//%2005////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2000, 2001, 2002 BMC Software; Hewlett-Packard Development
// Company, L.P.; IBM Corp.; The Open Group; Tivoli Systems.
// Copyright (c) 2003 BMC Software; Hewlett-Packard Development Company, L.P.;
// IBM Corp.; EMC Corporation, The Open Group.
// Copyright (c) 2004 BMC Software; Hewlett-Packard Development Company, L.P.;
// IBM Corp.; EMC Corporation; VERITAS Software Corporation; The Open Group.
// Copyright (c) 2005 Hewlett-Packard Development Company, L.P.; IBM Corp.;
// EMC Corporation; VERITAS Software Corporation; The Open Group.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// THE ABOVE COPYRIGHT NOTICE AND THIS PERMISSION NOTICE SHALL BE INCLUDED IN
// ALL COPIES OR SUBSTANTIAL PORTIONS OF THE SOFTWARE. THE SOFTWARE IS PROVIDED
// "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
// LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
// ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
//==============================================================================
//
// Author: Mike Day (mdday@us.ibm.com)
//
// Modified By: Markus Mueller
//              Roger Kumpf, Hewlett-Packard Company (roger_kumpf@hp.com)
//              Amit K Arora, IBM (amita@in.ibm.com) for PEP#101
//              David Dillard, VERITAS Software Corp.
//                  (david.dillard@veritas.com)
//              Sean Keenan, Hewlett-Packard Company (sean.keenan@hp.com)
//              Josephine Eskaline Joyce, IBM (jojustin@in.ibm.com) for Bug#2393
//
//%/////////////////////////////////////////////////////////////////////////////

#ifndef Pegasus_Thread_h
#define Pegasus_Thread_h

#include <cstring>
#include <Pegasus/Common/Config.h>
#include <Pegasus/Common/IPC.h>
#include <Pegasus/Common/InternalException.h>
#include <Pegasus/Common/DQueue.h>
#include <Pegasus/Common/AcceptLanguages.h>  // l10n
#include <Pegasus/Common/Linkage.h>
#include <Pegasus/Common/AutoPtr.h>

PEGASUS_NAMESPACE_BEGIN

class PEGASUS_COMMON_LINKAGE cleanup_handler
{

   public:
      cleanup_handler( void (*routine)(void *), void *arg  ) : _routine(routine), _arg(arg)  {}
      ~cleanup_handler()  {; }
      inline Boolean operator==(const void *key) const
      {
         if(key == (void *)_routine)
            return true;
         return false;
      }
      inline Boolean operator ==(const cleanup_handler & b) const
      {
         return(operator==((const void *)b._routine));
      }
   private:
      void execute() { _routine(_arg); }
      cleanup_handler();
      void (*_routine)(void *);

      void *_arg;
      PEGASUS_CLEANUP_HANDLE _cleanup_buffer;
      friend class DQueue<class cleanup_handler>;
      friend class Thread;
};

///////////////////////////////////////////////////////////////////////////////


class  PEGASUS_COMMON_LINKAGE thread_data
{

   public:
      static void default_delete(void *data);

      thread_data( const char *key ) : _delete_func(NULL) , _data(NULL), _size(0)
      {
         PEGASUS_ASSERT(key != NULL);
         size_t keysize = strlen(key);
         _key.reset(new char[keysize + 1]);
         memcpy(_key.get(), key, keysize);
         _key.get()[keysize] = 0x00;

      }

      thread_data(const char *key, size_t size) : _delete_func(default_delete), _size(size)
      {
         PEGASUS_ASSERT(key != NULL);
         size_t keysize = strlen(key);
         _key.reset(new char[keysize + 1]);
         memcpy(_key.get(), key, keysize);
         _key.get()[keysize] = 0x00;
         _data = ::operator new(_size);

      }

      thread_data(const char *key, size_t size, void *data) : _delete_func(default_delete), _size(size)
      {
         PEGASUS_ASSERT(key != NULL);
         PEGASUS_ASSERT(data != NULL);
         size_t keysize = strlen(key);

         _key.reset(new char[keysize + 1]);
         memcpy(_key.get(), key, keysize);
         _key.get()[keysize] = 0x00;
         _data = ::operator new(_size);
         memcpy(_data, data, size);
      }

      ~thread_data()
      {
         if( _data != NULL)
            if(_delete_func != NULL)
            {
               _delete_func( _data );
            }
      }

