102 lines
4.0 KiB
C
102 lines
4.0 KiB
C
/*
|
|
Copyright (c) 2011, 2015, Oracle and/or its affiliates. All rights reserved.
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License, version 2.0,
|
|
as published by the Free Software Foundation.
|
|
|
|
This program is also distributed with certain software (including
|
|
but not limited to OpenSSL) that is licensed under separate terms,
|
|
as designated in a particular file or component or in included license
|
|
documentation. The authors of MySQL hereby grant you an additional
|
|
permission to link the program and your derivative works with the
|
|
separately licensed software that they have included with MySQL.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License, version 2.0, for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
#include <pthread.h>
|
|
|
|
#include "ndbmemcache_global.h"
|
|
#include "timing.h"
|
|
#include "atomics.h"
|
|
|
|
/* Bounded FIFO SPMC work queue:
|
|
single producer, multiple consumers
|
|
*/
|
|
|
|
|
|
#define Q_INT_SIZE sizeof(int)
|
|
#define Q_GROUP1_SIZE (4 + Q_INT_SIZE + Q_INT_SIZE + sizeof (void *))
|
|
#define Q_CONDVAR_SIZE sizeof(pthread_cond_t)
|
|
#define Q_MUTEX_SIZE sizeof(pthread_mutex_t)
|
|
#define Q_GROUP2_SIZE (4 + Q_CONDVAR_SIZE + Q_CONDVAR_SIZE + Q_MUTEX_SIZE)
|
|
|
|
struct workqueue {
|
|
/* this is the producer's cache line */
|
|
atomic_int32_t freelist; /*< producer's current free item */
|
|
unsigned int size; /*< number of slots in the queue */
|
|
unsigned int p_mask; /*< used for modulo division */
|
|
void ** p_items; /*< the workqueue array */
|
|
|
|
char padding1[CACHE_LINE_SIZE - Q_GROUP1_SIZE];
|
|
|
|
/* these are used for empty/full signalling */
|
|
atomic_int32_t is_active; /*< set to 0 when the queue is shut down */
|
|
pthread_cond_t not_empty; /*< signal that there is data available */
|
|
pthread_cond_t not_full; /*< signal that there is free space */
|
|
pthread_mutex_t signal_lock; /*< mutex to protect empty/full signals */
|
|
|
|
char padding2[CACHE_LINE_SIZE - (Q_GROUP2_SIZE % CACHE_LINE_SIZE)];
|
|
|
|
volatile int depth; /*< heuristic indicator of queue depth */
|
|
|
|
char padding3[CACHE_LINE_SIZE - Q_INT_SIZE];
|
|
|
|
/* this is the consumer's cache line */
|
|
int threads; /*< actually nconsumers - 1 */
|
|
unsigned int c_mask; /*< consumer's copy of mask */
|
|
unsigned int minfree; /*< heuristic number of free slots desired */
|
|
atomic_int32_t consumer_spinlock; /*< for multiple consumer threads */
|
|
atomic_int32_t worklist; /*< consumer's current work item */
|
|
void ** c_items; /*< consumer's copy of the array addr */
|
|
};
|
|
|
|
|
|
/* This API has C linkage */
|
|
DECLARE_FUNCTIONS_WITH_C_LINKAGE
|
|
|
|
/*< Initialize a queue that has been allocated
|
|
@param size *must be a power of 2*
|
|
@param nconsumers the number of expected consumer threads
|
|
*/
|
|
int workqueue_init(struct workqueue *q, int size, int nconsumers);
|
|
|
|
/* Add an item to a workqueue. This can be called by one producer thread. */
|
|
int workqueue_add (struct workqueue *q, void *item);
|
|
|
|
/* Sleep until an item is available on the queue, then fetch it. */
|
|
void * workqueue_consumer_wait(struct workqueue *q);
|
|
|
|
/* Returns true if at item is available on the queue */
|
|
int workqueue_consumer_poll(struct workqueue *q);
|
|
|
|
/* Free the internal resources used by a workqueue.
|
|
The caller is still responsible for freeing the workqueue itself. */
|
|
void workqueue_destroy(struct workqueue *q);
|
|
|
|
/* Abort an active workqueue */
|
|
void workqueue_abort(struct workqueue *q);
|
|
|
|
/* Find out if a workqueue has been aborted */
|
|
int workqueue_is_aborted(struct workqueue *q);
|
|
|
|
END_FUNCTIONS_WITH_C_LINKAGE
|
|
|