glib/gio/gunixoutputstream.c
Dan Winship c20c2c0abd Add pollable input/output streams
When interfacing with APIs that expect unix-style async I/O, it is
useful to be able to tell in advance whether a read/write is going to
block. This adds new interfaces GPollableInputStream and
GPollableOutputStream that can be implemented by a GInputStream or
GOutputStream to add _is_readable/_is_writable, _create_source, and
_read_nonblocking/_write_nonblocking methods.

Also, implement for GUnixInput/OutputStream and
GSocketInput/OutputStream

https://bugzilla.gnome.org/show_bug.cgi?id=634241
2010-11-26 15:08:08 -05:00

644 lines
17 KiB
C

/* GIO - GLib Input, Output and Streaming Library
*
* Copyright (C) 2006-2007 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*
* Author: Alexander Larsson <alexl@redhat.com>
*/
#include "config.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <fcntl.h>
#include <glib.h>
#include <glib/gstdio.h>
#include "gioerror.h"
#include "gunixoutputstream.h"
#include "gcancellable.h"
#include "gsimpleasyncresult.h"
#include "gasynchelper.h"
#include "glibintl.h"
/**
* SECTION:gunixoutputstream
* @short_description: Streaming output operations for UNIX file descriptors
* @include: gio/gunixoutputstream.h
* @see_also: #GOutputStream
*
* #GUnixOutputStream implements #GOutputStream for writing to a
* UNIX file descriptor, including asynchronous operations. The file
* descriptor must be selectable, so it doesn't work with opened files.
*
* Note that <filename>&lt;gio/gunixoutputstream.h&gt;</filename> belongs
* to the UNIX-specific GIO interfaces, thus you have to use the
* <filename>gio-unix-2.0.pc</filename> pkg-config file when using it.
*/
enum {
PROP_0,
PROP_FD,
PROP_CLOSE_FD
};
static void g_unix_output_stream_pollable_iface_init (GPollableOutputStreamInterface *iface);
G_DEFINE_TYPE_WITH_CODE (GUnixOutputStream, g_unix_output_stream, G_TYPE_OUTPUT_STREAM,
G_IMPLEMENT_INTERFACE (G_TYPE_POLLABLE_OUTPUT_STREAM,
g_unix_output_stream_pollable_iface_init)
);
struct _GUnixOutputStreamPrivate {
int fd;
gboolean close_fd;
};
static void g_unix_output_stream_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec);
static void g_unix_output_stream_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec);
static gssize g_unix_output_stream_write (GOutputStream *stream,
const void *buffer,
gsize count,
GCancellable *cancellable,
GError **error);
static gboolean g_unix_output_stream_close (GOutputStream *stream,
GCancellable *cancellable,
GError **error);
static void g_unix_output_stream_write_async (GOutputStream *stream,
const void *buffer,
gsize count,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer data);
static gssize g_unix_output_stream_write_finish (GOutputStream *stream,
GAsyncResult *result,
GError **error);
static void g_unix_output_stream_close_async (GOutputStream *stream,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer data);
static gboolean g_unix_output_stream_close_finish (GOutputStream *stream,
GAsyncResult *result,
GError **error);
static gboolean g_unix_output_stream_pollable_is_writable (GPollableOutputStream *stream);
static GSource *g_unix_output_stream_pollable_create_source (GPollableOutputStream *stream,
GCancellable *cancellable);
static void
g_unix_output_stream_finalize (GObject *object)
{
G_OBJECT_CLASS (g_unix_output_stream_parent_class)->finalize (object);
}
static void
g_unix_output_stream_class_init (GUnixOutputStreamClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
GOutputStreamClass *stream_class = G_OUTPUT_STREAM_CLASS (klass);
g_type_class_add_private (klass, sizeof (GUnixOutputStreamPrivate));
gobject_class->get_property = g_unix_output_stream_get_property;
gobject_class->set_property = g_unix_output_stream_set_property;
gobject_class->finalize = g_unix_output_stream_finalize;
stream_class->write_fn = g_unix_output_stream_write;
stream_class->close_fn = g_unix_output_stream_close;
stream_class->write_async = g_unix_output_stream_write_async;
stream_class->write_finish = g_unix_output_stream_write_finish;
stream_class->close_async = g_unix_output_stream_close_async;
stream_class->close_finish = g_unix_output_stream_close_finish;
/**
* GUnixOutputStream:fd:
*
* The file descriptor that the stream writes to.
