su_poll_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_poll_port.c
 *
 * Port implementation using poll()
 *
 * @author Pekka Pessi <[e-mail]>
 * @author Kai Vehmanen <[e-mail]>
 *
 * @date Create: Fri Jan 26 20:44:14 2007 ppessi
 * @date Original: Tue Sep 14 15:51:04 1999 ppessi
 */

#include "config.h"

#define su_port_s su_poll_port_s

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

#if HAVE_POLL_PORT

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

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

struct su_poll_port_s {
  su_socket_port_t sup_base[1];

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

  unsigned         sup_multishot; /**< Multishot operation? */

  unsigned         sup_registers; /** Counter incremented by 
				      su_port_register() or 
				      su_port_unregister()
				   */

  int              sup_n_waits; /**< Active su_wait_t in su_waits */
  int              sup_size_waits; /**< Size of allocated su_waits */
  int              sup_pri_offset; /**< Offset to prioritized waits */

#define INDEX_MAX (0x7fffffff)

  /** Indices from index returned by su_root_register() to tables below. 
   *
   * Free elements are negative. Free elements form a list, value of free
   * element is (0 - index of next free element).
   *
   * First element sup_indices[0] points to first free element. 
   */
  int             *sup_indices;

  int             *sup_reverses; /** Reverse index */
  su_wakeup_f     *sup_wait_cbs; 
  su_wakeup_arg_t**sup_wait_args; 
  su_root_t      **sup_wait_roots; 
  su_wait_t       *sup_waits; 

};

static void su_poll_port_decref(su_port_t *, int blocking, char const *who);

static int su_poll_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_poll_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_poll_port_deregister(su_port_t *self, int i);
static int su_poll_port_unregister_all(su_port_t *self, su_root_t *root);
static int su_poll_port_eventmask(su_port_t *self, 
				  int index,
				  int socket,
				  int events);
static int su_poll_port_multishot(su_port_t *self, int multishot);
static int su_poll_port_wait_events(su_port_t *self, su_duration_t tout);
static char const *su_poll_port_name(su_port_t const *self);

su_port_vtable_t const su_poll_port_vtable[1] =
  {{
      /* su_vtable_size: */ sizeof su_poll_port_vtable,
      su_pthread_port_lock,
      su_pthread_port_unlock,
      su_base_port_incref,
      su_poll_port_decref,
      su_base_port_gsource,
      su_socket_port_send,
      su_poll_port_register,
      su_poll_port_unregister,
      su_poll_port_deregister,
      su_poll_port_unregister_all,
      su_poll_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_poll_port_multishot,
      su_poll_port_wait_events,
      su_base_port_getmsgs,
      su_base_port_getmsgs_from,
      su_poll_port_name,
      su_base_port_start_shared,
      su_pthread_port_wait,
      su_pthread_port_execute,
    }};

static char const *su_poll_port_name(su_port_t const *self)
{
  return "poll";
}

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

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

  su_socket_port_deinit(self->sup_base);
}

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

/** @internal
 *
 *  Register a @c 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_poll_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;

  assert(su_port_own_thread(self));

  n = self->sup_n_waits;

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

  if (n >= self->sup_size_waits) {
    su_home_t *h = self->sup_home;
    /* Reallocate size arrays */
    int size;
    int *indices;
    int *reverses;
    su_wait_t *waits;
    su_wakeup_f *wait_cbs;
    su_wakeup_arg_t **wait_args;
    su_root_t **wait_tasks;

    if (self->sup_size_waits == 0)
      size = su_root_size_hint;
    else 
      size = 2 * self->sup_size_waits;

    if (size < SU_WAIT_MIN)
      size = SU_WAIT_MIN;

