/*
   Copyright (c) 2006, 2014, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License, version 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
*/

#include "RWPool.hpp"
#include <ndbd_exit_codes.h>
#include <NdbOut.hpp>

#define JAM_FILE_ID 278


#define REC_NIL GLOBAL_PAGE_SIZE_WORDS

RWPool::RWPool() 
{
  memset(this, 0, sizeof(* this));
  m_current_pos = RWPage::RWPAGE_WORDS;
  m_current_first_free = REC_NIL;
  m_first_free_page = RNIL;
}

void
RWPool::init(const Record_info& ri, const Pool_context& pc)
{
  m_ctx = pc;
  m_record_info = ri;
  m_record_info.m_size = ((ri.m_size + 3) >> 2); // Align to word boundary
  m_record_info.m_offset_magic = ((ri.m_offset_magic + 3) >> 2);
  m_record_info.m_offset_next_pool = ((ri.m_offset_next_pool + 3) >> 2);
  m_memroot = (RWPage*)m_ctx.get_memroot();
#ifdef VM_TRACE
  ndbout_c("RWPool::init(%x, %d)",ri.m_type_id, m_record_info.m_size);
#endif
}

bool
RWPool::seize(Ptr<void>& ptr)
{
  Uint32 pos = m_current_pos;
  Uint32 size = m_record_info.m_size;
  Uint32 off = m_record_info.m_offset_magic;
  RWPage *pageP = m_current_page;
  if (likely(m_current_first_free != REC_NIL))
  {
seize_free:
    pos = m_current_first_free;
    ptr.i = (m_current_page_no << POOL_RECORD_BITS) + pos;
    ptr.p = pageP->m_data + pos;
    pageP->m_data[pos+off] = ~(Uint32)m_record_info.m_type_id;
    m_current_ref_count++;
    m_current_first_free = pageP->m_data[pos+m_record_info.m_offset_next_pool];
    return true;
  }
  else if (pos + size < RWPage::RWPAGE_WORDS)
  {
seize_first:
    ptr.i = (m_current_page_no << POOL_RECORD_BITS) + pos;
    ptr.p = (pageP->m_data + pos);
    pageP->m_data[pos+off] = ~(Uint32)m_record_info.m_type_id;
    m_current_ref_count++;
    m_current_pos = pos + size;
    return true;
  }

  if (m_current_page)
  {
    m_current_page->m_first_free = REC_NIL;
    m_current_page->m_next_page = RNIL;
    m_current_page->m_prev_page = RNIL;
    m_current_page->m_type_id = m_record_info.m_type_id;
    m_current_page->m_ref_count = m_current_ref_count;
  }

  if (m_first_free_page != RNIL)
  {
    pageP = m_current_page = m_memroot + m_first_free_page;
    m_current_page_no = m_first_free_page;
    m_current_pos = RWPage::RWPAGE_WORDS;
    m_current_first_free = m_current_page->m_first_free;
    m_first_free_page = m_current_page->m_next_page;
    m_current_ref_count = m_current_page->m_ref_count;
    if (m_first_free_page != RNIL)
    {
      (m_memroot + m_first_free_page)->m_prev_page = RNIL;
    }
    goto seize_free;
  }

  m_current_ref_count = 0;
  
  RWPage* page;
  Uint32 page_no = RNIL;
  if ((page = (RWPage*)m_ctx.alloc_page(m_record_info.m_type_id, &page_no)))
  {
    pos = 0;
    m_current_page_no = page_no;
    pageP = m_current_page = page;
    m_current_first_free = REC_NIL;
    page->m_type_id = m_record_info.m_type_id;
    goto seize_first;
  }

  m_current_page = 0;
  m_current_page_no = RNIL;
  m_current_pos = RWPage::RWPAGE_WORDS;
  m_current_first_free = REC_NIL;
  