      /**
       * This function is used to put data in thread space.
       *
       * Be aware that there is NOTHING in place to stop
       * other users of the thread to remove this data.
       * Or change the data.
       *
       * You, the developer has to make sure that there are
       * no situations in which this can arise (ie, have a
       * lock for the function which manipulates the TSD.
       *
       * @exception NullPointer
       */
      void put_data(void (*del)(void *), size_t size, void *data )
      {
         if(_data != NULL)
            if(_delete_func != NULL)
               _delete_func(_data);

         _delete_func = del;
         _data = data;
         _size = size;
         return;
      }

      size_t get_size() { return _size; }

      /**
       * This function is used to retrieve data from the
       * TSD, the thread specific data.
       *
       * Be aware that there is NOTHING in place to stop
       * other users of the thread to change the data you
       * get from this function.
       *
       * You, the developer has to make sure that there are
       * no situations in which this can arise (ie, have a
       * lock for the function which manipulates the TSD.
       */
      void get_data(void **data, size_t *size)
      {
         if(data == NULL || size == NULL)
            throw NullPointer();

         *data = _data;
         *size = _size;
         return;

      }

      // @exception NullPointer
      void copy_data(void **buf, size_t *size)
      {
         if((buf == NULL) || (size == NULL))
            throw NullPointer();
         *buf = ::operator new(_size);
         *size = _size;
         memcpy(*buf, _data, _size);
         return;
      }

      inline Boolean operator==(const void *key) const
      {
         if ( ! strcmp(_key.get(), reinterpret_cast<const char *>(key)))
            return(true);
         return(false);
      }

      inline Boolean operator==(const thread_data& b) const
      {
         return(operator==(b._key.get()));
      }

   private:
      void (*_delete_func) (void *data);
      thread_data();
      void *_data;
      size_t _size;
      AutoArrayPtr<char> _key;

      friend class DQueue<thread_data>;
      friend class Thread;
};


enum ThreadStatus { 
	PEGASUS_THREAD_OK = 1, /* No problems */
	PEGASUS_THREAD_INSUFFICIENT_RESOURCES, /* Can't allocate a thread. Not enough
				        memory. Try again later */
	PEGASUS_THREAD_SETUP_FAILURE, /* Could not allocate into the thread specific 
                                 data storage. */
	PEGASUS_THREAD_UNAVAILABLE  /* Service is being destroyed and no new threads can
                               be provided. */ 
};

///////////////////////////////////////////////////////////////////////////

class PEGASUS_COMMON_LINKAGE Thread
{
   public:

      Thread( PEGASUS_THREAD_RETURN (PEGASUS_THREAD_CDECL *start )(void *),
              void *parameter, Boolean detached );

      ~Thread();

      /**
          Start the thread.
          @return PEGASUS_THREAD_OK if the thread is started successfully, 
                  PEGASUS_THREAD_INSUFFICIENT_RESOURCES if the resources necessary 
                  to start the thread are not currently available.  
	          PEGASUS_THREAD_SETUP_FAILURE if the thread could not
                  be create properly - check the 'errno' value for specific operating
                  system return code.
       */
      ThreadStatus run();

      // get the user parameter
      inline void *get_parm() { return _thread_parm; }

      // cancellation must be deferred (not asynchronous)
      // for user-level threads the thread itself can decide
      // when it should die.
      void cancel();

      // cancel if there is a pending cancellation request
      void test_cancel();

      Boolean is_cancelled();

      // for user-level threads  - put the calling thread
      // to sleep and jump to the thread scheduler.
      // platforms with preemptive scheduling and native threads
      // can define this to be a no-op.
      // platforms without preemptive scheduling like NetWare
      // or gnu portable threads will have an existing
      // routine that can be mapped to this method

      void thread_switch();

#if defined(PEGASUS_PLATFORM_LINUX_GENERIC_GNU)
      // suspend this thread
      void suspend();

      // resume this thread
      void resume();
#endif

      static void sleep(Uint32 msec);

      // block the calling thread until this thread terminates
      void join();
      void thread_init();

      // thread routine needs to call this function when
      // it is ready to exit
      void exit_self(PEGASUS_THREAD_RETURN return_code);

      // stack of functions to be called when thread terminates
      // will be called last in first out (LIFO)
      // @exception IPCException
      void cleanup_push(void (*routine) (void *), void *parm);

      // @exception IPCException
      void cleanup_pop(Boolean execute = true);

      // create and initialize a tsd
      // @exception IPCException
      inline void create_tsd(const char *key, int size, void *buffer)
      {
        AutoPtr<thread_data> tsd(new thread_data(key, size, buffer));
        _tsd.insert_first(tsd.get());
        tsd.release();
      }

