//-----------------------------------------------------------------------------
// Copyright (c) 2013 GarageGames, LLC
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//-----------------------------------------------------------------------------



#include "console/console.h"
#include "platformX86UNIX/platformX86UNIX.h"
#include "platform/platformMutex.h"
#include "platformX86UNIX/x86UNIXMutex.h"

#include <pthread.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

void * Mutex::createMutex()
{
   pthread_mutex_t *mutex;
   pthread_mutexattr_t attr;

   pthread_mutexattr_init(&attr);
   pthread_mutexattr_settype(&attr,PTHREAD_MUTEX_RECURSIVE);
   
   mutex = new pthread_mutex_t;
   pthread_mutex_init(mutex, &attr);
   
   return((void*)mutex);
}

void Mutex::destroyMutex(void * mutex)
{
   pthread_mutex_t *pt_mutex = reinterpret_cast<pthread_mutex_t*>(mutex);
   AssertFatal(pt_mutex, "Mutex::destroyMutex: invalid mutex");
   pthread_mutex_destroy(pt_mutex);
   delete pt_mutex;
}

bool Mutex::lockMutex(void * mutex, bool block)
{
   pthread_mutex_t *pt_mutex = reinterpret_cast<pthread_mutex_t*>(mutex);
   AssertFatal(pt_mutex, "Mutex::lockMutex: invalid mutex");
   if(block)
   {
	   return pthread_mutex_lock(pt_mutex) == 0;
   }
   else
   {
	   return pthread_mutex_trylock(pt_mutex) == 0;
   }
}

void Mutex::unlockMutex(void * mutex)
{
   pthread_mutex_t *pt_mutex = reinterpret_cast<pthread_mutex_t*>(mutex);
   AssertFatal(pt_mutex, "Mutex::unlockMutex: invalid mutex");
   pthread_mutex_unlock(pt_mutex);
}

ProcessMutex::ProcessMutex()
{
   mFD = -1;
}

ProcessMutex::~ProcessMutex()
{
   release();
}

bool ProcessMutex::acquire(const char *mutexName)
{
   if (mFD != -1)
      return false;

   dSprintf(
      mLockFileName, LockFileNameSize, 
      "/tmp/%s.lock", mutexName);

   mFD = open(mLockFileName, 
      O_CREAT | O_RDWR, 
      S_IRUSR | S_IRGRP | S_IROTH |
      S_IWUSR | S_IWGRP | S_IWOTH);

   if (mFD == -1)
   {
      Con::printf("Couldn't open file: %s", mLockFileName);
      return false;
   }

   struct flock lock;
   //lock.l_type = F_RDLCK;
   lock.l_type = F_WRLCK;
   lock.l_whence = SEEK_SET;
   lock.l_start = 0;
   lock.l_len = 0;
   lock.l_pid = getpid();
   
   if (fcntl(mFD, F_SETLK, &lock) == -1)
   {
      Con::printf("Couldn't lock file: %s, %s", 
         mLockFileName, strerror(errno));
      if (fcntl(mFD, F_GETLK, &lock) != -1)
         Con::printf("Lock owned by pid: %d", lock.l_pid);
      Con::printf("Remove the file if lock is stale");
      close(mFD);
      mFD = -1;
      return false;
   }
   return true;
}

void ProcessMutex::release()
{
   if (mFD != -1)
   {
      close(mFD);
      mFD = -1;
      unlink(mLockFileName);
   }
}

ConsoleFunction(debug_testx86unixmutex, void, 1, 1, "debug_testx86unixmutex()")
{
   void* mutex = Mutex::createMutex();
   AssertFatal(mutex, "couldn't create mutex");
   Con::printf("created mutex");
   Mutex::lockMutex(mutex);
   Con::printf("locked mutex");
   Mutex::unlockMutex(mutex);
   Con::printf("unlocked mutex");
   Mutex::destroyMutex(mutex);
   Con::printf("destroyed mutex");
}