/* Copyright (c) 2010 - 2021 Advanced Micro Devices, Inc.

 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. */

//!
//! \file OCLThread.cpp
//!

#include <stdio.h>
#include <stdlib.h>

#include "OCL/Thread.h"
#ifdef _WIN32
#include <process.h>
#endif

//! pack the function pointer and data inside this struct
typedef struct __argsToThreadFunc {
  oclThreadFunc func;
  void* data;

} argsToThreadFunc;

#ifdef _WIN32
//! Windows thread callback - invokes the callback set by
//! the application in OCLThread constructor
unsigned _stdcall win32ThreadFunc(void* args) {
  argsToThreadFunc* ptr = (argsToThreadFunc*)args;
  OCLutil::Thread* obj = (OCLutil::Thread*)ptr->data;
  ptr->func(obj->getData());
  delete args;
  return 0;
}
#endif

////////////////////////////////////////////////////////////////////
//!
//! Constructor for OCLLock
//!
OCLutil::Lock::Lock() {
#ifdef _WIN32
  InitializeCriticalSection(&_cs);
#else
  pthread_mutex_init(&_lock, NULL);
#endif
}

////////////////////////////////////////////////////////////////////
//!
//! Destructor for OCLLock
//!
OCLutil::Lock::~Lock() {
#ifdef _WIN32
  DeleteCriticalSection(&_cs);
#else
  pthread_mutex_destroy(&_lock);
#endif
}

//////////////////////////////////////////////////////////////
//!
//! Try to acquire the lock, wait for the lock if unavailable
//! else hold the lock and enter the protected area
//!
void OCLutil::Lock::lock() {
#ifdef _WIN32
  EnterCriticalSection(&_cs);
#else
  pthread_mutex_lock(&_lock);
#endif
}

//////////////////////////////////////////////////////////////
//!
//! Try to acquire the lock, if unavailable the function returns
//! false and returns true if available(enters the critical
//! section as well in this case).
//!
bool OCLutil::Lock::tryLock() {
#ifdef _WIN32
  return (TryEnterCriticalSection(&_cs) != 0);
#else
  return !((bool)pthread_mutex_trylock(&_lock));
#endif
}

//////////////////////////////////////////////////////////////
//!
//! Unlock the lock
//!
void OCLutil::Lock::unlock() {
#ifdef _WIN32
  LeaveCriticalSection(&_cs);
#else
  pthread_mutex_unlock(&_lock);
#endif
}

////////////////////////////////////////////////////////////////////
//!
//! Constructor for OCLThread
//!
OCLutil::Thread::Thread() : _tid(0), _data(0) {
#ifdef _WIN32
  _ID = 0;
#else
#endif
}

////////////////////////////////////////////////////////////////////
//!
//! Destructor for OCLLock
//!
OCLutil::Thread::~Thread() {
#ifdef _WIN32
  CloseHandle(_tid);
#else
#endif
}

//////////////////////////////////////////////////////////////
//!
//! Create a new thread and return the status of the operation
//!
bool OCLutil::Thread::create(oclThreadFunc func, void* arg) {
  // Save the data internally
  _data = arg;

  unsigned int retVal;

  bool verbose = getenv("VERBOSE") != NULL;

#ifdef _WIN32
  // Setup the callback struct for thread function and pass to the
  // begin thread routine
  // xxx The following struct is allocated but never freed!!!!
  argsToThreadFunc* args = new argsToThreadFunc;
  args->func = func;
  args->data = this;

  _tid = (HANDLE)_beginthreadex(NULL, 0, win32ThreadFunc, args, 0, &retVal);

  if (verbose) {
    printf("Thread handle value = %p\n", _tid);

    printf("Done creating thread. Thread id value = %u\n", retVal);
  }
#else
  //! Now create the thread with pointer to self as the data
  retVal = pthread_create(&_tid, NULL, func, arg);

  if (verbose)
    printf("Done creating thread. Ret value %d, Self = %u\n", retVal, (unsigned int)pthread_self());
#endif

  if (retVal != 0) return false;

  return true;
}

//////////////////////////////////////////////////////////////
//!
//! Return the thread ID for the current OCLThread
//!
unsigned int OCLutil::Thread::getID() {
#ifdef _WIN32
  return GetCurrentThreadId();
  // Type cast the thread handle to unsigned in and send it over
#else
  return (unsigned int)pthread_self();
#endif
}

//////////////////////////////////////////////////////////////
//!
//! Wait for this thread to join
//!
bool OCLutil::Thread::join() {
#ifdef _WIN32
  DWORD rc = WaitForSingleObject(_tid, INFINITE);

  if (rc == WAIT_FAILED) {
    printf("Bad call to function(invalid handle?)\n");
  }
#else
  int rc = pthread_join(_tid, NULL);
#endif

  if (rc != 0) return false;

  return true;
}