The bitmap API

Defines
#define	hwloc_bitmap_foreach_begin(id, bitmap)
	Loop macro iterating on bitmap bitmap.
#define	hwloc_bitmap_foreach_end()
	End of loop. Needs a terminating ';'.
Typedefs
typedef struct hwloc_bitmap_s *	hwloc_bitmap_t
	Set of bits represented as an opaque pointer to an internal bitmap.
typedef struct hwloc_bitmap_s *	hwloc_const_bitmap_t
	a non-modifiable hwloc_bitmap_t
Functions
hwloc_bitmap_t	hwloc_bitmap_alloc (void)
	Allocate a new empty bitmap.
hwloc_bitmap_t	hwloc_bitmap_alloc_full (void)
	Allocate a new full bitmap.
void	hwloc_bitmap_free (hwloc_bitmap_t bitmap)
	Free bitmap bitmap.
hwloc_bitmap_t	hwloc_bitmap_dup (hwloc_const_bitmap_t bitmap)
	Duplicate bitmap bitmap by allocating a new bitmap and copying bitmap contents.
void	hwloc_bitmap_copy (hwloc_bitmap_t dst, hwloc_const_bitmap_t src)
	Copy the contents of bitmap src into the already allocated bitmap dst.
int	hwloc_bitmap_snprintf (char *restrict buf, size_t buflen, hwloc_const_bitmap_t bitmap)
	Stringify a bitmap.
int	hwloc_bitmap_asprintf (char **strp, hwloc_const_bitmap_t bitmap)
	Stringify a bitmap into a newly allocated string.
int	hwloc_bitmap_sscanf (hwloc_bitmap_t bitmap, const char *restrict string)
	Parse a bitmap string and stores it in bitmap bitmap.
int	hwloc_bitmap_taskset_snprintf (char *restrict buf, size_t buflen, hwloc_const_bitmap_t bitmap)
	Stringify a bitmap in the taskset-specific format.
int	hwloc_bitmap_taskset_asprintf (char **strp, hwloc_const_bitmap_t bitmap)
	Stringify a bitmap into a newly allocated taskset-specific string.
int	hwloc_bitmap_taskset_sscanf (hwloc_bitmap_t bitmap, const char *restrict string)
	Parse a taskset-specific bitmap string and stores it in bitmap bitmap.
void	hwloc_bitmap_zero (hwloc_bitmap_t bitmap)
	Empty the bitmap bitmap.
void	hwloc_bitmap_fill (hwloc_bitmap_t bitmap)
	Fill bitmap bitmap with all possible indexes (even if those objects don't exist or are otherwise unavailable)
void	hwloc_bitmap_only (hwloc_bitmap_t bitmap, unsigned id)
	Empty the bitmap bitmap and add bit id.
void	hwloc_bitmap_allbut (hwloc_bitmap_t bitmap, unsigned id)
	Fill the bitmap and clear the index id.
void	hwloc_bitmap_from_ulong (hwloc_bitmap_t bitmap, unsigned long mask)
	Setup bitmap bitmap from unsigned long mask.
void	hwloc_bitmap_from_ith_ulong (hwloc_bitmap_t bitmap, unsigned i, unsigned long mask)
	Setup bitmap bitmap from unsigned long mask used as i -th subset.
void	hwloc_bitmap_set (hwloc_bitmap_t bitmap, unsigned id)
	Add index id in bitmap bitmap.
void	hwloc_bitmap_set_range (hwloc_bitmap_t bitmap, unsigned begin, unsigned end)
	Add indexes from begin to end in bitmap bitmap.
void	hwloc_bitmap_set_ith_ulong (hwloc_bitmap_t bitmap, unsigned i, unsigned long mask)
	Replace i -th subset of bitmap bitmap with unsigned long mask.
void	hwloc_bitmap_clr (hwloc_bitmap_t bitmap, unsigned id)
	Remove index id from bitmap bitmap.
