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glib/glib/gmem.c
Behdad Esfahbod 8f80ff02af Bug 624968 - div by zero in g_malloc_n family
2010-07-21 16:11:35 -04:00

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/* GLIB - Library of useful routines for C programming
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/*
* Modified by the GLib Team and others 1997-2000. See the AUTHORS
* file for a list of people on the GLib Team. See the ChangeLog
* files for a list of changes. These files are distributed with
* GLib at ftp://ftp.gtk.org/pub/gtk/.
*/
/*
* MT safe
*/
#include "config.h"
#include "gmem.h"
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include "gbacktrace.h"
#include "gtestutils.h"
#include "gthread.h"
#include "glib_trace.h"
#define MEM_PROFILE_TABLE_SIZE 4096
/* notes on macros:
* having G_DISABLE_CHECKS defined disables use of glib_mem_profiler_table and
* g_mem_profile().
* REALLOC_0_WORKS is defined if g_realloc (NULL, x) works.
* SANE_MALLOC_PROTOS is defined if the systems malloc() and friends functions
* match the corresponding GLib prototypes, keep configure.ac and gmem.h in sync here.
* g_mem_gc_friendly is TRUE, freed memory should be 0-wiped.
*/
/* --- prototypes --- */
static gboolean g_mem_initialized = FALSE;
static void g_mem_init_nomessage (void);
/* --- malloc wrappers --- */
#ifndef REALLOC_0_WORKS
static gpointer
standard_realloc (gpointer mem,
gsize n_bytes)
{
if (!mem)
return malloc (n_bytes);
else
return realloc (mem, n_bytes);
}
#endif /* !REALLOC_0_WORKS */
#ifdef SANE_MALLOC_PROTOS
# define standard_malloc malloc
# ifdef REALLOC_0_WORKS
# define standard_realloc realloc
# endif /* REALLOC_0_WORKS */
# define standard_free free
# define standard_calloc calloc
# define standard_try_malloc malloc
# define standard_try_realloc realloc
#else /* !SANE_MALLOC_PROTOS */
static gpointer
standard_malloc (gsize n_bytes)
{
return malloc (n_bytes);
}
# ifdef REALLOC_0_WORKS
static gpointer
standard_realloc (gpointer mem,
gsize n_bytes)
{
return realloc (mem, n_bytes);
}
# endif /* REALLOC_0_WORKS */
static void
standard_free (gpointer mem)
{
free (mem);
}
static gpointer
standard_calloc (gsize n_blocks,
gsize n_bytes)
{
return calloc (n_blocks, n_bytes);
}
#define standard_try_malloc standard_malloc
#define standard_try_realloc standard_realloc
#endif /* !SANE_MALLOC_PROTOS */
/* --- variables --- */
static GMemVTable glib_mem_vtable = {
standard_malloc,
standard_realloc,
standard_free,
standard_calloc,
standard_try_malloc,
standard_try_realloc,
};
/* --- functions --- */
gpointer
g_malloc (gsize n_bytes)
{
if (G_UNLIKELY (!g_mem_initialized))
g_mem_init_nomessage();
if (G_LIKELY (n_bytes))
{
gpointer mem;
mem = glib_mem_vtable.malloc (n_bytes);
TRACE (GLIB_MEM_ALLOC((void*) mem, (unsigned int) n_bytes, 0, 0));
if (mem)
return mem;
g_error ("%s: failed to allocate %"G_GSIZE_FORMAT" bytes",
G_STRLOC, n_bytes);
}
TRACE(GLIB_MEM_ALLOC((void*) NULL, (int) n_bytes, 0, 0));
return NULL;
}
gpointer
g_malloc0 (gsize n_bytes)
{
if (G_UNLIKELY (!g_mem_initialized))
g_mem_init_nomessage();
if (G_LIKELY (n_bytes))
{
gpointer mem;
mem = glib_mem_vtable.calloc (1, n_bytes);
TRACE (GLIB_MEM_ALLOC((void*) mem, (unsigned int) n_bytes, 1, 0));
if (mem)
return mem;
g_error ("%s: failed to allocate %"G_GSIZE_FORMAT" bytes",
G_STRLOC, n_bytes);
}
TRACE(GLIB_MEM_ALLOC((void*) NULL, (int) n_bytes, 1, 0));
return NULL;
}
gpointer
g_realloc (gpointer mem,
gsize n_bytes)
{
gpointer newmem;
if (G_UNLIKELY (!g_mem_initialized))
g_mem_init_nomessage();
