cleanup
[platform/upstream/glib.git] / gio / goutputstream.c
index 510b090..2bec89e 100644 (file)
  * 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., 59 Temple Place, Suite 330,
- * Boston, MA 02111-1307, USA.
+ * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
  *
  * Author: Alexander Larsson <alexl@redhat.com>
  */
 
-#include <config.h>
+#include "config.h"
+#include <string.h>
 #include "goutputstream.h"
-#include "gsimpleasyncresult.h"
+#include "gcancellable.h"
+#include "gasyncresult.h"
+#include "gtask.h"
+#include "ginputstream.h"
+#include "gioerror.h"
+#include "gioprivate.h"
 #include "glibintl.h"
-
-#include "gioalias.h"
+#include "gpollableoutputstream.h"
 
 /**
  * SECTION:goutputstream
  * @short_description: Base class for implementing streaming output
+ * @include: gio/gio.h
  *
+ * #GOutputStream has functions to write to a stream (g_output_stream_write()),
+ * to close a stream (g_output_stream_close()) and to flush pending writes
+ * (g_output_stream_flush()). 
  *
+ * To copy the content of an input stream to an output stream without 
+ * manually handling the reads and writes, use g_output_stream_splice(). 
  *
+ * All of these functions have async variants too.
  **/
 
-G_DEFINE_TYPE (GOutputStream, g_output_stream, G_TYPE_OBJECT);
-
 struct _GOutputStreamPrivate {
   guint closed : 1;
   guint pending : 1;
-  guint cancelled : 1;
+  guint closing : 1;
   GAsyncReadyCallback outstanding_callback;
 };
 
+G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GOutputStream, g_output_stream, G_TYPE_OBJECT)
+
 static gssize   g_output_stream_real_splice        (GOutputStream             *stream,
                                                    GInputStream              *source,
                                                    GOutputStreamSpliceFlags   flags,
@@ -85,17 +95,17 @@ static void     g_output_stream_real_close_async   (GOutputStream             *s
 static gboolean g_output_stream_real_close_finish  (GOutputStream             *stream,
                                                    GAsyncResult              *result,
                                                    GError                   **error);
-
-static void
-g_output_stream_finalize (GObject *object)
-{
-  GOutputStream *stream;
-
-  stream = G_OUTPUT_STREAM (object);
-  
-  if (G_OBJECT_CLASS (g_output_stream_parent_class)->finalize)
-    (*G_OBJECT_CLASS (g_output_stream_parent_class)->finalize) (object);
-}
+static gboolean g_output_stream_internal_close     (GOutputStream             *stream,
+                                                    GCancellable              *cancellable,
+                                                    GError                   **error);
+static void     g_output_stream_internal_close_async (GOutputStream           *stream,
+                                                      int                      io_priority,
+                                                      GCancellable            *cancellable,
+                                                      GAsyncReadyCallback      callback,
+                                                      gpointer                 data);
+static gboolean g_output_stream_internal_close_finish (GOutputStream          *stream,
+                                                       GAsyncResult           *result,
+                                                       GError                **error);
 
 static void
 g_output_stream_dispose (GObject *object)
@@ -106,19 +116,15 @@ g_output_stream_dispose (GObject *object)
   
   if (!stream->priv->closed)
     g_output_stream_close (stream, NULL, NULL);
-  
-  if (G_OBJECT_CLASS (g_output_stream_parent_class)->dispose)
-    (*G_OBJECT_CLASS (g_output_stream_parent_class)->dispose) (object);
+
+  G_OBJECT_CLASS (g_output_stream_parent_class)->dispose (object);
 }
 
 static void
 g_output_stream_class_init (GOutputStreamClass *klass)
 {
   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
-  
-  g_type_class_add_private (klass, sizeof (GOutputStreamPrivate));
-  
-  gobject_class->finalize = g_output_stream_finalize;
+
   gobject_class->dispose = g_output_stream_dispose;
 
   klass->splice = g_output_stream_real_splice;
@@ -136,40 +142,41 @@ g_output_stream_class_init (GOutputStreamClass *klass)
 static void
 g_output_stream_init (GOutputStream *stream)
 {
-  stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream,
-                                             G_TYPE_OUTPUT_STREAM,
-                                             GOutputStreamPrivate);
+  stream->priv = g_output_stream_get_instance_private (stream);
 }
 
 /**
  * g_output_stream_write:
  * @stream: a #GOutputStream.
- * @buffer: the buffer containing the data to write. 
+ * @buffer: (array length=count) (element-type guint8): the buffer containing the data to write. 
  * @count: the number of bytes to write
- * @cancellable: optional cancellable object
- * @error: location to store the error occuring, or %NULL to ignore
+ * @cancellable: (allow-none): optional cancellable object
+ * @error: location to store the error occurring, or %NULL to ignore
  *
  * Tries to write @count bytes from @buffer into the stream. Will block
  * during the operation.
  * 
- * If count is zero returns zero and does nothing. A value of @count
+ * If count is 0, returns 0 and does nothing. A value of @count
  * larger than %G_MAXSSIZE will cause a %G_IO_ERROR_INVALID_ARGUMENT error.
  *
  * On success, the number of bytes written to the stream is returned.
  * It is not an error if this is not the same as the requested size, as it
- * can happen e.g. on a partial i/o error, or if the there is not enough
- * storage in the stream. All writes either block until at least one byte
- * is written, so zero is never returned (unless @count is zero).
+ * can happen e.g. on a partial I/O error, or if there is not enough
+ * storage in the stream. All writes block until at least one byte
+ * is written or an error occurs; 0 is never returned (unless
+ * @count is 0).
  * 
- * If @cancellable is not NULL, then the operation can be cancelled by
+ * If @cancellable is not %NULL, then the operation can be cancelled by
  * triggering the cancellable object from another thread. If the operation
- * was cancelled, the error G_IO_ERROR_CANCELLED will be returned. If an
+ * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. If an
  * operation was partially finished when the operation was cancelled the
  * partial result will be returned, without an error.
  *
  * On error -1 is returned and @error is set accordingly.
  * 
- * Return value: Number of bytes written, or -1 on error
+ * Virtual: write_fn
+ *
+ * Returns: Number of bytes written, or -1 on error
  **/
 gssize
 g_output_stream_write (GOutputStream  *stream,
@@ -190,7 +197,7 @@ g_output_stream_write (GOutputStream  *stream,
   if (((gssize) count) < 0)
     {
       g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
-                  _("Too large count value passed to g_output_stream_write"));
+                  _("Too large count value passed to %s"), G_STRFUNC);
       return -1;
     }
 
@@ -198,8 +205,8 @@ g_output_stream_write (GOutputStream  *stream,
 
   if (class->write_fn == NULL) 
     {
-      g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
-                  _("Output stream doesn't implement write"));
+      g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+                           _("Output stream doesn't implement write"));
       return -1;
     }
   
@@ -222,12 +229,12 @@ g_output_stream_write (GOutputStream  *stream,
 /**
  * g_output_stream_write_all:
  * @stream: a #GOutputStream.
- * @buffer: the buffer containing the data to write. 
+ * @buffer: (array length=count) (element-type guint8): the buffer containing the data to write. 
  * @count: the number of bytes to write
- * @bytes_written: location to store the number of bytes that was 
+ * @bytes_written: (out): location to store the number of bytes that was 
  *     written to the stream
- * @cancellable: optional #GCancellable object, %NULL to ignore.
- * @error: location to store the error occuring, or %NULL to ignore
+ * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
+ * @error: location to store the error occurring, or %NULL to ignore
  *
  * Tries to write @count bytes from @buffer into the stream. Will block
  * during the operation.
@@ -238,11 +245,18 @@ g_output_stream_write (GOutputStream  *stream,
  * On a successful write of @count bytes, %TRUE is returned, and @bytes_written
  * is set to @count.
  * 
- * If there is an error during the operation FALSE is returned and @error
- * is set to indicate the error status, @bytes_written is updated to contain
- * the number of bytes written into the stream before the error occured.
+ * If there is an error during the operation %FALSE is returned and @error
+ * is set to indicate the error status.
+ *
+ * As a special exception to the normal conventions for functions that
+ * use #GError, if this function returns %FALSE (and sets @error) then
+ * @bytes_written will be set to the number of bytes that were
+ * successfully written before the error was encountered.  This
+ * functionality is only available from C.  If you need it from another
+ * language then you must write your own loop around
+ * g_output_stream_write().
  *
- * Return value: %TRUE on success, %FALSE if there was an error
+ * Returns: %TRUE on success, %FALSE if there was an error
  **/
 gboolean
 g_output_stream_write_all (GOutputStream  *stream,
@@ -283,13 +297,150 @@ g_output_stream_write_all (GOutputStream  *stream,
 }
 