void	hwloc_bitmap_clr_range (hwloc_bitmap_t bitmap, unsigned begin, unsigned end)
	Remove indexes from begin to end in bitmap bitmap.
void	hwloc_bitmap_singlify (hwloc_bitmap_t bitmap)
	Keep a single index among those set in bitmap bitmap.
unsigned long	hwloc_bitmap_to_ulong (hwloc_const_bitmap_t bitmap)
	Convert the beginning part of bitmap bitmap into unsigned long mask.
unsigned long	hwloc_bitmap_to_ith_ulong (hwloc_const_bitmap_t bitmap, unsigned i)
	Convert the i -th subset of bitmap bitmap into unsigned long mask.
int	hwloc_bitmap_isset (hwloc_const_bitmap_t bitmap, unsigned id)
	Test whether index id is part of bitmap bitmap.
int	hwloc_bitmap_iszero (hwloc_const_bitmap_t bitmap)
	Test whether bitmap bitmap is empty.
int	hwloc_bitmap_isfull (hwloc_const_bitmap_t bitmap)
	Test whether bitmap bitmap is completely full.
int	hwloc_bitmap_first (hwloc_const_bitmap_t bitmap)
	Compute the first index (least significant bit) in bitmap bitmap.
int	hwloc_bitmap_next (hwloc_const_bitmap_t bitmap, unsigned prev)
	Compute the next index in bitmap bitmap which is after index prev.
int	hwloc_bitmap_last (hwloc_const_bitmap_t bitmap)
	Compute the last index (most significant bit) in bitmap bitmap.
int	hwloc_bitmap_weight (hwloc_const_bitmap_t bitmap)
	Compute the "weight" of bitmap bitmap (i.e., number of indexes that are in the bitmap).
void	hwloc_bitmap_or (hwloc_bitmap_t res, hwloc_const_bitmap_t bitmap1, hwloc_const_bitmap_t bitmap2)
	Or bitmaps bitmap1 and bitmap2 and store the result in bitmap res.
void	hwloc_bitmap_and (hwloc_bitmap_t res, hwloc_const_bitmap_t bitmap1, hwloc_const_bitmap_t bitmap2)
	And bitmaps bitmap1 and bitmap2 and store the result in bitmap res.
void	hwloc_bitmap_andnot (hwloc_bitmap_t res, hwloc_const_bitmap_t bitmap1, hwloc_const_bitmap_t bitmap2)
	And bitmap bitmap1 and the negation of bitmap2 and store the result in bitmap res.
void	hwloc_bitmap_xor (hwloc_bitmap_t res, hwloc_const_bitmap_t bitmap1, hwloc_const_bitmap_t bitmap2)
	Xor bitmaps bitmap1 and bitmap2 and store the result in bitmap res.
void	hwloc_bitmap_not (hwloc_bitmap_t res, hwloc_const_bitmap_t bitmap)
	Negate bitmap bitmap and store the result in bitmap res.
int	hwloc_bitmap_intersects (hwloc_const_bitmap_t bitmap1, hwloc_const_bitmap_t bitmap2)
	Test whether bitmaps bitmap1 and bitmap2 intersects.
int	hwloc_bitmap_isincluded (hwloc_const_bitmap_t sub_bitmap, hwloc_const_bitmap_t super_bitmap)
	Test whether bitmap sub_bitmap is part of bitmap super_bitmap.
int	hwloc_bitmap_isequal (hwloc_const_bitmap_t bitmap1, hwloc_const_bitmap_t bitmap2)
	Test whether bitmap bitmap1 is equal to bitmap bitmap2.
int	hwloc_bitmap_compare_first (hwloc_const_bitmap_t bitmap1, hwloc_const_bitmap_t bitmap2)
	Compare bitmaps bitmap1 and bitmap2 using their lowest index.
int	hwloc_bitmap_compare (hwloc_const_bitmap_t bitmap1, hwloc_const_bitmap_t bitmap2)
	Compare bitmaps bitmap1 and bitmap2 using their highest index.

