xref: /inferno-os/man/10/malloc (revision 46439007cf417cbd9ac8049bb4122c890097a0fa)
MALLOC 10.2
NAME
malloc, mallocz, smalloc, free, realloc, calloc - kernel memory allocators
SYNOPSIS
void* malloc(ulong size)

void* mallocz(ulong size, int clr)

void* smalloc(ulong size)

void* realloc(void *p, ulong size)

void* calloc(ulong n, ulong szelem)

void free(void *p)

DESCRIPTION
These functions allocate memory from the mainmem memory pool. All but smalloc (which sleeps) may safely be called by interrupt handlers.

Malloc returns a pointer to a block of at least size bytes, initialised to zero. The result is aligned on a 32-bit boundary. Mallocz is similar, but only clears the memory if clr is non-zero.

Smalloc returns a pointer to a block of size bytes, initialised to zero. If the memory is not immediately available, smalloc retries every 100 milliseconds until the memory is acquired.

Calloc returns a pointer to a block of memory of at least "n*szelem" bytes, initialised to zero.

Realloc changes the size of the block pointed to by p to size bytes, if possible without moving the data, and returns a pointer to the block. The contents are unchanged up to the lesser of old and new sizes, and any new space allocated is initialised to zero. If p is a null pointer, realloc returns the equivalent of "malloc(size)" .

The argument to free is a pointer to a block of memory allocated by one of the routines above, which is returned to the allocation pool, or a null pointer, which is ignored.

DIAGNOSTICS
All functions except smalloc return a null pointer if space is unavailable.
SEE ALSO
xalloc (10.2)