/*
//@HEADER
// ************************************************************************
// 
//                        Kokkos v. 2.0
//              Copyright (2014) Sandia Corporation
// 
// Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
// the U.S. Government retains certain rights in this software.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// 3. Neither the name of the Corporation nor the names of the
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "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 SANDIA CORPORATION OR THE
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Questions? Contact  H. Carter Edwards (hcedwar@sandia.gov)
// 
// ************************************************************************
//@HEADER
*/

#include <algorithm>
#include <Kokkos_Macros.hpp>

/*--------------------------------------------------------------------------*/

#if defined( __INTEL_COMPILER ) && ! defined ( KOKKOS_HAVE_CUDA )

// Intel specialized allocator does not interoperate with CUDA memory allocation

#define KOKKOS_INTEL_MM_ALLOC_AVAILABLE

#endif

/*--------------------------------------------------------------------------*/

#if defined(KOKKOS_POSIX_MEMALIGN_AVAILABLE)

#include <unistd.h>
#include <sys/mman.h>

/* mmap flags for private anonymous memory allocation */

#if defined( MAP_ANONYMOUS ) && defined( MAP_PRIVATE )
  #define KOKKOS_POSIX_MMAP_FLAGS (MAP_PRIVATE | MAP_ANONYMOUS)
#elif defined( MAP_ANON ) && defined( MAP_PRIVATE )
  #define KOKKOS_POSIX_MMAP_FLAGS (MAP_PRIVATE | MAP_ANON)
#endif

// mmap flags for huge page tables
// the Cuda driver does not interoperate with MAP_HUGETLB
#if defined( KOKKOS_POSIX_MMAP_FLAGS )
  #if defined( MAP_HUGETLB ) && ! defined( KOKKOS_HAVE_CUDA )
    #define KOKKOS_POSIX_MMAP_FLAGS_HUGE (KOKKOS_POSIX_MMAP_FLAGS | MAP_HUGETLB )
  #else
    #define KOKKOS_POSIX_MMAP_FLAGS_HUGE KOKKOS_POSIX_MMAP_FLAGS
  #endif
#endif

#endif

/*--------------------------------------------------------------------------*/

#include <stddef.h>
#include <stdlib.h>
#include <stdint.h>
#include <memory.h>

#include <iostream>
#include <sstream>
#include <cstring>

#include <Kokkos_HostSpace.hpp>
#include <impl/Kokkos_BasicAllocators.hpp>
#include <impl/Kokkos_Error.hpp>
#include <Kokkos_Atomic.hpp>

//----------------------------------------------------------------------------
//----------------------------------------------------------------------------

namespace Kokkos {
namespace {

static const int QUERY_SPACE_IN_PARALLEL_MAX = 16 ;

typedef int (* QuerySpaceInParallelPtr )();

QuerySpaceInParallelPtr s_in_parallel_query[ QUERY_SPACE_IN_PARALLEL_MAX ] ;
int s_in_parallel_query_count = 0 ;

} // namespace <empty>

void HostSpace::register_in_parallel( int (*device_in_parallel)() )
{
  if ( 0 == device_in_parallel ) {
    Kokkos::Impl::throw_runtime_exception( std::string("Kokkos::HostSpace::register_in_parallel ERROR : given NULL" ) );
  }

  int i = -1 ;

  if ( ! (device_in_parallel)() ) {
    for ( i = 0 ; i < s_in_parallel_query_count && ! (*(s_in_parallel_query[i]))() ; ++i );
  }

  if ( i < s_in_parallel_query_count ) {
    Kokkos::Impl::throw_runtime_exception( std::string("Kokkos::HostSpace::register_in_parallel_query ERROR : called in_parallel" ) );

  }

  if ( QUERY_SPACE_IN_PARALLEL_MAX <= i ) {
    Kokkos::Impl::throw_runtime_exception( std::string("Kokkos::HostSpace::register_in_parallel_query ERROR : exceeded maximum" ) );

