ck_epoch_synchronize(3)

NAME

ck_epoch_synchronize – block until a grace period has been detected

LIBRARY

Concurrency Kit (libck, -lck)

SYNOPSIS

In ck_epoch.h Ft void Fn ck_epoch_synchronize ck_epoch_record_t *record

DESCRIPTION

The Fn ck_epoch_synchronize 3 function will block the caller until a grace period has been detected, according to the semantics of epoch reclamation. Any objects requiring safe memory reclamation which are logically deleted are safe for physical deletion following a call to Fn ck_epoch_synchronize 3 . If you require that all callbacks be dispatched, then it is suggested that you use Fn ck_epoch_barrier 3 instead or follow a call of Fn ck_epoch_synchronize 3 with Fn 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 Fn ck_epoch_register 3 .