CK_EPOCH_SYNCHRONIZE(3) BSD Library Functions Manual CK_EPOCH_SYNCHRONIZE(3)NAMEck_epoch_synchronize — block until a grace period has been detected
LIBRARY
Concurrency Kit (libck, -lck)
SYNOPSIS
#include <ck_epoch.h>
void
ck_epoch_synchronize(ck_epoch_record_t *record);
DESCRIPTION
The ck_epoch_synchronize(3) function will block the caller until a grace
period has been detected, according to the semantics of epoch reclama‐
tion. Any objects requiring safe memory reclamation which are logically
deleted are safe for physical deletion following a call to
ck_epoch_synchronize(3). If you require that all callbacks be dis‐
patched, then it is suggested that you use ck_epoch_barrier(3) instead or
follow a call of ck_epoch_synchronize(3) with ck_epoch_reclaim(3).
EXAMPLE
#include <ck_epoch.h>
#include <ck_stack.h>
#include <stdlib.h>
/*
* epoch was previously initialized with ck_epoch_init.
* stack was previously initialized with ck_stack_init.
*/
ck_epoch_t *epoch;
ck_stack_t *stack;
void
function(void)
{
ck_epoch_record_t *record;
ck_stack_entry_t *s;
record = malloc(sizeof *record);
ck_epoch_register(&epoch, record);
/*
* We are using an epoch section here to guarantee no
* nodes in the stack are deleted while we are dereferencing
* them. This is needed here because there are multiple writers.
* If there was only one thread popping from the this stack,
* then there is no need to ck_epoch_begin/ck_epoch_end.
*/
ck_epoch_begin(record);
/* Logically delete an object. */
s = ck_stack_pop_upmc(stack);
ck_epoch_end(record);
/*
* Wait until no threads could possibly have a reference to the
* object we just popped (assume all threads are simply executing
* ck_stack_pop_upmc).
*/
ck_epoch_synchronize(record);
/* It is now safe to physically delete the object. */
free(s);
return;
}
RETURN VALUES
This function has no return value.
ERRORS
The object pointed to by .Fa record must have been previously registered
via ck_epoch_register(3).
SEE ALSOck_epoch_init(3), ck_epoch_register(3), ck_epoch_unregister(3),
ck_epoch_recycle(3), ck_epoch_poll(3), ck_epoch_reclaim(3),
ck_epoch_barrier(3), ck_epoch_call(3), ck_epoch_begin(3), ck_epoch_end(3)
Additional information available at http://concurrencykit.org/
September 2, 2012