*
* Since: 2.20
*/
g_object_class_install_property (gobject_class,
PROP_FD,
g_param_spec_int ("fd",
P_("File descriptor"),
P_("The file descriptor to write to"),
G_MININT, G_MAXINT, -1,
G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
/**
* GUnixOutputStream:close-fd:
*
* Whether to close the file descriptor when the stream is closed.
*
* Since: 2.20
*/
g_object_class_install_property (gobject_class,
PROP_CLOSE_FD,
g_param_spec_boolean ("close-fd",
P_("Close file descriptor"),
P_("Whether to close the file descriptor when the stream is closed"),
TRUE,
G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
}
static void
g_unix_output_stream_pollable_iface_init (GPollableOutputStreamInterface *iface)
{
iface->is_writable = g_unix_output_stream_pollable_is_writable;
iface->create_source = g_unix_output_stream_pollable_create_source;
}
static void
g_unix_output_stream_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GUnixOutputStream *unix_stream;
unix_stream = G_UNIX_OUTPUT_STREAM (object);
switch (prop_id)
{
case PROP_FD:
unix_stream->priv->fd = g_value_get_int (value);
break;
case PROP_CLOSE_FD:
unix_stream->priv->close_fd = g_value_get_boolean (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
g_unix_output_stream_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GUnixOutputStream *unix_stream;
unix_stream = G_UNIX_OUTPUT_STREAM (object);
switch (prop_id)
{
case PROP_FD:
g_value_set_int (value, unix_stream->priv->fd);
break;
case PROP_CLOSE_FD:
g_value_set_boolean (value, unix_stream->priv->close_fd);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
}
}
static void
g_unix_output_stream_init (GUnixOutputStream *unix_stream)
{
unix_stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (unix_stream,
G_TYPE_UNIX_OUTPUT_STREAM,
GUnixOutputStreamPrivate);
unix_stream->priv->fd = -1;
unix_stream->priv->close_fd = TRUE;
}
/**
* g_unix_output_stream_new:
* @fd: a UNIX file descriptor
* @close_fd: %TRUE to close the file descriptor when done
*
* Creates a new #GUnixOutputStream for the given @fd.
*
* If @close_fd, is %TRUE, the file descriptor will be closed when
* the output stream is destroyed.
*
* Returns: a new #GOutputStream
**/
GOutputStream *
g_unix_output_stream_new (gint fd,
gboolean close_fd)
{
GUnixOutputStream *stream;
g_return_val_if_fail (fd != -1, NULL);
stream = g_object_new (G_TYPE_UNIX_OUTPUT_STREAM,
"fd", fd,
"close-fd", close_fd,
NULL);
return G_OUTPUT_STREAM (stream);
}
/**
* g_unix_output_stream_set_close_fd:
* @stream: a #GUnixOutputStream
* @close_fd: %TRUE to close the file descriptor when done
*
* Sets whether the file descriptor of @stream shall be closed
* when the stream is closed.
*
* Since: 2.20
*/
void
g_unix_output_stream_set_close_fd (GUnixOutputStream *stream,
gboolean close_fd)
{
g_return_if_fail (G_IS_UNIX_OUTPUT_STREAM (stream));
close_fd = close_fd != FALSE;
if (stream->priv->close_fd != close_fd)
{
stream->priv->close_fd = close_fd;
g_object_notify (G_OBJECT (stream), "close-fd");
}
}
/**
* g_unix_output_stream_get_close_fd:
* @stream: a #GUnixOutputStream
*
* Returns whether the file descriptor of @stream will be
* closed when the stream is closed.