      // get the buffer associated with the key
      // NOTE: this call leaves the tsd LOCKED !!!!
      // @exception IPCException
      inline void *reference_tsd(const char *key)
      {
         _tsd.lock();
         thread_data *tsd = _tsd.reference(key);
         if(tsd != NULL)
            return( (void *)(tsd->_data) );
         else
            return(NULL);
      }

      // @exception IPCException
      inline void *try_reference_tsd(const char *key)
      {
         _tsd.try_lock();
         thread_data *tsd = _tsd.reference(key);
         if(tsd != NULL)
            return((void *)(tsd->_data) );
         else
            return(NULL);
      }


      // release the lock held on the tsd
      // NOTE: assumes a corresponding and prior call to reference_tsd() !!!
      // @exception IPCException
      inline void dereference_tsd()
      {
         _tsd.unlock();
      }

      // delete the tsd associated with the key
      // @exception IPCException
      inline void delete_tsd(const char *key)
      {
         AutoPtr<thread_data> tsd(_tsd.remove(key));
      }

      // Note: Caller must delete the thread_data object returned (if not null)
      // @exception IPCException
      inline void *remove_tsd(const char *key)
      {
         return(_tsd.remove((const void *)key));
      }

      // @exception IPCException
      inline void empty_tsd()
      {
         try
         {
            _tsd.try_lock();
         }
         catch(IPCException&)
         {
            return;
         }

         AutoPtr<thread_data> tsd(_tsd.next(0));
         while(tsd.get())
         {
            _tsd.remove_no_lock(tsd.get());
            tsd.reset(_tsd.next(0));
         }
         _tsd.unlock();
      }

      // create or re-initialize tsd associated with the key
      // if the tsd already exists, delete the existing buffer
      // @exception IPCException
      void put_tsd(const char *key, void (*delete_func)(void *), Uint32 size, void *value)
      {
         PEGASUS_ASSERT(key != NULL);
         AutoPtr<thread_data> tsd;
         tsd.reset(_tsd.remove((const void *)key));  // may throw an IPC exception
         tsd.reset();
         AutoPtr<thread_data> ntsd(new thread_data(key));
         ntsd->put_data(delete_func, size, value);
         try { _tsd.insert_first(ntsd.get()); }
         catch(IPCException& e) { e = e; throw; }
         ntsd.release();
      }
      inline PEGASUS_THREAD_RETURN get_exit() { return _exit_code; }
      inline PEGASUS_THREAD_TYPE self() {return pegasus_thread_self(); }

      PEGASUS_THREAD_HANDLE getThreadHandle() {return _handle;}

      inline Boolean operator==(const void *key) const
      {
         if ( (void *)this == key)
            return(true);
         return(false);
      }
      inline Boolean operator==(const Thread & b) const
      {
         return(operator==((const void *)&b ));
      }

      void detach();

      //
      //  Gets the Thread object associated with the caller's thread.
      //  Note: this may return NULL if no Thread object is associated
      //  with the caller's thread.
      //
      static Thread * getCurrent();  // l10n

      //
      //  Sets the Thread object associated with the caller's thread.
      //  Note: the Thread object must be placed on the heap.
      //
      static void setCurrent(Thread * thrd); // l10n

      //
      //  Gets the AcceptLanguages object associated with the caller's
      //  Thread.
      //  Note: this may return NULL if no Thread object, or no
      //  AcceptLanguages object, is associated with the caller's thread.
      //
      static AcceptLanguages * getLanguages(); //l10n

      //
      //  Sets the AcceptLanguages object associated with the caller's
      //  Thread.
      //  Note: a Thread object must have been previously associated with
      //  the caller's thread.
      //  Note: the AcceptLanguages object must be placed on the heap.
      //
      static void setLanguages(AcceptLanguages *langs); //l10n

      //
      //  Removes the AcceptLanguages object associated with the caller's
      //  Thread.
      //
      static void clearLanguages(); //l10n

   private:
      Thread();

      static Sint8 initializeKey();  // l10n

      // @exception IPCException
      inline void create_tsd(const char *key )
      {
         AutoPtr<thread_data> tsd(new thread_data(key));
         _tsd.insert_first(tsd.get());
         tsd.release();
      }
      PEGASUS_THREAD_HANDLE _handle;
      Boolean _is_detached;
      Boolean _cancel_enabled;
      Boolean _cancelled;

      PEGASUS_SEM_HANDLE _suspend_count;

      // always pass this * as the void * parameter to the thread
      // store the user parameter in _thread_parm