if (G_LIKELY (n_bytes))
{
newmem = glib_mem_vtable.realloc (mem, n_bytes);
TRACE (GLIB_MEM_REALLOC((void*) newmem, (void*)mem, (unsigned int) n_bytes, 0));
if (newmem)
return newmem;
g_error ("%s: failed to allocate %"G_GSIZE_FORMAT" bytes",
G_STRLOC, n_bytes);
}
if (mem)
glib_mem_vtable.free (mem);
TRACE (GLIB_MEM_REALLOC((void*) NULL, (void*)mem, 0, 0));
return NULL;
}
void
g_free (gpointer mem)
{
if (G_UNLIKELY (!g_mem_initialized))
g_mem_init_nomessage();
if (G_LIKELY (mem))
glib_mem_vtable.free (mem);
TRACE(GLIB_MEM_FREE((void*) mem));
}
gpointer
g_try_malloc (gsize n_bytes)
{
gpointer mem;
if (G_UNLIKELY (!g_mem_initialized))
g_mem_init_nomessage();
if (G_LIKELY (n_bytes))
mem = glib_mem_vtable.try_malloc (n_bytes);
else
mem = NULL;
TRACE (GLIB_MEM_ALLOC((void*) mem, (unsigned int) n_bytes, 0, 1));
return mem;
}
gpointer
g_try_malloc0 (gsize n_bytes)
{
gpointer mem;
if (G_UNLIKELY (!g_mem_initialized))
g_mem_init_nomessage();
if (G_LIKELY (n_bytes))
mem = glib_mem_vtable.try_malloc (n_bytes);
else
mem = NULL;
if (mem)
memset (mem, 0, n_bytes);
return mem;
}
gpointer
g_try_realloc (gpointer mem,
gsize n_bytes)
{
gpointer newmem;
if (G_UNLIKELY (!g_mem_initialized))
g_mem_init_nomessage();
if (G_LIKELY (n_bytes))
newmem = glib_mem_vtable.try_realloc (mem, n_bytes);
else
{
newmem = NULL;
if (mem)
glib_mem_vtable.free (mem);
}
TRACE (GLIB_MEM_REALLOC((void*) newmem, (void*)mem, (unsigned int) n_bytes, 1));
return newmem;
}
#define SIZE_OVERFLOWS(a,b) (G_UNLIKELY ((b) > 0 && (a) > G_MAXSIZE / (b)))
gpointer
g_malloc_n (gsize n_blocks,
gsize n_block_bytes)
{
if (SIZE_OVERFLOWS (n_blocks, n_block_bytes))
{
if (G_UNLIKELY (!g_mem_initialized))
g_mem_init_nomessage();
g_error ("%s: overflow allocating %"G_GSIZE_FORMAT"*%"G_GSIZE_FORMAT" bytes",
G_STRLOC, n_blocks, n_block_bytes);
}
return g_malloc (n_blocks * n_block_bytes);
}
gpointer
g_malloc0_n (gsize n_blocks,
gsize n_block_bytes)
{
if (SIZE_OVERFLOWS (n_blocks, n_block_bytes))
{
if (G_UNLIKELY (!g_mem_initialized))
g_mem_init_nomessage();
g_error ("%s: overflow allocating %"G_GSIZE_FORMAT"*%"G_GSIZE_FORMAT" bytes",
G_STRLOC, n_blocks, n_block_bytes);
}
return g_malloc0 (n_blocks * n_block_bytes);
}
gpointer
g_realloc_n (gpointer mem,
gsize n_blocks,
gsize n_block_bytes)
{
if (SIZE_OVERFLOWS (n_blocks, n_block_bytes))
{
if (G_UNLIKELY (!g_mem_initialized))
g_mem_init_nomessage();
g_error ("%s: overflow allocating %"G_GSIZE_FORMAT"*%"G_GSIZE_FORMAT" bytes",
G_STRLOC, n_blocks, n_block_bytes);
}
return g_realloc (mem, n_blocks * n_block_bytes);
}
gpointer
g_try_malloc_n (gsize n_blocks,
gsize n_block_bytes)
{
if (SIZE_OVERFLOWS (n_blocks, n_block_bytes))
return NULL;
return g_try_malloc (n_blocks * n_block_bytes);
}
gpointer
g_try_malloc0_n (gsize n_blocks,
gsize n_block_bytes)
{
if (SIZE_OVERFLOWS (n_blocks, n_block_bytes))
return NULL;
return g_try_malloc0 (n_blocks * n_block_bytes);
}
gpointer
g_try_realloc_n (gpointer mem,
gsize n_blocks,
gsize n_block_bytes)
{
if (SIZE_OVERFLOWS (n_blocks, n_block_bytes))
return NULL;
return g_try_realloc (mem, n_blocks * n_block_bytes);
}
static gpointer
fallback_calloc (gsize n_blocks,
gsize n_block_bytes)
{
gsize l = n_blocks * n_block_bytes;
gpointer mem = glib_mem_vtable.malloc (l);
if (mem)
memset (mem, 0, l);
return mem;
}
static gboolean vtable_set = FALSE;
/**
* g_mem_is_system_malloc
*
* Checks whether the allocator used by g_malloc() is the system's
* malloc implementation. If it returns %TRUE memory allocated with
* malloc() can be used interchangeable with memory allocated using g_malloc().
