/*
The contents of this file are subject to the Mozilla Public License Version 1.1
(the "License"); you may not use this file except in compliance with the License.
You may obtain a copy of the License at http://www.mozilla.org/MPL/

Software distributed under the License is distributed on an "AS IS" basis,
WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the
specific language governing rights and limitations under the License.

The Original Code is Lepton.

The Initial Developer of the Original Code is Chauvin-Arnoux.
Portions created by Chauvin-Arnoux are Copyright (C) 2011. All Rights Reserved.

Alternatively, the contents of this file may be used under the terms of the eCos GPL license
(the  [eCos GPL] License), in which case the provisions of [eCos GPL] License are applicable
instead of those above. If you wish to allow use of your version of this file only under the
terms of the [eCos GPL] License and not to allow others to use your version of this file under
the MPL, indicate your decision by deleting  the provisions above and replace
them with the notice and other provisions required by the [eCos GPL] License.
If you do not delete the provisions above, a recipient may use your version of this file under
either the MPL or the [eCos GPL] License."
*/


/*============================================
| Includes
==============================================*/
#include "kernel/core/errno.h"
#include "kernel/core/interrupt.h"
#include "kernel/core/syscall.h"
#include "kernel/core/kernel_pthread.h"

/*============================================
| Global Declaration
==============================================*/


/*============================================
| Implementation
==============================================*/
/*-------------------------------------------
| Name:pthread_mutex_init
| Description:
| Parameters:
| Return Type:
| Comments:
| See:
---------------------------------------------*/
int   kernel_pthread_mutex_init(kernel_pthread_mutex_t *mutex, const pthread_mutexattr_t *attr){
   //attr not used. preserved POSIX compatibility

#ifdef __KERNEL_UCORE_EMBOS
   OS_CreateRSema(&mutex->mutex);
#endif

   return 0;
}

/*-------------------------------------------
| Name:pthread_mutex_destroy
| Description:
| Parameters:
| Return Type:
| Comments:
| See:
---------------------------------------------*/
int   kernel_pthread_mutex_destroy(kernel_pthread_mutex_t *mutex){
   int count;
   //
   __atomic_in();
   //
#ifdef __KERNEL_UCORE_EMBOS
   count = OS_GetSemaValue(&mutex->mutex);
   if(!count) {
   #ifndef CPU_M16C62       //not supported on m16c embos architecture (embos version is too old for m16c)
      OS_DeleteRSema(&mutex->mutex);
   #endif
      __atomic_out();
      return 0;   //mutex is not owned by any thread. it could be destroyed.
   }
   if(!OS_Request(&mutex->mutex)) {
      __atomic_out();
      return -1;    //mutex is not owned by this thread. error it cannot be destroyed;
   }
   //
   count++;    //if request success mutex->count is incremented
   //mutex is owned by this thread;
   for(count; count>0; count--) {
      OS_Unuse(&mutex->mutex);
   }
#endif

#ifndef CPU_M16C62    //not supported on m16c embos architecture (embos version is too old for m16c)
   OS_DeleteRSema(&mutex->mutex);
#endif
   //
   __atomic_out();
   //
   return 0; //mutex is not owned by any thread. it could be destroyed.
}

/*--------------------------------------------
| Name:        kernel_pthread_mutex_owner_destroy
| Description:
| Parameters:  none
| Return Type: none
| Comments:
| See:
----------------------------------------------*/
int   kernel_pthread_mutex_owner_destroy(kernel_pthread_t* thread_ptr,kernel_pthread_mutex_t *mutex){
   int count;
   //
   __atomic_in();
   //
#ifdef __KERNEL_UCORE_EMBOS
   {
      OS_TASK *p = thread_ptr->tcb;
      count = OS_GetSemaValue(&mutex->mutex);
      if(!count) {
         __atomic_out();
         return -1; //mutex is not owned by any thread;
      }
      if(p!=OS_GetResourceOwner(&mutex->mutex)) {
         __atomic_out();
         return -1; //mutex is not owned by this thread;
      }
      //
      count++; //if request success mutex->count is incremented
      //mutex is owned by this thread;
      for(count; count>0; count--) {
         OS_Unuse(&mutex->mutex);
      }
   }
#endif

   //
   __atomic_out();
   //

   return 0;
}

/*-------------------------------------------
| Name:pthread_mutex_lock
| Description:
| Parameters:
| Return Type:
| Comments:
| See:
---------------------------------------------*/
int   kernel_pthread_mutex_lock(kernel_pthread_mutex_t *mutex){

   if(__kernel_is_in_static_mode())
      return 0;

#ifdef __KERNEL_UCORE_EMBOS
   OS_Use(&mutex->mutex);
#endif

   return 0;
}

/*-------------------------------------------
| Name:pthread_mutex_trylock
| Description:
| Parameters:
| Return Type:
| Comments:
| See:
---------------------------------------------*/
int   kernel_pthread_mutex_trylock(kernel_pthread_mutex_t *mutex){

   if(__kernel_is_in_static_mode())
      return 0;

#ifdef __KERNEL_UCORE_EMBOS
   if(!OS_Request(&mutex->mutex))
      return -EBUSY;
#endif

   return 0;
}

/*-------------------------------------------
| Name:pthread_mutex_unlock
| Description:
| Parameters:
| Return Type:
| Comments:
| See:
---------------------------------------------*/
int   kernel_pthread_mutex_unlock(kernel_pthread_mutex_t *mutex){

   if(__kernel_is_in_static_mode())
      return 0;

#ifdef __KERNEL_UCORE_EMBOS
   OS_Unuse(&mutex->mutex);
#endif

   return 0;
}

/*============================================
| End of Source  : kernel_pthread_mutex.c
==============================================*/
