/* GStreamer

 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>

 *                    2000 Wim Taymans <wtay@chello.be>

 *                    2004 Wim Taymans <wim@fluendo.com>

 *

 * gstclock.c: Clock subsystem for maintaining time sync

 *

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

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

 * License as published by the Free Software Foundation; either

 * version 2 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

 * Library General Public License for more details.

 *

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

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

 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,

 * Boston, MA 02111-1307, USA.

 */

/**

 * SECTION:gstclock

 * @short_description: Abstract class for global clocks

 * @see_also: #GstSystemClock, #GstPipeline

 *

 * GStreamer uses a global clock to synchronize the plugins in a pipeline.

 * Different clock implementations are possible by implementing this abstract

 *

 * The #GstClock returns a monotonically increasing time with the method

 * gst_clock_get_time(). Its accuracy and base time depend on the specific

 * clock implementation but time is always expressed in nanoseconds. Since the

 * baseline of the clock is undefined, the clock time returned is not

 * meaningful in itself, what matters are the deltas between two clock times.

 * The time returned by a clock is called the absolute time.

 *

 * renderers synchronize to the global clock using the buffer timestamps, the

 * newsegment events and the element's base time, see #GstPipeline.

 *

 * A clock implementation can support periodic and single shot clock

 * notifications both synchronous and asynchronous.

 *

 * One first needs to create a #GstClockID for the periodic or single shot

 * notification using gst_clock_new_single_shot_id() or

 * gst_clock_new_periodic_id().

 *

 * To perform a blocking wait for the specific time of the #GstClockID use the

 * gst_clock_id_wait(). To receive a callback when the specific time is reached

 * in the clock use gst_clock_id_wait_async(). Both these calls can be

 * interrupted with the gst_clock_id_unschedule() call. If the blocking wait is

 *

 * until it is unscheduled. To schedule a sync periodic callback,

 *

 * The async callbacks can happen from any thread, either provided by the core

 * or from a streaming thread. The application should be prepared for this.

 *

 * A #GstClockID that has been unscheduled cannot be used again for any wait

 * operation, a new #GstClockID should be created and the old unscheduled one

 *

 * It is possible to perform a blocking wait on the same #GstClockID from

 * multiple threads. However, registering the same #GstClockID for multiple

 * async notifications is not possible, the callback will only be called for

 * the thread registering the entry last.

 *

 * None of the wait operations unref the #GstClockID, the owner is responsible

 * for unreffing the ids itself. This holds for both periodic and single shot

 * notifications. The reason being that the owner of the #GstClockID has to

 * keep a handle to the #GstClockID to unblock the wait on FLUSHING events or

 * state changes and if the entry would be unreffed automatically, the handle 

 * might become invalid without any notification.

 *

 * will also occur when not in PLAYING state as if the clock just keeps on

 * running. Some clocks however do not progress when the element that provided

 * the clock is not PLAYING.

 *

 * slaved to another #GstClock with the gst_clock_set_master(). The clock will

 * sampling the master clock and the slave clock and recalibrating the slave

 * clock with gst_clock_set_calibration(). This feature is mostly useful for

 * plugins that have an internal clock but must operate with another clock

 * selected by the #GstPipeline.  They can track the offset and rate difference

 * of their internal clock relative to the master clock by using the

 * gst_clock_get_calibration() function. 

 *

 *

 */

#include "gst_private.h"

#include <time.h>

#include "gstclock.h"

#include "gstinfo.h"

#include "gstutils.h"

#ifndef GST_DISABLE_TRACE

/* #define GST_WITH_ALLOC_TRACE */

#include "gsttrace.h"

static GstAllocTrace *_gst_clock_entry_trace;

#endif

#ifdef __SYMBIAN32__

#include <glib_global.h>

#endif

/* #define DEBUGGING_ENABLED */

#define DEFAULT_STATS                   FALSE

#define DEFAULT_WINDOW_SIZE             32

#define DEFAULT_WINDOW_THRESHOLD        4

#define DEFAULT_TIMEOUT                 GST_SECOND / 10

enum

{

  PROP_0,

  PROP_STATS,

  PROP_WINDOW_SIZE,

  PROP_WINDOW_THRESHOLD,

  PROP_TIMEOUT

};

static void gst_clock_class_init (GstClockClass * klass);

static void gst_clock_init (GstClock * clock);

static void gst_clock_dispose (GObject * object);

static void gst_clock_finalize (GObject * object);

static void gst_clock_set_property (GObject * object, guint prop_id,

    const GValue * value, GParamSpec * pspec);

static void gst_clock_get_property (GObject * object, guint prop_id,

    GValue * value, GParamSpec * pspec);

static void gst_clock_update_stats (GstClock * clock);

static GstObjectClass *parent_class = NULL;

