code: 9ferno

ref: 44ce0097b612a1fefd754065bdf8d9d2e5ef60c8
dir: /man/10/malloc/

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.TH MALLOC 10.2
.SH NAME
malloc, mallocz, smalloc, free, realloc, calloc \- kernel memory allocators
.SH SYNOPSIS
.ta \w'\fLvoid* 'u
.B
void*	malloc(ulong size)
.PP
.B
void*	mallocz(ulong size, int clr)
.PP
.B
void*	smalloc(ulong size)
.PP
.B
void*	realloc(void *p, ulong size)
.PP
.B
void*	calloc(ulong n, ulong szelem)
.PP
.B
void	free(void *p)
.SH DESCRIPTION
These functions allocate memory from the
.B mainmem
memory pool.
All but
.I smalloc
(which sleeps)
may safely be called by interrupt handlers.
.PP
.I Malloc
returns a pointer to a block of at least
.I size
bytes, initialised to zero.
The result is aligned on a 32-bit boundary.
.I Mallocz
is similar, but only clears the memory if
.I clr
is non-zero.
.PP
.I Smalloc
returns a pointer to a block of
.I size
bytes, initialised to zero.
If the memory is not immediately available,
.I smalloc
retries every 100 milliseconds until the memory is acquired.
.PP
.I Calloc
returns a pointer to a block of memory of at least
.I "n*szelem"
bytes, initialised to zero.
.PP
.I Realloc
changes the size of the block pointed to by
.I p
to
.I 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
.I p
is a null pointer,
.I realloc
returns the equivalent of
.BR "malloc(size)" .
.PP
The argument to
.I 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.
.SH DIAGNOSTICS
All functions except
.I smalloc
return a null pointer if space is unavailable.
.SH SEE ALSO
.IR xalloc (10.2)