 /**
+ * g_output_stream_printf:
+ * @stream: a #GOutputStream.
+ * @bytes_written: (out): location to store the number of bytes that was
+ *     written to the stream
+ * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
+ * @error: location to store the error occurring, or %NULL to ignore
+ * @format: the format string. See the printf() documentation
+ * @...: the parameters to insert into the format string
+ *
+ * This is a utility function around g_output_stream_write_all(). It
+ * uses g_strdup_vprintf() to turn @format and @... into a string that
+ * is then written to @stream.
+ *
+ * See the documentation of g_output_stream_write_all() about the
+ * behavior of the actual write operation.
+ *
+ * Note that partial writes cannot be properly checked with this
+ * function due to the variable length of the written string, if you
+ * need precise control over partial write failures, you need to
+ * create you own printf()-like wrapper around g_output_stream_write()
+ * or g_output_stream_write_all().
+ *
+ * Since: 2.40
+ *
+ * Returns: %TRUE on success, %FALSE if there was an error
+ **/
+gboolean
+g_output_stream_printf (GOutputStream  *stream,
+                        gsize          *bytes_written,
+                        GCancellable   *cancellable,
+                        GError        **error,
+                        const gchar    *format,
+                        ...)
+{
+  va_list  args;
+  gboolean success;
+
+  va_start (args, format);
+  success = g_output_stream_vprintf (stream, bytes_written, cancellable,
+                                     error, format, args);
+  va_end (args);
+
+  return success;
+}
+
+/**
+ * g_output_stream_vprintf:
+ * @stream: a #GOutputStream.
+ * @bytes_written: (out): location to store the number of bytes that was
+ *     written to the stream
+ * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
+ * @error: location to store the error occurring, or %NULL to ignore
+ * @format: the format string. See the printf() documentation
+ * @args: the parameters to insert into the format string
+ *
+ * This is a utility function around g_output_stream_write_all(). It
+ * uses g_strdup_vprintf() to turn @format and @args into a string that
+ * is then written to @stream.
+ *
+ * See the documentation of g_output_stream_write_all() about the
+ * behavior of the actual write operation.
+ *
+ * Note that partial writes cannot be properly checked with this
+ * function due to the variable length of the written string, if you
+ * need precise control over partial write failures, you need to
+ * create you own printf()-like wrapper around g_output_stream_write()
+ * or g_output_stream_write_all().
+ *
+ * Since: 2.40
+ *
+ * Returns: %TRUE on success, %FALSE if there was an error
+ **/
+gboolean
+g_output_stream_vprintf (GOutputStream  *stream,
+                         gsize          *bytes_written,
+                         GCancellable   *cancellable,
+                         GError        **error,
+                         const gchar    *format,
+                         va_list         args)
+{
+  gchar    *text;
+  gboolean  success;
+
+  g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
+  g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (stream), FALSE);
+  g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
+  g_return_val_if_fail (format != NULL, FALSE);
+
+  text = g_strdup_vprintf (format, args);
+  success = g_output_stream_write_all (stream,
+                                       text, strlen (text),
+                                       bytes_written, cancellable, error);
+  g_free (text);
+
+  return success;
+}
+
+/**
+ * g_output_stream_write_bytes:
+ * @stream: a #GOutputStream.
+ * @bytes: the #GBytes to write
+ * @cancellable: (allow-none): optional cancellable object
+ * @error: location to store the error occurring, or %NULL to ignore
+ *
+ * A wrapper function for g_output_stream_write() which takes a
+ * #GBytes as input.  This can be more convenient for use by language
+ * bindings or in other cases where the refcounted nature of #GBytes
+ * is helpful over a bare pointer interface.
+ *
+ * However, note that this function may still perform partial writes,
+ * just like g_output_stream_write().  If that occurs, to continue
+ * writing, you will need to create a new #GBytes containing just the
+ * remaining bytes, using g_bytes_new_from_bytes(). Passing the same
+ * #GBytes instance multiple times potentially can result in duplicated
+ * data in the output stream.
+ *
+ * Returns: Number of bytes written, or -1 on error
+ **/
+gssize
+g_output_stream_write_bytes (GOutputStream  *stream,
+                            GBytes         *bytes,
+                            GCancellable   *cancellable,
+                            GError        **error)
+{
+  gsize size;
+  gconstpointer data;
+
+  data = g_bytes_get_data (bytes, &size);
+
+  return g_output_stream_write (stream,
+                                data, size,
+                               cancellable,
+                               error);
+}
+
+/**
  * g_output_stream_flush:
  * @stream: a #GOutputStream.
- * @cancellable: optional cancellable object
- * @error: location to store the error occuring, or %NULL to ignore
+ * @cancellable: (allow-none): optional cancellable object
+ * @error: location to store the error occurring, or %NULL to ignore
  *
- * Flushed any outstanding buffers in the stream. Will block during 
- * the operation. Closing the stream will implicitly cause a flush.
+ * Forces a write of all user-space buffered data for the given
+ * @stream. Will block during the operation. Closing the stream will
+ * implicitly cause a flush.
  *
  * This function is optional for inherited classes.
  * 
@@ -297,7 +448,7 @@ g_output_stream_write_all (GOutputStream  *stream,
  * triggering the cancellable object from another thread. If the operation
  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
  *
- * Return value: %TRUE on success, %FALSE on error
+ * Returns: %TRUE on success, %FALSE on error
  **/
 gboolean
 g_output_stream_flush (GOutputStream  *stream,
@@ -336,13 +487,17 @@ g_output_stream_flush (GOutputStream  *stream,
  * @stream: a #GOutputStream.
  * @source: a #GInputStream.
  * @flags: a set of #GOutputStreamSpliceFlags.
- * @cancellable: optional #GCancellable object, %NULL to ignore. 
- * @error: a #GError location to store the error occuring, or %NULL to 
+ * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
+ * @error: a #GError location to store the error occurring, or %NULL to
  * ignore.
  *
  * Splices an input stream into an output stream.
  *
- * Returns: a #gssize containig the size of the data spliced.
+ * Returns: a #gssize containing the size of the data spliced, or
+ *     -1 if an error occurred. Note that if the number of bytes
+ *     spliced is greater than %G_MAXSSIZE, then that will be
+ *     returned, and there is no way to determine the actual number
+ *     of bytes spliced.
  **/
 gssize
 g_output_stream_splice (GOutputStream             *stream,
@@ -352,35 +507,34 @@ g_output_stream_splice (GOutputStream             *stream,
                        GError                   **error)
 {
   GOutputStreamClass *class;
-  gboolean res;
+  gssize bytes_copied;
 
   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
   g_return_val_if_fail (G_IS_INPUT_STREAM (source), -1);
 
   if (g_input_stream_is_closed (source))
     {
-      g_set_error (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
-                  _("Source stream is already closed"));
+      g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
+                           _("Source stream is already closed"));
       return -1;
     }
 
   if (!g_output_stream_set_pending (stream, error))
     return -1;
-  
+
   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 
-  res = TRUE;
   if (cancellable)
     g_cancellable_push_current (cancellable);
-      
-  res = class->splice (stream, source, flags, cancellable, error);
-      
+
+  bytes_copied = class->splice (stream, source, flags, cancellable, error);
+
   if (cancellable)
     g_cancellable_pop_current (cancellable);
-  
+
   g_output_stream_clear_pending (stream);
 
-  return res;
+  return bytes_copied;
 }
 
 static gssize
@@ -392,21 +546,21 @@ g_output_stream_real_splice (GOutputStream             *stream,
 {
   GOutputStreamClass *class = G_OUTPUT_STREAM_GET_CLASS (stream);
   gssize n_read, n_written;
-  gssize bytes_copied;
+  gsize bytes_copied;
   char buffer[8192], *p;
   gboolean res;
 
   bytes_copied = 0;
-  if (class->write_fn == NULL) 
+  if (class->write_fn == NULL)
     {
-      g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
-                  _("Output stream doesn't implement write"));
+      g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+                           _("Output stream doesn't implement write"));
       res = FALSE;
       goto notsupported;
     }
-  
+
   res = TRUE;
-  do 
+  do
     {
       n_read = g_input_stream_read (source, buffer, sizeof (buffer), cancellable, error);
       if (n_read == -1)
@@ -414,7 +568,7 @@ g_output_stream_real_splice (GOutputStream             *stream,
          res = FALSE;
          break;
        }
-       
+
       if (n_read == 0)
        break;
 
@@ -432,6 +586,9 @@ g_output_stream_real_splice (GOutputStream             *stream,
          n_read -= n_written;
          bytes_copied += n_written;
        }
+
+      if (bytes_copied > G_MAXSSIZE)
+       bytes_copied = G_MAXSSIZE;
     }
   while (res);
 
@@ -439,31 +596,78 @@ g_output_stream_real_splice (GOutputStream             *stream,
   if (!res)
     error = NULL; /* Ignore further errors */
 
-  if (flags & G_OUTPUT_STREAM_SPLICE_FLAGS_CLOSE_SOURCE)
+  if (flags & G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE)
     {
       /* Don't care about errors in source here */
       g_input_stream_close (source, cancellable, NULL);
     }
 
-  if (flags & G_OUTPUT_STREAM_SPLICE_FLAGS_CLOSE_TARGET)
+  if (flags & G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET)
     {
       /* But write errors on close are bad! */
-      if (!class->close_fn (stream, cancellable, error))
-       res = FALSE;
+      res = g_output_stream_internal_close (stream, cancellable, error);
     }
 
   if (res)
     return bytes_copied;
-  
+
   return -1;
 }
 
+/* Must always be called inside
+ * g_output_stream_set_pending()/g_output_stream_clear_pending(). */
+static gboolean
+g_output_stream_internal_close (GOutputStream  *stream,
+                                GCancellable   *cancellable,
+                                GError        **error)
+{
+  GOutputStreamClass *class;
+  gboolean res;
+
+  if (stream->priv->closed)
+    return TRUE;
+
+  class = G_OUTPUT_STREAM_GET_CLASS (stream);
+
+  stream->priv->closing = TRUE;
+
+  if (cancellable)
+    g_cancellable_push_current (cancellable);
+
+  if (class->flush)
+    res = class->flush (stream, cancellable, error);
+  else
+    res = TRUE;
+
+  if (!res)
+    {
+      /* flushing caused the error that we want to return,
+       * but we still want to close the underlying stream if possible
+       */
+      if (class->close_fn)
+        class->close_fn (stream, cancellable, NULL);
+    }
+  else
+    {
+      res = TRUE;
+      if (class->close_fn)
+        res = class->close_fn (stream, cancellable, error);
+    }
+
+  if (cancellable)
+    g_cancellable_pop_current (cancellable);
+
+  stream->priv->closing = FALSE;
+  stream->priv->closed = TRUE;
+
+  return res;
+}
 
