drd/drd_malloc_wrappers.c

/*
  This file is part of drd, a data race detector.

  Copyright (C) 2006-2008 Bart Van Assche
  bart.vanassche@gmail.com

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License as
  published by the Free Software Foundation; either version 2 of the
  License, or (at your option) any later version.

  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 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., 59 Temple Place, Suite 330, Boston, MA
  02111-1307, USA.

  The GNU General Public License is contained in the file COPYING.
*/


#include "drd_malloc_wrappers.h"
#include "drd_thread.h"
#include "pub_tool_basics.h"
#include "pub_tool_execontext.h"
#include "pub_tool_hashtable.h"
#include "pub_tool_libcassert.h"
#include "pub_tool_libcbase.h"
#include "pub_tool_libcprint.h"
#include "pub_tool_mallocfree.h"
#include "pub_tool_options.h"
#include "pub_tool_replacemalloc.h"
#include "pub_tool_threadstate.h"
#include "pub_tool_tooliface.h"


/*------------------------------------------------------------*/
/*--- Definitions                                          ---*/
/*------------------------------------------------------------*/


typedef struct _DRD_Chunk {
  struct _DRD_Chunk* next;
  Addr          data;            // ptr to actual block
  SizeT         size : (sizeof(UWord)*8)-2; //size requested; 30 or 62 bits
  ExeContext*   where;           // where it was allocated
} DRD_Chunk;

static StartUsingMem s_start_using_mem_callback;
static StopUsingMem  s_stop_using_mem_callback;
/* Stats ... */
static SizeT cmalloc_n_mallocs  = 0;
static SizeT cmalloc_n_frees    = 0;
static SizeT cmalloc_bs_mallocd = 0;


/*------------------------------------------------------------*/
/*--- Tracking malloc'd and free'd blocks                  ---*/
/*------------------------------------------------------------*/

/* Record malloc'd blocks. */
static VgHashTable drd_malloc_list = NULL;


/* Allocate its shadow chunk, put it on the appropriate list. */
static
DRD_Chunk* create_DRD_Chunk(ThreadId tid, Addr p, SizeT size)
{
  DRD_Chunk* mc = VG_(malloc)(sizeof(DRD_Chunk));
  mc->data      = p;
  mc->size      = size;
  mc->where     = VG_(record_ExeContext)(tid, 0);

  return mc;
}

/*------------------------------------------------------------*/
/*--- client_malloc(), etc                                 ---*/
/*------------------------------------------------------------*/

/* Allocate memory and note change in memory available */
static
__inline__
void* drd_new_block(ThreadId tid,
                    SizeT size, SizeT align,
                    Bool is_zeroed)
{
  Addr p;

  cmalloc_n_mallocs ++;

  // Allocate and zero
  p = (Addr)VG_(cli_malloc)(align, size);
  if (!p) {
    return NULL;
  }
  if (is_zeroed) VG_(memset)((void*)p, 0, size);
  s_start_using_mem_callback(p, p + size, 0/*ec_uniq*/);

  // Only update this stat if allocation succeeded.
  cmalloc_bs_mallocd += size;

  VG_(HT_add_node)(drd_malloc_list, create_DRD_Chunk(tid, p, size));

  return (void*)p;
}

static
void* drd_malloc(ThreadId tid, SizeT n)
{
  return drd_new_block(tid, n, VG_(clo_alignment), /*is_zeroed*/False);
}

static
void* drd_memalign(ThreadId tid, SizeT align, SizeT n)
{
  return drd_new_block(tid, n, align, /*is_zeroed*/False);
}

static
void* drd_calloc(ThreadId tid, SizeT nmemb, SizeT size1)
{
  return drd_new_block(tid, nmemb*size1, VG_(clo_alignment),
                       /*is_zeroed*/True);
}

static
__inline__
void drd_handle_free(ThreadId tid, Addr p)
{
  DRD_Chunk* mc;

  cmalloc_n_frees++;

  mc = VG_(HT_remove)(drd_malloc_list, (UWord)p);
  if (mc == NULL)
  {
    tl_assert(0);
  }
  else
  {
    tl_assert(p == mc->data);
    if (mc->size > 0)
      s_stop_using_mem_callback(mc->data, mc->size);
    VG_(cli_free)((void*)p);
    VG_(free)(mc);
  }
}

static
void drd_free(ThreadId tid, void* p)
{
  drd_handle_free(tid, (Addr)p);
}

static
void* drd_realloc(ThreadId tid, void* p_old, SizeT new_size)
{
  DRD_Chunk* mc;
  void*     p_new;
  SizeT     old_size;

  cmalloc_n_frees ++;
  cmalloc_n_mallocs ++;
  cmalloc_bs_mallocd += new_size;

  /* Remove the old block */
  mc = VG_(HT_remove)(drd_malloc_list, (UWord)p_old);
  if (mc == NULL) {
    tl_assert(0);
    return NULL;
  }

  old_size = mc->size;

  if (old_size == new_size)
  {
    /* size unchanged */
    mc->where = VG_(record_ExeContext)(tid, 0);
    p_new = p_old;
      
