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

# ck\_epoch\_call(3)

defer function execution until a grace period

## NAME

**ck\_epoch\_call** – defer function execution until a grace period

## LIBRARY

Concurrency Kit (libck, -lck)

## SYNOPSIS

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

typedef struct ck\_epoch\_entry ck\_epoch\_entry\_t;\
 typedef void ck\_epoch\_cb\_t(ck\_epoch\_entry\_t \*);

*void*\

**ck\_epoch\_call**(*ck\_epoch\_record\_t \*record*, *ck\_epoch\_entry\_t \*entry*, *ck\_epoch\_cb\_t \*function*);

## DESCRIPTION

The **ck\_epoch\_call**(*3*) function will defer the execution of the function pointed to by *function* until a grace-period has been detected in *epoch*. The function will be provided the pointer specified by *entry*. The function will execute at some time in the future via calls to **ck\_epoch\_reclaim**(*3*), **ck\_epoch\_barrier**(*3*) or **ck\_epoch\_poll**(*3*).

## EXAMPLE

```
#include <ck_epoch.h>
#include <ck_stack.h>
#include <stdlib.h>
/*
 * epoch was previously initialized with ck_epoch_init.
 */
ck_epoch_t *epoch;
struct object {
	int value;
	ck_epoch_entry_t epoch_entry;
};
static struct object *global;
CK_EPOCH_CONTAINER(struct object, epoch_entry, object_container)
void
destroy_object(ck_epoch_entry_t *e)
{
	struct object *o = object_container(e);
	free(o);
	return;
}
void
function(void)
{
	ck_epoch_record_t *record;
	struct object *n;
	record = malloc(sizeof *record);
	ck_epoch_register(&epoch, record, NULL);
	n = malloc(sizeof *n);
	if (n == NULL)
		return;
	n->value = 1;
	/*
	 * We are using an epoch section here because there are multiple
	 * writers. It is also an option to use other forms of blocking
	 * write-side synchronization such as mutexes.
	 */
	ck_epoch_begin(record);
	n = ck_pr_fas_ptr(&global, n);
	ck_epoch_end(record);
	/* Defer destruction of previous object. */
	ck_epoch_call(record, &n->epoch_entry, destroy_object);
	/* Poll epoch sub-system in non-blocking manner. */
	ck_epoch_poll(record);
	return;
}
```

## RETURN VALUES

This function has no return value.

## ERRORS

The object pointed to by *record* must have been previously registered via **ck\_epoch\_register**(*3*).

## SEE ALSO

[ck\_epoch\_init(3)](/ck_epoch_init/3.md), [ck\_epoch\_register(3)](/ck_epoch_register/3.md), [ck\_epoch\_unregister(3)](/ck_epoch_unregister/3.md), [ck\_epoch\_recycle(3)](/ck_epoch_recycle/3.md), [ck\_epoch\_poll(3)](/ck_epoch_poll/3.md), [ck\_epoch\_synchronize(3)](/ck_epoch_synchronize/3.md), [ck\_epoch\_reclaim(3)](/ck_epoch_reclaim/3.md), [ck\_epoch\_barrier(3)](/ck_epoch_barrier/3.md), [ck\_epoch\_begin(3)](/ck_epoch_begin/3.md), [ck\_epoch\_end(3)](/ck_epoch_end/3.md)

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