// -*- c++ -*-
/* $Id: thread.ccg,v 1.2 2004/02/10 14:26:06 murrayc Exp $ */

/* Copyright (C) 2002 The gtkmm Development Team
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <glibmm/exceptionhandler.h>
#include <glib/gmessages.h>


namespace
{

void* call_thread_entry_slot(void* data)
{
  sigc::slot_base *const slot = reinterpret_cast<sigc::slot_base*>(data);

  try
  {
    // Recreate the specific slot, and drop the reference obtained by create().
    (*static_cast<sigc::slot<void>*>(slot))();
  }
  catch(Glib::Thread::Exit&)
  {
    // Just exit from the thread.  The Thread::Exit exception
    // is our sane C++ replacement of g_thread_exit().
  }
  catch(...)
  {
    Glib::exception_handlers_invoke();
  }

  delete slot;
  return 0;
}

} // anonymous namespace


namespace Glib
{

// internal
void thread_init_impl()
{
  // Make sure the exception map is initialized before creating any thread.
  Glib::Error::register_init();
}


/**** Glib::Thread *********************************************************/

// static
Thread* Thread::create(const sigc::slot<void>& slot, bool joinable)
{
  // Make a copy of slot on the heap
  sigc::slot_base *const slot_copy = new sigc::slot<void>(slot);

  GError* error = 0;

  GThread *const thread = g_thread_create(
      &call_thread_entry_slot, slot_copy, joinable, &error);

  if(error)
  {
    delete slot_copy;
    Glib::Error::throw_exception(error);
  }

  return reinterpret_cast<Thread*>(thread);
}

// static
Thread* Thread::create(const sigc::slot<void>& slot, unsigned long stack_size,
                       bool joinable, bool bound, ThreadPriority priority)
{
  // Make a copy of slot on the heap
  sigc::slot_base *const slot_copy = new sigc::slot<void>(slot);

  GError* error = 0;

  GThread *const thread = g_thread_create_full(
      &call_thread_entry_slot, slot_copy, stack_size, joinable,
      bound, (GThreadPriority) priority, &error);

  if(error)
  {
    delete slot_copy;
    Glib::Error::throw_exception(error);
  }

  return reinterpret_cast<Thread*>(thread);
}

// static
Thread* Thread::self()
{
  return reinterpret_cast<Thread*>(g_thread_self());
}

bool Thread::joinable() const
{
  return gobject_.joinable;
}

void Thread::join()
{
  g_thread_join(&gobject_);
}

void Thread::set_priority(ThreadPriority priority)
{
  g_thread_set_priority(&gobject_, (GThreadPriority) priority);
}

ThreadPriority Thread::get_priority() const
{
  return (ThreadPriority) gobject_.priority;
}

// static
void Thread::yield()
{
  g_thread_yield();
}

Thread* wrap(GThread* gobject)
{
  return reinterpret_cast<Thread*>(gobject);
}


/**** Glib::StaticMutex ****************************************************/

void StaticMutex::lock()
{
  g_static_mutex_lock(&gobject_);
}

bool StaticMutex::trylock()
{
  return g_static_mutex_trylock(&gobject_);
}

void StaticMutex::unlock()
{
  g_static_mutex_unlock(&gobject_);
}

StaticMutex::operator Mutex&()
{
  // If GStaticMutex is implemented as struct (e.g. on Linux), its first struct
  // member (runtime_mutex) is a GMutex pointer.  If the gthread implementation
  // is native (i.e. the vtable pointer passed to g_thread_init() was 0), then
  // the runtime_mutex pointer is unused, and the rest of the GStaticMutex
  // struct resembles the mutex data.
  //
  // On Win32, GStaticMutex is just a typedef to struct _GMutex*.  Either way,
  // the first sizeof(GMutex*) bytes of GStaticMutex always resemble a GMutex
  // pointer.  The gthread implementation relies on that, and we'll also do so.