* This function is useful for avoiding an extra copy of allocated memory returned
* by a non-GLib-based API.
*
* A different allocator can be set using g_mem_set_vtable().
*
* Return value: if %TRUE, malloc() and g_malloc() can be mixed.
**/
gboolean
g_mem_is_system_malloc (void)
{
return !vtable_set;
}
void
g_mem_set_vtable (GMemVTable *vtable)
{
if (!vtable_set)
{
if (vtable->malloc && vtable->realloc && vtable->free)
{
glib_mem_vtable.malloc = vtable->malloc;
glib_mem_vtable.realloc = vtable->realloc;
glib_mem_vtable.free = vtable->free;
glib_mem_vtable.calloc = vtable->calloc ? vtable->calloc : fallback_calloc;
glib_mem_vtable.try_malloc = vtable->try_malloc ? vtable->try_malloc : glib_mem_vtable.malloc;
glib_mem_vtable.try_realloc = vtable->try_realloc ? vtable->try_realloc : glib_mem_vtable.realloc;
vtable_set = TRUE;
}
else
g_warning (G_STRLOC ": memory allocation vtable lacks one of malloc(), realloc() or free()");
}
else
g_warning (G_STRLOC ": memory allocation vtable can only be set once at startup");
}
/* --- memory profiling and checking --- */
#ifdef G_DISABLE_CHECKS
GMemVTable *glib_mem_profiler_table = &glib_mem_vtable;
void
g_mem_profile (void)
{
}
#else /* !G_DISABLE_CHECKS */
typedef enum {
PROFILER_FREE = 0,
PROFILER_ALLOC = 1,
PROFILER_RELOC = 2,
PROFILER_ZINIT = 4
} ProfilerJob;
static guint *profile_data = NULL;
static gsize profile_allocs = 0;
static gsize profile_zinit = 0;
static gsize profile_frees = 0;
static GMutex *gmem_profile_mutex = NULL;
#ifdef G_ENABLE_DEBUG
static volatile gsize g_trap_free_size = 0;
static volatile gsize g_trap_realloc_size = 0;
static volatile gsize g_trap_malloc_size = 0;
#endif /* G_ENABLE_DEBUG */
#define PROFILE_TABLE(f1,f2,f3) ( ( ((f3) << 2) | ((f2) << 1) | (f1) ) * (MEM_PROFILE_TABLE_SIZE + 1))
static void
profiler_log (ProfilerJob job,
gsize n_bytes,
gboolean success)
{
g_mutex_lock (gmem_profile_mutex);
if (!profile_data)
{
profile_data = standard_calloc ((MEM_PROFILE_TABLE_SIZE + 1) * 8,
sizeof (profile_data[0]));
if (!profile_data) /* memory system kiddin' me, eh? */
{
g_mutex_unlock (gmem_profile_mutex);
return;
}
}
if (n_bytes < MEM_PROFILE_TABLE_SIZE)
profile_data[n_bytes + PROFILE_TABLE ((job & PROFILER_ALLOC) != 0,
(job & PROFILER_RELOC) != 0,
success != 0)] += 1;
else
profile_data[MEM_PROFILE_TABLE_SIZE + PROFILE_TABLE ((job & PROFILER_ALLOC) != 0,
(job & PROFILER_RELOC) != 0,
success != 0)] += 1;
if (success)
{
if (job & PROFILER_ALLOC)
{
profile_allocs += n_bytes;
if (job & PROFILER_ZINIT)
profile_zinit += n_bytes;
}
else
profile_frees += n_bytes;
}
g_mutex_unlock (gmem_profile_mutex);
}
static void
profile_print_locked (guint *local_data,
gboolean success)
{
gboolean need_header = TRUE;
guint i;
for (i = 0; i <= MEM_PROFILE_TABLE_SIZE; i++)
{
glong t_malloc = local_data[i + PROFILE_TABLE (1, 0, success)];
glong t_realloc = local_data[i + PROFILE_TABLE (1, 1, success)];
glong t_free = local_data[i + PROFILE_TABLE (0, 0, success)];
glong t_refree = local_data[i + PROFILE_TABLE (0, 1, success)];
if (!t_malloc && !t_realloc && !t_free && !t_refree)
continue;
else if (need_header)
{
need_header = FALSE;
g_print (" blocks of | allocated | freed | allocated | freed | n_bytes \n");
g_print (" n_bytes | n_times by | n_times by | n_times by | n_times by | remaining \n");
