MALLOC_USABLE_SIZE(3) Linux Programmer's Manual MALLOC_USABLE_SIZE(3)NAME
malloc_usable_size - obtain size of block of memory allocated from heap
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 allo-
cated 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 |
+---------------------+---------------+---------+
CONFORMING TO
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)GNU 2015-03-02 MALLOC_USABLE_SIZE(3)
Check Out this Related Man Page
MALLOC_USABLE_SIZE(3) Linux Programmer's Manual MALLOC_USABLE_SIZE(3)NAME
malloc_usable_size - obtain size of block of memory allocated from heap
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 allo-
cated 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 |
+---------------------+---------------+---------+
CONFORMING TO
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)COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the
latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.
GNU 2017-09-15 MALLOC_USABLE_SIZE(3)
Is it generally not a good idea in a multithreaded program to make lots of malloc calls (dynamic memory requests) because of the limited nature of the memory heap ?
Out of curiosity (warning it may sound silly), but would using mutexs (mutual exclusion) help to minimise chances of runtime errors... (12 Replies)
When allocating memory for two different nodes, the resulting memory are the same. Clearly, this will lead to a mistake. This happened in a function. And the process must be in a function.
(gdb) p tree->list
$43 = (node *) 0x8be4180
(gdb) p tree->list
$44 = (node *) 0x8be4180
At the... (2 Replies)
Hi everyone,
I'm not new to C programming, but I'm having question regarding the memory allocation of a pointer variable which, for instance, will be declared in main(), but its memory will be allocated in subroutine.
To clearify my question, I provide a small working example:
#include... (1 Reply)