|| Linux Programmer's Manual
NAME malloc_usable_size - obtain size of block of memory allocated from heap
size_t malloc_usable_size (void *
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.
malloc_usable_size() returns the number of usable bytes in the block of allocated memory pointed to by
ptr is NULL, 0 is returned.
CONFORMING TO This function is a GNU extension.
The value returned by
() 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.
COLOPHON This page is part of release 3.53 of the Linux
man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.