su_select_port.c

Sofia SIP is an open-source SIP User-Agent library, compliant with the IETF RFC3261 specification.

/*
 * This file is part of the Sofia-SIP package
 *
 * Copyright (C) 2005 Nokia Corporation.
 *
 * Contact: Pekka Pessi <[e-mail]>
 *
 * 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; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * 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 St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

/**@ingroup su_wait
 * @CFILE su_select_port.c
 *
 * Port implementation using select().
 *
 * @author Pekka Pessi <[e-mail]>
 * @author Kai Vehmanen <[e-mail]>
 *
 * @date Created: Fri Jan 26 17:56:34 2007 ppessi
 */

#include "config.h"

#if HAVE_SELECT

#define su_port_s su_select_port_s

#include "sofia-sip/su.h"
#include "su_port.h"
#include "sofia-sip/su_alloc.h"

#include <stdlib.h>
#include <assert.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <limits.h>
#include <errno.h>

#if HAVE_WIN32
#error winsock select() not supported yet
#else
#if HAVE_SYS_SELECT_H
#include <sys/select.h>
#elif HAVE_SYS_TIME_H
#include <sys/time.h>
#endif

#include <sys/types.h>
#include <unistd.h>

#ifndef __NFDBITS
#define __NFDBITS (8 * sizeof (long int))
#endif

#undef FDSETSIZE
/* Size of fd set in bytes */
#define FDSETSIZE(n) (((n) + __NFDBITS - 1) / __NFDBITS * (__NFDBITS / 8))
#endif

/** Port based on select(). */

struct su_select_port_s {
  su_socket_port_t sup_base[1];

#define sup_home sup_base->sup_base->sup_base->sup_home

  /** epoll fd */
  int              sup_epoll;
  unsigned         sup_multishot; /**< Multishot operation? */

  unsigned         sup_registers; /** Counter incremented by 
				      su_port_register() or 
				      su_port_unregister()
				   */
  int              sup_n_registrations;
  int              sup_max_index; /**< Indexes are equal or smaller than this */
  int              sup_size_indices; /**< Size of allocated index table */

  /** Structure containing registration data */
  struct su_select_register {
    struct su_select_register *ser_next; /* Next in free list */
    su_wakeup_f     ser_cb; 
    su_wakeup_arg_t*ser_arg; 
    su_root_t      *ser_root; 
    int             ser_id; /** registration identifier */
    su_wait_t       ser_wait[1];
  } **sup_indices;

  int               sup_maxfd, sup_allocfd;
  
  fd_set           *sup_readfds, *sup_readfds2;
  fd_set           *sup_writefds, *sup_writefds2;
};

static void su_select_port_decref(su_port_t *self,
				 int blocking,
				 char const *who);
static int su_select_port_register(su_port_t *self,
				  su_root_t *root, 
				  su_wait_t *wait, 
				  su_wakeup_f callback,
				  su_wakeup_arg_t *arg,
				  int priority);
static int su_select_port_unregister(su_port_t *port,
				    su_root_t *root, 
				    su_wait_t *wait,	
				    su_wakeup_f callback, 
				    su_wakeup_arg_t *arg);
static int su_select_port_deregister(su_port_t *self, int i);
static int su_select_port_unregister_all(su_port_t *self, su_root_t *root);
static int su_select_port_eventmask(su_port_t *self, 
				   int index,
				   int socket,
				   int events);
static int su_select_port_multishot(su_port_t *self, int multishot);
static int su_select_port_wait_events(su_port_t *self, su_duration_t tout);
static char const *su_select_port_name(su_port_t const *self);

su_port_vtable_t const su_select_port_vtable[1] =
  {{
      /* su_vtable_size: */ sizeof su_select_port_vtable,
      su_pthread_port_lock,
      su_pthread_port_unlock,
      su_base_port_incref,
      su_select_port_decref,
      su_base_port_gsource,
      su_socket_port_send,
      su_select_port_register,
      su_select_port_unregister,
      su_select_port_deregister,
      su_select_port_unregister_all,
      su_select_port_eventmask,
      su_base_port_run,
      su_base_port_break,
      su_base_port_step,
      su_pthread_port_thread,
      su_base_port_add_prepoll,
      su_base_port_remove_prepoll,
      su_base_port_timers,
      su_select_port_multishot,
      su_select_port_wait_events,
      su_base_port_getmsgs,
      su_base_port_getmsgs_from,
      su_select_port_name,
      su_base_port_start_shared,
      su_pthread_port_wait,
      su_pthread_port_execute,
    }};

static char const *su_select_port_name(su_port_t const *self)
{
  return "select";
}

static void su_select_port_decref(su_port_t *self, int blocking, char const *who)
{
  (void)su_base_port_decref(self, blocking, who);
}

static void su_select_port_deinit(void *arg)
{
  su_port_t *self = arg;

