon how can overcome this blocking call?
Many Thanks

Answer 1

Thanks
But i have alreay mentioned that dbms_alert.remove doesn't work.
Here is a code snippet -
As one can see below that i m looking for code snippet under '_Stop' function as i want to stop the thread workign which is blocked inside 'Action' function.
ie when i sent SIGNAL
kill -SIGTERM <PID>
OTLThread.h
===========
#ifndef OTLThreadh_
#define OTLThreadh_
#include <iostream>
#define OTL_ORA8 // Compile OTL 4.0/OCI8
#define OTL_STL // Turn on STL features
#define OTL_ANSI_CPP // Turn on ANSI C++ typecasts
#include <otlv4.h> // include the OTL 4.0 header file
#include <boost/thread/thread.hpp>
#include <boost/thread/condition.hpp>
using namespace std;
class OTLThread
     boost::mutex                    m_mtxEvent;
     boost::mutex                    m_mtxExclusive;
     boost::condition          m_cndEvent;
     bool                                        m_bWantPause;
     bool                                        m_bWantStop;
     bool                                        m_bFirstRun;
     protected:
     static OTLThread *          M_pOTLThread;
     otl_connect db; // connect object
     otl_stream                                   oRslts;     
     std::string strSQL;
     public:
                    OTLThread();               
     bool     WantStop();
     bool     WantPause();
     void     _Resume();
     static void Resume(){ if (M_pOTLThread) M_pOTLThread->_Resume(); }
     void     _Pause();
     static void Pause(){ if (M_pOTLThread) M_pOTLThread->_Pause(); }
     void     _Stop();
     static void Stop(){ if (M_pOTLThread) M_pOTLThread->_Stop(); }
     void     Run();
     bool DBConnect();
     bool DBDisConnect();
     void Action();
     void     operator()();
};//class OTLThread
#endif/*OTLThreadh_*/
OTLThread.cpp
=============
#include "OTLThread.h"
OTLThread * OTLThread::M_pOTLThread = NULL;
OTLThread::OTLThread():
     m_bWantStop(false),
//Set this to true for a 'start-paused' thread model
//and set this to false for a 'start-running' model.
     m_bWantPause(false),
     m_bFirstRun(true)
     if (!M_pOTLThread)
          M_pOTLThread = this;
void OTLThread::_Resume()
     boost::mutex::scoped_lock lk (m_mtxExclusive);
     if(m_bWantPause)
          m_bWantPause = false;
          m_cndEvent.notify_all();
     else
          cout
          << "[OTLThread]: Already Resumed, please Pause first"
          << endl;
void OTLThread::_Pause()
     boost::mutex::scoped_lock lk (m_mtxExclusive);
     if (!m_bWantPause)
          m_bWantPause = true;
          m_cndEvent.notify_all();
     else
          cout
          << "[OTLThread]: Already Paused, please Resume first"
          << endl;
void OTLThread::_Stop()
     boost::mutex::scoped_lock lk (m_mtxExclusive);
//     oRslts.close();
     std::string sql;
     sql = "call dbms_alert.REMOVE('INSERTALERT')";
otl_cursor::direct_exec
db,
sql.c_str()
); // Registering the Alert
     m_bWantStop = true;
     m_cndEvent.notify_all();
void OTLThread::Run()
     boost::mutex::scoped_lock lk (m_mtxEvent);
     DBConnect();
     while (true)
          if (m_bWantStop) break;
          if (m_bWantPause)
               cout
               << "\n\t\t"
               << "[" << getpid() << "] "
               << "[OTLThread]: Pausing..."
