/*****************************************************************************************
 Copyright (c) 2002-2004, 2017 The UbixOS Project
 All rights reserved.

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 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,
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 OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 $Id: ubthread.c 54 2016-01-11 01:29:55Z reddawg $

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

/* All these must be converted to be done atomically */

#include <ubixos/ubthread.h>
#include <ubixos/exec.h>
#include <ubixos/sched.h>
#include <ubixos/time.h>
#include <ubixos/spinlock.h>
#include <ubixos/vitals.h>
#include <lib/kmalloc.h>
#include <lib/kprintf.h>

struct ubthread_cond_list *conds = 0x0;
struct ubthread_mutex_list *mutex = 0x0;

kTask_t *ubthread_self() {
  return (_current);
}

int ubthread_cond_init(ubthread_cond_t *cond, const uint32_t attr) {
  ubthread_cond_t ubcond = kmalloc(sizeof(struct ubthread_cond));
  memset(ubcond, 0x0, sizeof(struct ubthread_cond));

  ubcond->id = (int) cond;
  ubcond->lock = ATOMIC_VAR_INIT(0);

  *cond = ubcond;
  return (0x0);
}

int ubthread_mutex_init(ubthread_mutex_t *mutex, const uint32_t attr) {
  ubthread_mutex_t ubmutex = kmalloc(sizeof(struct ubthread_mutex));
  memset(ubmutex, 0x0, sizeof(struct ubthread_mutex));

  ubmutex->id = (int) mutex;
  ubmutex->lock = ATOMIC_VAR_INIT(0);

  *mutex = ubmutex;
  return (0x0);
}

int ubthread_cond_destroy(ubthread_cond_t *cond) {
  kfree(*cond);
  *cond = 0x0;
  return (0x0);
}

int ubthread_mutex_destroy(ubthread_mutex_t *mutex) {
  kfree(*mutex);
  *mutex = 0x0;
  return (0x0);
}

int ubthread_create(kTask_t **thread, const uInt32 *attr, void (*tproc)(void), void *arg) {
  *thread = (void *) execThread(tproc, (int) (kmalloc(0x2000) + 0x2000), arg);
  return (0x0);
}

int ubthread_mutex_lock(ubthread_mutex_t *mutex) {
  ubthread_mutex_t ubmutex = *mutex;

  if (ubmutex->lock == TRUE && ubmutex->pid == _current->id) {
    kprintf("Mutex Already Locked By This Thread");
    kpanic("WHY?");
    return (0x0);
  }

  while (1) {
    if (xchg_32(&ubmutex->lock, TRUE) == FALSE)
      break;

    while (ubmutex->lock == TRUE)
      sched_yield();
  }

  ubmutex->pid = _current->id;
  return (0x0);
}

int ubthread_mutex_unlock(ubthread_mutex_t *mutex) {
  ubthread_mutex_t ubmutex = *mutex;

  if (ubmutex->lock != TRUE)
    kpanic("NOT LOCKED?");

  if (ubmutex->pid != _current->id)
    kprintf("Trying To Unlock Mutex From No Locking Thread[%i - %i:0x%X]\n", ubmutex->pid, _current->id, *ubmutex);

  while (1) {
    if (xchg_32(&ubmutex->lock, FALSE) == TRUE)
      break;
    while (ubmutex->lock == FALSE)
      sched_yield();
  }

  ubmutex->pid = 0x0;
  return (0x0);
}

int ubthread_cond_timedwait(ubthread_cond_t *cond, ubthread_mutex_t *mutex, const struct timespec *abstime) {
  ubthread_cond_t ubcond = *cond;
  ubthread_mutex_t ubmutex = *mutex;

  uint32_t enterTime = systemVitals->sysUptime + 20;

  ubthread_mutex_unlock(mutex);

  while (enterTime > systemVitals->sysUptime) {
    if (ubcond->lock == FALSE)
      break;
    sched_yield();
  }

  ubthread_mutex_lock(mutex);

  return (0x0);
}

int ubthread_cond_wait(ubthread_cond_t *cond, ubthread_mutex_t *mutex) {
  ubthread_cond_t ubcond = *cond;
  ubthread_mutex_unlock(mutex);
  while (ubcond->lock == TRUE)
    sched_yield();
  ubthread_mutex_lock(mutex);
  return (0x0);
}

int ubthread_cond_signal(ubthread_cond_t *cond) {
  ubthread_cond_t ubcond = *cond;
  while (xchg_32(&ubcond->lock, FALSE))
    sched_yield();
  return (0x0);
}

int ubthread_cond_broadcast(ubthread_cond_t *cond) {
  ubthread_cond_t ubcond = *cond;
  while (xchg_32(&ubcond->lock, FALSE))
    sched_yield();
  return (0x0);
}