/* 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 2.1 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, see <http://www.gnu.org/licenses/>.
*/
/*
* 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 "gslice.h"
#include "gbacktrace.h"
#include "gtestutils.h"
#include "gthread.h"
#include "glib_trace.h"
/* notes on macros:
* having G_DISABLE_CHECKS defined disables use of glib_mem_profiler_table and
* g_mem_profile().
* If g_mem_gc_friendly is TRUE, freed memory should be 0-wiped.
*/
/* --- variables --- */
static GMemVTable glib_mem_vtable = {
malloc,
realloc,
free,
calloc,
malloc,
realloc,
};
/**
* SECTION:memory
* @Short_Description: general memory-handling
* @Title: Memory Allocation
*
* These functions provide support for allocating and freeing memory.
*
* If any call to allocate memory using functions g_new(), g_new0(), g_renew(),
* g_malloc(), g_malloc0(), g_malloc0_n(), g_realloc(), and g_realloc_n()
* fails, the application is terminated. This also means that there is no
* need to check if the call succeeded. On the other hand, g_try_...() family
* of functions returns %NULL on failure that can be used as a check
* for unsuccessful memory allocation. The application is not terminated
* in this case.
*
* It's important to match g_malloc() (and wrappers such as g_new()) with
* g_free(), g_slice_alloc() (and wrappers such as g_slice_new()) with
* g_slice_free(), plain malloc() with free(), and (if you're using C++)
* new with delete and new[] with delete[]. Otherwise bad things can happen,
* since these allocators may use different memory pools (and new/delete call
* constructors and destructors).
*/
/* --- functions --- */
/**
* g_malloc:
* @n_bytes: the number of bytes to allocate
*
* Allocates @n_bytes bytes of memory.
* If @n_bytes is 0 it returns %NULL.
*
* Returns: a pointer to the allocated memory
*/
gpointer
g_malloc (gsize n_bytes)
{
if (G_LIKELY (n_bytes))
{
gpointer mem;
mem = 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;
}
/**
* g_malloc0:
* @n_bytes: the number of bytes to allocate
*
* Allocates @n_bytes bytes of memory, initialized to 0's.
* If @n_bytes is 0 it returns %NULL.
*
* Returns: a pointer to the allocated memory
*/
gpointer
g_malloc0 (gsize n_bytes)
{
if (G_LIKELY (n_bytes))
{
gpointer mem;
mem = 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;
}
/**
* g_realloc:
* @mem: (nullable): the memory to reallocate
* @n_bytes: new size of the memory in bytes
*
* Reallocates the memory pointed to by @mem, so that it now has space for
* @n_bytes bytes of memory. It returns the new address of the memory, which may
* have been moved. @mem may be %NULL, in which case it's considered to
* have zero-length. @n_bytes may be 0, in which case %NULL will be returned
* and @mem will be freed unless it is %NULL.
*
* Returns: the new address of the allocated memory
*/
gpointer
g_realloc (gpointer mem,
gsize n_bytes)
{
gpointer newmem;
if (G_LIKELY (n_bytes))
{
newmem = 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)
free (mem);
TRACE (GLIB_MEM_REALLOC((void*) NULL, (void*)mem, 0, 0));
return NULL;
}
/**
* g_free:
* @mem: (nullable): the memory to free
*
* Frees the memory pointed to by @mem.
*
* If @mem is %NULL it simply returns, so there is no need to check @mem
* against %NULL before calling this function.
*/
void
g_free (gpointer mem)
{
if (G_LIKELY (mem))
free (mem);
TRACE(GLIB_MEM_FREE((void*) mem));
}
/**
* g_clear_pointer: (skip)
* @pp: (not nullable): a pointer to a variable, struct member etc. holding a
* pointer
* @destroy: a function to which a gpointer can be passed, to destroy *@pp
*
* Clears a reference to a variable.
*
* @pp must not be %NULL.
*
* If the reference is %NULL then this function does nothing.
* Otherwise, the variable is destroyed using @destroy and the
* pointer is set to %NULL.
*
* A macro is also included that allows this function to be used without
* pointer casts.
*
* Since: 2.34
**/
#undef g_clear_pointer
void
g_clear_pointer (gpointer *pp,
GDestroyNotify destroy)
{
gpointer _p;
_p = *pp;
if (_p)
{
*pp = NULL;
destroy (_p);
}
}
/**
* g_try_malloc:
* @n_bytes: number of bytes to allocate.
*
* Attempts to allocate @n_bytes, and returns %NULL on failure.
* Contrast with g_malloc(), which aborts the program on failure.
*
* Returns: the allocated memory, or %NULL.
*/
gpointer
g_try_malloc (gsize n_bytes)
{
gpointer mem;
if (G_LIKELY (n_bytes))
mem = malloc (n_bytes);
else
mem = NULL;
TRACE (GLIB_MEM_ALLOC((void*) mem, (unsigned int) n_bytes, 0, 1));
return mem;
}
/**
* g_try_malloc0:
* @n_bytes: number of bytes to allocate
*
* Attempts to allocate @n_bytes, initialized to 0's, and returns %NULL on
* failure. Contrast with g_malloc0(), which aborts the program on failure.
