su_source.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
 *
 */

/**
 * @file su_source.c
 * @brief Wrapper for glib GSource.
 *  
 * Refs: 
 *  - http://sofia-sip.sourceforge.net/refdocs/su/group__su__wait.html
 *  - http://developer.gnome.org/doc/API/glib/glib-the-main-event-loop.html
 *
 * @author Pekka Pessi <[e-mail]>.
 * 
 * @date Created: Thu Mar  4 15:15:15 2004 ppessi
 * 
 */

#include "config.h"

#include <glib.h>

#if HAVE_OPEN_C
#include <glib/gthread.h>
#include <glib_global.h>
#endif

#define SU_PORT_IMPLEMENTATION 1

#define SU_MSG_ARG_T union { char anoymous[4]; }

#define su_port_s su_source_s

#include "sofia-sip/su_source.h"
#include "sofia-sip/su_glib.h"

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

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

#if 1
#define PORT_LOCK_DEBUG(x)  ((void)0)
#else
#define PORT_LOCK_DEBUG(x)  printf x
#endif

static su_port_t *su_source_port_create(void) __attribute__((__malloc__));
static gboolean su_source_prepare(GSource *gs, gint *return_tout);
static gboolean su_source_check(GSource *gs);
static gboolean su_source_dispatch(GSource *gs,
				   GSourceFunc callback,
				   gpointer user_data);
static void su_source_finalize(GSource *source);

static
GSourceFuncs su_source_funcs[1] = {{
    su_source_prepare,
    su_source_check,
    su_source_dispatch,
    su_source_finalize,
    NULL,
    NULL
  }};

static int su_source_port_init(su_port_t *self, su_port_vtable_t const *vtable);
static void su_source_port_deinit(su_port_t *self);

static void su_source_lock(su_port_t *self, char const *who);
static void su_source_unlock(su_port_t *self, char const *who);
static void su_source_incref(su_port_t *self, char const *who);
static void su_source_decref(su_port_t *self, int blocking, char const *who);
static struct _GSource *su_source_gsource(su_port_t *port);

static int su_source_send(su_port_t *self, su_msg_r rmsg);

static int su_source_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_source_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_source_deregister(su_port_t *self, int i);
static int su_source_unregister_all(su_port_t *self,
				  su_root_t *root);
static int su_source_eventmask(su_port_t *self, 
			     int index, int socket, int events);
static void su_source_run(su_port_t *self);
static void su_source_break(su_port_t *self);
static su_duration_t su_source_step(su_port_t *self, su_duration_t tout);
static int su_source_thread(su_port_t *self, enum su_port_thread_op op);
static int su_source_add_prepoll(su_port_t *port,
				 su_root_t *root, 
				 su_prepoll_f *, 
				 su_prepoll_magic_t *);
static int su_source_remove_prepoll(su_port_t *port,
				  su_root_t *root);
static int su_source_multishot(su_port_t *self, int multishot);

static char const *su_source_name(su_port_t const *self);

static 
su_port_vtable_t const su_source_port_vtable[1] =
  {{
      /* su_vtable_size: */ sizeof su_source_port_vtable,
      su_source_lock,
      su_source_unlock,

      su_source_incref,
      su_source_decref,

      su_source_gsource,

      su_source_send,
      su_source_register,
      su_source_unregister,
      su_source_deregister,
      su_source_unregister_all,
      su_source_eventmask,
      su_source_run,
      su_source_break,
      su_source_step,
      su_source_thread,
      su_source_add_prepoll,
      su_source_remove_prepoll,
      su_base_port_timers,
      su_source_multishot,
      /*su_source_wait_events*/ NULL,
      su_base_port_getmsgs,
      su_base_port_getmsgs_from,
      su_source_name,
      su_base_port_start_shared,
      su_base_port_wait,
      NULL,
    }};

static char const *su_source_name(su_port_t const *self)
{
  return "GSource";
}

/** 
 * Port is a per-thread reactor.  
 *
 * Multiple root objects executed by single thread share a su_port_t object. 
 */
struct su_source_s {
  su_base_port_t   sup_base[1];
  
  GThread         *sup_tid;
  GStaticMutex     sup_obtained[1];

  GStaticMutex     sup_mutex[1];

  GSource         *sup_source;	/**< Backpointer to source */
  GMainLoop       *sup_main_loop; /**< Reference to mainloop while running */
  
  /* Waits */
  unsigned         sup_registers; /** Counter incremented by 
				      su_port_register() or 
				      su_port_unregister()
				  */
  unsigned         sup_n_waits; 
  unsigned         sup_size_waits; 
  unsigned         sup_max_index;
  unsigned        *sup_indices; 
  su_wait_t       *sup_waits; 
  su_wakeup_f     *sup_wait_cbs; 
  su_wakeup_arg_t**sup_wait_args; 
  su_root_t      **sup_wait_roots; 
};

typedef struct _SuSource
{
  GSource    ss_source[1];
  su_port_t  ss_port[1];
} SuSource;