 /**
  * g_output_stream_close:
  * @stream: A #GOutputStream.
- * @cancellable: optional cancellable object
- * @error: location to store the error occuring, or %NULL to ignore
+ * @cancellable: (allow-none): optional cancellable object
+ * @error: location to store the error occurring, or %NULL to ignore
  *
  * Closes the stream, releasing resources related to it.
  *
@@ -474,8 +678,8 @@ g_output_stream_real_splice (GOutputStream             *stream,
  * stream.
  *
  * Streams will be automatically closed when the last reference
- * is dropped, but you might want to call make sure resources
- * are released as early as possible.
+ * is dropped, but you might want to call this function to make sure 
+ * resources are released as early as possible.
  *
  * Some streams might keep the backing store of the stream (e.g. a file descriptor)
  * open after the stream is closed. See the documentation for the individual
@@ -483,11 +687,11 @@ g_output_stream_real_splice (GOutputStream             *stream,
  *
  * On failure the first error that happened will be reported, but the close
  * operation will finish as much as possible. A stream that failed to
- * close will still return %G_IO_ERROR_CLOSED all operations. Still, it
+ * close will still return %G_IO_ERROR_CLOSED for all operations. Still, it
  * is important to check and report the error to the user, otherwise
  * there might be a loss of data as all data might not be written.
  * 
- * If @cancellable is not NULL, then the operation can be cancelled by
+ * If @cancellable is not %NULL, then the operation can be cancelled by
  * triggering the cancellable object from another thread. If the operation
  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
  * Cancelling a close will still leave the stream closed, but there some streams
@@ -495,98 +699,72 @@ g_output_stream_real_splice (GOutputStream             *stream,
  * cancellation (as with any error) there is no guarantee that all written
  * data will reach the target. 
  *
- * Return value: %TRUE on success, %FALSE on failure
+ * Returns: %TRUE on success, %FALSE on failure
  **/
 gboolean
 g_output_stream_close (GOutputStream  *stream,
                       GCancellable   *cancellable,
                       GError        **error)
 {
-  GOutputStreamClass *class;
   gboolean res;
 
   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 
-  class = G_OUTPUT_STREAM_GET_CLASS (stream);
-
   if (stream->priv->closed)
     return TRUE;
 
   if (!g_output_stream_set_pending (stream, error))
     return FALSE;
 
-  if (cancellable)
-    g_cancellable_push_current (cancellable);
+  res = g_output_stream_internal_close (stream, cancellable, error);
 
-  if (class->flush)
-    res = class->flush (stream, cancellable, error);
-  else
-    res = TRUE;
-  
-  if (!res)
-    {
-      /* flushing caused the error that we want to return,
-       * but we still want to close the underlying stream if possible
-       */
-      if (class->close_fn)
-       class->close_fn (stream, cancellable, NULL);
-    }
-  else
-    {
-      res = TRUE;
-      if (class->close_fn)
-       res = class->close_fn (stream, cancellable, error);
-    }
-  
-  if (cancellable)
-    g_cancellable_pop_current (cancellable);
-  
-  stream->priv->closed = TRUE;
   g_output_stream_clear_pending (stream);
   
   return res;
 }
 
 static void
-async_ready_callback_wrapper (GObject      *source_object,
-                              GAsyncResult *res,
-                              gpointer      user_data)
-{
-  GOutputStream *stream = G_OUTPUT_STREAM (source_object);
-
-  g_output_stream_clear_pending (stream);
-  if (stream->priv->outstanding_callback)
-    (*stream->priv->outstanding_callback) (source_object, res, user_data);
-  g_object_unref (stream);
-}
-
-static void
-async_ready_close_callback_wrapper (GObject      *source_object,
+async_ready_write_callback_wrapper (GObject      *source_object,
                                     GAsyncResult *res,
                                     gpointer      user_data)
 {
   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
+  GOutputStreamClass *class;
+  GTask *task = user_data;
+  gssize nwrote;
+  GError *error = NULL;
 
-  stream->priv->closed = TRUE;
   g_output_stream_clear_pending (stream);
-  if (stream->priv->outstanding_callback)
-    (*stream->priv->outstanding_callback) (source_object, res, user_data);
-  g_object_unref (stream);
+  
+  if (g_async_result_legacy_propagate_error (res, &error))
+    nwrote = -1;
+  else
+    {
+      class = G_OUTPUT_STREAM_GET_CLASS (stream);
+      nwrote = class->write_finish (stream, res, &error);
+    }
+
+  if (nwrote >= 0)
+    g_task_return_int (task, nwrote);
+  else
+    g_task_return_error (task, error);
+  g_object_unref (task);
 }
 
 /**
  * g_output_stream_write_async:
  * @stream: A #GOutputStream.
- * @buffer: the buffer containing the data to write. 
+ * @buffer: (array length=count) (element-type guint8): the buffer containing the data to write. 
  * @count: the number of bytes to write
  * @io_priority: the io priority of the request.
- * @cancellable: optional #GCancellable object, %NULL to ignore.
- * @callback: callback to call when the request is satisfied
- * @user_data: the data to pass to callback function
+ * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
+ * @callback: (scope async): callback to call when the request is satisfied
+ * @user_data: (closure): the data to pass to callback function
  *
  * Request an asynchronous write of @count bytes from @buffer into 
- * the stream. When the operation is finished @callback will be called, 
- * giving the results.
+ * the stream. When the operation is finished @callback will be called.
+ * You can then call g_output_stream_write_finish() to get the result of the 
+ * operation.
  *
  * During an async request no other sync and async calls are allowed, 
  * and will result in %G_IO_ERROR_PENDING errors. 
@@ -599,6 +777,10 @@ async_ready_close_callback_wrapper (GObject      *source_object,
  * requested size, as it can happen e.g. on a partial I/O error, 
  * but generally we try to write as many bytes as requested. 
  *
+ * You are guaranteed that this method will never fail with
+ * %G_IO_ERROR_WOULD_BLOCK - if @stream can't accept more data, the
+ * method will just wait until this changes.
+ *
  * Any outstanding I/O request with higher priority (lower numerical 
  * value) will be executed before an outstanding request with lower 
  * priority. Default priority is %G_PRIORITY_DEFAULT.
@@ -609,7 +791,12 @@ async_ready_close_callback_wrapper (GObject      *source_object,
  *
  * For the synchronous, blocking version of this function, see 
  * g_output_stream_write().
- **/
+ *
+ * Note that no copy of @buffer will be made, so it must stay valid
+ * until @callback is called. See g_output_stream_write_bytes_async()
+ * for a #GBytes version that will automatically hold a reference to
+ * the contents (without copying) for the duration of the call.
+ */
 void
 g_output_stream_write_async (GOutputStream       *stream,
                             const void          *buffer,
@@ -620,56 +807,50 @@ g_output_stream_write_async (GOutputStream       *stream,
                             gpointer             user_data)
 {
   GOutputStreamClass *class;
-  GSimpleAsyncResult *simple;
   GError *error = NULL;
+  GTask *task;
 
   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
   g_return_if_fail (buffer != NULL);
 
+  task = g_task_new (stream, cancellable, callback, user_data);
+  g_task_set_source_tag (task, g_output_stream_write_async);
+  g_task_set_priority (task, io_priority);
+
   if (count == 0)
     {
-      simple = g_simple_async_result_new (G_OBJECT (stream),
-                                         callback,
-                                         user_data,
-                                         g_output_stream_write_async);
-      g_simple_async_result_complete_in_idle (simple);
-      g_object_unref (simple);
+      g_task_return_int (task, 0);
+      g_object_unref (task);
       return;
     }
 
   if (((gssize) count) < 0)
     {
-      g_simple_async_report_error_in_idle (G_OBJECT (stream),
-                                          callback,
-                                          user_data,
-                                          G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
-                                          _("Too large count value passed to g_output_stream_write_async"));
+      g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
+                               _("Too large count value passed to %s"),
+                               G_STRFUNC);
+      g_object_unref (task);
       return;
     }
 
   if (!g_output_stream_set_pending (stream, &error))
     {
-      g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
-                                           callback,
-                                           user_data,
-                                           error);
-      g_error_free (error);
+      g_task_return_error (task, error);
+      g_object_unref (task);
       return;
     }
   
   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 
-  stream->priv->outstanding_callback = callback;
-  g_object_ref (stream);
   class->write_async (stream, buffer, count, io_priority, cancellable,
-                     async_ready_callback_wrapper, user_data);
+                      async_ready_write_callback_wrapper, task);
 }
 
 /**
  * g_output_stream_write_finish:
  * @stream: a #GOutputStream.
  * @result: a #GAsyncResult.
- * @error: a #GError location to store the error occuring, or %NULL to 
+ * @error: a #GError location to store the error occurring, or %NULL to 
  * ignore.
  * 
  * Finishes a stream write operation.
@@ -681,155 +862,449 @@ g_output_stream_write_finish (GOutputStream  *stream,
                               GAsyncResult   *result,
                               GError        **error)
 {
-  GSimpleAsyncResult *simple;
-  GOutputStreamClass *class;
+  g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
+  g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
+  g_return_val_if_fail (g_async_result_is_tagged (result, g_output_stream_write_async), FALSE);
 
-  g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
-  g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
+  /* @result is always the GTask created by g_output_stream_write_async();
+   * we called class->write_finish() from async_ready_write_callback_wrapper.
+   */
+  return g_task_propagate_int (G_TASK (result), error);
+}
+
+typedef struct
+{
+  const guint8 *buffer;
+  gsize to_write;
+  gsize bytes_written;
+} AsyncWriteAll;
+
+static void
+free_async_write_all (gpointer data)
+{
+  g_slice_free (AsyncWriteAll, data);
+}
 
