manpagez: man pages & more
man hwloc_bitmap_to_ulong(3)
Home | html | info | man
hwlocality_bitmap(3)        Hardware Locality (hwloc)       hwlocality_bitmap(3)




NAME

       hwlocality_bitmap - The bitmap API


SYNOPSIS

   Macros
       #define hwloc_bitmap_foreach_begin(id,  bitmap)
       #define hwloc_bitmap_foreach_end()

   Typedefs
       typedef struct hwloc_bitmap_s * hwloc_bitmap_t
       typedef const struct hwloc_bitmap_s * hwloc_const_bitmap_t

   Functions
       hwloc_bitmap_t hwloc_bitmap_alloc (void)
       hwloc_bitmap_t hwloc_bitmap_alloc_full (void)
       void hwloc_bitmap_free (hwloc_bitmap_t bitmap)
       hwloc_bitmap_t hwloc_bitmap_dup (hwloc_const_bitmap_t bitmap)
       int hwloc_bitmap_copy (hwloc_bitmap_t dst, hwloc_const_bitmap_t src)
       int hwloc_bitmap_snprintf (char *restrict buf, size_t buflen,
           hwloc_const_bitmap_t bitmap)
       int hwloc_bitmap_asprintf (char **strp, hwloc_const_bitmap_t bitmap)
       int hwloc_bitmap_sscanf (hwloc_bitmap_t bitmap, const char *restrict
           string)
       int hwloc_bitmap_list_snprintf (char *restrict buf, size_t buflen,
           hwloc_const_bitmap_t bitmap)
       int hwloc_bitmap_list_asprintf (char **strp, hwloc_const_bitmap_t bitmap)
       int hwloc_bitmap_list_sscanf (hwloc_bitmap_t bitmap, const char *restrict
           string)
       int hwloc_bitmap_taskset_snprintf (char *restrict buf, size_t buflen,
           hwloc_const_bitmap_t bitmap)
       int hwloc_bitmap_taskset_asprintf (char **strp, hwloc_const_bitmap_t
           bitmap)
       int hwloc_bitmap_taskset_sscanf (hwloc_bitmap_t bitmap, const char
           *restrict string)
       void hwloc_bitmap_zero (hwloc_bitmap_t bitmap)
       void hwloc_bitmap_fill (hwloc_bitmap_t bitmap)
       int hwloc_bitmap_only (hwloc_bitmap_t bitmap, unsigned id)
       int hwloc_bitmap_allbut (hwloc_bitmap_t bitmap, unsigned id)
       int hwloc_bitmap_from_ulong (hwloc_bitmap_t bitmap, unsigned long mask)
       int hwloc_bitmap_from_ith_ulong (hwloc_bitmap_t bitmap, unsigned i,
           unsigned long mask)
       int hwloc_bitmap_from_ulongs (hwloc_bitmap_t bitmap, unsigned nr, const
           unsigned long *masks)
       int hwloc_bitmap_set (hwloc_bitmap_t bitmap, unsigned id)
       int hwloc_bitmap_set_range (hwloc_bitmap_t bitmap, unsigned begin, int
           end)
       int hwloc_bitmap_set_ith_ulong (hwloc_bitmap_t bitmap, unsigned i,
           unsigned long mask)
       int hwloc_bitmap_clr (hwloc_bitmap_t bitmap, unsigned id)
       int hwloc_bitmap_clr_range (hwloc_bitmap_t bitmap, unsigned begin, int
           end)
       int hwloc_bitmap_singlify (hwloc_bitmap_t bitmap)
       unsigned long hwloc_bitmap_to_ulong (hwloc_const_bitmap_t bitmap)
       unsigned long hwloc_bitmap_to_ith_ulong (hwloc_const_bitmap_t bitmap,
           unsigned i)
       int hwloc_bitmap_to_ulongs (hwloc_const_bitmap_t bitmap, unsigned nr,
           unsigned long *masks)
       int hwloc_bitmap_nr_ulongs (hwloc_const_bitmap_t bitmap)
       int hwloc_bitmap_isset (hwloc_const_bitmap_t bitmap, unsigned id)
       int hwloc_bitmap_iszero (hwloc_const_bitmap_t bitmap)
       int hwloc_bitmap_isfull (hwloc_const_bitmap_t bitmap)
       int hwloc_bitmap_first (hwloc_const_bitmap_t bitmap)
       int hwloc_bitmap_next (hwloc_const_bitmap_t bitmap, int prev)
       int hwloc_bitmap_last (hwloc_const_bitmap_t bitmap)
       int hwloc_bitmap_weight (hwloc_const_bitmap_t bitmap)
       int hwloc_bitmap_first_unset (hwloc_const_bitmap_t bitmap)
       int hwloc_bitmap_next_unset (hwloc_const_bitmap_t bitmap, int prev)
       int hwloc_bitmap_last_unset (hwloc_const_bitmap_t bitmap)
       int hwloc_bitmap_or (hwloc_bitmap_t res, hwloc_const_bitmap_t bitmap1,
           hwloc_const_bitmap_t bitmap2)
       int hwloc_bitmap_and (hwloc_bitmap_t res, hwloc_const_bitmap_t bitmap1,
           hwloc_const_bitmap_t bitmap2)
       int hwloc_bitmap_andnot (hwloc_bitmap_t res, hwloc_const_bitmap_t
           bitmap1, hwloc_const_bitmap_t bitmap2)
       int hwloc_bitmap_xor (hwloc_bitmap_t res, hwloc_const_bitmap_t bitmap1,
           hwloc_const_bitmap_t bitmap2)
       int hwloc_bitmap_not (hwloc_bitmap_t res, hwloc_const_bitmap_t bitmap)
       int hwloc_bitmap_intersects (hwloc_const_bitmap_t bitmap1,
           hwloc_const_bitmap_t bitmap2)
       int hwloc_bitmap_isincluded (hwloc_const_bitmap_t sub_bitmap,
           hwloc_const_bitmap_t super_bitmap)
       int hwloc_bitmap_isequal (hwloc_const_bitmap_t bitmap1,
           hwloc_const_bitmap_t bitmap2)
       int hwloc_bitmap_compare_first (hwloc_const_bitmap_t bitmap1,
           hwloc_const_bitmap_t bitmap2)
       int hwloc_bitmap_compare (hwloc_const_bitmap_t bitmap1,
           hwloc_const_bitmap_t bitmap2)


