gio: minor GPollableInputStream / GPollableOutputStream fixes

Make g_pollable_input_stream_read() and
g_pollable_output_stream_write() look a little bit more like the
non-pollable versions in terms of error handling, etc. Also, use the
read_fn and write_fn virtual methods directly rather than calling
g_input_stream_read()/g_output_stream_write(), to avoid problems with
re-entrancy involving the "pending" flag.

Also belatedly add single-include guards to the header files.

https://bugzilla.gnome.org/show_bug.cgi?id=673997

4 files changed, 74 insertions, 24 deletions

diff --git a/gio/gpollableinputstream.c b/gio/gpollableinputstream.c
index 35384bc0b..b2c0b8855 100644
--- a/gio/gpollableinputstream.c
+++ b/gio/gpollableinputstream.c
@@ -45,7 +45,7 @@ G_DEFINE_INTERFACE (GPollableInputStream, g_pollable_input_stream, G_TYPE_INPUT_
 static gboolean g_pollable_input_stream_default_can_poll         (GPollableInputStream *stream);
 static gssize   g_pollable_input_stream_default_read_nonblocking (GPollableInputStream  *stream,
 								  void                  *buffer,
-								  gsize                  size,
+								  gsize                  count,
 								  GError               **error);
 
 static void
@@ -144,7 +144,7 @@ g_pollable_input_stream_create_source (GPollableInputStream *stream,
 static gssize
 g_pollable_input_stream_default_read_nonblocking (GPollableInputStream  *stream,
 						  void                  *buffer,
-						  gsize                  size,
+						  gsize                  count,
 						  GError               **error)
 {
   if (!g_pollable_input_stream_is_readable (stream))
@@ -154,20 +154,20 @@ g_pollable_input_stream_default_read_nonblocking (GPollableInputStream  *stream,
       return -1;
     }
 
-  return g_input_stream_read (G_INPUT_STREAM (stream), buffer, size,
-			      NULL, error);
+  return G_INPUT_STREAM_GET_CLASS (stream)->
+    read_fn (G_INPUT_STREAM (stream), buffer, count, NULL, error);
 }
 
 /**
  * g_pollable_input_stream_read_nonblocking:
  * @stream: a #GPollableInputStream
- * @buffer: a buffer to read data into (which should be at least @size
+ * @buffer: a buffer to read data into (which should be at least @count
  *     bytes long).
- * @size: the number of bytes you want to read
+ * @count: the number of bytes you want to read
  * @cancellable: (allow-none): a #GCancellable, or %NULL
  * @error: #GError for error reporting, or %NULL to ignore.
  *
- * Attempts to read up to @size bytes from @stream into @buffer, as
+ * Attempts to read up to @count bytes from @stream into @buffer, as
  * with g_input_stream_read(). If @stream is not currently readable,
  * this will immediately return %G_IO_ERROR_WOULD_BLOCK, and you can
  * use g_pollable_input_stream_create_source() to create a #GSource
@@ -186,17 +186,38 @@ g_pollable_input_stream_default_read_nonblocking (GPollableInputStream  *stream,
 gssize
 g_pollable_input_stream_read_nonblocking (GPollableInputStream  *stream,
 					  void                  *buffer,
-					  gsize                  size,
+					  gsize                  count,
 					  GCancellable          *cancellable,
 					  GError               **error)
 {
+  gssize res;
+
   g_return_val_if_fail (G_IS_POLLABLE_INPUT_STREAM (stream), -1);
+  g_return_val_if_fail (buffer != NULL, 0);
 
   if (g_cancellable_set_error_if_cancelled (cancellable, error))
     return -1;
 
-  return G_POLLABLE_INPUT_STREAM_GET_INTERFACE (stream)->
-    read_nonblocking (stream, buffer, size, error);
+  if (count == 0)
+    return 0;
+
+  if (((gssize) count) < 0)
+    {
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
+		   _("Too large count value passed to %s"), G_STRFUNC);
+      return -1;
+    }
+
+  if (cancellable)
+    g_cancellable_push_current (cancellable);
+
+  res = G_POLLABLE_INPUT_STREAM_GET_INTERFACE (stream)->
+    read_nonblocking (stream, buffer, count, error);
+
+  if (cancellable)
+    g_cancellable_pop_current (cancellable);
+
+  return res;
 }
 
 /* GPollableSource */
diff --git a/gio/gpollableinputstream.h b/gio/gpollableinputstream.h
index 3b57460fd..634ff2aeb 100644
--- a/gio/gpollableinputstream.h
+++ b/gio/gpollableinputstream.h
@@ -18,6 +18,10 @@
  * Boston, MA 02111-1307, USA.
  */
 
