// PThreadCondition.h

#ifndef dset__PThreadCondition_H
#define dset__PThreadCondition_H

// Class to hold an integer PThread condition variable and
// associated mutex.

#include <iosfwd>

class PThreadCondition {

public:  // Embedded classes.

  class Imp;

private:  // data

  Imp* pimp;

private:  // Hide copy and assignment.

  // Copy.
  PThreadCondition(const PThreadCondition& rhs);

  // Assignment.
  PThreadCondition& operator=(const PThreadCondition& rhs);

public:  // static methods

  // Return values.
  static int ok();
  static int invalid_argument();
  static int mutex_not_locked();
  static int invalid_mutex_lock_count();
  static int timed_out();

public:  // methods

  // Constructor.
  // A new mutex is created.
  // Predicate is set to zero.
  PThreadCondition();

  // Destructor.
  ~PThreadCondition();

  // Set the variable.
  // Returns 0 for success.
  int set(int val);

  // Retrieve the variable.
  int get() const;

  // Signal the condition.
  // This wakes up one thread waiting on the condition.
  // Returns 0 for success.
  int signal();

  // Broadcast the condition.
  // This wakes up all threads waiting on the condition.
  // Returns 0 for success.
  int broadcast();

  // Wait on the condition.
  // Mutex must be locked before this is called.
  // Lock count must be one.
  // Unlocks mutex while waiting for signal.
  // Locks mutex before return.
  // Return values:
  //   ok() 
  //   invalid_argument()
  //   mutex_not_locked()
  //   invalid_mutex_lock_count()
  int wait();

  // Wait on the condition for a maximum of dtim seconds.
  // Mutex must be locked before this is called.
  // Lock count must be one.
  // Unlocks mutex while waiting for signal.
  // Locks mutex before return.
  // Return values:
  //   ok()
  //   invalid_argument()
  //   mutex_not_locked()
  //   invalid_mutex_lock_count()
  //   timed_out()
  int wait(unsigned int dtim);

  // Lock the mutex.
  int lock();

  // Try to lock the mutex.
  // Returns EBUSY if the mutex is already locked.
  int trylock();

  // Unlock the mutex.
  int unlock();

  // Return the mutex status.
  bool is_locked() const;

  // Return the ID of the thread that has locked the mutex.
  // Returns 0 if the mutex is unlocked.
  // May return null for a locked mutex if another thread has
  // not yet completed that operation.
#ifndef __CINT__
  pthread_t lock_owner() const;
#endif

};

// Output stream.
std::ostream& operator<<(std::ostream& lhs, const PThreadCondition& rhs);

#endif