  return false;
}

void
RWPool::release(Ptr<void> ptr)
{
  Uint32 cur_page = m_current_page_no;
  Uint32 ptr_page = ptr.i >> POOL_RECORD_BITS;
  Uint32 *record_ptr = (Uint32*)ptr.p;
  Uint32 magic_val = * (record_ptr + m_record_info.m_offset_magic);
  
  if (likely(magic_val == ~(Uint32)m_record_info.m_type_id))
  {
    * (record_ptr + m_record_info.m_offset_magic) = 0;
    if (cur_page == ptr_page)
    {
      * (record_ptr + m_record_info.m_offset_next_pool) = m_current_first_free;
      assert(m_current_ref_count);
      m_current_ref_count--;
      m_current_first_free = ptr.i & POOL_RECORD_MASK;
      return;
    }

    // Cache miss on page...
    RWPage* page = m_memroot + ptr_page;
    Uint32 ref_cnt = page->m_ref_count;
    Uint32 ff = page->m_first_free;

    * (record_ptr + m_record_info.m_offset_next_pool) = ff;
    page->m_first_free = ptr.i & POOL_RECORD_MASK;
    page->m_ref_count = ref_cnt - 1;
    
    if (ff == REC_NIL)
    {
      /**
       * It was full...add to free page list
       */
      Uint32 ffp = m_first_free_page;
      if (ffp != RNIL)
      {
	RWPage* next = (m_memroot + ffp);
	assert(next->m_prev_page == RNIL);
	next->m_prev_page = ptr_page;
      }
      page->m_next_page = ffp;
      page->m_prev_page = RNIL;
      m_first_free_page = ptr_page;
      return;
    }
    else if(ref_cnt == 1)
    {
      /**
       * It's now empty...release it
       */
      Uint32 prev = page->m_prev_page;
      Uint32 next = page->m_next_page;
      if (prev != RNIL)
      {
	(m_memroot + prev)->m_next_page = next;
      }
      else
      {
	assert(m_first_free_page == ptr_page);
	m_first_free_page = next;
      }
      
      if (next != RNIL)
      {
	(m_memroot + next)->m_prev_page = prev;
      }
      m_ctx.release_page(m_record_info.m_type_id, ptr_page);
      return;
    }
    return;
  }
  handle_invalid_release(ptr);
}

void
RWPool::handle_invalid_release(Ptr<void> ptr)
{
  char buf[255];

  Uint32 pos = ptr.i & POOL_RECORD_MASK;
  Uint32 pageI = ptr.i >> POOL_RECORD_BITS;
  Uint32 * record_ptr_p = (Uint32*)ptr.p;
  Uint32 * record_ptr_i = (m_memroot+pageI)->m_data + pos;
  
  Uint32 magic = * (record_ptr_p + m_record_info.m_offset_magic);
  BaseString::snprintf(buf, sizeof(buf),
	   "Invalid memory release: ptr (%x %p %p) magic: (%.8x %.8x) memroot: %p page: %x",
	   ptr.i, ptr.p, record_ptr_i, magic, m_record_info.m_type_id,
	   m_memroot,
	   (m_memroot+pageI)->m_type_id);
  
  m_ctx.handleAbort(NDBD_EXIT_PRGERR, buf);
}

void
RWPool::handle_invalid_get_ptr(Uint32 ptrI)
{
  char buf[255];

  Uint32 pos = ptrI & POOL_RECORD_MASK;
  Uint32 pageI = ptrI >> POOL_RECORD_BITS;
  Uint32 * record_ptr_i = (m_memroot+pageI)->m_data + pos;
  
  Uint32 magic = * (record_ptr_i + m_record_info.m_offset_magic);
  BaseString::snprintf(buf, sizeof(buf),
	   "Invalid memory access: ptr (%x %p) magic: (%.8x %.8x) memroot: %p page: %x",
	   ptrI, record_ptr_i, magic, m_record_info.m_type_id,
	   m_memroot,
	   (m_memroot+pageI)->m_type_id);
  
  m_ctx.handleAbort(NDBD_EXIT_PRGERR, buf);
}