---

Detailed Description

The hwloc_bitmap_t type represents a set of objects, typically OS processors -- which may actually be hardware threads (represented by hwloc_cpuset_t, which is a typedef for hwloc_bitmap_t) -- or memory nodes (represented by hwloc_nodeset_t, which is also a typedef for hwloc_bitmap_t).

Both CPU and node sets are always indexed by OS physical number.

Note:

CPU sets and nodesets are described in Object sets (hwloc_cpuset_t and hwloc_nodeset_t).

A bitmap may be of infinite size.

---

Define Documentation

#define hwloc_bitmap_foreach_begin	(		id,
			bitmap
	)

Loop macro iterating on bitmap bitmap.

index is the loop variable; it should be an unsigned int. The first iteration will set index to the lowest index in the bitmap. Successive iterations will iterate through, in order, all remaining indexes that in the bitmap. To be specific: each iteration will return a value for index such that hwloc_bitmap_isset(bitmap, index) is true.

The assert prevents the loop from being infinite if the bitmap is infinite.

#define hwloc_bitmap_foreach_end

(

)

End of loop. Needs a terminating ';'.

See also:

hwloc_bitmap_foreach_begin

---

Typedef Documentation

typedef struct hwloc_bitmap_s* hwloc_bitmap_t

Set of bits represented as an opaque pointer to an internal bitmap.

typedef struct hwloc_bitmap_s* hwloc_const_bitmap_t

a non-modifiable hwloc_bitmap_t

---

Function Documentation

void hwloc_bitmap_allbut	(	hwloc_bitmap_t	bitmap,
		unsigned	id
	)

Fill the bitmap and clear the index id.

hwloc_bitmap_t hwloc_bitmap_alloc

(

void

)

Allocate a new empty bitmap.

Returns:

A valid bitmap or NULL.

The bitmap should be freed by a corresponding call to hwloc_bitmap_free().

hwloc_bitmap_t hwloc_bitmap_alloc_full

(

void

)

Allocate a new full bitmap.

void hwloc_bitmap_and	(	hwloc_bitmap_t	res,
		hwloc_const_bitmap_t	bitmap1,
		hwloc_const_bitmap_t	bitmap2
	)

And bitmaps bitmap1 and bitmap2 and store the result in bitmap res.

void hwloc_bitmap_andnot	(	hwloc_bitmap_t	res,
		hwloc_const_bitmap_t	bitmap1,
		hwloc_const_bitmap_t	bitmap2
	)

And bitmap bitmap1 and the negation of bitmap2 and store the result in bitmap res.

int hwloc_bitmap_asprintf	(	char **	strp,
		hwloc_const_bitmap_t	bitmap
	)

Stringify a bitmap into a newly allocated string.

void hwloc_bitmap_clr	(	hwloc_bitmap_t	bitmap,
		unsigned	id
	)

Remove index id from bitmap bitmap.

void hwloc_bitmap_clr_range	(	hwloc_bitmap_t	bitmap,
		unsigned	begin,
		unsigned	end
	)

Remove indexes from begin to end in bitmap bitmap.

int hwloc_bitmap_compare	(	hwloc_const_bitmap_t	bitmap1,
		hwloc_const_bitmap_t	bitmap2
	)

Compare bitmaps bitmap1 and bitmap2 using their highest index.

Higher most significant bit is higher. The empty bitmap is considered lower than anything.

int hwloc_bitmap_compare_first	(	hwloc_const_bitmap_t	bitmap1,
		hwloc_const_bitmap_t	bitmap2
	)

Compare bitmaps bitmap1 and bitmap2 using their lowest index.

Smaller least significant bit is smaller. The empty bitmap is considered higher than anything.

void hwloc_bitmap_copy	(	hwloc_bitmap_t	dst,
		hwloc_const_bitmap_t	src
	)

Copy the contents of bitmap src into the already allocated bitmap dst.

hwloc_bitmap_t hwloc_bitmap_dup

(

hwloc_const_bitmap_t

bitmap

)

Duplicate bitmap bitmap by allocating a new bitmap and copying bitmap contents.

void hwloc_bitmap_fill

(

hwloc_bitmap_t

bitmap

)

Fill bitmap bitmap with all possible indexes (even if those objects don't exist or are otherwise unavailable)

int hwloc_bitmap_first

(

hwloc_const_bitmap_t

bitmap

)

Compute the first index (least significant bit) in bitmap bitmap.

Returns:

-1 if no index is set.

void hwloc_bitmap_free

(

hwloc_bitmap_t

bitmap

)

Free bitmap bitmap.

If bitmap is NULL, no operation is performed.

void hwloc_bitmap_from_ith_ulong	(	hwloc_bitmap_t	bitmap,
		unsigned	i,
		unsigned long	mask
	)

Setup bitmap bitmap from unsigned long mask used as i -th subset.

void hwloc_bitmap_from_ulong	(	hwloc_bitmap_t	bitmap,
		unsigned long	mask
	)

Setup bitmap bitmap from unsigned long mask.

int hwloc_bitmap_intersects	(	hwloc_const_bitmap_t	bitmap1,
		hwloc_const_bitmap_t	bitmap2
	)

Test whether bitmaps bitmap1 and bitmap2 intersects.

int hwloc_bitmap_isequal	(	hwloc_const_bitmap_t	bitmap1,
		hwloc_const_bitmap_t	bitmap2
	)

Test whether bitmap bitmap1 is equal to bitmap bitmap2.

int hwloc_bitmap_isfull

(

hwloc_const_bitmap_t

bitmap

)

Test whether bitmap bitmap is completely full.

int hwloc_bitmap_isincluded	(	hwloc_const_bitmap_t	sub_bitmap,
		hwloc_const_bitmap_t	super_bitmap
	)

Test whether bitmap sub_bitmap is part of bitmap super_bitmap.

int hwloc_bitmap_isset	(	hwloc_const_bitmap_t	bitmap,
		unsigned	id
	)

Test whether index id is part of bitmap bitmap.

int hwloc_bitmap_iszero

(

hwloc_const_bitmap_t

bitmap

)

Test whether bitmap bitmap is empty.

int hwloc_bitmap_last

(

hwloc_const_bitmap_t

bitmap

)

Compute the last index (most significant bit) in bitmap bitmap.