  }

  for ( i = 0 ; i < s_in_parallel_query_count && s_in_parallel_query[i] != device_in_parallel ; ++i );

  if ( i == s_in_parallel_query_count ) {
    s_in_parallel_query[s_in_parallel_query_count++] = device_in_parallel ;
  }
}

int HostSpace::in_parallel()
{
  const int n = s_in_parallel_query_count ;

  int i = 0 ;

  while ( i < n && ! (*(s_in_parallel_query[i]))() ) { ++i ; }

  return i < n ;
}

} // namespace Kokkos

/*--------------------------------------------------------------------------*/

#if ! defined( KOKKOS_USING_EXPERIMENTAL_VIEW )

namespace Kokkos {

Impl::AllocationTracker HostSpace::allocate_and_track( const std::string & label, const size_t size )
{
  return Impl::AllocationTracker( allocator(), size, label );
}

} // namespace Kokkos

#endif /* #if ! defined( KOKKOS_USING_EXPERIMENTAL_VIEW ) */

/*--------------------------------------------------------------------------*/

namespace Kokkos {

/* Default allocation mechanism */
HostSpace::HostSpace()
  : m_alloc_mech(
#if defined( KOKKOS_INTEL_MM_ALLOC_AVAILABLE )
      HostSpace::INTEL_MM_ALLOC
#elif defined( KOKKOS_POSIX_MMAP_FLAGS )
      HostSpace::POSIX_MMAP
#elif defined( KOKKOS_POSIX_MEMALIGN_AVAILABLE )
      HostSpace::POSIX_MEMALIGN
#else
      HostSpace::STD_MALLOC
#endif
    )
{}

/* Default allocation mechanism */
HostSpace::HostSpace( const HostSpace::AllocationMechanism & arg_alloc_mech )
  : m_alloc_mech( HostSpace::STD_MALLOC )
{
  if ( arg_alloc_mech == STD_MALLOC ) {
    m_alloc_mech = HostSpace::STD_MALLOC ;
  }
#if defined( KOKKOS_INTEL_MM_ALLOC_AVAILABLE )
  else if ( arg_alloc_mech == HostSpace::INTEL_MM_ALLOC ) {
    m_alloc_mech = HostSpace::INTEL_MM_ALLOC ;
  }
#elif defined( KOKKOS_POSIX_MEMALIGN_AVAILABLE )
  else if ( arg_alloc_mech == HostSpace::POSIX_MEMALIGN ) {
    m_alloc_mech = HostSpace::POSIX_MEMALIGN ;
  }
#elif defined( KOKKOS_POSIX_MMAP_FLAGS )
  else if ( arg_alloc_mech == HostSpace::POSIX_MMAP ) {
    m_alloc_mech = HostSpace::POSIX_MMAP ;
  }
#endif
  else {
    const char * const mech =
      ( arg_alloc_mech == HostSpace::INTEL_MM_ALLOC ) ? "INTEL_MM_ALLOC" : (
      ( arg_alloc_mech == HostSpace::POSIX_MEMALIGN ) ? "POSIX_MEMALIGN" : (
      ( arg_alloc_mech == HostSpace::POSIX_MMAP     ) ? "POSIX_MMAP" : "" ));

    std::string msg ;
    msg.append("Kokkos::HostSpace ");
    msg.append(mech);
    msg.append(" is not available" );
    Kokkos::Impl::throw_runtime_exception( msg );
  }
}

void * HostSpace::allocate( const size_t arg_alloc_size ) const
{
  static_assert( sizeof(void*) == sizeof(uintptr_t)
               , "Error sizeof(void*) != sizeof(uintptr_t)" );

  static_assert( Kokkos::Impl::is_integral_power_of_two( Kokkos::Impl::MEMORY_ALIGNMENT )
               , "Memory alignment must be power of two" );

  constexpr uintptr_t alignment = Kokkos::Impl::MEMORY_ALIGNMENT ;
  constexpr uintptr_t alignment_mask = alignment - 1 ;

  void * ptr = 0 ;

  if ( arg_alloc_size ) {

    if ( m_alloc_mech == STD_MALLOC ) {
      // Over-allocate to and round up to guarantee proper alignment.
      size_t size_padded = arg_alloc_size + sizeof(void*) + alignment ;

      void * alloc_ptr = malloc( size_padded );

      if (alloc_ptr) {
        uintptr_t address = reinterpret_cast<uintptr_t>(alloc_ptr);