-  if (G_IS_SIMPLE_ASYNC_RESULT (result))
+static void
+write_all_callback (GObject      *stream,
+                    GAsyncResult *result,
+                    gpointer      user_data)
+{
+  GTask *task = user_data;
+  AsyncWriteAll *data = g_task_get_task_data (task);
+
+  if (result)
     {
-      simple = G_SIMPLE_ASYNC_RESULT (result);
-      if (g_simple_async_result_propagate_error (simple, error))
-       return -1;
+      GError *error = NULL;
+      gssize nwritten;
+
+      nwritten = g_output_stream_write_finish (G_OUTPUT_STREAM (stream), result, &error);
 
-      /* Special case writes of 0 bytes */
-      if (g_simple_async_result_get_source_tag (simple) == g_output_stream_write_async)
-       return 0;
+      if (nwritten == -1)
+        {
+          g_task_return_error (task, error);
+          g_object_unref (task);
+          return;
+        }
+
+      g_assert_cmpint (nwritten, <=, data->to_write);
+      g_warn_if_fail (nwritten > 0);
+
+      data->to_write -= nwritten;
+      data->bytes_written += nwritten;
     }
-  
-  class = G_OUTPUT_STREAM_GET_CLASS (stream);
-  return class->write_finish (stream, result, error);
-}
 
-typedef struct {
-  GInputStream *source;
-  gpointer user_data;
-  GAsyncReadyCallback callback;
-} SpliceUserData;
+  if (data->to_write == 0)
+    {
+      g_task_return_boolean (task, TRUE);
+      g_object_unref (task);
+    }
+
+  else
+    g_output_stream_write_async (G_OUTPUT_STREAM (stream),
+                                 data->buffer + data->bytes_written,
+                                 data->to_write,
+                                 g_task_get_priority (task),
+                                 g_task_get_cancellable (task),
+                                 write_all_callback, task);
+}
 
 static void
-async_ready_splice_callback_wrapper (GObject      *source_object,
-                                     GAsyncResult *res,
-                                     gpointer     _data)
+write_all_async_thread (GTask        *task,
+                        gpointer      source_object,
+                        gpointer      task_data,
+                        GCancellable *cancellable)
 {
-  GOutputStream *stream = G_OUTPUT_STREAM (source_object);
-  SpliceUserData *data = _data;
-  
-  g_output_stream_clear_pending (stream);
-  
-  if (data->callback)
-    (*data->callback) (source_object, res, data->user_data);
-  
-  g_object_unref (stream);
-  g_object_unref (data->source);
-  g_free (data);
+  GOutputStream *stream = source_object;
+  AsyncWriteAll *data = task_data;
+  GError *error = NULL;
+
+  if (g_output_stream_write_all (stream, data->buffer, data->to_write, &data->bytes_written,
+                                 g_task_get_cancellable (task), &error))
+    g_task_return_boolean (task, TRUE);
+  else
+    g_task_return_error (task, error);
 }
 
 /**
- * g_output_stream_splice_async:
- * @stream: a #GOutputStream.
- * @source: a #GInputStream. 
- * @flags: a set of #GOutputStreamSpliceFlags.
- * @io_priority: the io priority of the request.
- * @cancellable: optional #GCancellable object, %NULL to ignore. 
- * @callback: a #GAsyncReadyCallback. 
- * @user_data: user data passed to @callback.
- * 
- * Splices a stream asynchronously.
- * 
- **/
+ * g_output_stream_write_all_async:
+ * @stream: A #GOutputStream
+ * @buffer: (array length=count) (element-type guint8): the buffer containing the data to write
+ * @count: the number of bytes to write
+ * @io_priority: the io priority of the request
+ * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore
+ * @callback: (scope async): callback to call when the request is satisfied
+ * @user_data: (closure): the data to pass to callback function
+ *
+ * Request an asynchronous write of @count bytes from @buffer into
+ * the stream. When the operation is finished @callback will be called.
+ * You can then call g_output_stream_write_all_finish() to get the result of the
+ * operation.
+ *
+ * This is the asynchronous version of g_output_stream_write_all().
+ *
+ * Call g_output_stream_write_all_finish() to collect the result.
+ *
+ * Any outstanding I/O request with higher priority (lower numerical
+ * value) will be executed before an outstanding request with lower
+ * priority. Default priority is %G_PRIORITY_DEFAULT.
+ *
+ * Note that no copy of @buffer will be made, so it must stay valid
+ * until @callback is called.
+ *
+ * Since: 2.44
+ */
 void
-g_output_stream_splice_async (GOutputStream            *stream,
-                             GInputStream             *source,
-                             GOutputStreamSpliceFlags  flags,
-                             int                       io_priority,
-                             GCancellable             *cancellable,
-                             GAsyncReadyCallback       callback,
-                             gpointer                  user_data)
+g_output_stream_write_all_async (GOutputStream       *stream,
+                                 const void          *buffer,
+                                 gsize                count,
+                                 int                  io_priority,
+                                 GCancellable        *cancellable,
+                                 GAsyncReadyCallback  callback,
+                                 gpointer             user_data)
 {
-  GOutputStreamClass *class;
-  SpliceUserData *data;
-  GError *error = NULL;
+  AsyncWriteAll *data;
+  GTask *task;
 
   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
-  g_return_if_fail (G_IS_INPUT_STREAM (source));
+  g_return_if_fail (buffer != NULL || count == 0);
 
-  if (g_input_stream_is_closed (source))
-    {
-      g_simple_async_report_error_in_idle (G_OBJECT (stream),
-                                          callback,
-                                          user_data,
-                                          G_IO_ERROR, G_IO_ERROR_CLOSED,
-                                          _("Source stream is already closed"));
-      return;
-    }
-  
-  if (!g_output_stream_set_pending (stream, &error))
-    {
-      g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
-                                           callback,
-                                           user_data,
-                                           error);
-      g_error_free (error);
-      return;
-    }
+  task = g_task_new (stream, cancellable, callback, user_data);
+  data = g_slice_new0 (AsyncWriteAll);
+  data->buffer = buffer;
+  data->to_write = count;
 
-  class = G_OUTPUT_STREAM_GET_CLASS (stream);
+  g_task_set_task_data (task, data, free_async_write_all);
+  g_task_set_priority (task, io_priority);
 
-  data = g_new0 (SpliceUserData, 1);
-  data->callback = callback;
-  data->user_data = user_data;
-  data->source = g_object_ref (source);
-  
-  g_object_ref (stream);
-  class->splice_async (stream, source, flags, io_priority, cancellable,
-                     async_ready_splice_callback_wrapper, data);
+  /* If async writes are going to be handled via the threadpool anyway
+   * then we may as well do it with a single dispatch instead of
+   * bouncing in and out.
+   */
+  if (g_output_stream_async_write_is_via_threads (stream))
+    {
+      g_task_run_in_thread (task, write_all_async_thread);
+      g_object_unref (task);
+    }
+  else
+    write_all_callback (G_OBJECT (stream), NULL, task);
 }
 