g_print (" | malloc() | free() | realloc() | realloc() | \n");
g_print ("===========|============|============|============|============|===========\n");
}
if (i < MEM_PROFILE_TABLE_SIZE)
g_print ("%10u | %10ld | %10ld | %10ld | %10ld |%+11ld\n",
i, t_malloc, t_free, t_realloc, t_refree,
(t_malloc - t_free + t_realloc - t_refree) * i);
else if (i >= MEM_PROFILE_TABLE_SIZE)
g_print (" >%6u | %10ld | %10ld | %10ld | %10ld | ***\n",
i, t_malloc, t_free, t_realloc, t_refree);
}
if (need_header)
g_print (" --- none ---\n");
}
void
g_mem_profile (void)
{
guint local_data[(MEM_PROFILE_TABLE_SIZE + 1) * 8 * sizeof (profile_data[0])];
gsize local_allocs;
gsize local_zinit;
gsize local_frees;
if (G_UNLIKELY (!g_mem_initialized))
g_mem_init_nomessage();
g_mutex_lock (gmem_profile_mutex);
local_allocs = profile_allocs;
local_zinit = profile_zinit;
local_frees = profile_frees;
if (!profile_data)
{
g_mutex_unlock (gmem_profile_mutex);
return;
}
memcpy (local_data, profile_data,
(MEM_PROFILE_TABLE_SIZE + 1) * 8 * sizeof (profile_data[0]));
g_mutex_unlock (gmem_profile_mutex);
g_print ("GLib Memory statistics (successful operations):\n");
profile_print_locked (local_data, TRUE);
g_print ("GLib Memory statistics (failing operations):\n");
profile_print_locked (local_data, FALSE);
g_print ("Total bytes: allocated=%"G_GSIZE_FORMAT", "
"zero-initialized=%"G_GSIZE_FORMAT" (%.2f%%), "
"freed=%"G_GSIZE_FORMAT" (%.2f%%), "
"remaining=%"G_GSIZE_FORMAT"\n",
local_allocs,
local_zinit,
((gdouble) local_zinit) / local_allocs * 100.0,
local_frees,
((gdouble) local_frees) / local_allocs * 100.0,
local_allocs - local_frees);
}
static gpointer
profiler_try_malloc (gsize n_bytes)
{
gsize *p;
#ifdef G_ENABLE_DEBUG
if (g_trap_malloc_size == n_bytes)
G_BREAKPOINT ();
#endif /* G_ENABLE_DEBUG */
p = standard_malloc (sizeof (gsize) * 2 + n_bytes);
if (p)
{
p[0] = 0; /* free count */
p[1] = n_bytes; /* length */
profiler_log (PROFILER_ALLOC, n_bytes, TRUE);
p += 2;
}
else
profiler_log (PROFILER_ALLOC, n_bytes, FALSE);
return p;
}
static gpointer
profiler_malloc (gsize n_bytes)
{
gpointer mem = profiler_try_malloc (n_bytes);
if (!mem)
g_mem_profile ();
return mem;
}
static gpointer
profiler_calloc (gsize n_blocks,
gsize n_block_bytes)
{
gsize l = n_blocks * n_block_bytes;
gsize *p;
#ifdef G_ENABLE_DEBUG
if (g_trap_malloc_size == l)
G_BREAKPOINT ();
#endif /* G_ENABLE_DEBUG */
p = standard_calloc (1, sizeof (gsize) * 2 + l);
if (p)
{
p[0] = 0; /* free count */
p[1] = l; /* length */
profiler_log (PROFILER_ALLOC | PROFILER_ZINIT, l, TRUE);
p += 2;
}
else
{
profiler_log (PROFILER_ALLOC | PROFILER_ZINIT, l, FALSE);
g_mem_profile ();
}
return p;
}
static void
profiler_free (gpointer mem)
{
gsize *p = mem;
p -= 2;
if (p[0]) /* free count */
{
g_warning ("free(%p): memory has been freed %"G_GSIZE_FORMAT" times already",
p + 2, p[0]);
profiler_log (PROFILER_FREE,
p[1], /* length */
FALSE);
}
else
{
#ifdef G_ENABLE_DEBUG
if (g_trap_free_size == p[1])
G_BREAKPOINT ();
#endif /* G_ENABLE_DEBUG */
profiler_log (PROFILER_FREE,
p[1], /* length */
TRUE);
memset (p + 2, 0xaa, p[1]);
/* for all those that miss standard_free (p); in this place, yes,
* we do leak all memory when profiling, and that is intentional
* to catch double frees. patch submissions are futile.