    /* Too large */
    if (-3 - size > 0)
      return (errno = ENOMEM), -1;

    indices = su_realloc(h, self->sup_indices, (size + 1) * sizeof(*indices));
    if (indices) {
      self->sup_indices = indices;

      if (self->sup_size_waits == 0)
	indices[0] = -1;

      for (i = self->sup_size_waits + 1; i <= size; i++)
	indices[i] = -1 - i;
    }

    reverses = su_realloc(h, self->sup_reverses, size * sizeof(*waits));
    if (reverses) {
      for (i = self->sup_size_waits; i < size; i++)
	reverses[i] = -1;
      self->sup_reverses = reverses;
    }
      
    waits = su_realloc(h, self->sup_waits, size * sizeof(*waits));
    if (waits)
      self->sup_waits = waits;

    wait_cbs = su_realloc(h, self->sup_wait_cbs, size * sizeof(*wait_cbs));
    if (wait_cbs)
      self->sup_wait_cbs = wait_cbs;

    wait_args = su_realloc(h, self->sup_wait_args, size * sizeof(*wait_args));
    if (wait_args)
      self->sup_wait_args = wait_args;

    /* Add sup_wait_roots array, if needed */
    wait_tasks = su_realloc(h, self->sup_wait_roots, size * sizeof(*wait_tasks));
    if (wait_tasks) 
      self->sup_wait_roots = wait_tasks;

    if (!(indices && 
	  reverses && waits && wait_cbs && wait_args && wait_tasks)) {
      return -1;
    }

    self->sup_size_waits = size;
  }

  i = -self->sup_indices[0]; assert(i <= self->sup_size_waits);

  if (priority > 0) {
    /* Insert */
    for (n = self->sup_n_waits; n > 0; n--) {
      j = self->sup_reverses[n-1]; assert(self->sup_indices[j] == n - 1);
      self->sup_indices[j] = n;
      self->sup_reverses[n] = j;
      self->sup_waits[n] = self->sup_waits[n-1];
      self->sup_wait_cbs[n] = self->sup_wait_cbs[n-1];
      self->sup_wait_args[n] = self->sup_wait_args[n-1];
      self->sup_wait_roots[n] = self->sup_wait_roots[n-1];	
    }

    self->sup_pri_offset++;
  }
  else {
    /* Append - no need to move anything */
    n = self->sup_n_waits;
  }

  self->sup_n_waits++;

  self->sup_indices[0] = self->sup_indices[i];  /* Free index */
  self->sup_indices[i] = n;

  self->sup_reverses[n] = i;
  self->sup_waits[n] = *wait;
  self->sup_wait_cbs[n] = callback;
  self->sup_wait_args[n] = arg;
  self->sup_wait_roots[n] = root;

  self->sup_registers++;

  /* Just like epoll, we return -1 or positive integer */

  return i;
}

/** Deregister a su_wait_t object. */
static int su_poll_port_deregister0(su_port_t *self, int i, int destroy_wait)
{
  int n, N, *indices, *reverses;

  indices = self->sup_indices;
  reverses = self->sup_reverses;

  n = indices[i]; assert(n >= 0);

  if (destroy_wait)
    su_wait_destroy(&self->sup_waits[n]);
  
  N = --self->sup_n_waits;
  
  if (n < self->sup_pri_offset) {
    int j = --self->sup_pri_offset;
    if (n != j) {
      assert(reverses[j] > 0);
      assert(indices[reverses[j]] == j);
      indices[reverses[j]] = n;
      reverses[n] = reverses[j];

      self->sup_waits[n] = self->sup_waits[j];
      self->sup_wait_cbs[n] = self->sup_wait_cbs[j];
      self->sup_wait_args[n] = self->sup_wait_args[j];
      self->sup_wait_roots[n] = self->sup_wait_roots[j];
      n = j;
    }
  }

  if (n < N) {
    assert(reverses[N] > 0);
    assert(indices[reverses[N]] == N);

    indices[reverses[N]] = n;
    reverses[n] = reverses[N];

    self->sup_waits[n] = self->sup_waits[N];
    self->sup_wait_cbs[n] = self->sup_wait_cbs[N];
    self->sup_wait_args[n] = self->sup_wait_args[N];