---
name: "ck_ht_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_ht_gc"
---

# ck\_ht\_gc(3)

perform maintenance on a hash table

## NAME

**ck\_ht\_gc** – perform maintenance on a hash table

## LIBRARY

Concurrency Kit (libck, -lck)

## SYNOPSIS

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

*bool*\

**ck\_ht\_gc**(*ck\_ht\_t \*ht*, *unsigned long cycles*, *unsigned long seed*);

## DESCRIPTION

The **ck\_ht\_gc**() function will perform various maintenance routines on the hash table pointed to by *ht*, 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 table entries should be subject to attempted maintenance. If *cycles* is 0, then maintenance is performed on the complete hash table. 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\_ht\_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\_ht\_count(3)](/ck_ht_count/3.md), [ck\_ht\_stat(3)](/ck_ht_stat/3.md), [ck\_ht\_init(3)](/ck_ht_init/3.md), [ck\_ht\_destroy(3)](/ck_ht_destroy/3.md), [ck\_ht\_hash(3)](/ck_ht_hash/3.md), [ck\_ht\_hash\_direct(3)](/ck_ht_hash_direct/3.md), [ck\_ht\_set\_spmc(3)](/ck_ht_set_spmc/3.md), [ck\_ht\_put\_spmc(3)](/ck_ht_put_spmc/3.md), [ck\_ht\_get\_spmc(3)](/ck_ht_get_spmc/3.md), [ck\_ht\_grow\_spmc(3)](/ck_ht_grow_spmc/3.md), [ck\_ht\_remove\_spmc(3)](/ck_ht_remove_spmc/3.md), [ck\_ht\_reset\_size\_spmc(3)](/ck_ht_reset_size_spmc/3.md), [ck\_ht\_reset\_spmc(3)](/ck_ht_reset_spmc/3.md), [ck\_ht\_entry\_empty(3)](/ck_ht_entry_empty/3.md), [ck\_ht\_entry\_key\_set(3)](/ck_ht_entry_key_set/3.md), [ck\_ht\_entry\_key\_set\_direct(3)](/ck_ht_entry_key_set_direct/3.md), [ck\_ht\_entry\_key(3)](/ck_ht_entry_key/3.md), [ck\_ht\_entry\_key\_length(3)](/ck_ht_entry_key_length/3.md), [ck\_ht\_entry\_value(3)](/ck_ht_entry_value/3.md), [ck\_ht\_entry\_set(3)](/ck_ht_entry_set/3.md), [ck\_ht\_entry\_set\_direct(3)](/ck_ht_entry_set_direct/3.md), [ck\_ht\_entry\_key\_direct(3)](/ck_ht_entry_key_direct/3.md), [ck\_ht\_entry\_value\_direct(3)](/ck_ht_entry_value_direct/3.md), [ck\_ht\_iterator\_init(3)](/ck_ht_iterator_init/3.md), [ck\_ht\_next(3)](/ck_ht_next/3.md)

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