 /**
- * g_output_stream_splice_finish:
+ * g_output_stream_write_all_finish:
+ * @stream: a #GOutputStream
+ * @result: a #GAsyncResult
+ * @bytes_written: (out): location to store the number of bytes that was written to the stream
+ * @error: a #GError location to store the error occurring, or %NULL to ignore.
+ *
+ * Finishes an asynchronous stream write operation started with
+ * g_output_stream_write_all_async().
+ *
+ * As a special exception to the normal conventions for functions that
+ * use #GError, if this function returns %FALSE (and sets @error) then
+ * @bytes_written will be set to the number of bytes that were
+ * successfully written before the error was encountered.  This
+ * functionality is only available from C.  If you need it from another
+ * language then you must write your own loop around
+ * g_output_stream_write_async().
+ *
+ * Returns: %TRUE on success, %FALSE if there was an error
+ *
+ * Since: 2.44
+ **/
+gboolean
+g_output_stream_write_all_finish (GOutputStream  *stream,
+                                  GAsyncResult   *result,
+                                  gsize          *bytes_written,
+                                  GError        **error)
+{
+  GTask *task;
+
+  g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
+  g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
+
+  task = G_TASK (result);
+
+  if (bytes_written)
+    {
+      AsyncWriteAll *data = (AsyncWriteAll *)g_task_get_task_data (task);
+
+      *bytes_written = data->bytes_written;
+    }
+
+  return g_task_propagate_boolean (task, error);
+}
+
+static void
+write_bytes_callback (GObject      *stream,
+                      GAsyncResult *result,
+                      gpointer      user_data)
+{
+  GTask *task = user_data;
+  GError *error = NULL;
+  gssize nwrote;
+
+  nwrote = g_output_stream_write_finish (G_OUTPUT_STREAM (stream),
+                                         result, &error);
+  if (nwrote == -1)
+    g_task_return_error (task, error);
+  else
+    g_task_return_int (task, nwrote);
+  g_object_unref (task);
+}
+
+/**
+ * g_output_stream_write_bytes_async:
+ * @stream: A #GOutputStream.
+ * @bytes: The bytes to write
+ * @io_priority: the io priority of the request.
+ * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
+ * @callback: (scope async): callback to call when the request is satisfied
+ * @user_data: (closure): the data to pass to callback function
+ *
+ * This function is similar to g_output_stream_write_async(), but
+ * takes a #GBytes as input.  Due to the refcounted nature of #GBytes,
+ * this allows the stream to avoid taking a copy of the data.
+ *
+ * However, note that this function may still perform partial writes,
+ * just like g_output_stream_write_async(). If that occurs, to continue
+ * writing, you will need to create a new #GBytes containing just the
+ * remaining bytes, using g_bytes_new_from_bytes(). Passing the same
+ * #GBytes instance multiple times potentially can result in duplicated
+ * data in the output stream.
+ *
+ * For the synchronous, blocking version of this function, see
+ * g_output_stream_write_bytes().
+ **/
+void
+g_output_stream_write_bytes_async (GOutputStream       *stream,
+                                  GBytes              *bytes,
+                                  int                  io_priority,
+                                  GCancellable        *cancellable,
+                                  GAsyncReadyCallback  callback,
+                                  gpointer             user_data)
+{
+  GTask *task;
+  gsize size;
+  gconstpointer data;
+
+  data = g_bytes_get_data (bytes, &size);
+
+  task = g_task_new (stream, cancellable, callback, user_data);
+  g_task_set_task_data (task, g_bytes_ref (bytes),
+                        (GDestroyNotify) g_bytes_unref);
+
+  g_output_stream_write_async (stream,
+                               data, size,
+                               io_priority,
+                               cancellable,
+                               write_bytes_callback,
+                               task);
+}
+
+/**
+ * g_output_stream_write_bytes_finish:
+ * @stream: a #GOutputStream.
+ * @result: a #GAsyncResult.
+ * @error: a #GError location to store the error occurring, or %NULL to
+ * ignore.
+ *
+ * Finishes a stream write-from-#GBytes operation.
+ *
+ * Returns: a #gssize containing the number of bytes written to the stream.
+ **/
+gssize
+g_output_stream_write_bytes_finish (GOutputStream  *stream,
+                                   GAsyncResult   *result,
+                                   GError        **error)
+{
+  g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
+  g_return_val_if_fail (g_task_is_valid (result, stream), -1);
+
+  return g_task_propagate_int (G_TASK (result), error);
+}
+
+static void
+async_ready_splice_callback_wrapper (GObject      *source_object,
+                                     GAsyncResult *res,
+                                     gpointer     _data)
+{
+  GOutputStream *stream = G_OUTPUT_STREAM (source_object);
+  GOutputStreamClass *class;
+  GTask *task = _data;
+  gssize nspliced;
+  GError *error = NULL;
+
+  g_output_stream_clear_pending (stream);
+  
+  if (g_async_result_legacy_propagate_error (res, &error))
+    nspliced = -1;
+  else
+    {
+      class = G_OUTPUT_STREAM_GET_CLASS (stream);
+      nspliced = class->splice_finish (stream, res, &error);
+    }
+
+  if (nspliced >= 0)
+    g_task_return_int (task, nspliced);
+  else
+    g_task_return_error (task, error);
+  g_object_unref (task);
+}
+
+/**
+ * g_output_stream_splice_async:
+ * @stream: a #GOutputStream.
+ * @source: a #GInputStream. 
+ * @flags: a set of #GOutputStreamSpliceFlags.
+ * @io_priority: the io priority of the request.
+ * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore. 
+ * @callback: (scope async): a #GAsyncReadyCallback. 
+ * @user_data: (closure): user data passed to @callback.
+ * 
+ * Splices a stream asynchronously.
+ * When the operation is finished @callback will be called.
+ * You can then call g_output_stream_splice_finish() to get the 
+ * result of the operation.
+ *
+ * For the synchronous, blocking version of this function, see 
+ * g_output_stream_splice().
+ **/
+void
+g_output_stream_splice_async (GOutputStream            *stream,
+                             GInputStream             *source,
+                             GOutputStreamSpliceFlags  flags,
+                             int                       io_priority,
+                             GCancellable             *cancellable,
+                             GAsyncReadyCallback       callback,
+                             gpointer                  user_data)
+{
+  GOutputStreamClass *class;
+  GTask *task;
+  GError *error = NULL;
+
+  g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
+  g_return_if_fail (G_IS_INPUT_STREAM (source));
+
+  task = g_task_new (stream, cancellable, callback, user_data);
+  g_task_set_source_tag (task, g_output_stream_splice_async);
+  g_task_set_priority (task, io_priority);
+  g_task_set_task_data (task, g_object_ref (source), g_object_unref);
+
+  if (g_input_stream_is_closed (source))
+    {
+      g_task_return_new_error (task,
+                               G_IO_ERROR, G_IO_ERROR_CLOSED,
+                               _("Source stream is already closed"));
+      g_object_unref (task);
+      return;
+    }
+  
+  if (!g_output_stream_set_pending (stream, &error))
+    {
+      g_task_return_error (task, error);
+      g_object_unref (task);
+      return;
+    }
+
+  class = G_OUTPUT_STREAM_GET_CLASS (stream);
+
+  class->splice_async (stream, source, flags, io_priority, cancellable,
+                       async_ready_splice_callback_wrapper, task);
+}
+
+/**
+ * g_output_stream_splice_finish:
  * @stream: a #GOutputStream.
  * @result: a #GAsyncResult.
- * @error: a #GError location to store the error occuring, or %NULL to 
+ * @error: a #GError location to store the error occurring, or %NULL to 
  * ignore.
  *
  * Finishes an asynchronous stream splice operation.
  * 
- * Returns: a #gssize of the number of bytes spliced.
+ * Returns: a #gssize of the number of bytes spliced. Note that if the
+ *     number of bytes spliced is greater than %G_MAXSSIZE, then that
+ *     will be returned, and there is no way to determine the actual
+ *     number of bytes spliced.
  **/
 gssize
 g_output_stream_splice_finish (GOutputStream  *stream,
                               GAsyncResult   *result,
                               GError        **error)
 {
-  GSimpleAsyncResult *simple;
-  GOutputStreamClass *class;
+  g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
+  g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
+  g_return_val_if_fail (g_async_result_is_tagged (result, g_output_stream_splice_async), FALSE);
 
-  g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
-  g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
+  /* @result is always the GTask created by g_output_stream_splice_async();
+   * we called class->splice_finish() from async_ready_splice_callback_wrapper.
+   */
+  return g_task_propagate_int (G_TASK (result), error);
+}
+
+static void
+async_ready_flush_callback_wrapper (GObject      *source_object,
+                                    GAsyncResult *res,
+                                    gpointer      user_data)
+{
+  GOutputStream *stream = G_OUTPUT_STREAM (source_object);
+  GOutputStreamClass *class;
+  GTask *task = user_data;
+  gboolean flushed;
+  GError *error = NULL;
 
-  if (G_IS_SIMPLE_ASYNC_RESULT (result))
+  g_output_stream_clear_pending (stream);
+  
+  if (g_async_result_legacy_propagate_error (res, &error))
+    flushed = FALSE;
+  else
     {
-      simple = G_SIMPLE_ASYNC_RESULT (result);
-      if (g_simple_async_result_propagate_error (simple, error))
-       return -1;
+      class = G_OUTPUT_STREAM_GET_CLASS (stream);
+      flushed = class->flush_finish (stream, res, &error);
     }
-  
-  class = G_OUTPUT_STREAM_GET_CLASS (stream);
-  return class->splice_finish (stream, result, error);
+
+  if (flushed)
+    g_task_return_boolean (task, TRUE);
+  else
+    g_task_return_error (task, error);
+  g_object_unref (task);
 }
 
 /**
  * g_output_stream_flush_async:
  * @stream: a #GOutputStream.
  * @io_priority: the io priority of the request.
- * @cancellable: optional #GCancellable object, %NULL to ignore.
- * @callback: a #GAsyncReadyCallback to call when the request is satisfied
- * @user_data: the data to pass to callback function
- * 
- * Flushes a stream asynchronously.
+ * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
+ * @callback: (scope async): a #GAsyncReadyCallback to call when the request is satisfied
+ * @user_data: (closure): the data to pass to callback function
  * 
+ * Forces an asynchronous write of all user-space buffered data for
+ * the given @stream.
+ * For behaviour details see g_output_stream_flush().
+ *
+ * When the operation is finished @callback will be 
+ * called. You can then call g_output_stream_flush_finish() to get the 
+ * result of the operation.
  **/
 void
 g_output_stream_flush_async (GOutputStream       *stream,
@@ -839,90 +1314,152 @@ g_output_stream_flush_async (GOutputStream       *stream,
                              gpointer             user_data)
 {
   GOutputStreamClass *class;
-  GSimpleAsyncResult *simple;
+  GTask *task;
   GError *error = NULL;
 
   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 
+  task = g_task_new (stream, cancellable, callback, user_data);
+  g_task_set_source_tag (task, g_output_stream_flush_async);
+  g_task_set_priority (task, io_priority);
+
   if (!g_output_stream_set_pending (stream, &error))
     {
-      g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
-                                           callback,
-                                           user_data,
-                                           error);
-      g_error_free (error);
+      g_task_return_error (task, error);
+      g_object_unref (task);
       return;
     }
 
-  stream->priv->outstanding_callback = callback;
-  g_object_ref (stream);
-
   class = G_OUTPUT_STREAM_GET_CLASS (stream);
   
   if (class->flush_async == NULL)
     {
-      simple = g_simple_async_result_new (G_OBJECT (stream),
-                                         async_ready_callback_wrapper,
-                                         user_data,
-                                         g_output_stream_flush_async);
-      g_simple_async_result_complete_in_idle (simple);
-      g_object_unref (simple);
+      g_task_return_boolean (task, TRUE);
+      g_object_unref (task);
       return;
     }
       
   class->flush_async (stream, io_priority, cancellable,
-                     async_ready_callback_wrapper, user_data);
+                      async_ready_flush_callback_wrapper, task);
 }
 
 /**
  * g_output_stream_flush_finish:
  * @stream: a #GOutputStream.
  * @result: a GAsyncResult.
- * @error: a #GError location to store the error occuring, or %NULL to 
+ * @error: a #GError location to store the error occurring, or %NULL to 
  * ignore.
  * 
  * Finishes flushing an output stream.
  * 
- * Returns: %TRUE if flush operation suceeded, %FALSE otherwise.
+ * Returns: %TRUE if flush operation succeeded, %FALSE otherwise.
  **/
 gboolean
 g_output_stream_flush_finish (GOutputStream  *stream,
                               GAsyncResult   *result,
                               GError        **error)
 {
-  GSimpleAsyncResult *simple;
-  GOutputStreamClass *klass;
-
   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
-  g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
+  g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
+  g_return_val_if_fail (g_async_result_is_tagged (result, g_output_stream_flush_async), FALSE);
 