        // offset enough to record the alloc_ptr
        address += sizeof(void *);
        uintptr_t rem = address % alignment;
        uintptr_t offset = rem ? (alignment - rem) : 0u;
        address += offset;
        ptr = reinterpret_cast<void *>(address);
        // record the alloc'd pointer
        address -= sizeof(void *);
        *reinterpret_cast<void **>(address) = alloc_ptr;
      }
    }

#if defined( KOKKOS_INTEL_MM_ALLOC_AVAILABLE )
    else if ( m_alloc_mech == INTEL_MM_ALLOC ) {
      ptr = _mm_malloc( arg_alloc_size , alignment );
    }
#endif

#if defined( KOKKOS_POSIX_MEMALIGN_AVAILABLE )
    else if ( m_alloc_mech == POSIX_MEMALIGN ) {
      posix_memalign( & ptr, alignment , arg_alloc_size );
    }
#endif

#if defined( KOKKOS_POSIX_MMAP_FLAGS )
    else if ( m_alloc_mech == POSIX_MMAP ) {
      constexpr size_t use_huge_pages = (1u << 27);
      constexpr int    prot  = PROT_READ | PROT_WRITE ;
      const int flags = arg_alloc_size < use_huge_pages
                      ? KOKKOS_POSIX_MMAP_FLAGS
                      : KOKKOS_POSIX_MMAP_FLAGS_HUGE ;

      // read write access to private memory

      ptr = mmap( NULL /* address hint, if NULL OS kernel chooses address */
                , arg_alloc_size /* size in bytes */
                , prot           /* memory protection */
                , flags          /* visibility of updates */
                , -1             /* file descriptor */
                ,  0             /* offset */
                );

/* Associated reallocation:
       ptr = mremap( old_ptr , old_size , new_size , MREMAP_MAYMOVE );
*/
    }
#endif
  }

  if ( ( ptr == 0 ) || ( reinterpret_cast<uintptr_t>(ptr) == ~uintptr_t(0) )
       || ( reinterpret_cast<uintptr_t>(ptr) & alignment_mask ) ) {
    std::ostringstream msg ;
    msg << "Kokkos::HostSpace::allocate[ " ;
    switch( m_alloc_mech ) {
    case STD_MALLOC: msg << "STD_MALLOC" ; break ;
    case POSIX_MEMALIGN: msg << "POSIX_MEMALIGN" ; break ;
    case POSIX_MMAP: msg << "POSIX_MMAP" ; break ;
    case INTEL_MM_ALLOC: msg << "INTEL_MM_ALLOC" ; break ;
    }
    msg << " ]( " << arg_alloc_size << " ) FAILED" ;
    if ( ptr == NULL ) { msg << " NULL" ; } 
    else { msg << " NOT ALIGNED " << ptr ; }

    std::cerr << msg.str() << std::endl ;
    std::cerr.flush();

    Kokkos::Impl::throw_runtime_exception( msg.str() );
  }

  return ptr;
}


void HostSpace::deallocate( void * const arg_alloc_ptr , const size_t arg_alloc_size ) const
{
  if ( arg_alloc_ptr ) {

    if ( m_alloc_mech == STD_MALLOC ) {
      void * alloc_ptr = *(reinterpret_cast<void **>(arg_alloc_ptr) -1);
      free( alloc_ptr );
    }    

#if defined( KOKKOS_INTEL_MM_ALLOC_AVAILABLE )
    else if ( m_alloc_mech == INTEL_MM_ALLOC ) {
      _mm_free( arg_alloc_ptr );
    }
#endif

#if defined( KOKKOS_POSIX_MEMALIGN_AVAILABLE )
    else if ( m_alloc_mech == POSIX_MEMALIGN ) {
      free( arg_alloc_ptr );
    }
#endif