*
* Since: 2.8
* Returns: the allocated memory, or %NULL
*/
gpointer
g_try_malloc0 (gsize n_bytes)
{
gpointer mem;
if (G_LIKELY (n_bytes))
mem = calloc (1, n_bytes);
else
mem = NULL;
return mem;
}
/**
* g_try_realloc:
* @mem: (nullable): previously-allocated memory, or %NULL.
* @n_bytes: number of bytes to allocate.
*
* Attempts to realloc @mem to a new size, @n_bytes, and returns %NULL
* on failure. Contrast with g_realloc(), which aborts the program
* on failure.
*
* If @mem is %NULL, behaves the same as g_try_malloc().
*
* Returns: the allocated memory, or %NULL.
*/
gpointer
g_try_realloc (gpointer mem,
gsize n_bytes)
{
gpointer newmem;
if (G_LIKELY (n_bytes))
newmem = realloc (mem, n_bytes);
else
{
newmem = NULL;
if (mem)
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)))
/**
* g_malloc_n:
* @n_blocks: the number of blocks to allocate
* @n_block_bytes: the size of each block in bytes
*
* This function is similar to g_malloc(), allocating (@n_blocks * @n_block_bytes) bytes,
* but care is taken to detect possible overflow during multiplication.
*
* Since: 2.24
* Returns: a pointer to the allocated memory
*/
gpointer
g_malloc_n (gsize n_blocks,
gsize n_block_bytes)
{
if (SIZE_OVERFLOWS (n_blocks, n_block_bytes))
{
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);
}
/**
* g_malloc0_n:
* @n_blocks: the number of blocks to allocate
* @n_block_bytes: the size of each block in bytes
*
* This function is similar to g_malloc0(), allocating (@n_blocks * @n_block_bytes) bytes,
* but care is taken to detect possible overflow during multiplication.
*
* Since: 2.24
* Returns: a pointer to the allocated memory
*/
gpointer
g_malloc0_n (gsize n_blocks,
gsize n_block_bytes)
{
if (SIZE_OVERFLOWS (n_blocks, n_block_bytes))
{
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);
}
/**
* g_realloc_n:
* @mem: (nullable): the memory to reallocate
* @n_blocks: the number of blocks to allocate
* @n_block_bytes: the size of each block in bytes
*
* This function is similar to g_realloc(), allocating (@n_blocks * @n_block_bytes) bytes,
* but care is taken to detect possible overflow during multiplication.
*
* Since: 2.24
* Returns: the new address of the allocated memory
*/
gpointer
g_realloc_n (gpointer mem,
gsize n_blocks,
gsize n_block_bytes)
{
if (SIZE_OVERFLOWS (n_blocks, n_block_bytes))
{
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);
}
/**
* g_try_malloc_n:
* @n_blocks: the number of blocks to allocate
* @n_block_bytes: the size of each block in bytes
*
* This function is similar to g_try_malloc(), allocating (@n_blocks * @n_block_bytes) bytes,
* but care is taken to detect possible overflow during multiplication.
*
* Since: 2.24
* Returns: the allocated memory, or %NULL.
*/
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);
}
/**
* g_try_malloc0_n:
* @n_blocks: the number of blocks to allocate
* @n_block_bytes: the size of each block in bytes
*
* This function is similar to g_try_malloc0(), allocating (@n_blocks * @n_block_bytes) bytes,
* but care is taken to detect possible overflow during multiplication.
*
* Since: 2.24
* Returns: the allocated memory, or %NULL
*/
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);
}
/**
* g_try_realloc_n:
* @mem: (nullable): previously-allocated memory, or %NULL.
* @n_blocks: the number of blocks to allocate
* @n_block_bytes: the size of each block in bytes
*
* This function is similar to g_try_realloc(), allocating (@n_blocks * @n_block_bytes) bytes,
* but care is taken to detect possible overflow during multiplication.
*
* Since: 2.24
* Returns: the allocated memory, or %NULL.
*/
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);
}
/**
* 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.
*
* Returns: if %TRUE, malloc() and g_malloc() can be mixed.
*
* Deprecated: 2.46: GLib always uses the system malloc, so this function always
* returns %TRUE.
**/
gboolean
g_mem_is_system_malloc (void)
{
return TRUE;
}
/**
* g_mem_set_vtable:
* @vtable: table of memory allocation routines.
*
* This function used to let you override the memory allocation function.
* However, its use was incompatible with the use of global constructors
* in GLib and GIO, because those use the GLib allocators before main is
* reached. Therefore this function is now deprecated and is just a stub.
*
* Deprecated: 2.46: This function now does nothing. Use other memory
* profiling tools instead
*/
void
g_mem_set_vtable (GMemVTable *vtable)
{
g_warning (G_STRLOC ": custom memory allocation vtable not supported");
}
/**
* glib_mem_profiler_table:
*
* Used to be a #GMemVTable containing profiling variants of the memory
* allocation functions, but this variable shouldn't be modified anymore.
*
* Deprecated: 2.46: Use other memory profiling tools instead
*/
GMemVTable *glib_mem_profiler_table = &glib_mem_vtable;
/**
* g_mem_profile:
*
* GLib used to support some tools for memory profiling, but this
* no longer works. There are many other useful tools for memory
* profiling these days which can be used instead.
*
* Deprecated: 2.46: Use other memory profiling tools instead
*/
void
g_mem_profile (void)
{
g_warning (G_STRLOC ": memory profiling not supported");
}