*
* Return value: %TRUE if the file descriptor is closed when done
*
* Since: 2.20
*/
gboolean
g_unix_output_stream_get_close_fd (GUnixOutputStream *stream)
{
g_return_val_if_fail (G_IS_UNIX_OUTPUT_STREAM (stream), FALSE);
return stream->priv->close_fd;
}
/**
* g_unix_output_stream_get_fd:
* @stream: a #GUnixOutputStream
*
* Return the UNIX file descriptor that the stream writes to.
*
* Return value: The file descriptor of @stream
*
* Since: 2.20
*/
gint
g_unix_output_stream_get_fd (GUnixOutputStream *stream)
{
g_return_val_if_fail (G_IS_UNIX_OUTPUT_STREAM (stream), -1);
return stream->priv->fd;
}
static gssize
g_unix_output_stream_write (GOutputStream *stream,
const void *buffer,
gsize count,
GCancellable *cancellable,
GError **error)
{
GUnixOutputStream *unix_stream;
gssize res;
GPollFD poll_fds[2];
int poll_ret;
unix_stream = G_UNIX_OUTPUT_STREAM (stream);
if (g_cancellable_make_pollfd (cancellable, &poll_fds[1]))
{
poll_fds[0].fd = unix_stream->priv->fd;
poll_fds[0].events = G_IO_OUT;
do
poll_ret = g_poll (poll_fds, 2, -1);
while (poll_ret == -1 && errno == EINTR);
g_cancellable_release_fd (cancellable);
if (poll_ret == -1)
{
int errsv = errno;
g_set_error (error, G_IO_ERROR,
g_io_error_from_errno (errsv),
_("Error writing to unix: %s"),
g_strerror (errsv));
return -1;
}
}
while (1)
{
if (g_cancellable_set_error_if_cancelled (cancellable, error))
return -1;
res = write (unix_stream->priv->fd, buffer, count);
if (res == -1)
{
int errsv = errno;
if (errsv == EINTR)
continue;
g_set_error (error, G_IO_ERROR,
g_io_error_from_errno (errsv),
_("Error writing to unix: %s"),
g_strerror (errsv));
}
break;
}
return res;
}
static gboolean
g_unix_output_stream_close (GOutputStream *stream,
GCancellable *cancellable,
GError **error)
{
GUnixOutputStream *unix_stream;
int res;
unix_stream = G_UNIX_OUTPUT_STREAM (stream);
if (!unix_stream->priv->close_fd)
return TRUE;
while (1)
{
/* This might block during the close. Doesn't seem to be a way to avoid it though. */
res = close (unix_stream->priv->fd);
if (res == -1)
{
int errsv = errno;
g_set_error (error, G_IO_ERROR,
g_io_error_from_errno (errsv),
_("Error closing unix: %s"),
g_strerror (errsv));
}
break;
}
return res != -1;
}
typedef struct {
gsize count;
const void *buffer;
GAsyncReadyCallback callback;
gpointer user_data;
GCancellable *cancellable;
GUnixOutputStream *stream;
} WriteAsyncData;
static gboolean
write_async_cb (int fd,
GIOCondition condition,
WriteAsyncData *data)
{
GSimpleAsyncResult *simple;
GError *error = NULL;
gssize count_written;
while (1)
{
if (g_cancellable_set_error_if_cancelled (data->cancellable, &error))
{
count_written = -1;
break;
}
count_written = write (data->stream->priv->fd, data->buffer, data->count);
if (count_written == -1)
{
int errsv = errno;
if (errsv == EINTR)
continue;
g_set_error (&error, G_IO_ERROR,
g_io_error_from_errno (errsv),
_("Error writing to unix: %s"),
g_strerror (errsv));
}
break;
}
simple = g_simple_async_result_new (G_OBJECT (data->stream),
data->callback,
data->user_data,
g_unix_output_stream_write_async);
g_simple_async_result_set_op_res_gssize (simple, count_written);
if (count_written == -1)
g_simple_async_result_take_error (simple, error);
/* Complete immediately, not in idle, since we're already in a mainloop callout */
g_simple_async_result_complete (simple);
g_object_unref (simple);
return FALSE;
}
static void
g_unix_output_stream_write_async (GOutputStream *stream,
const void *buffer,
gsize count,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