Detailed Description

       The hwloc_bitmap_t type represents a set of integers (positive or null).
       A bitmap may be of infinite size (all bits are set after some point). A
       bitmap may even be full if all bits are set.

       Bitmaps are used by hwloc for sets of OS processors (which may actually
       be hardware threads) as by hwloc_cpuset_t (a typedef for hwloc_bitmap_t),
       or sets of NUMA memory nodes as hwloc_nodeset_t (also a typedef for
       hwloc_bitmap_t). Those are used for cpuset and nodeset fields in the
       hwloc_obj structure, see Object Sets (hwloc_cpuset_t and
       hwloc_nodeset_t).

       Both CPU and node sets are always indexed by OS physical number. However
       users should usually not build CPU and node sets manually (e.g. with
       hwloc_bitmap_set()). One should rather use existing object sets and
       combine them with hwloc_bitmap_or(), etc. For instance, binding the
       current thread on a pair of cores may be performed with:

       hwloc_obj_t core1 = ... , core2 = ... ;
       hwloc_bitmap_t set = hwloc_bitmap_alloc();
       hwloc_bitmap_or(set, core1->cpuset, core2->cpuset);
       hwloc_set_cpubind(topology, set, HWLOC_CPUBIND_THREAD);
       hwloc_bitmap_free(set);


       Note
           Most functions below return an int that may be negative in case of
           error. The usual error case would be an internal failure to
           realloc/extend the storage of the bitmap (errno would be set to
           ENOMEM).

           Several examples of using the bitmap API are available under the
           doc/examples/ directory in the source tree. Regression tests such as
           tests/hwloc/hwloc_bitmap*.c also make intensive use of this API.


Macro Definition Documentation

   #define hwloc_bitmap_foreach_begin(id, bitmap)
       Loop macro iterating on bitmap bitmap. The loop must start with
       hwloc_bitmap_foreach_begin() and end with hwloc_bitmap_foreach_end()
       followed by a terminating ';'.

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

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

   #define hwloc_bitmap_foreach_end()
       End of loop macro iterating on a bitmap. 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 const struct hwloc_bitmap_s* hwloc_const_bitmap_t
       a non-modifiable hwloc_bitmap_t


Function Documentation

   int 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.

   int 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. res
       can be the same as bitmap1 or bitmap2

   int 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. res can be the same as bitmap1 or bitmap2

   int hwloc_bitmap_asprintf (char ** strp, hwloc_const_bitmap_t bitmap)
       Stringify a bitmap into a newly allocated string.

