malloc_usable_size
Section: C Library Functions (3)
Updated: 2022-12-15
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NAME
malloc_usable_size - obtain size of block of memory allocated from heap
LIBRARY
Standard C library
(libc, -lc)
SYNOPSIS
#include <malloc.h>
size_t malloc_usable_size(void *ptr);
DESCRIPTION
The
malloc_usable_size()
function returns the number of usable bytes in the block pointed to by
ptr,
a pointer to a block of memory allocated by
malloc(3)
or a related function.
RETURN VALUE
malloc_usable_size()
returns the number of usable bytes in
the block of allocated memory pointed to by
ptr.
If
ptr
is NULL, 0 is returned.
ATTRIBUTES
For an explanation of the terms used in this section, see
attributes(7).
Interface | Attribute | Value
|
malloc_usable_size()
| Thread safety | MT-Safe
|
STANDARDS
This function is a GNU extension.
NOTES
The value returned by
malloc_usable_size()
may be greater than the requested size of the allocation because
of alignment and minimum size constraints.
Although the excess bytes can be overwritten by the application
without ill effects,
this is not good programming practice:
the number of excess bytes in an allocation depends on
the underlying implementation.
The main use of this function is for debugging and introspection.
SEE ALSO
malloc(3)
Index
- NAME
-
- LIBRARY
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ATTRIBUTES
-
- STANDARDS
-
- NOTES
-
- SEE ALSO
-
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Time: 06:47:56 GMT, April 23, 2024