GSource *source;
GUnixOutputStream *unix_stream;
WriteAsyncData *data;
unix_stream = G_UNIX_OUTPUT_STREAM (stream);
data = g_new0 (WriteAsyncData, 1);
data->count = count;
data->buffer = buffer;
data->callback = callback;
data->user_data = user_data;
data->cancellable = cancellable;
data->stream = unix_stream;
source = _g_fd_source_new (unix_stream->priv->fd,
G_IO_OUT,
cancellable);
g_source_set_name (source, "GUnixOutputStream");
g_source_set_callback (source, (GSourceFunc)write_async_cb, data, g_free);
g_source_attach (source, g_main_context_get_thread_default ());
g_source_unref (source);
}
static gssize
g_unix_output_stream_write_finish (GOutputStream *stream,
GAsyncResult *result,
GError **error)
{
GSimpleAsyncResult *simple;
gssize nwritten;
simple = G_SIMPLE_ASYNC_RESULT (result);
g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_unix_output_stream_write_async);
nwritten = g_simple_async_result_get_op_res_gssize (simple);
return nwritten;
}
typedef struct {
GOutputStream *stream;
GAsyncReadyCallback callback;
gpointer user_data;
} CloseAsyncData;
static gboolean
close_async_cb (CloseAsyncData *data)
{
GUnixOutputStream *unix_stream;
GSimpleAsyncResult *simple;
GError *error = NULL;
gboolean result;
int res;
unix_stream = G_UNIX_OUTPUT_STREAM (data->stream);
if (!unix_stream->priv->close_fd)
{
result = TRUE;
goto out;
}
while (1)
{
res = close (unix_stream->priv->fd);
if (res == -1)
{
int errsv = errno;
g_set_error (&error, G_IO_ERROR,
g_io_error_from_errno (errsv),
_("Error closing unix: %s"),
g_strerror (errsv));
}
break;
}
result = res != -1;
out:
simple = g_simple_async_result_new (G_OBJECT (data->stream),
data->callback,
data->user_data,
g_unix_output_stream_close_async);
if (!result)
g_simple_async_result_take_error (simple, error);
/* Complete immediately, not in idle, since we're already in a mainloop callout */
g_simple_async_result_complete (simple);
g_object_unref (simple);
return FALSE;
}
static void
g_unix_output_stream_close_async (GOutputStream *stream,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
GSource *idle;
CloseAsyncData *data;
data = g_new0 (CloseAsyncData, 1);
data->stream = stream;
data->callback = callback;
data->user_data = user_data;
idle = g_idle_source_new ();
g_source_set_callback (idle, (GSourceFunc)close_async_cb, data, g_free);
g_source_attach (idle, g_main_context_get_thread_default ());
g_source_unref (idle);
}
static gboolean
g_unix_output_stream_close_finish (GOutputStream *stream,
GAsyncResult *result,
GError **error)
{
/* Failures handled in generic close_finish code */
return TRUE;
}
static gboolean
g_unix_output_stream_pollable_is_writable (GPollableOutputStream *stream)
{
GUnixOutputStream *unix_stream = G_UNIX_OUTPUT_STREAM (stream);
GPollFD poll_fd;
gint result;
poll_fd.fd = unix_stream->priv->fd;
poll_fd.events = G_IO_OUT;
do
result = g_poll (&poll_fd, 1, 0);
while (result == -1 && errno == EINTR);
return poll_fd.revents != 0;
}
static GSource *
g_unix_output_stream_pollable_create_source (GPollableOutputStream *stream,
GCancellable *cancellable)
{
GUnixOutputStream *unix_stream = G_UNIX_OUTPUT_STREAM (stream);
GSource *inner_source, *pollable_source;
pollable_source = g_pollable_source_new (G_OBJECT (stream));
inner_source = _g_fd_source_new (unix_stream->priv->fd, G_IO_OUT, cancellable);
g_source_set_dummy_callback (inner_source);
g_source_add_child_source (pollable_source, inner_source);
g_source_unref (inner_source);
return pollable_source;
}