-  if (G_IS_SIMPLE_ASYNC_RESULT (result))
+  /* @result is always the GTask created by g_output_stream_flush_async();
+   * we called class->flush_finish() from async_ready_flush_callback_wrapper.
+   */
+  return g_task_propagate_boolean (G_TASK (result), error);
+}
+
+
+static void
+async_ready_close_callback_wrapper (GObject      *source_object,
+                                    GAsyncResult *res,
+                                    gpointer      user_data)
+{
+  GOutputStream *stream = G_OUTPUT_STREAM (source_object);
+  GOutputStreamClass *class;
+  GTask *task = user_data;
+  GError *error = g_task_get_task_data (task);
+
+  stream->priv->closing = FALSE;
+  stream->priv->closed = TRUE;
+
+  if (!error && !g_async_result_legacy_propagate_error (res, &error))
     {
-      simple = G_SIMPLE_ASYNC_RESULT (result);
-      if (g_simple_async_result_propagate_error (simple, error))
-       return FALSE;
+      class = G_OUTPUT_STREAM_GET_CLASS (stream);
 
-      /* Special case default implementation */
-      if (g_simple_async_result_get_source_tag (simple) == g_output_stream_flush_async)
-       return TRUE;
+      class->close_finish (stream, res,
+                           error ? NULL : &error);
     }
 
-  klass = G_OUTPUT_STREAM_GET_CLASS (stream);
-  return klass->flush_finish (stream, result, error);
+  if (error != NULL)
+    g_task_return_error (task, error);
+  else
+    g_task_return_boolean (task, TRUE);
+  g_object_unref (task);
 }
 
+static void
+async_ready_close_flushed_callback_wrapper (GObject      *source_object,
+                                            GAsyncResult *res,
+                                            gpointer      user_data)
+{
+  GOutputStream *stream = G_OUTPUT_STREAM (source_object);
+  GOutputStreamClass *class;
+  GTask *task = user_data;
+  GError *error = NULL;
+
+  class = G_OUTPUT_STREAM_GET_CLASS (stream);
+
+  if (!g_async_result_legacy_propagate_error (res, &error))
+    {
+      class->flush_finish (stream, res, &error);
+    }
+
+  /* propagate the possible error */
+  if (error)
+    g_task_set_task_data (task, error, NULL);
+
+  /* we still close, even if there was a flush error */
+  class->close_async (stream,
+                      g_task_get_priority (task),
+                      g_task_get_cancellable (task),
+                      async_ready_close_callback_wrapper, task);
+}
+
+static void
+real_close_async_cb (GObject      *source_object,
+                     GAsyncResult *res,
+                     gpointer      user_data)
+{
+  GOutputStream *stream = G_OUTPUT_STREAM (source_object);
+  GTask *task = user_data;
+  GError *error = NULL;
+  gboolean ret;
+
+  g_output_stream_clear_pending (stream);
+
+  ret = g_output_stream_internal_close_finish (stream, res, &error);
+
+  if (error != NULL)
+    g_task_return_error (task, error);
+  else
+    g_task_return_boolean (task, ret);
+
+  g_object_unref (task);
+}
 
 /**
  * g_output_stream_close_async:
  * @stream: A #GOutputStream.
  * @io_priority: the io priority of the request.
- * @callback: callback to call when the request is satisfied
- * @user_data: the data to pass to callback function
- * @cancellable: optional cancellable object
+ * @cancellable: (allow-none): optional cancellable object
+ * @callback: (scope async): callback to call when the request is satisfied
+ * @user_data: (closure): the data to pass to callback function
  *
  * Requests an asynchronous close of the stream, releasing resources 
  * related to it. When the operation is finished @callback will be 
- * called, giving the results.
+ * called. You can then call g_output_stream_close_finish() to get 
+ * the result of the operation.
  *
  * For behaviour details see g_output_stream_close().
  *
@@ -937,45 +1474,88 @@ g_output_stream_close_async (GOutputStream       *stream,
                              GAsyncReadyCallback  callback,
                              gpointer             user_data)
 {
-  GOutputStreamClass *class;
-  GSimpleAsyncResult *simple;
+  GTask *task;
   GError *error = NULL;
 
   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
   
-  if (stream->priv->closed)
+  task = g_task_new (stream, cancellable, callback, user_data);
+  g_task_set_source_tag (task, g_output_stream_close_async);
+  g_task_set_priority (task, io_priority);
+
+  if (!g_output_stream_set_pending (stream, &error))
     {
-      simple = g_simple_async_result_new (G_OBJECT (stream),
-                                         callback,
-                                         user_data,
-                                         g_output_stream_close_async);
-      g_simple_async_result_complete_in_idle (simple);
-      g_object_unref (simple);
+      g_task_return_error (task, error);
+      g_object_unref (task);
       return;
     }
 
-  if (!g_output_stream_set_pending (stream, &error))
+  g_output_stream_internal_close_async (stream, io_priority, cancellable,
+                                        real_close_async_cb, task);
+}
+
+/* Must always be called inside
+ * g_output_stream_set_pending()/g_output_stream_clear_pending().
+ */
+void
+g_output_stream_internal_close_async (GOutputStream       *stream,
+                                      int                  io_priority,
+                                      GCancellable        *cancellable,
+                                      GAsyncReadyCallback  callback,
+                                      gpointer             user_data)
+{
+  GOutputStreamClass *class;
+  GTask *task;
+
+  task = g_task_new (stream, cancellable, callback, user_data);
+  g_task_set_source_tag (task, g_output_stream_internal_close_async);
+  g_task_set_priority (task, io_priority);
+
+  if (stream->priv->closed)
     {
-      g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
-                                           callback,
-                                           user_data,
-                                           error);
-      g_error_free (error);
+      g_task_return_boolean (task, TRUE);
+      g_object_unref (task);
       return;
     }
-  
+
   class = G_OUTPUT_STREAM_GET_CLASS (stream);
-  stream->priv->outstanding_callback = callback;
-  g_object_ref (stream);
-  class->close_async (stream, io_priority, cancellable,
-                     async_ready_close_callback_wrapper, user_data);
+  stream->priv->closing = TRUE;
+
+  /* Call close_async directly if there is no need to flush, or if the flush
+     can be done sync (in the output stream async close thread) */
+  if (class->flush_async == NULL ||
+      (class->flush_async == g_output_stream_real_flush_async &&
+       (class->flush == NULL || class->close_async == g_output_stream_real_close_async)))
+    {
+      class->close_async (stream, io_priority, cancellable,
+                          async_ready_close_callback_wrapper, task);
+    }
+  else
+    {
+      /* First do an async flush, then do the async close in the callback
+         wrapper (see async_ready_close_flushed_callback_wrapper) */
+      class->flush_async (stream, io_priority, cancellable,
+                          async_ready_close_flushed_callback_wrapper, task);
+    }
+}
+
+static gboolean
+g_output_stream_internal_close_finish (GOutputStream  *stream,
+                                       GAsyncResult   *result,
+                                       GError        **error)
+{
+  g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
+  g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
+  g_return_val_if_fail (g_async_result_is_tagged (result, g_output_stream_internal_close_async), FALSE);
+
+  return g_task_propagate_boolean (G_TASK (result), error);
 }
 
 /**
  * g_output_stream_close_finish:
  * @stream: a #GOutputStream.
  * @result: a #GAsyncResult.
- * @error: a #GError location to store the error occuring, or %NULL to 
+ * @error: a #GError location to store the error occurring, or %NULL to 
  * ignore.
  * 
  * Closes an output stream.
@@ -987,25 +1567,14 @@ g_output_stream_close_finish (GOutputStream  *stream,
                               GAsyncResult   *result,
                               GError        **error)
 {
-  GSimpleAsyncResult *simple;
-  GOutputStreamClass *class;
-
   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
-  g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
-
-  if (G_IS_SIMPLE_ASYNC_RESULT (result))
-    {
-      simple = G_SIMPLE_ASYNC_RESULT (result);
-      if (g_simple_async_result_propagate_error (simple, error))
-       return FALSE;
-
-      /* Special case already closed */
-      if (g_simple_async_result_get_source_tag (simple) == g_output_stream_close_async)
-       return TRUE;
-    }
+  g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
+  g_return_val_if_fail (g_async_result_is_tagged (result, g_output_stream_close_async), FALSE);
 
-  class = G_OUTPUT_STREAM_GET_CLASS (stream);
-  return class->close_finish (stream, result, error);
+  /* @result is always the GTask created by g_output_stream_close_async();
+   * we called class->close_finish() from async_ready_close_callback_wrapper.
+   */
+  return g_task_propagate_boolean (G_TASK (result), error);
 }
 