Returns:

-1 if no index is bitmap, or if the index bitmap is infinite.

int hwloc_bitmap_next	(	hwloc_const_bitmap_t	bitmap,
		unsigned	prev
	)

Compute the next index in bitmap bitmap which is after index prev.

Returns:

-1 if no index with higher index is bitmap.

void hwloc_bitmap_not	(	hwloc_bitmap_t	res,
		hwloc_const_bitmap_t	bitmap
	)

Negate bitmap bitmap and store the result in bitmap res.

void hwloc_bitmap_only	(	hwloc_bitmap_t	bitmap,
		unsigned	id
	)

Empty the bitmap bitmap and add bit id.

void hwloc_bitmap_or	(	hwloc_bitmap_t	res,
		hwloc_const_bitmap_t	bitmap1,
		hwloc_const_bitmap_t	bitmap2
	)

Or bitmaps bitmap1 and bitmap2 and store the result in bitmap res.

void hwloc_bitmap_set	(	hwloc_bitmap_t	bitmap,
		unsigned	id
	)

Add index id in bitmap bitmap.

void hwloc_bitmap_set_ith_ulong	(	hwloc_bitmap_t	bitmap,
		unsigned	i,
		unsigned long	mask
	)

Replace i -th subset of bitmap bitmap with unsigned long mask.

void hwloc_bitmap_set_range	(	hwloc_bitmap_t	bitmap,
		unsigned	begin,
		unsigned	end
	)

Add indexes from begin to end in bitmap bitmap.

void hwloc_bitmap_singlify

(

hwloc_bitmap_t

bitmap

)

Keep a single index among those set in bitmap bitmap.

May be useful before binding so that the process does not have a chance of migrating between multiple logical CPUs in the original mask.

int hwloc_bitmap_snprintf	(	char *restrict	buf,
		size_t	buflen,
		hwloc_const_bitmap_t	bitmap
	)

Stringify a bitmap.

Up to buflen characters may be written in buffer buf.

If buflen is 0, buf may safely be NULL.

Returns:

the number of character that were actually written if not truncating, or that would have been written (not including the ending \0).

int hwloc_bitmap_sscanf	(	hwloc_bitmap_t	bitmap,
		const char *restrict	string
	)

Parse a bitmap string and stores it in bitmap bitmap.

int hwloc_bitmap_taskset_asprintf	(	char **	strp,
		hwloc_const_bitmap_t	bitmap
	)

Stringify a bitmap into a newly allocated taskset-specific string.

int hwloc_bitmap_taskset_snprintf	(	char *restrict	buf,
		size_t	buflen,
		hwloc_const_bitmap_t	bitmap
	)

Stringify a bitmap in the taskset-specific format.

The taskset command manipulates bitmap strings that contain a single (possible very long) hexadecimal number starting with 0x.

Up to buflen characters may be written in buffer buf.

If buflen is 0, buf may safely be NULL.

Returns:

the number of character that were actually written if not truncating, or that would have been written (not including the ending \0).

int hwloc_bitmap_taskset_sscanf	(	hwloc_bitmap_t	bitmap,
		const char *restrict	string
	)

Parse a taskset-specific bitmap string and stores it in bitmap bitmap.

unsigned long hwloc_bitmap_to_ith_ulong	(	hwloc_const_bitmap_t	bitmap,
		unsigned	i
	)

Convert the i -th subset of bitmap bitmap into unsigned long mask.

unsigned long hwloc_bitmap_to_ulong

(

hwloc_const_bitmap_t

bitmap

)

Convert the beginning part of bitmap bitmap into unsigned long mask.

int hwloc_bitmap_weight

(

hwloc_const_bitmap_t

bitmap

)

Compute the "weight" of bitmap bitmap (i.e., number of indexes that are in the bitmap).

Returns:

the number of indexes that are in the bitmap.

void hwloc_bitmap_xor	(	hwloc_bitmap_t	res,
		hwloc_const_bitmap_t	bitmap1,
		hwloc_const_bitmap_t	bitmap2
	)

Xor bitmaps bitmap1 and bitmap2 and store the result in bitmap res.

void hwloc_bitmap_zero

(

hwloc_bitmap_t

bitmap

)

Empty the bitmap bitmap.