*/
}
p[0] += 1;
}
static gpointer
profiler_try_realloc (gpointer mem,
gsize n_bytes)
{
gsize *p = mem;
p -= 2;
#ifdef G_ENABLE_DEBUG
if (g_trap_realloc_size == n_bytes)
G_BREAKPOINT ();
#endif /* G_ENABLE_DEBUG */
if (mem && p[0]) /* free count */
{
g_warning ("realloc(%p, %"G_GSIZE_FORMAT"): "
"memory has been freed %"G_GSIZE_FORMAT" times already",
p + 2, (gsize) n_bytes, p[0]);
profiler_log (PROFILER_ALLOC | PROFILER_RELOC, n_bytes, FALSE);
return NULL;
}
else
{
p = standard_realloc (mem ? p : NULL, sizeof (gsize) * 2 + n_bytes);
if (p)
{
if (mem)
profiler_log (PROFILER_FREE | PROFILER_RELOC, p[1], TRUE);
p[0] = 0;
p[1] = n_bytes;
profiler_log (PROFILER_ALLOC | PROFILER_RELOC, p[1], TRUE);
p += 2;
}
else
profiler_log (PROFILER_ALLOC | PROFILER_RELOC, n_bytes, FALSE);
return p;
}
}
static gpointer
profiler_realloc (gpointer mem,
gsize n_bytes)
{
mem = profiler_try_realloc (mem, n_bytes);
if (!mem)
g_mem_profile ();
return mem;
}
static GMemVTable profiler_table = {
profiler_malloc,
profiler_realloc,
profiler_free,
profiler_calloc,
profiler_try_malloc,
profiler_try_realloc,
};
GMemVTable *glib_mem_profiler_table = &profiler_table;
#endif /* !G_DISABLE_CHECKS */
/* --- MemChunks --- */
/**
* SECTION: allocators
* @title: Memory Allocators
* @short_description: deprecated way to allocate chunks of memory for
* GList, GSList and GNode
*
* Prior to 2.10, #GAllocator was used as an efficient way to allocate
* small pieces of memory for use with the #GList, #GSList and #GNode
* data structures. Since 2.10, it has been completely replaced by the
* <link linkend="glib-Memory-Slices">slice allocator</link> and
* deprecated.
**/
/**
* SECTION: memory_chunks
* @title: Memory Chunks
* @short_description: deprecated way to allocate groups of equal-sized
* chunks of memory
*
* Memory chunks provide an space-efficient way to allocate equal-sized
* pieces of memory, called atoms. However, due to the administrative
* overhead (in particular for #G_ALLOC_AND_FREE, and when used from
* multiple threads), they are in practise often slower than direct use
* of g_malloc(). Therefore, memory chunks have been deprecated in
* favor of the <link linkend="glib-Memory-Slices">slice
* allocator</link>, which has been added in 2.10. All internal uses of
* memory chunks in GLib have been converted to the
* <literal>g_slice</literal> API.
*
* There are two types of memory chunks, #G_ALLOC_ONLY, and
* #G_ALLOC_AND_FREE. <itemizedlist> <listitem><para> #G_ALLOC_ONLY
* chunks only allow allocation of atoms. The atoms can never be freed
* individually. The memory chunk can only be free in its entirety.
* </para></listitem> <listitem><para> #G_ALLOC_AND_FREE chunks do
* allow atoms to be freed individually. The disadvantage of this is
* that the memory chunk has to keep track of which atoms have been
* freed. This results in more memory being used and a slight
* degradation in performance. </para></listitem> </itemizedlist>
*
* To create a memory chunk use g_mem_chunk_new() or the convenience
* macro g_mem_chunk_create().
*
* To allocate a new atom use g_mem_chunk_alloc(),
* g_mem_chunk_alloc0(), or the convenience macros g_chunk_new() or
* g_chunk_new0().
*
* To free an atom use g_mem_chunk_free(), or the convenience macro
* g_chunk_free(). (Atoms can only be freed if the memory chunk is
* created with the type set to #G_ALLOC_AND_FREE.)
*
* To free any blocks of memory which are no longer being used, use
* g_mem_chunk_clean(). To clean all memory chunks, use g_blow_chunks().
*
* To reset the memory chunk, freeing all of the atoms, use
* g_mem_chunk_reset().
*
* To destroy a memory chunk, use g_mem_chunk_destroy().
*
* To help debug memory chunks, use g_mem_chunk_info() and
* g_mem_chunk_print().