 /**
@@ -1025,6 +1594,27 @@ g_output_stream_is_closed (GOutputStream *stream)
 }
 
 /**
+ * g_output_stream_is_closing:
+ * @stream: a #GOutputStream.
+ *
+ * Checks if an output stream is being closed. This can be
+ * used inside e.g. a flush implementation to see if the
+ * flush (or other i/o operation) is called from within
+ * the closing operation.
+ *
+ * Returns: %TRUE if @stream is being closed. %FALSE otherwise.
+ *
+ * Since: 2.24
+ **/
+gboolean
+g_output_stream_is_closing (GOutputStream *stream)
+{
+  g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), TRUE);
+
+  return stream->priv->closing;
+}
+
+/**
  * g_output_stream_has_pending:
  * @stream: a #GOutputStream.
  * 
@@ -1043,14 +1633,14 @@ g_output_stream_has_pending (GOutputStream *stream)
 /**
  * g_output_stream_set_pending:
  * @stream: a #GOutputStream.
- * @error: a #GError location to store the error occuring, or %NULL to 
+ * @error: a #GError location to store the error occurring, or %NULL to 
  * ignore.
  * 
  * Sets @stream to have actions pending. If the pending flag is
  * already set or @stream is closed, it will return %FALSE and set
  * @error.
  *
- * Return value: %TRUE if pending was previously unset and is now set.
+ * Returns: %TRUE if pending was previously unset and is now set.
  **/
 gboolean
 g_output_stream_set_pending (GOutputStream *stream,
@@ -1060,15 +1650,18 @@ g_output_stream_set_pending (GOutputStream *stream,
   
   if (stream->priv->closed)
     {
-      g_set_error (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
-                  _("Stream is already closed"));
+      g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
+                           _("Stream is already closed"));
       return FALSE;
     }
   
   if (stream->priv->pending)
     {
-      g_set_error (error, G_IO_ERROR, G_IO_ERROR_PENDING,
-                  _("Stream has outstanding operation"));
+      g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING,
+                           /* Translators: This is an error you get if there is
+                            * already an operation running against this stream when
+                            * you try to start one */
+                           _("Stream has outstanding operation"));
       return FALSE;
     }
   
@@ -1090,6 +1683,28 @@ g_output_stream_clear_pending (GOutputStream *stream)
   stream->priv->pending = FALSE;
 }
 
+/**
+ * g_output_stream_async_write_is_via_threads:
+ * @stream: a #GOutputStream.
+ *
+ * Checks if an ouput stream's write_async function uses threads.
+ *
+ * Returns: %TRUE if @stream's write_async function uses threads.
+ **/
+gboolean
+g_output_stream_async_write_is_via_threads (GOutputStream *stream)
+{
+  GOutputStreamClass *class;
+
+  g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
+
+  class = G_OUTPUT_STREAM_GET_CLASS (stream);
+
+  return (class->write_async == g_output_stream_real_write_async &&
+      !(G_IS_POLLABLE_OUTPUT_STREAM (stream) &&
+        g_pollable_output_stream_can_poll (G_POLLABLE_OUTPUT_STREAM (stream))));
+}
+
 
 /********************************************
  *   Default implementation of async ops    *
@@ -1102,23 +1717,77 @@ typedef struct {
 } WriteData;
 
 static void
-write_async_thread (GSimpleAsyncResult *res,
-                    GObject            *object,
-                    GCancellable       *cancellable)
+free_write_data (WriteData *op)
 {
-  WriteData *op;
+  g_slice_free (WriteData, op);
+}
+
+static void
+write_async_thread (GTask        *task,
+                    gpointer      source_object,
+                    gpointer      task_data,
+                    GCancellable *cancellable)
+{
+  GOutputStream *stream = source_object;
+  WriteData *op = task_data;
   GOutputStreamClass *class;
   GError *error = NULL;
+  gssize count_written;
+
+  class = G_OUTPUT_STREAM_GET_CLASS (stream);
+  count_written = class->write_fn (stream, op->buffer, op->count_requested,
+                                   cancellable, &error);
+  if (count_written == -1)
+    g_task_return_error (task, error);
+  else
+    g_task_return_int (task, count_written);
+}
+
+static void write_async_pollable (GPollableOutputStream *stream,
+                                  GTask                 *task);
+
+static gboolean
+write_async_pollable_ready (GPollableOutputStream *stream,
+                           gpointer               user_data)
+{
+  GTask *task = user_data;
+
+  write_async_pollable (stream, task);
+  return FALSE;
+}
+
+static void
+write_async_pollable (GPollableOutputStream *stream,
+                      GTask                 *task)
+{
+  GError *error = NULL;
+  WriteData *op = g_task_get_task_data (task);
+  gssize count_written;
+
+  if (g_task_return_error_if_cancelled (task))
+    return;
 
-  class = G_OUTPUT_STREAM_GET_CLASS (object);
-  op = g_simple_async_result_get_op_res_gpointer (res);
-  op->count_written = class->write_fn (G_OUTPUT_STREAM (object), op->buffer, op->count_requested,
-                                      cancellable, &error);
-  if (op->count_written == -1)
+  count_written = G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream)->
+    write_nonblocking (stream, op->buffer, op->count_requested, &error);
+
+  if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK))
     {
-      g_simple_async_result_set_from_error (res, error);
+      GSource *source;
+
       g_error_free (error);
+
+      source = g_pollable_output_stream_create_source (stream,
+                                                       g_task_get_cancellable (task));
+      g_task_attach_source (task, source,
+                            (GSourceFunc) write_async_pollable_ready);
+      g_source_unref (source);
+      return;
     }
+
+  if (count_written == -1)
+    g_task_return_error (task, error);
+  else
+    g_task_return_int (task, count_written);
 }
 
 static void
@@ -1130,17 +1799,21 @@ g_output_stream_real_write_async (GOutputStream       *stream,
                                   GAsyncReadyCallback  callback,
                                   gpointer             user_data)
 {
-  GSimpleAsyncResult *res;
+  GTask *task;
   WriteData *op;
 
-  op = g_new0 (WriteData, 1);
-  res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_write_async);
-  g_simple_async_result_set_op_res_gpointer (res, op, g_free);
+  op = g_slice_new0 (WriteData);
+  task = g_task_new (stream, cancellable, callback, user_data);
+  g_task_set_check_cancellable (task, FALSE);
+  g_task_set_task_data (task, op, (GDestroyNotify) free_write_data);
   op->buffer = buffer;
   op->count_requested = count;
-  
-  g_simple_async_result_run_in_thread (res, write_async_thread, io_priority, cancellable);
-  g_object_unref (res);
+
+  if (!g_output_stream_async_write_is_via_threads (stream))
+    write_async_pollable (G_POLLABLE_OUTPUT_STREAM (stream), task);
+  else
+    g_task_run_in_thread (task, write_async_thread);
+  g_object_unref (task);
 }
 
 static gssize
@@ -1148,44 +1821,207 @@ g_output_stream_real_write_finish (GOutputStream  *stream,
                                    GAsyncResult   *result,
                                    GError        **error)
 {
-  GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
-  WriteData *op;
+  g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
 
-  g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_write_async);
-  op = g_simple_async_result_get_op_res_gpointer (simple);
-  return op->count_written;
+  return g_task_propagate_int (G_TASK (result), error);
 }
 
 typedef struct {
   GInputStream *source;
   GOutputStreamSpliceFlags flags;
-  gssize bytes_copied;
+  gssize n_read;
+  gssize n_written;
+  gsize bytes_copied;
+  GError *error;
+  guint8 *buffer;
 } SpliceData;
 
 static void
-splice_async_thread (GSimpleAsyncResult *result,
-                     GObject            *object,
-                     GCancellable       *cancellable)
+free_splice_data (SpliceData *op)
+{
+  g_clear_pointer (&op->buffer, g_free);
+  g_object_unref (op->source);
+  g_clear_error (&op->error);
+  g_free (op);
+}
+
+static void
+real_splice_async_complete_cb (GTask *task)
+{
+  SpliceData *op = g_task_get_task_data (task);
+
+  if (op->flags & G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE &&
+      !g_input_stream_is_closed (op->source))
+    return;
+
+  if (op->flags & G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET &&
+      !g_output_stream_is_closed (g_task_get_source_object (task)))
+    return;
+
+  if (op->error != NULL)
+    {
+      g_task_return_error (task, op->error);
+      op->error = NULL;
+    }
+  else
+    {
+      g_task_return_int (task, op->bytes_copied);
+    }
+
+  g_object_unref (task);
+}
+
+static void
+real_splice_async_close_input_cb (GObject      *source,
+                                  GAsyncResult *res,
+                                  gpointer      user_data)
+{
+  GTask *task = user_data;
+
+  g_input_stream_close_finish (G_INPUT_STREAM (source), res, NULL);
+
+  real_splice_async_complete_cb (task);
+}
+
+static void
+real_splice_async_close_output_cb (GObject      *source,
+                                   GAsyncResult *res,
+                                   gpointer      user_data)
+{
+  GTask *task = G_TASK (user_data);
+  SpliceData *op = g_task_get_task_data (task);
+  GError **error = (op->error == NULL) ? &op->error : NULL;
+
+  g_output_stream_internal_close_finish (G_OUTPUT_STREAM (source), res, error);
+
+  real_splice_async_complete_cb (task);
+}
+
+static void
+real_splice_async_complete (GTask *task)
+{
+  SpliceData *op = g_task_get_task_data (task);
+  gboolean done = TRUE;
+
+  if (op->flags & G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE)
+    {
+      done = FALSE;
+      g_input_stream_close_async (op->source, g_task_get_priority (task),
+                                  g_task_get_cancellable (task),
+                                  real_splice_async_close_input_cb, task);
+    }
+
+  if (op->flags & G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET)
+    {
+      done = FALSE;
+      g_output_stream_internal_close_async (g_task_get_source_object (task),
+                                            g_task_get_priority (task),
+                                            g_task_get_cancellable (task),
+                                            real_splice_async_close_output_cb,
+                                            task);
+    }
+
+  if (done)
+    real_splice_async_complete_cb (task);
+}
+
+static void real_splice_async_read_cb (GObject      *source,
+                                       GAsyncResult *res,
+                                       gpointer      user_data);
+
+static void
+real_splice_async_write_cb (GObject      *source,
+                            GAsyncResult *res,
+                            gpointer      user_data)
 {
-  SpliceData *op;
   GOutputStreamClass *class;
-  GError *error = NULL;
-  GOutputStream *stream;
+  GTask *task = G_TASK (user_data);
+  SpliceData *op = g_task_get_task_data (task);
+  gssize ret;
 