               << endl;
               m_cndEvent.wait(lk);
          if (m_bWantStop) break;
          Action();
     cout
     << "\n\t\t"
     << "[" << getpid() << "] "
     << "Activity: [" << "OLT" << "]: Stopping...\n"
     << endl;
     DBDisConnect();
bool OTLThread::DBConnect()
otl_connect::otl_initialize(); // initialize OCI environment
try{
db.rlogon("sam/sam"); // connect to Oracle
     std::string sql;
     sql = "call dbms_alert.register('INSERTALERT')";
otl_cursor::direct_exec
db,
sql.c_str()
); // Registering the Alert
catch(otl_exception& p){ // intercept OTL exceptions
cerr<<p.msg<<endl; // print out error message
cerr<<p.stm_text<<endl; // print out SQL that caused the error
cerr<<p.var_info<<endl; // print out the variable that caused the error
     return false;
return true;
bool OTLThread::DBDisConnect()
try{
     db.logoff(); // disconnect from Oracle
catch(otl_exception& p){ // intercept OTL exceptions
cerr<<p.msg<<endl; // print out error message
cerr<<p.stm_text<<endl; // print out SQL that caused the error
cerr<<p.var_info<<endl; // print out the variable that caused the error
     return false;
return true;
void OTLThread::Action()
     strSQL = "call dbms_alert.waitone('INSERTALERT', :f1<char,out>, :f2<int,out>)";
     char     Result;
     char f1;
     int f2;
try{
          db.set_max_long_size(7000);
          oRslts.open(1,strSQL.c_str(),db);          //Waiting for Insert to happen Blocking Call
          oRslts>>f1>>f2>>Result;
          if(f2 == 0)
     std::cout<<"Hey! there is some record in ap3_soln_trigger"<<std::endl;
          oRslts.close();
catch(otl_exception& p){ // intercept OTL exceptions
// cerr<<p.msg<<endl; // print out error message
// cerr<<p.stm_text<<endl; // print out SQL that caused the error
// cerr<<p.var_info<<endl; // print out the variable that caused the error
     oRslts.close();
void OTLThread::operator()()
     Run();
OTLThreadMain.cpp
=================
#include <csignal>
#include <iostream>
#include "OTLThread.h"
void Handler(int iSigno)
     if (iSigno == SIGTERM)
          OTLThread::Stop();
     else if (iSigno == SIGUSR1)
          OTLThread::Pause();
     else if (iSigno == SIGUSR2)
          OTLThread::Resume();
int main(int argc, char *argv[])
     OTLThread*                                                            pT;
     boost::thread_group*                              ptg;
     signal(SIGTERM, Handler);
     signal(SIGUSR1, Handler);
     signal(SIGUSR2, Handler);
     ptg = new boost::thread_group();
     pT = new OTLThread();
ptg->create_thread(boost::ref(*pT));
ptg->join_all();
return EXIT_SUCCESS;
Makefile
========
# To use this Makefile on WIN32 (if at all there are Makefiles in WIN32): #
# - Set BUILDER_ROOT to the directory which contains the directory in which #
# you unzipped this zip archive #
# - Set BOOST_ROOT to the boost source tree #
# - Set BOOST_INC_ROOT to the boost include files' root directory #
# - Set BOOST_LIB_ROOT to the boost libs root directory #
# - Set BOOST_THREAD_INCDIR to the boost.threads include directory #
# - Set BOOST_THREAD_LIBS to the boost.threads libs directory #
# - Set BOOST_THREAD_LIBS as required by the WIN32 linkage rules #
# - Run make (and don't fume if it doesn't work ... I am just a novice #
# when it comes to WIN32) #
CC = c++
COMPILE = -c
DEBUG = -g
BOOST_ROOT = /home/lalit/Development/Libs/boost_1_30_0
BOOST_INC_ROOT = $(BOOST_ROOT)/boost
BOOST_LIB_ROOT = $(BOOST_ROOT)/libs
BOOST_THREAD_INCDIR = $(BOOST_INC_ROOT)/thread
BOOST_THREAD_LIBDIR = $(BOOST_LIB_ROOT)/thread/build/bin-stage
BOOST_THREAD_LIBS = -lboost_threadd -lboost_thread
OTL_INCLUDE = /home/lalit/Development/Libs/OTL_4_1_18/include
CFLAGS = -I$(BOOST_ROOT)
CFLAGS += -I$(OTL_INCLUDE)
CFLAGS += -I$(ORACLE_HOME)/rdbms/demo
CFLAGS += -I$(ORACLE_HOME)/rdbms/public
CFLAGS += $(DEBUG)
LDFLAGS = -L$(BOOST_THREAD_LIBDIR) $(BOOST_THREAD_LIBS)
LDFLAGS += -L$(ORACLE_HOME)/lib -lclntsh
OBJS = OTLThread.o
FINAL = OTLThreadMain
All : $(FINAL)
$(FINAL) : OTLThreadMain.o OTLThread.o
     $(CC) $(LDFLAGS) -o $@ $< $(OBJS)
OTLThreadMain.o : OTLThreadMain.cpp
     $(CC) $(COMPILE) $(CFLAGS) $<
OTLThread.o : OTLThread.cpp OTLThread.h
     $(CC) $(COMPILE) $(CFLAGS) $<
clean:
     rm -f *.o $(FINAL)