  GMutex*& runtime_mutex = reinterpret_cast<GMutex*&>(gobject_);

  // Fortunately, it cannot hurt if we set this to the GMutex pointer returned
  // by g_static_mutex_get_mutex().  Either we just overwrite it with the same
  // value, or it was unused anyway.  Doing that allows casting the pointer
  // location to a Glib::Mutex reference (its only data member is a GMutex*).

  runtime_mutex = g_static_mutex_get_mutex(&gobject_);

  return reinterpret_cast<Mutex&>(runtime_mutex);
}


/**** Glib::Mutex **********************************************************/

Mutex::Mutex()
:
  gobject_ (g_mutex_new())
{}

Mutex::~Mutex()
{
  g_mutex_free(gobject_);
}

void Mutex::lock()
{
  g_mutex_lock(gobject_);
}

bool Mutex::trylock()
{
  return g_mutex_trylock(gobject_);
}

void Mutex::unlock()
{
  g_mutex_unlock(gobject_);
}


/**** Glib::StaticRecMutex *************************************************/

void StaticRecMutex::lock()
{
  g_static_rec_mutex_lock(&gobject_);
}

bool StaticRecMutex::trylock()
{
  return g_static_rec_mutex_trylock(&gobject_);
}

void StaticRecMutex::unlock()
{
  g_static_rec_mutex_unlock(&gobject_);
}

void StaticRecMutex::lock_full(unsigned int depth)
{
  g_static_rec_mutex_lock_full(&gobject_, depth);
}

unsigned int StaticRecMutex::unlock_full()
{
  return g_static_rec_mutex_unlock_full(&gobject_);
}

StaticRecMutex::operator RecMutex&()
{
  return static_cast<RecMutex&>(*this);
}


/**** Glib::RecMutex *******************************************************/

RecMutex::RecMutex()
{
  g_static_rec_mutex_init(&gobject_);

  // GLib doesn't have GRecMutex, only GStaticRecMutex.  Force initialization
  // of the mutex now, to mimic the behaviour of a (hypothetical) GRecMutex.
  g_static_mutex_get_mutex(&gobject_.mutex);
}

RecMutex::~RecMutex()
{
  g_static_rec_mutex_free(&gobject_);
}


/**** Glib::StaticRWLock ***************************************************/

void StaticRWLock::reader_lock()
{
  g_static_rw_lock_reader_lock(&gobject_);
}

bool StaticRWLock::reader_trylock()
{
  return g_static_rw_lock_reader_trylock(&gobject_);
}

void StaticRWLock::reader_unlock()
{
  g_static_rw_lock_reader_unlock(&gobject_);
}

void StaticRWLock::writer_lock()
{
  g_static_rw_lock_writer_lock(&gobject_);
}

bool StaticRWLock::writer_trylock()
{
  return g_static_rw_lock_writer_trylock(&gobject_);
}

void StaticRWLock::writer_unlock()
{
  g_static_rw_lock_writer_unlock(&gobject_);
}

StaticRWLock::operator RWLock&()
{
  return static_cast<RWLock&>(*this);
}


/**** Glib::RWLock *********************************************************/

RWLock::RWLock()
{
  g_static_rw_lock_init(&gobject_);

  // GLib doesn't have GRWLock, only GStaticRWLock.  Force initialization
  // of the mutex and the condition variables now, to mimic the behaviour
  // of a (hypothetical) GRWLock.

  if(g_static_mutex_get_mutex(&gobject_.mutex))
  {
    gobject_.read_cond  = g_cond_new();
    gobject_.write_cond = g_cond_new();
  }
}

RWLock::~RWLock()
{
  g_static_rw_lock_free(&gobject_);
}


/**** Glib::Cond ***********************************************************/

Cond::Cond()
:
  gobject_ (g_cond_new())
{}

Cond::~Cond()
{
  g_cond_free(gobject_);
}

void Cond::signal()
{
  g_cond_signal(gobject_);
}

void Cond::broadcast()
{
  g_cond_broadcast(gobject_);
}

void Cond::wait(Mutex& mutex)
{
  g_cond_wait(gobject_, mutex.gobj());
}

bool Cond::timed_wait(Mutex& mutex, const Glib::TimeVal& abs_time)
{
  return g_cond_timed_wait(gobject_, mutex.gobj(), const_cast<Glib::TimeVal*>(&abs_time));
}

} // namespace Glib

