/*****************************************************************************************
 Copyright (c) 2002-2004 The UbixOS Project
 All rights reserved.

 Redistribution and use in source and binary forms, with or without modification, are
 permitted provided that the following conditions are met:

 Redistributions of source code must retain the above copyright notice, this list of
 conditions, the following disclaimer and the list of authors.  Redistributions in binary
 form must reproduce the above copyright notice, this list of conditions, the following
 disclaimer and the list of authors in the documentation and/or other materials provided
 with the distribution. Neither the name of the UbixOS Project nor the names of its
 contributors may be used to endorse or promote products derived from this software
 without specific prior written permission.

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
 THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 $Id$

*****************************************************************************************/

#include <mpi/mpi.h>
#include <lib/kmalloc.h>
#include <lib/string.h>
#include <ubixos/spinlock.h>

static mpiMbox_t  *mboxList    = 0x0;
static spinLock_t  mpiSpinLock = SPIN_LOCK_INITIALIZER;

/*****************************************************************************************

 Function: static mpiMbox_t * mpiFindMbox(char *name)

 Description: This function will find a mail box that matches the supplied name

 Notes:

*****************************************************************************************/
static mpiMbox_t * mpiFindMbox(char *name) {
  mpiMbox_t *mbox = 0x0;

  for (mbox = mboxList;mbox;mbox = mbox->next) {
    if (!kstrcmp(mbox->name,name)) {
       spinUnlock(&mpiSpinLock);
       return(mbox);
       }
    }

  return(0x0);
  }

/*****************************************************************************************

 Function: int mpiCreateMbox(char *name)

 Description: This function will create a new mailbox if it fails it will return -1
              otherwise it returns 0x0

 Notes:

*****************************************************************************************/
int mpiCreateMbox(char *name) {
  mpiMbox_t *mbox = 0x0;

  spinLock(&mpiSpinLock);

  if (mpiFindMbox(name) != 0x0) {
    spinUnlock(&mpiSpinLock);
    return(-1);
    }

  mbox = (mpiMbox_t *)kmalloc(sizeof(mpiMbox_t));

  sprintf(mbox->name,name);
  mbox->pid = _current->id;

  if (mboxList == 0x0) {
    mbox->prev = 0x0;
    mbox->next = 0x0;
    mboxList   = mbox;
    }
  else {
    mbox->next     = mboxList;
    mbox->prev     = 0x0;
    mboxList->prev = mbox;
    mboxList       = mbox;
    }

  spinUnlock(&mpiSpinLock);
  return(0x0);
  }

/*****************************************************************************************

 Function: int mpiSpam(uInt32 type,void *data)

 Description: This function will send a message to every mailbox

 Notes:

*****************************************************************************************/
int mpiSpam(uInt32 type,void *data) {
  mpiMbox_t    *mbox    = 0x0;
  mpiMessage_t *message = 0x0;
 
  spinLock(&mpiSpinLock);

  for (mbox = mboxList;mbox;mbox = mbox->next) {
    message = (mpiMessage_t *)kmalloc(sizeof(mpiMessage_t));

    message->type = type;
    kmemcpy(message->data,data,MESSAGE_LENGTH);
    message->next = 0x0;

    if (mbox->msg == 0x0) {
      mbox->msg       = message;
      }
    else {
      mbox->msgLast->next = message;
      mbox->msgLast       = message;
      }
    }

  spinUnlock(&mpiSpinLock);
  return(0x0);
  }

/*****************************************************************************************

 Function: int mpiPostMessage(char *name,uInt32 type,void *data)

 Description: This function will post a message to specified mailbox

 Notes:

*****************************************************************************************/
int mpiPostMessage(char *name,uInt32 type,void *data) {
  mpiMbox_t    *mbox    = 0x0;
  mpiMessage_t *message = 0x0;

  spinLock(&mpiSpinLock);

  mbox = mpiFindMbox(name);

  if (mbox == 0x0) {
    spinUnlock(&mpiSpinLock);
    return(-1);
    }

  message = (mpiMessage_t *)kmalloc(sizeof(mpiMessage_t));

  message->type = type;
  kmemcpy(message->data,data,MESSAGE_LENGTH);
  message->next = 0x0;

  if (mbox->msg == 0x0) {
    mbox->msg       = message;
    }
  else {
    mbox->msgLast->next = message;
    mbox->msgLast       = message;
    }

  spinUnlock(&mpiSpinLock);
  return(0x0);
  }

/*****************************************************************************************

 Function: int mpiFetchMessage(char *name,mpiMessage_t *msg)

 Description: This function will fetch the next message out of the specified mailbox

 Notes:

*****************************************************************************************/
int mpiFetchMessage(char *name,mpiMessage_t *msg) {
  mpiMbox_t    *mbox   = 0x0;
  mpiMessage_t *tmpMsg = 0x0;

  spinLock(&mpiSpinLock);

  mbox = mpiFindMbox(name);

  if (mbox == 0x0) {
    spinUnlock(&mpiSpinLock);
    return(-1);
    }

  if (mbox->msg == 0x0) {
    spinUnlock(&mpiSpinLock);
    return(-1);
    }

  if (mbox->pid != _current->id) {
    spinUnlock(&mpiSpinLock);
    return(-1);
    }

  msg->type = mbox->msg->type;
  kmemcpy(msg->data,mbox->msg->data,MESSAGE_LENGTH);

  tmpMsg    = mbox->msg;
  mbox->msg = mbox->msg->next;
  
  kfree(tmpMsg);

  spinUnlock(&mpiSpinLock);
  return(0x0);
  }

/*****************************************************************************************

 Function: int mpiDestroyMbox(char *name)

 Description: This function will fetch the next message out of the specified mailbox

 Notes:

*****************************************************************************************/
int mpiDestroyMbox(char *name) {
  mpiMbox_t    *mbox   = 0x0;

  spinLock(&mpiSpinLock);

  for (mbox = mboxList;mbox;mbox=mbox->next) {
    if (!kstrcmp(mbox->name,name)) {
      if (mbox->pid != _current->id) {
        spinUnlock(&mpiSpinLock);
        return(-1);
        }
      mbox->prev->next = mbox->next;
      mbox->next->prev = mbox->prev;
      kfree(mbox);
      spinUnlock(&mpiSpinLock);
      return(0x0);
      }
    }

  spinUnlock(&mpiSpinLock);
  return(-1);
  }

/***
 $Log$
 Revision 1.9  2004/05/26 15:34:29  reddawg
 mpi: oops forgot a spinUnlock

 Revision 1.8  2004/05/26 11:58:37  reddawg
 mpi: Fixed security now the pid used at time of mpiCreateMbox is the only pid
      allowed to do mpiFetchMessage and mpiDestroyMbox against that mail box

 Revision 1.7  2004/05/25 22:25:39  reddawg
 Typo Fix

 Revision 1.6  2004/05/25 18:32:02  reddawg
 Made MESSAGE_LENGTH define instead of hard coded message size

 Revision 1.4  2004/05/25 16:52:22  reddawg
 We now have mpiDestroyMbox(char *) This will of course destroy a mail box

 Revision 1.3  2004/05/25 16:33:26  reddawg
 Added some basic documentation

 Revision 1.2  2004/05/25 15:42:18  reddawg
 Enabled mpiSpam();

 Revision 1.1  2004/05/25 14:03:22  reddawg
 First insertion of the MPI into our kernel

 END
 ***/