*
* <example>
* <title>Using a #GMemChunk</title>
* <programlisting>
* GMemChunk *mem_chunk;
* gchar *mem[10000];
* gint i;
*
* /<!-- -->* Create a GMemChunk with atoms 50 bytes long, and memory
* blocks holding 100 bytes. Note that this means that only 2 atoms
* fit into each memory block and so isn't very efficient. *<!-- -->/
* mem_chunk = g_mem_chunk_new ("test mem chunk", 50, 100, G_ALLOC_AND_FREE);
* /<!-- -->* Now allocate 10000 atoms. *<!-- -->/
* for (i = 0; i &lt; 10000; i++)
* {
* mem[i] = g_chunk_new (gchar, mem_chunk);
* /<!-- -->* Fill in the atom memory with some junk. *<!-- -->/
* for (j = 0; j &lt; 50; j++)
* mem[i][j] = i * j;
* }
* /<!-- -->* Now free all of the atoms. Note that since we are going to
* destroy the GMemChunk, this wouldn't normally be used. *<!-- -->/
* for (i = 0; i &lt; 10000; i++)
* {
* g_mem_chunk_free (mem_chunk, mem[i]);
* }
* /<!-- -->* We are finished with the GMemChunk, so we destroy it. *<!-- -->/
* g_mem_chunk_destroy (mem_chunk);
* </programlisting>
* </example>
*
* <example>
* <title>Using a #GMemChunk with data structures</title>
* <programlisting>
* GMemChunk *array_mem_chunk;
* GRealArray *array;
* /<!-- -->* Create a GMemChunk to hold GRealArray structures, using
* the g_mem_chunk_create(<!-- -->) convenience macro. We want 1024 atoms in each
* memory block, and we want to be able to free individual atoms. *<!-- -->/
* array_mem_chunk = g_mem_chunk_create (GRealArray, 1024, G_ALLOC_AND_FREE);
* /<!-- -->* Allocate one atom, using the g_chunk_new(<!-- -->) convenience macro. *<!-- -->/
* array = g_chunk_new (GRealArray, array_mem_chunk);
* /<!-- -->* We can now use array just like a normal pointer to a structure. *<!-- -->/
* array->data = NULL;
* array->len = 0;
* array->alloc = 0;
* array->zero_terminated = (zero_terminated ? 1 : 0);
* array->clear = (clear ? 1 : 0);
* array->elt_size = elt_size;
* /<!-- -->* We can free the element, so it can be reused. *<!-- -->/
* g_chunk_free (array, array_mem_chunk);
* /<!-- -->* We destroy the GMemChunk when we are finished with it. *<!-- -->/
* g_mem_chunk_destroy (array_mem_chunk);
* </programlisting>
* </example>
**/
#ifndef G_ALLOC_AND_FREE
/**
* GAllocator:
*
* The #GAllocator struct contains private data. and should only be
* accessed using the following functions.
**/
typedef struct _GAllocator GAllocator;
/**
* GMemChunk:
*
* The #GMemChunk struct is an opaque data structure representing a
* memory chunk. It should be accessed only through the use of the
* following functions.
**/
typedef struct _GMemChunk GMemChunk;
/**
* G_ALLOC_ONLY:
*
* Specifies the type of a #GMemChunk. Used in g_mem_chunk_new() and
* g_mem_chunk_create() to specify that atoms will never be freed
* individually.
**/
#define G_ALLOC_ONLY 1
/**
* G_ALLOC_AND_FREE:
*
* Specifies the type of a #GMemChunk. Used in g_mem_chunk_new() and
* g_mem_chunk_create() to specify that atoms will be freed
* individually.
**/
#define G_ALLOC_AND_FREE 2
#endif
struct _GMemChunk {
guint alloc_size; /* the size of an atom */
};
/**
* g_mem_chunk_new:
* @name: a string to identify the #GMemChunk. It is not copied so it
* should be valid for the lifetime of the #GMemChunk. It is
* only used in g_mem_chunk_print(), which is used for debugging.
* @atom_size: the size, in bytes, of each element in the #GMemChunk.
* @area_size: the size, in bytes, of each block of memory allocated to
* contain the atoms.
* @type: the type of the #GMemChunk. #G_ALLOC_AND_FREE is used if the
* atoms will be freed individually. #G_ALLOC_ONLY should be
* used if atoms will never be freed individually.
* #G_ALLOC_ONLY is quicker, since it does not need to track
* free atoms, but it obviously wastes memory if you no longer
* need many of the atoms.
* @Returns: the new #GMemChunk.
*
* Creates a new #GMemChunk.