#if defined( KOKKOS_POSIX_MMAP_FLAGS )
    else if ( m_alloc_mech == POSIX_MMAP ) {
      munmap( arg_alloc_ptr , arg_alloc_size );
    }
#endif

  }
}

} // namespace Kokkos

//----------------------------------------------------------------------------
//----------------------------------------------------------------------------

namespace Kokkos {
namespace Experimental {
namespace Impl {

SharedAllocationRecord< void , void >
SharedAllocationRecord< Kokkos::HostSpace , void >::s_root_record ;

void
SharedAllocationRecord< Kokkos::HostSpace , void >::
deallocate( SharedAllocationRecord< void , void > * arg_rec )
{
  delete static_cast<SharedAllocationRecord*>(arg_rec);
}

SharedAllocationRecord< Kokkos::HostSpace , void >::
~SharedAllocationRecord()
{
  m_space.deallocate( SharedAllocationRecord< void , void >::m_alloc_ptr
                    , SharedAllocationRecord< void , void >::m_alloc_size
                    );
}

SharedAllocationRecord< Kokkos::HostSpace , void >::
SharedAllocationRecord( const Kokkos::HostSpace & arg_space
                      , const std::string       & arg_label
                      , const size_t              arg_alloc_size
                      , const SharedAllocationRecord< void , void >::function_type arg_dealloc
                      )
  // Pass through allocated [ SharedAllocationHeader , user_memory ]
  // Pass through deallocation function
  : SharedAllocationRecord< void , void >
      ( & SharedAllocationRecord< Kokkos::HostSpace , void >::s_root_record
      , reinterpret_cast<SharedAllocationHeader*>( arg_space.allocate( sizeof(SharedAllocationHeader) + arg_alloc_size ) )
      , sizeof(SharedAllocationHeader) + arg_alloc_size
      , arg_dealloc
      )
  , m_space( arg_space )
{
  // Fill in the Header information
  RecordBase::m_alloc_ptr->m_record = static_cast< SharedAllocationRecord< void , void > * >( this );

  strncpy( RecordBase::m_alloc_ptr->m_label
          , arg_label.c_str()
          , SharedAllocationHeader::maximum_label_length
          );
}

//----------------------------------------------------------------------------

void * SharedAllocationRecord< Kokkos::HostSpace , void >::
allocate_tracked( const Kokkos::HostSpace & arg_space
                , const std::string & arg_alloc_label 
                , const size_t arg_alloc_size )
{
  if ( ! arg_alloc_size ) return (void *) 0 ;

  SharedAllocationRecord * const r =
    allocate( arg_space , arg_alloc_label , arg_alloc_size );

  RecordBase::increment( r );

  return r->data();
}

void SharedAllocationRecord< Kokkos::HostSpace , void >::
deallocate_tracked( void * const arg_alloc_ptr )
{
  if ( arg_alloc_ptr != 0 ) {
    SharedAllocationRecord * const r = get_record( arg_alloc_ptr );

    RecordBase::decrement( r );
  }
}

void * SharedAllocationRecord< Kokkos::HostSpace , void >::
reallocate_tracked( void * const arg_alloc_ptr
                  , const size_t arg_alloc_size )
{
  SharedAllocationRecord * const r_old = get_record( arg_alloc_ptr );
  SharedAllocationRecord * const r_new = allocate( r_old->m_space , r_old->get_label() , arg_alloc_size );

  Kokkos::Impl::DeepCopy<HostSpace,HostSpace>( r_new->data() , r_old->data()
                                             , std::min( r_old->size() , r_new->size() ) );

  RecordBase::increment( r_new );
  RecordBase::decrement( r_old );

  return r_new->data();
}

SharedAllocationRecord< Kokkos::HostSpace , void > *
SharedAllocationRecord< Kokkos::HostSpace , void >::get_record( void * alloc_ptr )
{
  typedef SharedAllocationHeader  Header ;
  typedef SharedAllocationRecord< Kokkos::HostSpace , void >  RecordHost ;