#define SU_SOURCE_OWN_THREAD(p)   ((p)->sup_tid == g_thread_self())

#if 1
#define SU_SOURCE_INCREF(p, f)    (g_source_ref(p->sup_source))
#define SU_SOURCE_DECREF(p, f)    (g_source_unref(p->sup_source))

#else

/* Debugging versions */
#define SU_SOURCE_INCREF(p, f)    (g_source_ref(p->sup_source), printf("incref(%p) by %s\n", (p), f))
#define SU_SOURCE_DECREF(p, f)    do { printf("decref(%p) by %s\n", (p), f), \
  g_source_unref(p->sup_source); } while(0)

#endif

#if HAVE_FUNC
#define enter (void)SU_DEBUG_9(("%s: entering\n", __func__))
#elif HAVE_FUNCTION
#define enter (void)SU_DEBUG_9(("%s: entering\n", __FUNCTION__))
#else
#define enter (void)0
#endif

/*=============== Public function definitions ===============*/

/** Create a root that uses GSource as reactor */
su_root_t *su_glib_root_create(su_root_magic_t *magic)
{
  return su_root_create_with_port(magic, su_source_port_create());
}

/** Deprecated */
su_root_t *su_root_source_create(su_root_magic_t *magic)
{
  return su_glib_root_create(magic);
}

/** 
 * Returns a GSource object for the root 
 *
 * Note that you need to unref the GSource with g_source_unref() 
 * before destroying the root object.
 *
 * @return NULL on error (for instance if root was not created with 
 *         su_glib_root_create())
 */
GSource *su_glib_root_gsource(su_root_t *root)
{
  g_assert(root);
  return su_root_gsource(root);
}

/*=============== Private function definitions ===============*/

/** Initialize source port */
static int su_source_port_init(su_port_t *self,
			       su_port_vtable_t const *vtable)
{
  GSource *gs = (GSource *)((char *)self - offsetof(SuSource, ss_port));

  self->sup_source = gs;

  g_static_mutex_init(self->sup_obtained);

  g_static_mutex_init(self->sup_mutex);

  return su_base_port_init(self, vtable);
}


static void su_source_port_deinit(su_port_t *self)
{
  su_base_port_deinit(self);

  g_static_mutex_free(self->sup_mutex);
  g_static_mutex_free(self->sup_obtained);

  if (self->sup_indices)
    free (self->sup_indices), self->sup_indices = NULL;
  if (self->sup_waits)
    free (self->sup_waits), self->sup_waits = NULL;
  if (self->sup_wait_cbs)
    free (self->sup_wait_cbs), self->sup_wait_cbs = NULL;
  if (self->sup_wait_args)
    free (self->sup_wait_args), self->sup_wait_args = NULL;
  if (self->sup_wait_roots)
    free (self->sup_wait_roots), self->sup_wait_roots = NULL;

  su_home_deinit(self->sup_base->sup_home);
}


/** @internal Destroy a port. */
static 
void su_source_finalize(GSource *gs)
{
  SuSource *ss = (SuSource *)gs;
  assert(gs);
  SU_DEBUG_9(("su_source_finalize() called\n"));
  su_source_port_deinit(ss->ss_port);
}

void su_source_port_lock(su_port_t *self, char const *who)
{
  PORT_LOCK_DEBUG(("%p at %s locking(%p)...",
		   (void *)g_thread_self(), who, self));

  g_static_mutex_lock(self->sup_mutex);

  PORT_LOCK_DEBUG((" ...%p at %s locked(%p)...", 
		   (void *)g_thread_self(), who, self));
}

void su_source_port_unlock(su_port_t *self, char const *who)
{
  g_static_mutex_unlock(self->sup_mutex);

  PORT_LOCK_DEBUG((" ...%p at %s unlocked(%p)\n", 
		   (void *)g_thread_self(), who, self));
}

/** @internal Send a message to the port. */
int su_source_send(su_port_t *self, su_msg_r rmsg)
{
  int wakeup = su_base_port_send(self, rmsg);
  GMainContext *gmc;

  if (wakeup < 0)
    return -1;
  if (wakeup == 0)
    return 0;

  gmc = g_source_get_context(self->sup_source);

  if (gmc)
    g_main_context_wakeup(gmc);

  return 0;
}

/** @internal
 *
 * Change or query ownership of the port object.
 *
 * @param self pointer to a port object
 * @param op operation 
 *
 * @ERRORS
 * @ERROR EALREADY port already has an owner (or has no owner)
 */
static int su_source_thread(su_port_t *self, enum su_port_thread_op op)
{
  GThread *me = g_thread_self();

