glib/glib/gmem.c
Christian Hergert 18a33f72db introspection: use (nullable) or (optional) instead of (allow-none)
If we have an input parameter (or return value) we need to use (nullable).
However, if it is an (inout) or (out) parameter, (optional) is sufficient.

It looks like (nullable) could be used for everything according to the
Annotation documentation, but (optional) is more specific.
2016-11-22 14:14:37 -08:00

511 lines
13 KiB
C

/* 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, 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 fails, the application is terminated.
* This also means that there is no need to check if the call succeeded.
*
* 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: 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");
}