  SharedAllocationHeader const * const head   = alloc_ptr ? Header::get_header( alloc_ptr ) : (SharedAllocationHeader *)0 ;
  RecordHost                   * const record = head ? static_cast< RecordHost * >( head->m_record ) : (RecordHost *) 0 ;

  if ( ! alloc_ptr || record->m_alloc_ptr != head ) {
    Kokkos::Impl::throw_runtime_exception( std::string("Kokkos::Experimental::Impl::SharedAllocationRecord< Kokkos::HostSpace , void >::get_record ERROR" ) );
  }

  return record ;
}

// Iterate records to print orphaned memory ...
void SharedAllocationRecord< Kokkos::HostSpace , void >::
print_records( std::ostream & s , const Kokkos::HostSpace & space , bool detail )
{
  SharedAllocationRecord< void , void >::print_host_accessible_records( s , "HostSpace" , & s_root_record , detail );
}

} // namespace Impl
} // namespace Experimental
} // namespace Kokkos

/*--------------------------------------------------------------------------*/
/*--------------------------------------------------------------------------*/

namespace Kokkos {
namespace Experimental {
namespace Impl {

template< class >
struct ViewOperatorBoundsErrorAbort ;

template<>
struct ViewOperatorBoundsErrorAbort< Kokkos::HostSpace > {
 static void apply( const size_t rank
                  , const size_t n0 , const size_t n1
                  , const size_t n2 , const size_t n3
                  , const size_t n4 , const size_t n5
                  , const size_t n6 , const size_t n7
                  , const size_t i0 , const size_t i1
                  , const size_t i2 , const size_t i3
                  , const size_t i4 , const size_t i5
                  , const size_t i6 , const size_t i7 );
};

void ViewOperatorBoundsErrorAbort< Kokkos::HostSpace >::
apply( const size_t rank
     , const size_t n0 , const size_t n1
     , const size_t n2 , const size_t n3
     , const size_t n4 , const size_t n5
     , const size_t n6 , const size_t n7
     , const size_t i0 , const size_t i1
     , const size_t i2 , const size_t i3
     , const size_t i4 , const size_t i5
     , const size_t i6 , const size_t i7 )
{
  char buffer[512];

  snprintf( buffer , sizeof(buffer)
          , "View operator bounds error : rank(%lu) dim(%lu,%lu,%lu,%lu,%lu,%lu,%lu,%lu) index(%lu,%lu,%lu,%lu,%lu,%lu,%lu,%lu)"
          , rank , n0 , n1 , n2 , n3 , n4 , n5 , n6 , n7
                 , i0 , i1 , i2 , i3 , i4 , i5 , i6 , i7 );

  Kokkos::Impl::throw_runtime_exception( buffer );
}

} // namespace Impl
} // namespace Experimental
} // namespace Kokkos

/*--------------------------------------------------------------------------*/
/*--------------------------------------------------------------------------*/

namespace Kokkos {
namespace {
  const unsigned HOST_SPACE_ATOMIC_MASK = 0xFFFF;
  const unsigned HOST_SPACE_ATOMIC_XOR_MASK = 0x5A39;
  static int HOST_SPACE_ATOMIC_LOCKS[HOST_SPACE_ATOMIC_MASK+1];
}

namespace Impl {
void init_lock_array_host_space() {
  static int is_initialized = 0;
  if(! is_initialized)
    for(int i = 0; i < static_cast<int> (HOST_SPACE_ATOMIC_MASK+1); i++)
      HOST_SPACE_ATOMIC_LOCKS[i] = 0;
}

bool lock_address_host_space(void* ptr) {
  return 0 == atomic_compare_exchange( &HOST_SPACE_ATOMIC_LOCKS[
      (( size_t(ptr) >> 2 ) & HOST_SPACE_ATOMIC_MASK) ^ HOST_SPACE_ATOMIC_XOR_MASK] ,
                                  0 , 1);
}

void unlock_address_host_space(void* ptr) {
   atomic_exchange( &HOST_SPACE_ATOMIC_LOCKS[
      (( size_t(ptr) >> 2 ) & HOST_SPACE_ATOMIC_MASK) ^ HOST_SPACE_ATOMIC_XOR_MASK] ,
                    0);
}

}
}
