.TH LIBSIMPLE_VMEMALLOC 3 2018-11-03 libsimple
.SH NAME
libsimple_vmemalloc \- allocate memory in a flexible manner
.SH SYNOPSIS
.nf
#include <libsimple.h>

enum libsimple_memalloc_option {
	/* constants omitted, see \fBDESCRIPTION\fP */
};

void *libsimple_vmemalloc(size_t \fIn\fP, va_list \fIap\fP);
void *libsimple_envmemalloc(int \fIstatus\fP, size_t \fIn\fP, va_list \fIap\fP);
static inline void *libsimple_evmemalloc(size_t \fIn\fP, va_list \fIap\fP);
static inline void *libsimple_memalloc(size_t \fIn\fP, ..., /* LIBSIMPLE_MEMALLOC_END */);
static inline void *libsimple_enmemalloc(int \fIstatus\fP, size_t \fIn\fP, ..., /* LIBSIMPLE_MEMALLOC_END */);
static inline void *libsimple_ememalloc(size_t \fIn\fP, ..., /* LIBSIMPLE_MEMALLOC_END */);
.fi
.PP
Link with
.IR \-lsimple .
.SH DESCRIPTION
The
.BR libsimple_vmemalloc ()
function is a flexible alternative to standard allocation
functions.
.PP
.I va
is a list of options that specify the behaviour, its
end is marked by
.BR LIBSIMPLE_MEMALLOC_END ,
the following options (which is the type
.BR "enum libsimple_memalloc_option" )
are recognised:
.TP
.B LIBSIMPLE_MEMALLOC_ZERO_INIT
The allocated memory shall be initialisd with NUL bytes.
.TP
.B LIBSIMPLE_MEMALLOC_CONDITIONAL_ZERO_INIT
The allocated memory shall be initialisd with NUL bytes
with the argument, which should be of the type
.BR int ,
is nonzero.
.TP
.B LIBSIMPLE_MEMALLOC_UNIQUE_IF_ZERO
If attempting to allocate 0 bytes,
rather than failing with
.I errno
set to
.BR EINVAL ,
a unique pointer (that can be deallocated)
should be returned.
.TP
.B LIBSIMPLE_MEMALLOC_NULL_IF_ZERO
If attempting to allocate 0 bytes,
rather than failing with
.I errno
set to
.BR EINVAL ,
a
.B NULL
should be returned.
.TP
.B LIBSIMPLE_MEMALLOC_ALIGNMENT
The value of the next argument, which should be of the type
.BR size_t ,
should be used as the alignment of the returned pointer.
By default the alignment is
.IR "alignof(max_align_t)" .
.TP
.B LIBSIMPLE_MEMALLOC_PAGE_ALIGNMENT
The alignment of the returned pointer should be the page size.
By default the alignment is
.IR "alignof(max_align_t)" .
.TP
.B LIBSIMPLE_MEMALLOC_ROUND_UP_SIZE_TO_ALIGNMENT
The number of bytes to allocated should be rounded up to
the next multiple of the alignment, unless it already is
a multiple of the alignment.
.TP
.B LIBSIMPLE_MEMALLOC_ELEMENT_SIZE
The next argument, which should be of the type
.BR size_t ,
shall act as a multiplier for the number of bytes to allocate
(default multiplier is 1), effectively, making the specified
allocation size specified in elements rather than in bytes.
.TP
.B LIBSIMPLE_MEMALLOC_PRODUCT_SIZE
If
.I n
is zero, the product of the following arguments,
which should be of the type
.BR size_t ,
up to the first 0, shall be used as the allocation size.
If
.I n
is not zero, the product of the following
.I n
arguments, also of type
.BR size_t ,
shall be used as the allocation size.
By default
.I n
bytes are allocated.
.TP
.B LIBSIMPLE_MEMALLOC_VA_PRODUCT_SIZE
Like
.BR LIBSIMPLE_MEMALLOC_PRODUCT_SIZE ,
the arguments are read from the next argument,
which should be of the type
.BR va_list .
.TP
.B LIBSIMPLE_MEMALLOC_1_VA_PRODUCT_SIZE
Like
.BR LIBSIMPLE_MEMALLOC_PRODUCT_SIZE ,
except two arguments read from
.IR ap :
a
.BR size_t ,
which act as the first factor, and a
.B va_list
with the rest of the factors.
.TP
.B LIBSIMPLE_MEMALLOC_VA_LIST
Arguments from the next argument, which should be of the type
.B va_list
and should end with
.BR LIBSIMPLE_MEMALLOC_END ,
shall be parsed as options for the memory allocation.