       Returns
           -1 on error.

   int hwloc_bitmap_clr (hwloc_bitmap_t bitmap, unsigned id)
       Remove index id from bitmap bitmap.

   int hwloc_bitmap_clr_range (hwloc_bitmap_t bitmap, unsigned begin, int end)
       Remove indexes from begin to end in bitmap bitmap. If end is -1, the
       range is infinite.

   int hwloc_bitmap_compare (hwloc_const_bitmap_t bitmap1, hwloc_const_bitmap_t
       bitmap2)
       Compare bitmaps bitmap1 and bitmap2 in lexicographic order. Lexicographic
       comparison of bitmaps, starting for their highest indexes. Compare last
       indexes first, then second, etc. The empty bitmap is considered lower
       than anything.

       Returns
           -1 if bitmap1 is considered smaller than bitmap2.

           1 if bitmap1 is considered larger than bitmap2.

           0 if bitmaps are equal (contrary to hwloc_bitmap_compare_first()).

       For instance comparing binary bitmaps 0011 and 0110 returns -1 (hence
       0011 is considered smaller than 0110). Comparing 00101 and 01010 returns
       -1 too.

       Note
           This is different from the non-existing hwloc_bitmap_compare_last()
           which would only compare the highest index of each bitmap.

   int hwloc_bitmap_compare_first (hwloc_const_bitmap_t bitmap1,
       hwloc_const_bitmap_t bitmap2)
       Compare bitmaps bitmap1 and bitmap2 using their lowest index. A bitmap is
       considered smaller if its least significant bit is smaller. The empty
       bitmap is considered higher than anything (because its least significant
       bit does not exist).

       Returns
           -1 if bitmap1 is considered smaller than bitmap2.

           1 if bitmap1 is considered larger than bitmap2.

       For instance comparing binary bitmaps 0011 and 0110 returns -1 (hence
       0011 is considered smaller than 0110) because least significant bit of
       0011 (0001) is smaller than least significant bit of 0110 (0010).
       Comparing 01001 and 00110 would also return -1 for the same reason.

       Returns
           0 if bitmaps are considered equal, even if they are not strictly
           equal. They just need to have the same least significant bit. For
           instance, comparing binary bitmaps 0010 and 0110 returns 0 because
           they have the same least significant bit.

   int 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. If bitmap is NULL, NULL is returned.

   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 in bitmap.

   int hwloc_bitmap_first_unset (hwloc_const_bitmap_t bitmap)
       Compute the first unset index (least significant bit) in bitmap bitmap.

       Returns
           -1 if no index is unset in bitmap.

   void hwloc_bitmap_free (hwloc_bitmap_t bitmap)
       Free bitmap bitmap. If bitmap is NULL, no operation is performed.

   int 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.

   int hwloc_bitmap_from_ulong (hwloc_bitmap_t bitmap, unsigned long mask)
       Setup bitmap bitmap from unsigned long mask.

   int hwloc_bitmap_from_ulongs (hwloc_bitmap_t bitmap, unsigned nr, const
       unsigned long * masks)
       Setup bitmap bitmap from unsigned longs masks used as first nr subsets.

   int hwloc_bitmap_intersects (hwloc_const_bitmap_t bitmap1,
       hwloc_const_bitmap_t bitmap2)
       Test whether bitmaps bitmap1 and bitmap2 intersects.

       Returns
           1 if bitmaps intersect, 0 otherwise.

   int hwloc_bitmap_isequal (hwloc_const_bitmap_t bitmap1, hwloc_const_bitmap_t
       bitmap2)
       Test whether bitmap bitmap1 is equal to bitmap bitmap2.

       Returns
           1 if bitmaps are equal, 0 otherwise.

   int hwloc_bitmap_isfull (hwloc_const_bitmap_t bitmap)
       Test whether bitmap bitmap is completely full.

       Returns
           1 if bitmap is full, 0 otherwise.

       Note
           A full bitmap is always infinitely set.

   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.

       Returns
           1 if sub_bitmap is included in super_bitmap, 0 otherwise.

       Note
           The empty bitmap is considered included in any other bitmap.

   int hwloc_bitmap_isset (hwloc_const_bitmap_t bitmap, unsigned id)
       Test whether index id is part of bitmap bitmap.

       Returns
           1 if the bit at index id is set in bitmap bitmap, 0 otherwise.

   int hwloc_bitmap_iszero (hwloc_const_bitmap_t bitmap)
       Test whether bitmap bitmap is empty.

       Returns
           1 if bitmap is empty, 0 otherwise.

   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 set in bitmap, or if bitmap is infinitely set.

   int hwloc_bitmap_last_unset (hwloc_const_bitmap_t bitmap)
       Compute the last unset index (most significant bit) in bitmap bitmap.

