---
name: "ck_hs_gc"
section: "3"
platform: "linux"
package: "libck-dev"
version: "0.7.2-6"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/ck_hs_gc"
---

# ck\_hs\_gc(3)

perform maintenance on a hash set

## NAME

**ck\_hs\_gc** – perform maintenance on a hash set

## LIBRARY

Concurrency Kit (libck, -lck)

## SYNOPSIS

**#include \<ck\_hs.h\>**

*bool*\

**ck\_hs\_gc**(*ck\_hs\_t \*hs*, *unsigned long cycles*, *unsigned long seed*);

## DESCRIPTION

The **ck\_hs\_gc**(*3*) function will perform various maintenance routines on the hash set pointed to by *hs*, including defragmentation of probe sequences with respect to tombstones and in the case that the delete workload hint has been passed, recalculation of probe sequence bounds. The *cycles* argument is used to indicate how many hash set entries should be subject to attempted maintenance. If *cycles* is 0, then maintenance is performed on the complete hash set. The *seed* argument determines the start location of the maintenance process. If *cycles* is non-zero, it is recommended that *seed* is some random value. If the delete hint has been passed, the function will require an additional 12% of memory (with respect to existing memory usage of the set), until operation completion.

## RETURN VALUES

Upon successful completion, **ck\_hs\_gc**(*3*) returns true and otherwise returns false on failure due to memory allocation failure.

## ERRORS

This function will only return false if there are internal memory allocation failures.

## SEE ALSO

[ck\_hs\_init(3)](/ck_hs_init/3.md), [ck\_hs\_move(3)](/ck_hs_move/3.md), [ck\_hs\_destroy(3)](/ck_hs_destroy/3.md), [CK\_HS\_HASH(3)](/CK_HS_HASH/3.md), [ck\_hs\_iterator\_init(3)](/ck_hs_iterator_init/3.md), [ck\_hs\_next(3)](/ck_hs_next/3.md), [ck\_hs\_get(3)](/ck_hs_get/3.md), [ck\_hs\_put(3)](/ck_hs_put/3.md), [ck\_hs\_put\_unique(3)](/ck_hs_put_unique/3.md), [ck\_hs\_grow(3)](/ck_hs_grow/3.md), [ck\_hs\_rebuild(3)](/ck_hs_rebuild/3.md), [ck\_hs\_set(3)](/ck_hs_set/3.md), [ck\_hs\_fas(3)](/ck_hs_fas/3.md), [ck\_hs\_remove(3)](/ck_hs_remove/3.md), [ck\_hs\_count(3)](/ck_hs_count/3.md), [ck\_hs\_reset(3)](/ck_hs_reset/3.md), [ck\_hs\_reset\_size(3)](/ck_hs_reset_size/3.md), [ck\_hs\_stat(3)](/ck_hs_stat/3.md)

Additional information available at http://concurrencykit.org/