  switch (op) {

  case su_port_thread_op_is_obtained:
    if (self->sup_tid == me)
      return 2;
    else if (self->sup_tid)
      return 1;
    else
      return 0;

  case su_port_thread_op_release:
    if (self->sup_tid != me)
      return errno = EALREADY, -1;
    self->sup_tid = NULL;
    g_static_mutex_unlock(self->sup_obtained);
    return 0;

  case su_port_thread_op_obtain:
    if (su_home_threadsafe(su_port_home(self)) == -1)
      return -1;
    g_static_mutex_lock(self->sup_obtained);
    self->sup_tid = me;
    return 0;

  default:
    return errno = ENOSYS, -1;
  }
}

/* -- Registering and unregistering ------------------------------------- */

/* Seconds from 1.1.1900 to 1.1.1970 */
#define NTP_EPOCH 2208988800UL 

/** Prepare to wait - calculate time to next timer */
static
gboolean su_source_prepare(GSource *gs, gint *return_tout)
{
  SuSource *ss = (SuSource *)gs;
  su_port_t *self = ss->ss_port;

  enter;
  
  if (self->sup_base->sup_head) {
    *return_tout = 0;
    return TRUE;
  }

  if (self->sup_base->sup_timers) {
    su_time_t now;
    GTimeVal  gtimeval;
    su_duration_t tout;

    g_source_get_current_time(gs, &gtimeval);
    now.tv_sec = gtimeval.tv_sec + 2208988800UL;
    now.tv_usec = gtimeval.tv_usec;

    tout = su_timer_next_expires(self->sup_base->sup_timers, now);

    *return_tout = (tout < 0 || tout > (su_duration_t)G_MAXINT)?
	-1 : (gint)tout;

    return (tout == 0);
  }

  return FALSE;
}

static
gboolean su_source_check(GSource *gs)
{
  SuSource *ss = (SuSource *)gs;
  su_port_t *self = ss->ss_port;
  gint tout;
  unsigned i, I;

  enter;

  I = self->sup_n_waits;

#if SU_HAVE_POLL
  for (i = 0; i < I; i++) {
    if (self->sup_waits[i].revents)
      return TRUE;
  }
#endif

  return su_source_prepare(gs, &tout);
}

static 
gboolean su_source_dispatch(GSource *gs,
			    GSourceFunc callback,
			    gpointer user_data)
{
  SuSource *ss = (SuSource *)gs;
  su_port_t *self = ss->ss_port;

  enter;

  if (self->sup_base->sup_head)
    su_base_port_getmsgs(self);

  if (self->sup_base->sup_timers) {
    su_time_t now;
    GTimeVal  gtimeval;
    su_duration_t tout;
    int timers = 0;

    tout = SU_DURATION_MAX;

    g_source_get_current_time(gs, &gtimeval);

    now.tv_sec = gtimeval.tv_sec + 2208988800UL;
    now.tv_usec = gtimeval.tv_usec;

    timers = su_timer_expire(&self->sup_base->sup_timers, &tout, now);
  }

#if SU_HAVE_POLL
  {
    su_root_t *root;
    su_wait_t *waits = self->sup_waits;
    unsigned i, n = self->sup_n_waits;
    unsigned version = self->sup_registers;

    for (i = 0; i < n; i++) {
      if (waits[i].revents) {
	root = self->sup_wait_roots[i];
	self->sup_wait_cbs[i](root ? su_root_magic(root) : NULL, 
			      &waits[i], 
			      self->sup_wait_args[i]);
	/* Callback used su_register()/su_unregister() */
	if (version != self->sup_registers)
	  break;
      }
    }
  }
#endif

  if (!callback)
    return TRUE;

  return callback(user_data);
}

static void su_source_lock(su_port_t *self, char const *who)
{
  PORT_LOCK_DEBUG(("%p at %s locking(%p)...",
		   (void *)g_thread_self(), who, self));
  g_static_mutex_lock(self->sup_mutex);

  PORT_LOCK_DEBUG((" ...%p at %s locked(%p)...", 
		   (void *)g_thread_self(), who, self));
}

static void su_source_unlock(su_port_t *self, char const *who)
{
  g_static_mutex_unlock(self->sup_mutex);

  PORT_LOCK_DEBUG((" ...%p at %s unlocked(%p)\n", 
		   (void *)g_thread_self(), who, self));
}

static void su_source_incref(su_port_t *self, char const *who)
{
  SU_SOURCE_INCREF(self, who);
}

static void su_source_decref(su_port_t *self, int blocking, char const *who)
{
  /* XXX - blocking? */
  SU_SOURCE_DECREF(self, who);
}

GSource *su_source_gsource(su_port_t *self)
{
  return self->sup_source;
}

/** @internal
 *
 *  Register a @c su_wait_t object. The wait object, a callback function and
 *  a 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)