*
* Deprecated:2.10: Use the <link linkend="glib-Memory-Slices">slice
* allocator</link> instead
**/
GMemChunk*
g_mem_chunk_new (const gchar *name,
gint atom_size,
gsize area_size,
gint type)
{
GMemChunk *mem_chunk;
g_return_val_if_fail (atom_size > 0, NULL);
mem_chunk = g_slice_new (GMemChunk);
mem_chunk->alloc_size = atom_size;
return mem_chunk;
}
/**
* g_mem_chunk_destroy:
* @mem_chunk: a #GMemChunk.
*
* Frees all of the memory allocated for a #GMemChunk.
*
* Deprecated:2.10: Use the <link linkend="glib-Memory-Slices">slice
* allocator</link> instead
**/
void
g_mem_chunk_destroy (GMemChunk *mem_chunk)
{
g_return_if_fail (mem_chunk != NULL);
g_slice_free (GMemChunk, mem_chunk);
}
/**
* g_mem_chunk_alloc:
* @mem_chunk: a #GMemChunk.
* @Returns: a pointer to the allocated atom.
*
* Allocates an atom of memory from a #GMemChunk.
*
* Deprecated:2.10: Use g_slice_alloc() instead
**/
gpointer
g_mem_chunk_alloc (GMemChunk *mem_chunk)
{
g_return_val_if_fail (mem_chunk != NULL, NULL);
return g_slice_alloc (mem_chunk->alloc_size);
}
/**
* g_mem_chunk_alloc0:
* @mem_chunk: a #GMemChunk.
* @Returns: a pointer to the allocated atom.
*
* Allocates an atom of memory from a #GMemChunk, setting the memory to
* 0.
*
* Deprecated:2.10: Use g_slice_alloc0() instead
**/
gpointer
g_mem_chunk_alloc0 (GMemChunk *mem_chunk)
{
g_return_val_if_fail (mem_chunk != NULL, NULL);
return g_slice_alloc0 (mem_chunk->alloc_size);
}
/**
* g_mem_chunk_free:
* @mem_chunk: a #GMemChunk.
* @mem: a pointer to the atom to free.
*
* Frees an atom in a #GMemChunk. This should only be called if the
* #GMemChunk was created with #G_ALLOC_AND_FREE. Otherwise it will
* simply return.
*
* Deprecated:2.10: Use g_slice_free1() instead
**/
void
g_mem_chunk_free (GMemChunk *mem_chunk,
gpointer mem)
{
g_return_if_fail (mem_chunk != NULL);
g_slice_free1 (mem_chunk->alloc_size, mem);
}
/**
* g_mem_chunk_clean:
* @mem_chunk: a #GMemChunk.
*
* Frees any blocks in a #GMemChunk which are no longer being used.
*
* Deprecated:2.10: Use the <link linkend="glib-Memory-Slices">slice
* allocator</link> instead
**/
void g_mem_chunk_clean (GMemChunk *mem_chunk) {}
/**
* g_mem_chunk_reset:
* @mem_chunk: a #GMemChunk.
*
* Resets a GMemChunk to its initial state. It frees all of the
* currently allocated blocks of memory.
*
* Deprecated:2.10: Use the <link linkend="glib-Memory-Slices">slice
* allocator</link> instead
**/
void g_mem_chunk_reset (GMemChunk *mem_chunk) {}
/**
* g_mem_chunk_print:
* @mem_chunk: a #GMemChunk.
*
* Outputs debugging information for a #GMemChunk. It outputs the name
* of the #GMemChunk (set with g_mem_chunk_new()), the number of bytes
* used, and the number of blocks of memory allocated.
*
* Deprecated:2.10: Use the <link linkend="glib-Memory-Slices">slice
* allocator</link> instead
**/
void g_mem_chunk_print (GMemChunk *mem_chunk) {}
/**
* g_mem_chunk_info:
*
* Outputs debugging information for all #GMemChunk objects currently
* in use. It outputs the number of #GMemChunk objects currently
* allocated, and calls g_mem_chunk_print() to output information on
* each one.
*
* Deprecated:2.10: Use the <link linkend="glib-Memory-Slices">slice
* allocator</link> instead
**/
void g_mem_chunk_info (void) {}
/**
* g_blow_chunks:
*
* Calls g_mem_chunk_clean() on all #GMemChunk objects.
*
* Deprecated:2.10: Use the <link linkend="glib-Memory-Slices">slice
* allocator</link> instead
**/
void g_blow_chunks (void) {}
/**
* g_chunk_new0:
* @type: the type of the #GMemChunk atoms, typically a structure name.
* @chunk: a #GMemChunk.
* @Returns: a pointer to the allocated atom, cast to a pointer to
* @type.