/* static guint gst_clock_signals[LAST_SIGNAL] = { 0 }; */

static GstClockID

gst_clock_entry_new (GstClock * clock, GstClockTime time,

    GstClockTime interval, GstClockEntryType type)

{

  GstClockEntry *entry;

#ifndef GST_DISABLE_TRACE

  gst_alloc_trace_new (_gst_clock_entry_trace, entry);

#endif

  GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,

      "created entry %p, time %" GST_TIME_FORMAT, entry, GST_TIME_ARGS (time));

  entry->clock = clock;

  entry->type = type;

  entry->time = time;

  entry->interval = interval;

  entry->func = NULL;

  entry->user_data = NULL;

  return (GstClockID) entry;

}

/**

 * gst_clock_id_ref:

 * @id: The #GstClockID to ref

 *

 * Increase the refcount of given @id.

 *

 * Returns: The same #GstClockID with increased refcount.

 *

 * MT safe.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstClockID

gst_clock_id_ref (GstClockID id)

{

  g_return_val_if_fail (id != NULL, NULL);

  g_atomic_int_inc (&((GstClockEntry *) id)->refcount);

  return id;

}

static void

_gst_clock_id_free (GstClockID id)

{

  g_return_if_fail (id != NULL);

  GST_CAT_DEBUG (GST_CAT_CLOCK, "freed entry %p", id);

#ifndef GST_DISABLE_TRACE

  gst_alloc_trace_free (_gst_clock_entry_trace, id);

#endif

}

/**

 * gst_clock_id_unref:

 * @id: The #GstClockID to unref

 *

 * Unref given @id. When the refcount reaches 0 the

 * #GstClockID will be freed.

 *

 * MT safe.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

void

gst_clock_id_unref (GstClockID id)

{

  gint zero;

  g_return_if_fail (id != NULL);

  zero = g_atomic_int_dec_and_test (&((GstClockEntry *) id)->refcount);

  /* if we ended up with the refcount at zero, free the id */

  if (zero) {

    _gst_clock_id_free (id);

  }

}

/**

 * gst_clock_new_single_shot_id

 * @clock: The #GstClockID to get a single shot notification from

 * @time: the requested time

 *

 * Get a #GstClockID from @clock to trigger a single shot

 * notification at the requested time. The single shot id should be

 * unreffed after usage.

 *

 * Returns: A #GstClockID that can be used to request the time notification.

 *

 * MT safe.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstClockID

gst_clock_new_single_shot_id (GstClock * clock, GstClockTime time)

{

  g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);

  return gst_clock_entry_new (clock,

      time, GST_CLOCK_TIME_NONE, GST_CLOCK_ENTRY_SINGLE);

}

/**

 * gst_clock_new_periodic_id

 * @clock: The #GstClockID to get a periodic notification id from

 * @start_time: the requested start time

 * @interval: the requested interval

 *

 * Get an ID from @clock to trigger a periodic notification.

 * after usage.

 *

 * Returns: A #GstClockID that can be used to request the time notification.

 *

 * MT safe.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstClockID

gst_clock_new_periodic_id (GstClock * clock, GstClockTime start_time,

    GstClockTime interval)

{

  g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);

  g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (start_time), NULL);

  g_return_val_if_fail (interval != 0, NULL);

  g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (interval), NULL);

  return gst_clock_entry_new (clock,

      start_time, interval, GST_CLOCK_ENTRY_PERIODIC);

}

/**

 * gst_clock_id_compare_func

 * @id1: A #GstClockID

 * @id2: A #GstClockID to compare with

 *

 * Compares the two #GstClockID instances. This function can be used

 * as a GCompareFunc when sorting ids.

 *

 * Returns: negative value if a < b; zero if a = b; positive value if a > b

 *

 * MT safe.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

gint

gst_clock_id_compare_func (gconstpointer id1, gconstpointer id2)

{

  GstClockEntry *entry1, *entry2;

  entry1 = (GstClockEntry *) id1;

  entry2 = (GstClockEntry *) id2;

  if (GST_CLOCK_ENTRY_TIME (entry1) > GST_CLOCK_ENTRY_TIME (entry2)) {

    return 1;

  }

  if (GST_CLOCK_ENTRY_TIME (entry1) < GST_CLOCK_ENTRY_TIME (entry2)) {

    return -1;

  }

  return 0;

}

/**

 * gst_clock_id_get_time

 * @id: The #GstClockID to query

 *

 * Get the time of the clock ID

 *

 * Returns: the time of the given clock id.

