/*

 * include/haproxy/port_range.h

 * This file defines everything needed to manage port ranges

 *

 * Copyright (C) 2000-2020 Willy Tarreau - w@1wt.eu

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation, version 2.1

 * exclusively.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 */

#ifndef _HAPROXY_PORT_RANGE_H

#define _HAPROXY_PORT_RANGE_H

#include <stdlib.h>

#include <haproxy/api.h>

#include <haproxy/port_range-t.h>

#define GET_NEXT_OFF(range, off) ((off) == (range)->size - 1 ? 0 : (off) + 1)

/* return an available port from range <range>, or zero if none is left */

static inline int port_range_alloc_port(struct port_range *range)

{

  int ret;

  int get;

  int put;

  get = _HA_ATOMIC_LOAD(&range->get);

  do {

    /* barrier to make sure get is loaded before put */

    __ha_barrier_atomic_load();

    put = _HA_ATOMIC_LOAD(&range->put_t);

    if (unlikely(put == get))

      return 0;

    ret = range->ports[get];

  } while (!(_HA_ATOMIC_CAS(&range->get, &get, GET_NEXT_OFF(range, get))));

  return ret;

}

Unexecuted instantiation: fd.c:port_range_alloc_port

Unexecuted instantiation: server.c:port_range_alloc_port

Unexecuted instantiation: check.c:port_range_alloc_port

Unexecuted instantiation: proto_tcp.c:port_range_alloc_port

/* release port <port> into port range <range>. Does nothing if <port> is zero

 * nor if <range> is null. The caller is responsible for marking the port

 * unused by either setting the port to zero or the range to NULL.

 */

static inline void port_range_release_port(struct port_range *range, int port)

{

  int put;

  if (!port || !range)

    return;

  put = range->put_h;

  /* put_h is reserved for producers, so that they can each get a

   * free slot, put_t is what is used by consumers to know if there's

   * elements available or not

   */

  /* First reserve or slot, we know the ring buffer can't be full,

   * as we will only ever release port we allocated before

   */

  while (!(_HA_ATOMIC_CAS(&range->put_h, &put, GET_NEXT_OFF(range, put))));

  _HA_ATOMIC_STORE(&range->ports[put], port);

  /* Barrier to make sure the new port is visible before we change put_t */

  __ha_barrier_atomic_store();

  /* Wait until all the threads that got a slot before us are done */

  while ((volatile int)range->put_t != put)

    __ha_compiler_barrier();

  /* Let the world know we're done, and any potential consumer they

   * can use that port.

   */

  _HA_ATOMIC_STORE(&range->put_t, GET_NEXT_OFF(range, put));

}

Unexecuted instantiation: fd.c:port_range_release_port

Unexecuted instantiation: server.c:port_range_release_port

Unexecuted instantiation: check.c:port_range_release_port

Unexecuted instantiation: proto_tcp.c:port_range_release_port

/* return a new initialized port range of N ports. The ports are not

 * filled in, it's up to the caller to do it.

 */

static inline struct port_range *port_range_alloc_range(int n)

{

  struct port_range *ret;

  ret = calloc(1, sizeof(struct port_range) +

         (n + 1) * sizeof(((struct port_range *)0)->ports[0]));

  if (!ret)

    return NULL;

  ret->size = n + 1;

  /* Start at the first free element */

  ret->put_h = ret->put_t = n;

  return ret;

}

Unexecuted instantiation: fd.c:port_range_alloc_range

Unexecuted instantiation: server.c:port_range_alloc_range

Unexecuted instantiation: check.c:port_range_alloc_range

Unexecuted instantiation: proto_tcp.c:port_range_alloc_range

#endif /* _HAPROXY_PORT_RANGE_H */

/*

 * Local variables:

 *  c-indent-level: 8

 *  c-basic-offset: 8

 * End:

 */