*
* A convenience macro to allocate an atom of memory from a #GMemChunk.
* It calls g_mem_chunk_alloc0() and casts the returned atom to a
* pointer to the given type, avoiding a type cast in the source code.
*
* Deprecated:2.10: Use g_slice_new0() instead
**/
/**
* g_chunk_free:
* @mem: a pointer to the atom to be freed.
* @mem_chunk: a #GMemChunk.
*
* A convenience macro to free an atom of memory from a #GMemChunk. It
* simply switches the arguments and calls g_mem_chunk_free() It is
* included simply to complement the other convenience macros,
* g_chunk_new() and g_chunk_new0().
*
* Deprecated:2.10: Use g_slice_free() instead
**/
/**
* g_chunk_new:
* @type: the type of the #GMemChunk atoms, typically a structure name.
* @chunk: a #GMemChunk.
* @Returns: a pointer to the allocated atom, cast to a pointer to
* @type.
*
* A convenience macro to allocate an atom of memory from a #GMemChunk.
* It calls g_mem_chunk_alloc() and casts the returned atom to a
* pointer to the given type, avoiding a type cast in the source code.
*
* Deprecated:2.10: Use g_slice_new() instead
**/
/**
* g_mem_chunk_create:
* @type: the type of the atoms, typically a structure name.
* @pre_alloc: the number of atoms to store in each block of memory.
* @alloc_type: the type of the #GMemChunk. #G_ALLOC_AND_FREE is used
* if the atoms will be freed individually. #G_ALLOC_ONLY
* should be used if atoms will never be freed
* individually. #G_ALLOC_ONLY is quicker, since it does
* not need to track free atoms, but it obviously wastes
* memory if you no longer need many of the atoms.
* @Returns: the new #GMemChunk.
*
* A convenience macro for creating a new #GMemChunk. It calls
* g_mem_chunk_new(), using the given type to create the #GMemChunk
* name. The atom size is determined using
* <function>sizeof()</function>, and the area size is calculated by
* multiplying the @pre_alloc parameter with the atom size.
*
* Deprecated:2.10: Use the <link linkend="glib-Memory-Slices">slice
* allocator</link> instead
**/
/**
* g_allocator_new:
* @name: the name of the #GAllocator. This name is used to set the
* name of the #GMemChunk used by the #GAllocator, and is only
* used for debugging.
* @n_preallocs: the number of elements in each block of memory
* allocated. Larger blocks mean less calls to
* g_malloc(), but some memory may be wasted. (GLib uses
* 128 elements per block by default.) The value must be
* between 1 and 65535.
* @Returns: a new #GAllocator.
*
* Creates a new #GAllocator.
*
* Deprecated:2.10: Use the <link linkend="glib-Memory-Slices">slice
* allocator</link> instead
**/
GAllocator*
g_allocator_new (const gchar *name,
guint n_preallocs)
{
static struct _GAllocator {
gchar *name;
guint16 n_preallocs;
guint is_unused : 1;
guint type : 4;
GAllocator *last;
GMemChunk *mem_chunk;
gpointer free_list;
} dummy = {
"GAllocator is deprecated", 1, TRUE, 0, NULL, NULL, NULL,
};
/* some (broken) GAllocator uses depend on non-NULL allocators */
return (void*) &dummy;
}
/**
* g_allocator_free:
* @allocator: a #GAllocator.
*
* Frees all of the memory allocated by the #GAllocator.
*
* Deprecated:2.10: Use the <link linkend="glib-Memory-Slices">slice
* allocator</link> instead
**/
void
g_allocator_free (GAllocator *allocator)
{
}
#ifdef ENABLE_GC_FRIENDLY_DEFAULT
gboolean g_mem_gc_friendly = TRUE;
#else
gboolean g_mem_gc_friendly = FALSE;
#endif
static void
g_mem_init_nomessage (void)
{
gchar buffer[1024];
const gchar *val;
const GDebugKey keys[] = {
{ "gc-friendly", 1 },
};
gint flags;
if (g_mem_initialized)
return;
/* don't use g_malloc/g_message here */
val = _g_getenv_nomalloc ("G_DEBUG", buffer);
flags = !val ? 0 : g_parse_debug_string (val, keys, G_N_ELEMENTS (keys));
if (flags & 1) /* gc-friendly */
{
g_mem_gc_friendly = TRUE;
}
g_mem_initialized = TRUE;
}
void
_g_mem_thread_init_noprivate_nomessage (void)
{
/* we may only create mutexes here, locking/
* unlocking a mutex does not yet work.
*/
g_mem_init_nomessage();
#ifndef G_DISABLE_CHECKS
gmem_profile_mutex = g_mutex_new ();
#endif
}
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