  SU_DEBUG_9(("%s(%p) called\n", "su_select_port_deinit", (void *)self));

  su_socket_port_deinit(self->sup_base);
}

/** @internal
 *
 *  Register a #su_wait_t object. The wait object, a callback function and
 *  an argument pointer is stored in the port object.  The callback function
 *  will be called when the wait object is signaled.
 *
 *  Please note if identical wait objects are inserted, only first one is
 *  ever signalled.
 * 
 * @param self	     pointer to port
 * @param root	     pointer to root object
 * @param waits	     pointer to wait object
 * @param callback   callback function pointer
 * @param arg	     argument given to callback function when it is invoked
 * @param priority   relative priority of the wait object 
 *              (0 is normal, 1 important, 2 realtime)
 * 
 * @return
 *   Positive index of the wait object, 
 *   or -1 upon an error.
 */
int su_select_port_register(su_port_t *self,
			   su_root_t *root, 
			   su_wait_t *wait, 
			   su_wakeup_f callback,
			   su_wakeup_arg_t *arg,
			   int priority)
{
  int i, j, n;
  struct su_select_register *ser;
  struct su_select_register **indices = self->sup_indices;
  int allocfd = self->sup_allocfd;
  fd_set *readfds = self->sup_readfds, *readfds2 = self->sup_readfds2;
  fd_set *writefds = self->sup_writefds, *writefds2 = self->sup_writefds2;

  assert(su_port_own_thread(self));

  n = self->sup_size_indices;

  if (n >= SU_WAIT_MAX)
    return su_seterrno(ENOMEM);

  self->sup_registers++;

  if (wait->fd >= allocfd) 
    allocfd += __NFDBITS;		/* long at a time */

  if (allocfd >= self->sup_allocfd) {
    size_t bytes = FDSETSIZE(allocfd);
    size_t bytes0 = FDSETSIZE(self->sup_allocfd);
    /* (Re)allocate fd_sets  */

    readfds = su_realloc(self->sup_home, readfds, bytes);
    if (readfds) self->sup_readfds = readfds;
    readfds2 = su_realloc(self->sup_home, readfds2, bytes);
    if (readfds2) self->sup_readfds2 = readfds2;
    if (!readfds || !readfds2)
      return -1;

    writefds = su_realloc(self->sup_home, writefds, bytes);
    if (writefds) self->sup_writefds = writefds;
    writefds2 = su_realloc(self->sup_home, writefds2, bytes);
    if (writefds2) self->sup_writefds2 = writefds2;
    if (!writefds || !writefds2)
      return -1;

    memset((char *)readfds + bytes0, 0, bytes - bytes0);
    memset((char *)writefds + bytes0, 0, bytes - bytes0);

    self->sup_allocfd = allocfd;
  }

  ser = indices[0];

  if (!ser) {
    su_home_t *h = su_port_home(self);

    i = self->sup_max_index, j = i == 0 ? 15 : i + 16;
    
    if (j >= self->sup_size_indices) {
      /* Reallocate index table */
      n = n < 1024 ? 2 * n : n + 1024;
      indices = su_realloc(h, indices, n * sizeof(indices[0]));
      if (!indices)
	return -1;
      self->sup_indices = indices;
      self->sup_size_indices = n;
    }

    /* Allocate registrations */
    ser = su_zalloc(h, (j - i) * (sizeof *ser));
    if (!ser)
      return -1;

    indices[0] = ser;

    for (i++; i <= j; i++) {
      ser->ser_id = i;
      ser->ser_next = i < j ? ser + 1 : NULL;
      indices[i] = ser++;
    }

    self->sup_max_index = j;

    ser = indices[0];
  }

  i = ser->ser_id;

  indices[0] = ser->ser_next;
  
  ser->ser_next = NULL;
  *ser->ser_wait = *wait;
  ser->ser_cb = callback;
  ser->ser_arg = arg;
  ser->ser_root = root;

  if (wait->events & SU_WAIT_IN)
    FD_SET(wait->fd, readfds);
  if (wait->events & SU_WAIT_OUT)
    FD_SET(wait->fd, writefds);

  if (wait->fd >= self->sup_maxfd)
    self->sup_maxfd = wait->fd + 1;

  self->sup_n_registrations++;

  return i;			/* return index */
}

static void su_select_port_update_maxfd(su_port_t *self)
{
  int i;
  su_socket_t maxfd = 0;

  for (i = 1; i <= self->sup_max_index; i++) {
    if (!self->sup_indices[i]->ser_cb)
      continue;
    if (maxfd <= self->sup_indices[i]->ser_wait->fd)
      maxfd = self->sup_indices[i]->ser_wait->fd + 1;
  }

  self->sup_maxfd = maxfd;
}

/** Deregister a su_wait_t object. */