      PEGASUS_THREAD_RETURN  ( PEGASUS_THREAD_CDECL *_start)(void *);
      DQueue<class cleanup_handler> _cleanup;
      DQueue<class thread_data> _tsd;

      void *_thread_parm;
      PEGASUS_THREAD_RETURN _exit_code;
      static Boolean _signals_blocked;
      static PEGASUS_THREAD_KEY_TYPE _platform_thread_key;  //l10n
      static Boolean _key_initialized; // l10n
      static Boolean _key_error; // l10n
};


class PEGASUS_COMMON_LINKAGE ThreadPool
{
public:

    /**
        Constructs a new ThreadPool object.
        @param initialSize The number of threads that are initially added to
            the thread pool.
        @param key A name for this thread pool that can be used to determine
            equality of two thread pool objects.  Only the first 16 characters
            of this value are used.
        @param minThreads The minimum number of threads that should be
            contained in this thread pool at any given time.
        @param maxThreads The maximum number of threads that should be
            contained in this thread pool at any given time.
        @param deallocateWait The minimum time that a thread should be idle
            before it is removed from the pool and cleaned up.
     */
    ThreadPool(
        Sint16 initialSize,
        const char* key,
        Sint16 minThreads,
        Sint16 maxThreads,
        struct timeval& deallocateWait);

    /**
        Destructs the ThreadPool object.
     */
    ~ThreadPool();

    /**
        Allocate and start a thread to do a unit of work.
        @param parm A generic parameter to pass to the thread
        @param work A pointer to the function that is to be executed by
                    the thread
        @param blocking A pointer to an optional semaphore which, if
                        specified, is signaled after the thread finishes
                        executing the work function
        @return PEGASUS_THREAD_OK if the thread is started successfully, 
		PEGASUS_THREAD_INSUFFICIENT_RESOURCES  if the
                resources necessary to start the thread are not currently
                available.  PEGASUS_THREAD_SETUP_FAILURE if the thread
                could not be setup properly. PEGASUS_THREAD_UNAVAILABLE
                if this service is shutting down and no more threads can
                be allocated.
        @exception IPCException
     */
    ThreadStatus allocate_and_awaken(
        void* parm,
        PEGASUS_THREAD_RETURN (PEGASUS_THREAD_CDECL* work)(void *),
        Semaphore* blocking = 0);

    /**
        Cleans up idle threads if they have been running longer than the
        deallocate_wait configuration and more than the configured
        minimum number of threads is running.
        @return The number of threads that were cleaned up.
        @exception IPCException
     */
    Uint32 cleanupIdleThreads();

    void get_key(Sint8* buf, int bufsize);

    inline Boolean operator==(const char* key) const
    {
        return (!strncmp(key, _key, 16));
    }

    Boolean operator==(const void* p) const
    {
        return ((void *)this == p);
    }

    Boolean operator==(const ThreadPool & p) const
    {
        return operator==((const void *)&p);
    }

    inline void setMinThreads(Sint16 min)
    {
        _minThreads = min;
    }

    inline Sint16 getMinThreads() const
    {
        return _minThreads;
    }

    inline void setMaxThreads(Sint16 max)
    {
        _maxThreads = max;
    }

    inline Sint16 getMaxThreads() const
    {
        return _maxThreads;
    }

    inline Uint32 runningCount()
    {
        return _runningThreads.count();
    }

    inline Uint32 idleCount()
    {
        return _idleThreads.count();
    }

private:

    ThreadPool();    // Unimplemented
    ThreadPool(const ThreadPool&);    // Unimplemented
    ThreadPool& operator=(const ThreadPool&);    // Unimplemented

    static PEGASUS_THREAD_RETURN PEGASUS_THREAD_CDECL _loop(void *);

    static Boolean _timeIntervalExpired(
        struct timeval* start,
        struct timeval* interval);

    static void _deleteSemaphore(void* p);

    void _cleanupThread(Thread* thread);
    Thread* _initializeThread();
    void _addToIdleThreadsQueue(Thread* th);

    Sint16 _maxThreads;
    Sint16 _minThreads;
    AtomicInt _currentThreads;
    struct timeval _deallocateWait;
    char _key[17];
    DQueue<Thread> _idleThreads;
    DQueue<Thread> _runningThreads;
    AtomicInt _dying;
};


#if defined(PEGASUS_OS_TYPE_WINDOWS)
# include "ThreadWindows_inline.h"
#elif defined(PEGASUS_PLATFORM_ZOS_ZSERIES_IBM)
# include "ThreadzOS_inline.h"
#elif defined(PEGASUS_OS_TYPE_UNIX)
# include "ThreadUnix_inline.h"
#elif defined(PEGASUS_OS_VMS)
# include "ThreadVms_inline.h"
#endif

PEGASUS_NAMESPACE_END

#endif // Pegasus_Thread_h