-  stream = G_OUTPUT_STREAM (object);
-  class = G_OUTPUT_STREAM_GET_CLASS (object);
-  op = g_simple_async_result_get_op_res_gpointer (result);
-  
-  op->bytes_copied = class->splice (stream,
-                                   op->source,
-                                   op->flags,
-                                   cancellable,
-                                   &error);
-  if (op->bytes_copied == -1)
+  class = G_OUTPUT_STREAM_GET_CLASS (g_task_get_source_object (task));
+
+  ret = class->write_finish (G_OUTPUT_STREAM (source), res, &op->error);
+
+  if (ret == -1)
     {
-      g_simple_async_result_set_from_error (result, error);
-      g_error_free (error);
+      real_splice_async_complete (task);
+      return;
+    }
+
+  op->n_written += ret;
+  op->bytes_copied += ret;
+  if (op->bytes_copied > G_MAXSSIZE)
+    op->bytes_copied = G_MAXSSIZE;
+
+  if (op->n_written < op->n_read)
+    {
+      class->write_async (g_task_get_source_object (task),
+                          op->buffer + op->n_written,
+                          op->n_read - op->n_written,
+                          g_task_get_priority (task),
+                          g_task_get_cancellable (task),
+                          real_splice_async_write_cb, task);
+      return;
     }
+
+  g_input_stream_read_async (op->source, op->buffer, 8192,
+                             g_task_get_priority (task),
+                             g_task_get_cancellable (task),
+                             real_splice_async_read_cb, task);
+}
+
+static void
+real_splice_async_read_cb (GObject      *source,
+                           GAsyncResult *res,
+                           gpointer      user_data)
+{
+  GOutputStreamClass *class;
+  GTask *task = G_TASK (user_data);
+  SpliceData *op = g_task_get_task_data (task);
+  gssize ret;
+
+  class = G_OUTPUT_STREAM_GET_CLASS (g_task_get_source_object (task));
+
+  ret = g_input_stream_read_finish (op->source, res, &op->error);
+  if (ret == -1 || ret == 0)
+    {
+      real_splice_async_complete (task);
+      return;
+    }
+
+  op->n_read = ret;
+  op->n_written = 0;
+
+  class->write_async (g_task_get_source_object (task), op->buffer,
+                      op->n_read, g_task_get_priority (task),
+                      g_task_get_cancellable (task),
+                      real_splice_async_write_cb, task);
+}
+
+static void
+splice_async_thread (GTask        *task,
+                     gpointer      source_object,
+                     gpointer      task_data,
+                     GCancellable *cancellable)
+{
+  GOutputStream *stream = source_object;
+  SpliceData *op = task_data;
+  GOutputStreamClass *class;
+  GError *error = NULL;
+  gssize bytes_copied;
+
+  class = G_OUTPUT_STREAM_GET_CLASS (stream);
+  
+  bytes_copied = class->splice (stream,
+                                op->source,
+                                op->flags,
+                                cancellable,
+                                &error);
+  if (bytes_copied == -1)
+    g_task_return_error (task, error);
+  else
+    g_task_return_int (task, bytes_copied);
 }
 
 static void
@@ -1197,20 +2033,29 @@ g_output_stream_real_splice_async (GOutputStream             *stream,
                                    GAsyncReadyCallback        callback,
                                    gpointer                   user_data)
 {
-  GSimpleAsyncResult *res;
+  GTask *task;
   SpliceData *op;
 
   op = g_new0 (SpliceData, 1);
-  res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_splice_async);
-  g_simple_async_result_set_op_res_gpointer (res, op, g_free);
+  task = g_task_new (stream, cancellable, callback, user_data);
+  g_task_set_task_data (task, op, (GDestroyNotify)free_splice_data);
   op->flags = flags;
-  op->source = source;
+  op->source = g_object_ref (source);
 
-  /* TODO: In the case where both source and destintion have
-     non-threadbased async calls we can use a true async copy here */
-  
-  g_simple_async_result_run_in_thread (res, splice_async_thread, io_priority, cancellable);
-  g_object_unref (res);
+  if (g_input_stream_async_read_is_via_threads (source) &&
+      g_output_stream_async_write_is_via_threads (stream))
+    {
+      g_task_run_in_thread (task, splice_async_thread);
+      g_object_unref (task);
+    }
+  else
+    {
+      op->buffer = g_malloc (8192);
+      g_input_stream_read_async (op->source, op->buffer, 8192,
+                                 g_task_get_priority (task),
+                                 g_task_get_cancellable (task),
+                                 real_splice_async_read_cb, task);
+    }
 }
 
 static gssize
@@ -1218,34 +2063,32 @@ g_output_stream_real_splice_finish (GOutputStream  *stream,
                                     GAsyncResult   *result,
                                     GError        **error)
 {
-  GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
-  SpliceData *op;
+  g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
 
-  g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_splice_async);
-  op = g_simple_async_result_get_op_res_gpointer (simple);
-  return op->bytes_copied;
+  return g_task_propagate_int (G_TASK (result), error);
 }
 
 
 static void
-flush_async_thread (GSimpleAsyncResult *res,
-                    GObject            *object,
-                    GCancellable       *cancellable)
+flush_async_thread (GTask        *task,
+                    gpointer      source_object,
+                    gpointer      task_data,
+                    GCancellable *cancellable)
 {
+  GOutputStream *stream = source_object;
   GOutputStreamClass *class;
   gboolean result;
   GError *error = NULL;
 
-  class = G_OUTPUT_STREAM_GET_CLASS (object);
+  class = G_OUTPUT_STREAM_GET_CLASS (stream);
   result = TRUE;
   if (class->flush)
-    result = class->flush (G_OUTPUT_STREAM (object), cancellable, &error);
+    result = class->flush (stream, cancellable, &error);
 
-  if (!result)
-    {
-      g_simple_async_result_set_from_error (res, error);
-      g_error_free (error);
-    }
+  if (result)
+    g_task_return_boolean (task, TRUE);
+  else
+    g_task_return_error (task, error);
 }
 
 static void
@@ -1255,12 +2098,12 @@ g_output_stream_real_flush_async (GOutputStream       *stream,
                                   GAsyncReadyCallback  callback,
                                   gpointer             user_data)
 {
-  GSimpleAsyncResult *res;
+  GTask *task;
 
-  res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_write_async);
-  
-  g_simple_async_result_run_in_thread (res, flush_async_thread, io_priority, cancellable);
-  g_object_unref (res);
+  task = g_task_new (stream, cancellable, callback, user_data);
+  g_task_set_priority (task, io_priority);
+  g_task_run_in_thread (task, flush_async_thread);
+  g_object_unref (task);
 }
 
 static gboolean
@@ -1268,30 +2111,52 @@ g_output_stream_real_flush_finish (GOutputStream  *stream,
                                    GAsyncResult   *result,
                                    GError        **error)
 {
-  return TRUE;
+  g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
+
+  return g_task_propagate_boolean (G_TASK (result), error);
 }
 
 static void
-close_async_thread (GSimpleAsyncResult *res,
-                    GObject            *object,
-                    GCancellable       *cancellable)
+close_async_thread (GTask        *task,
+                    gpointer      source_object,
+                    gpointer      task_data,
+                    GCancellable *cancellable)
 {
+  GOutputStream *stream = source_object;
   GOutputStreamClass *class;
   GError *error = NULL;
-  gboolean result;
+  gboolean result = TRUE;
+
+  class = G_OUTPUT_STREAM_GET_CLASS (stream);
+
+  /* Do a flush here if there is a flush function, and we did not have to do
+   * an async flush before (see g_output_stream_close_async)
+   */
+  if (class->flush != NULL &&
+      (class->flush_async == NULL ||
+       class->flush_async == g_output_stream_real_flush_async))
+    {
+      result = class->flush (stream, cancellable, &error);
+    }
 
   /* Auto handling of cancelation disabled, and ignore
      cancellation, since we want to close things anyway, although
      possibly in a quick-n-dirty way. At least we never want to leak
      open handles */
-  
-  class = G_OUTPUT_STREAM_GET_CLASS (object);
-  result = class->close_fn (G_OUTPUT_STREAM (object), cancellable, &error);
-  if (!result)
+
+  if (class->close_fn)
     {
-      g_simple_async_result_set_from_error (res, error);
-      g_error_free (error);
+      /* Make sure to close, even if the flush failed (see sync close) */
+      if (!result)
+        class->close_fn (stream, cancellable, NULL);
+      else
+        result = class->close_fn (stream, cancellable, &error);
     }
+
+  if (result)
+    g_task_return_boolean (task, TRUE);
+  else
+    g_task_return_error (task, error);
 }
 
 static void
@@ -1301,14 +2166,12 @@ g_output_stream_real_close_async (GOutputStream       *stream,
                                   GAsyncReadyCallback  callback,
                                   gpointer             user_data)
 {
-  GSimpleAsyncResult *res;
-  
-  res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_close_async);
+  GTask *task;
 
-  g_simple_async_result_set_handle_cancellation (res, FALSE);
-  
-  g_simple_async_result_run_in_thread (res, close_async_thread, io_priority, cancellable);
-  g_object_unref (res);
+  task = g_task_new (stream, cancellable, callback, user_data);
+  g_task_set_priority (task, io_priority);
+  g_task_run_in_thread (task, close_async_thread);
+  g_object_unref (task);
 }
 
 static gboolean
@@ -1316,10 +2179,7 @@ g_output_stream_real_close_finish (GOutputStream  *stream,
                                    GAsyncResult   *result,
                                    GError        **error)
 {
-  GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
-  g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_close_async);
-  return TRUE;
-}
+  g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
 
-#define __G_OUTPUT_STREAM_C__
-#include "gioaliasdef.c"
+  return g_task_propagate_boolean (G_TASK (result), error);
+}