.PP
Each
.B enum libsimple_memalloc_option
constant have a self-referencing macros defined
which can be used to test which constants are defined.
.PP
The
.BR libsimple_envmemalloc ()
and
.BR libsimple_evmemalloc ()
functions are versions of the
.BR libsimple_vmemalloc ()
that terminate the process by calling the
.BR libsimple_enprintf (3)
(with
.I status
as the exit value) and
.BR libsimple_eprintf (3)
functions, respectively.
.PP
The
.BR libsimple_memalloc (),
.BR libsimple_enmemalloc (),
and
.BR libsimple_ememalloc ()
functions are versions of the
.BR libsimple_vmemalloc (),
.BR libsimple_envmemalloc (),
and
.BR libsimple_evmemalloc ()
functions, respectively, that use variadic arguments
instead of
.BR va_list .
.SH RETURN VALUE
The
.BR libsimple_vmemalloc (),
.BR libsimple_envmemalloc (),
.BR libsimple_ememalloc (),
.BR libsimple_memalloc (),
.BR libsimple_enmemalloc (),
and
.BR libsimple_ememalloc ()
functions return the a pointer to the allocated
memory upon successful completion; otherwise the
.BR libsimple_vmemalloc ()
and
.BR libsimple_memalloc ()
functions return
.B NULL
and set
.I errno
to indicate the error, whereas the
.BR libsimple_envmemalloc (),
.BR libsimple_ememalloc (),
.BR libsimple_enmemalloc (),
and
.BR libsimple_ememalloc ()
functions terminate the process.
.SH ERRORS
The
.BR libsimple_vmemalloc ()
and
.BR libsimple_memalloc ()
functions will fail if
.TP
.B EINVAL
An invalid argument is specified.
.TP
.B EINVAL
An option is specified twice or in
conjunction with a mutually exclusive option.
.TP
.B ENOMEM
Enough memory could not be allocated.
.PP
The
.BR libsimple_envmemalloc (),
.BR libsimple_ememalloc (),
.BR libsimple_enmemalloc (),
and
.BR libsimple_ememalloc ()
functions terminate the process on failure.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lb lb lb
l l l.
Interface	Attribute	Value
T{
.BR libsimple_vmemalloc (),
.br
.BR libsimple_envmemalloc (),
.br
.BR libsimple_ememalloc (),
.br
.BR libsimple_memalloc (),
.br
.BR libsimple_enmemalloc (),
.br
.BR libsimple_ememalloc ()
T}	Thread safety	MT-Safe
T{
.BR libsimple_vmemalloc (),
.br
.BR libsimple_envmemalloc (),
.br
.BR libsimple_ememalloc (),
.br
.BR libsimple_memalloc (),
.br
.BR libsimple_enmemalloc (),
.br
.BR libsimple_ememalloc ()
T}	Async-signal safety	AS-Safe
T{
.BR libsimple_vmemalloc (),
.br
.BR libsimple_envmemalloc (),
.br
.BR libsimple_ememalloc (),
.br
.BR libsimple_memalloc (),
.br
.BR libsimple_enmemalloc (),
.br
.BR libsimple_ememalloc ()
T}	Async-cancel safety	AC-Safe
.TE
.SH EXAMPLES
None.
.SH APPLICATION USAGE
None.
.SH RATIONALE
None.
.SH FUTURE DIRECTIONS
None.
.SH NOTES
None.
.SH BUGS
None.
.SH SEE ALSO
.BR libsimple_varrayalloc (3),
.BR libsimple_enmalloc (3),
.BR libsimple_mallocz (3),
.BR libsimple_vmallocn (3),
.BR libsimple_vmalloczn (3),
.BR libsimple_encalloc (3),
.BR libsimple_vcallocn (3),
.BR libsimple_enrealloc (3),
.BR libsimple_vreallocn (3),
.BR libsimple_memalign (3),
.BR libsimple_memalignz (3),
.BR libsimple_vmemalignn (3),
.BR libsimple_vmemalignzn (3),
.BR libsimple_enposix_memalign (3),
.BR libsimple_posix_memalignz (3),
.BR libsimple_vposix_memalignn (3),
.BR libsimple_vposix_memalignzn (3),
.BR libsimple_enaligned_alloc (3),
.BR libsimple_aligned_allocz (3),
.BR libsimple_valigned_allocn (3),
.BR libsimple_valigned_alloczn (3),
.BR libsimple_pvalloc (3),
.BR libsimple_pvallocz (3),
.BR libsimple_vpvallocn (3),
.BR libsimple_vpvalloczn (3),
.BR libsimple_valloc (3),
.BR libsimple_vallocz (3),
.BR libsimple_vvallocn (3),
.BR libsimple_vvalloczn (3)