GOutputStream: Add g_output_stream_async_write_is_via_threads()

In implementing a better g_output_stream_splice_async() and possibly
other situtations it's helpful to know whether the output stream's
write function internally uses threads. If it and the input stream's
read async functions use threads, then the splice function could
spawn a single thread for better efficiency.

This patch adds a function to determine whether an output stream's
g_output_stream_write_async() function internally uses threads.

https://bugzilla.gnome.org/show_bug.cgi?id=691581
This commit is contained in:
Mike Ruprecht 2013-02-23 17:42:49 -06:00 committed by Dan Winship
parent 94a232a4ed
commit dec3bfeebc
2 changed files with 26 additions and 2 deletions

View File

@ -22,10 +22,12 @@
#define __G_IO_PRIVATE_H__
#include "ginputstream.h"
#include "goutputstream.h"
G_BEGIN_DECLS
gboolean g_input_stream_async_read_is_via_threads (GInputStream *stream);
gboolean g_output_stream_async_write_is_via_threads (GOutputStream *stream);
G_END_DECLS

View File

@ -27,6 +27,7 @@
#include "gtask.h"
#include "ginputstream.h"
#include "gioerror.h"
#include "gioprivate.h"
#include "glibintl.h"
#include "gpollableoutputstream.h"
@ -1352,6 +1353,28 @@ 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 *
@ -1456,8 +1479,7 @@ g_output_stream_real_write_async (GOutputStream *stream,
op->buffer = buffer;
op->count_requested = count;
if (G_IS_POLLABLE_OUTPUT_STREAM (stream) &&
g_pollable_output_stream_can_poll (G_POLLABLE_OUTPUT_STREAM (stream)))
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);