  }
  else if (old_size > new_size)
  {
    /* new size is smaller */
    s_stop_using_mem_callback(mc->data + new_size, old_size);
    mc->size = new_size;
    mc->where = VG_(record_ExeContext)(tid, 0);
    p_new = p_old;

  }
  else
  {
    /* new size is bigger */
    /* Get new memory */
    const Addr a_new = (Addr)VG_(cli_malloc)(VG_(clo_alignment), new_size);

    if (a_new)
    {
      /* Copy from old to new */
      VG_(memcpy)((void*)a_new, p_old, mc->size);

      /* Free old memory */
      s_stop_using_mem_callback(mc->data, mc->size);
      VG_(free)(mc);

      // Allocate a new chunk.
      mc = create_DRD_Chunk(tid, a_new, new_size);
      s_start_using_mem_callback(a_new, a_new + new_size, 0/*ec_uniq*/);
    }
    else
    {
      /* Allocation failed -- leave original block untouched. */
    }

    p_new = (void*)a_new;
  }  

  // Now insert the new mc (with a possibly new 'data' field) into
  // malloc_list.  If this realloc() did not increase the memory size, we
  // will have removed and then re-added mc unnecessarily.  But that's ok
  // because shrinking a block with realloc() is (presumably) much rarer
  // than growing it, and this way simplifies the growing case.
  VG_(HT_add_node)(drd_malloc_list, mc);

  return p_new;
}

static
void* drd___builtin_new(ThreadId tid, SizeT n)
{
  void* const result = drd_new_block(tid, n, VG_(clo_alignment), /*is_zeroed*/False);
  //VG_(message)(Vg_DebugMsg, "__builtin_new(%d, %d) = %p", tid, n, result);
  return result;
}

static
void drd___builtin_delete(ThreadId tid, void* p)
{
  //VG_(message)(Vg_DebugMsg, "__builtin_delete(%d, %p)", tid, p);
  drd_handle_free(tid, (Addr)p);
}

static
void* drd___builtin_vec_new(ThreadId tid, SizeT n)
{
  return drd_new_block(tid, n, VG_(clo_alignment), /*is_zeroed*/False);
}

static
void drd___builtin_vec_delete(ThreadId tid, void* p)
{
  drd_handle_free(tid, (Addr)p);
}

void drd_register_malloc_wrappers(const StartUsingMem start_using_mem_callback,
                                  const StopUsingMem stop_using_mem_callback)
{
  tl_assert(drd_malloc_list == 0);
  drd_malloc_list = VG_(HT_construct)("drd_malloc_list");   // a big prime
  tl_assert(drd_malloc_list != 0);
  tl_assert(stop_using_mem_callback);

  s_start_using_mem_callback = start_using_mem_callback;
  s_stop_using_mem_callback  = stop_using_mem_callback;

  VG_(needs_malloc_replacement)(drd_malloc,
                                drd___builtin_new,
                                drd___builtin_vec_new,
                                drd_memalign,
                                drd_calloc,
                                drd_free,
                                drd___builtin_delete,
                                drd___builtin_vec_delete,
                                drd_realloc,
                                0);
}

Bool drd_heap_addrinfo(Addr const a,
                       Addr* const data,
                       SizeT* const size,
                       ExeContext** const where)
{
  DRD_Chunk* mc;

  tl_assert(data);
  tl_assert(size);
  tl_assert(where);

  VG_(HT_ResetIter)(drd_malloc_list);
  while ((mc = VG_(HT_Next)(drd_malloc_list)))
  {
    if (mc->data <= a && a < mc->data + mc->size)
    {
      *data  = mc->data;
      *size  = mc->size;
      *where = mc->where;
      return True;
    }
  }
  return False;
}

/*------------------------------------------------------------*/
/*--- Statistics printing                                  ---*/
/*------------------------------------------------------------*/

void drd_print_malloc_stats(void)
{
  DRD_Chunk* mc;
  SizeT     nblocks = 0;
  SizeT     nbytes  = 0;
   
  if (VG_(clo_verbosity) == 0)
    return;
  if (VG_(clo_xml))
    return;

  /* Count memory still in use. */
  VG_(HT_ResetIter)(drd_malloc_list);
  while ((mc = VG_(HT_Next)(drd_malloc_list)))
  {
    nblocks++;
    nbytes += mc->size;
  }

  VG_(message)(Vg_DebugMsg, 
               "malloc/free: in use at exit: %lu bytes in %lu blocks.",
               nbytes, nblocks);
  VG_(message)(Vg_DebugMsg, 
               "malloc/free: %lu allocs, %lu frees, %lu bytes allocated.",
               cmalloc_n_mallocs,
               cmalloc_n_frees, cmalloc_bs_mallocd);
  if (VG_(clo_verbosity) > 1)
    VG_(message)(Vg_DebugMsg, " ");
}

/*--------------------------------------------------------------------*/
/*--- end                                                          ---*/
/*--------------------------------------------------------------------*/