NAME

       ck_epoch_barrier — block until a grace period and all callbacks have been dispatched

LIBRARY

       Concurrency Kit (libck, -lck)

SYNOPSIS

       #include <ck_epoch.h>

       void
       ck_epoch_barrier(ck_epoch_record_t *record);

DESCRIPTION

       The  ck_epoch_barrier(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 ck_epoch_barrier(3). This function  will  also
       dispatch all callbacks associated with epoch that were previously scheduled via ck_epoch_call(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, NULL);

                     /*
                      * 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_barrier(record);

                     /* It is now safe to physically delete the object. */
                     free(s);
                     return;
             }

RETURN VALUES

       This function has no return value.

ERRORS

       Behavior  is  undefined if the object pointed to by epoch is not a valid epoch object. The object pointed
       to by record must have been previously registered via ck_epoch_register(3).

SEE ALSO

       ck_epoch_init(3), ck_epoch_register(3),  ck_epoch_unregister(3),  ck_epoch_recycle(3),  ck_epoch_poll(3),
       ck_epoch_synchronize(3), ck_epoch_reclaim(3), ck_epoch_call(3), ck_epoch_begin(3), ck_epoch_end(3)

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

                                                September 2, 2012                            CK_EPOCH_BARRIER(3)