       Returns
           -1 if no index is unset in bitmap, or if bitmap is infinitely set.

   int hwloc_bitmap_list_asprintf (char ** strp, hwloc_const_bitmap_t bitmap)
       Stringify a bitmap into a newly allocated list string.

       Returns
           -1 on error.

   int hwloc_bitmap_list_snprintf (char *restrict buf, size_t buflen,
       hwloc_const_bitmap_t bitmap)
       Stringify a bitmap in the list format. Lists are comma-separated indexes
       or ranges. Ranges are dash separated indexes. The last range may not have
       an ending indexes if the bitmap is infinitely set.

       Up to buflen characters may be written in buffer buf.

       If buflen is 0, buf may safely be NULL.

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

   int hwloc_bitmap_list_sscanf (hwloc_bitmap_t bitmap, const char *restrict
       string)
       Parse a list string and stores it in bitmap bitmap.

   int hwloc_bitmap_next (hwloc_const_bitmap_t bitmap, int prev)
       Compute the next index in bitmap bitmap which is after index prev. If
       prev is -1, the first index is returned.

       Returns
           -1 if no index with higher index is set in bitmap.

   int hwloc_bitmap_next_unset (hwloc_const_bitmap_t bitmap, int prev)
       Compute the next unset index in bitmap bitmap which is after index prev.
       If prev is -1, the first unset index is returned.

       Returns
           -1 if no index with higher index is unset in bitmap.

   int hwloc_bitmap_not (hwloc_bitmap_t res, hwloc_const_bitmap_t bitmap)
       Negate bitmap bitmap and store the result in bitmap res. res can be the
       same as bitmap

   int hwloc_bitmap_nr_ulongs (hwloc_const_bitmap_t bitmap)
       Return the number of unsigned longs required for storing bitmap bitmap
       entirely. This is the number of contiguous unsigned longs from the very
       first bit of the bitmap (even if unset) up to the last set bit. This is
       useful for knowing the nr parameter to pass to hwloc_bitmap_to_ulongs()
       (or which calls to hwloc_bitmap_to_ith_ulong() are needed) to entirely
       convert a bitmap into multiple unsigned longs.

       When called on the output of hwloc_topology_get_topology_cpuset(), the
       returned number is large enough for all cpusets of the topology.

       Returns
           -1 if bitmap is infinite.

   int hwloc_bitmap_only (hwloc_bitmap_t bitmap, unsigned id)
       Empty the bitmap bitmap and add bit id.

   int 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. res
       can be the same as bitmap1 or bitmap2

   int hwloc_bitmap_set (hwloc_bitmap_t bitmap, unsigned id)
       Add index id in bitmap bitmap.

   int 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.

   int hwloc_bitmap_set_range (hwloc_bitmap_t bitmap, unsigned begin, int end)
       Add indexes from begin to end in bitmap bitmap. If end is -1, the range
       is infinite.

   int 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 processors in the original mask. Instead of running the
       task on any PU inside the given CPU set, the operating system scheduler
       will be forced to run it on a single of these PUs. It avoids a migration
       overhead and cache-line ping-pongs between PUs.

       Note
           This function is NOT meant to distribute multiple processes within a
           single CPU set. It always return the same single bit when called
           multiple times on the same input set. hwloc_distrib() may be used for
           generating CPU sets to distribute multiple tasks below a single
           multi-PU object.

           This function cannot be applied to an object set directly. It should
           be applied to a copy (which may be obtained with hwloc_bitmap_dup()).

   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 characters 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.

       Returns
           -1 on error.

   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 characters 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_to_ulongs (hwloc_const_bitmap_t bitmap, unsigned nr,
       unsigned long * masks)
       Convert the first nr subsets of bitmap bitmap into the array of nr
       unsigned long masks. nr may be determined earlier with
       hwloc_bitmap_nr_ulongs().

       Returns
           0

   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.

           -1 if bitmap is infinitely set.

   int 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. res
       can be the same as bitmap1 or bitmap2

   void hwloc_bitmap_zero (hwloc_bitmap_t bitmap)
       Empty the bitmap bitmap.


Author

       Generated automatically by Doxygen for Hardware Locality (hwloc) from the
       source code.



Version 2.9.1                    Tue Mar 28 2023            hwlocality_bitmap(3)

hwloc 2.9.1 - Generated Fri Apr 21 05:46:33 CDT 2023
© manpagez.com 2000-2024
Individual documents may contain additional copyright information.