 *

 * MT safe.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstClockTime

gst_clock_id_get_time (GstClockID id)

{

  g_return_val_if_fail (id != NULL, GST_CLOCK_TIME_NONE);

  return GST_CLOCK_ENTRY_TIME ((GstClockEntry *) id);

}

/**

 * gst_clock_id_wait

 * @id: The #GstClockID to wait on

 *

 * Perform a blocking wait on @id. 

 * @id should have been created with gst_clock_new_single_shot_id()

 * or gst_clock_new_periodic_id() and should not have been unscheduled

 * with a call to gst_clock_id_unschedule(). 

 *

 * or #GST_CLOCK_EARLY, it will contain the difference

 * against the clock and the time of @id when this method was

 * called. 

 * Positive values indicate how late @id was relative to the clock

 * (in which case this function will return #GST_CLOCK_EARLY). 

 * Negative values indicate how much time was spent waiting on the clock 

 * before this function returned.

 *

 * Returns: the result of the blocking wait. #GST_CLOCK_EARLY will be returned

 * if the current clock time is past the time of @id, #GST_CLOCK_OK if 

 * @id was scheduled in time. #GST_CLOCK_UNSCHEDULED if @id was 

 * unscheduled with gst_clock_id_unschedule().

 *

 * MT safe.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstClockReturn

gst_clock_id_wait (GstClockID id, GstClockTimeDiff * jitter)

{

  GstClockEntry *entry;

  GstClock *clock;

  GstClockReturn res;

  GstClockTime requested;

  GstClockClass *cclass;

  g_return_val_if_fail (id != NULL, GST_CLOCK_ERROR);

  entry = (GstClockEntry *) id;

  requested = GST_CLOCK_ENTRY_TIME (entry);

  clock = GST_CLOCK_ENTRY_CLOCK (entry);

  /* can't sync on invalid times */

  if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (requested)))

    goto invalid_time;

  cclass = GST_CLOCK_GET_CLASS (clock);

  GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "waiting on clock entry %p", id);

  /* if we have a wait_jitter function, use that */

  if (G_LIKELY (cclass->wait_jitter)) {

    res = cclass->wait_jitter (clock, entry, jitter);

  } else {

    /* check if we have a simple _wait function otherwise. The function without

     * the jitter arg is less optimal as we need to do an additional _get_time()

     * which is not atomic with the _wait() and a typical _wait() function does

     * yet another _get_time() anyway. */

    if (G_UNLIKELY (cclass->wait == NULL))

      goto not_supported;

    if (jitter) {

      GstClockTime now = gst_clock_get_time (clock);

      /* jitter is the diff against the clock when this entry is scheduled. Negative

       * values mean that the entry was in time, a positive value means that the

       * entry was too late. */

      *jitter = GST_CLOCK_DIFF (requested, now);

    }

    res = cclass->wait (clock, entry);

  }

  GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,

      "done waiting entry %p, res: %d", id, res);

  if (entry->type == GST_CLOCK_ENTRY_PERIODIC)

    entry->time = requested + entry->interval;

    gst_clock_update_stats (clock);

  return res;

  /* ERRORS */

invalid_time:

  {

    GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,

        "invalid time requested, returning _BADTIME");

    return GST_CLOCK_BADTIME;

  }

not_supported:

  {

    GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "clock wait is not supported");

    return GST_CLOCK_UNSUPPORTED;

  }

}

/**

 * gst_clock_id_wait_async:

 * @id: a #GstClockID to wait on

 * @func: The callback function

 *

 * Register a callback on the given #GstClockID @id with the given

 * function and user_data. When passing a #GstClockID with an invalid

 * with  a time set to GST_CLOCK_TIME_NONE. The callback will

 * be called when the time of @id has been reached.

 *

 * Returns: the result of the non blocking wait.

 *

 * MT safe.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstClockReturn

gst_clock_id_wait_async (GstClockID id,

    GstClockCallback func, gpointer user_data)

{

  GstClockEntry *entry;

  GstClock *clock;

  GstClockReturn res;

  GstClockClass *cclass;

  GstClockTime requested;

  g_return_val_if_fail (id != NULL, GST_CLOCK_ERROR);

  g_return_val_if_fail (func != NULL, GST_CLOCK_ERROR);

  entry = (GstClockEntry *) id;

  requested = GST_CLOCK_ENTRY_TIME (entry);

  clock = GST_CLOCK_ENTRY_CLOCK (entry);

  /* can't sync on invalid times */

  if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (requested)))

    goto invalid_time;

  cclass = GST_CLOCK_GET_CLASS (clock);