#ifndef VTHREAD_HEADER
#define VTHREAD_HEADER 1
//////////////////////////////////////////////////////////////
//! file="amma/Drivers/Thread/Base/VThread.hh"
//! lib=VThread
//! userlevel=Obsolete
//! author="Charles Galambos"
//! date="12/10/1995"
//! docentry="Utilities.Threads"
//! rcsid="$Id: VThread.hh,v 1.10 2000/03/09 11:58:10 ees1cg Exp $"

#include "amma/Boolean.hh"


class VThreadBody;

//: Thread base class. 
// This class represents a single thread of execution within the program.  <p>
// Use PThread (Posix threads) library instead.

class VThread {
public:
  VThread(int MinStackSize = 16000,BooleanT Bind = FALSE);
  // Construct a new thread.
  
  virtual ~VThread();             
  // Destroy a thread, this will suspend the execution of the
  // thread.  Care should be taken when deleting a thread to
  // ensure its not holding any external resources.
  
  // ------------- Base Interface ----------------------
  
  BooleanT Execute(void);
  // Start thread running, use this command to start thread running
  // after it has been created.  This function can only be called 
  // once.
  
  virtual int Start(void); 
  // Called when thread started.  This function should be overloaded
  // is a derived class.  It is called with the new thread after 
  // Execute() is called.  There is no need to call this function 
  // directly. 
  
  virtual int End(void);
  // Called when thread terminates normally.  Overloading this method
  // is optional.  There is no need to call this function 
  // directly. 
  
  // ------------- Execution control ----------------------
  // These may be called by any thread.

  void Yield(void);     
  // Yield control of processor, call if you wish a brief delay
  // in execution.

  void Terminate(void);
  // Terminate thread.
  // Call to stop the thread running.

  BooleanT Pause(void);    
  // Stop thread running temporarly.
  
  BooleanT Continue(void);
  // Continue thread running again after call to Pause().
  
  BooleanT SetPriority(int Pri);
  // Set the priority of the process
  // 0 to 32767, Higher faster.
  
  // ------------- Thread ID ----------------------
  // Functions to identify threads.
  
  int GetID(void);
  // Get a unique ID for this thread.
  // NB. An id may no be assigned to the thread until
  // after Execute() has been called.
  
  static IntT GetCurrentThreadID();
  //: Get ID of current thread.
  
  static VThread *GetCurrentThread(void);
  // Get a pointer to the currently executing thread.
  
  friend VThreadBody;
  
private:
  VThreadBody *Body;
};


#endif