+#if !defined (__GIO_GIO_H_INSIDE__) && !defined (GIO_COMPILATION)
+#error "Only <gio/gio.h> can be included directly."
+#endif
+
 #ifndef __G_POLLABLE_INPUT_STREAM_H__
 #define __G_POLLABLE_INPUT_STREAM_H__
 
@@ -73,7 +77,7 @@ struct _GPollableInputStreamInterface
 				    GCancellable          *cancellable);
   gssize       (*read_nonblocking) (GPollableInputStream  *stream,
 				    void                  *buffer,
-				    gsize                  size,
+				    gsize                  count,
 				    GError               **error);
 };
 
@@ -87,7 +91,7 @@ GSource *g_pollable_input_stream_create_source    (GPollableInputStream  *stream
 
 gssize   g_pollable_input_stream_read_nonblocking (GPollableInputStream  *stream,
 						   void                  *buffer,
-						   gsize                  size,
+						   gsize                  count,
 						   GCancellable          *cancellable,
 						   GError               **error);
 
diff --git a/gio/gpollableoutputstream.c b/gio/gpollableoutputstream.c
index f8656b32e..57568e316 100644
--- a/gio/gpollableoutputstream.c
+++ b/gio/gpollableoutputstream.c
@@ -46,7 +46,7 @@ G_DEFINE_INTERFACE (GPollableOutputStream, g_pollable_output_stream, G_TYPE_OUTP
 static gboolean g_pollable_output_stream_default_can_poll          (GPollableOutputStream *stream);
 static gssize   g_pollable_output_stream_default_write_nonblocking (GPollableOutputStream  *stream,
 								    const void             *buffer,
-								    gsize                   size,
+								    gsize                   count,
 								    GError                **error);
 
 static void
@@ -145,7 +145,7 @@ g_pollable_output_stream_create_source (GPollableOutputStream *stream,
 static gssize
 g_pollable_output_stream_default_write_nonblocking (GPollableOutputStream  *stream,
 						    const void             *buffer,
-						    gsize                   size,
+						    gsize                   count,
 						    GError                **error)
 {
   if (!g_pollable_output_stream_is_writable (stream))
@@ -155,20 +155,20 @@ g_pollable_output_stream_default_write_nonblocking (GPollableOutputStream  *stre
       return -1;
     }
 
-  return g_output_stream_write (G_OUTPUT_STREAM (stream), buffer, size,
-				NULL, error);
+  return G_OUTPUT_STREAM_GET_CLASS (stream)->
+    write_fn (G_OUTPUT_STREAM (stream), buffer, count, NULL, error);
 }
 
 /**
  * g_pollable_output_stream_write_nonblocking:
  * @stream: a #GPollableOutputStream
- * @buffer: (array length=size) (element-type guint8): a buffer to write
+ * @buffer: (array length=count) (element-type guint8): a buffer to write
  *     data from
- * @size: the number of bytes you want to write
+ * @count: the number of bytes you want to write
  * @cancellable: (allow-none): a #GCancellable, or %NULL
  * @error: #GError for error reporting, or %NULL to ignore.
  *
- * Attempts to write up to @size bytes from @buffer to @stream, as
+ * Attempts to write up to @count bytes from @buffer to @stream, as
  * with g_output_stream_write(). If @stream is not currently writable,
  * this will immediately return %G_IO_ERROR_WOULD_BLOCK, and you can
  * use g_pollable_output_stream_create_source() to create a #GSource
@@ -187,15 +187,36 @@ g_pollable_output_stream_default_write_nonblocking (GPollableOutputStream  *stre
 gssize
 g_pollable_output_stream_write_nonblocking (GPollableOutputStream  *stream,
 					    const void             *buffer,
-					    gsize                   size,
+					    gsize                   count,
 					    GCancellable           *cancellable,
 					    GError                **error)
 {
+  gssize res;
+
   g_return_val_if_fail (G_IS_POLLABLE_OUTPUT_STREAM (stream), -1);
+  g_return_val_if_fail (buffer != NULL, 0);
 
   if (g_cancellable_set_error_if_cancelled (cancellable, error))
     return -1;
 
-  return G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream)->
-    write_nonblocking (stream, buffer, size, error);
+  if (count == 0)
+    return 0;
+
+  if (((gssize) count) < 0)
+    {
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
+		   _("Too large count value passed to %s"), G_STRFUNC);
+      return -1;
+    }
+
+  if (cancellable)
+    g_cancellable_push_current (cancellable);
+
+  res = G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream)->
+    write_nonblocking (stream, buffer, count, error);
+
+  if (cancellable)
+    g_cancellable_pop_current (cancellable);
+
+  return res;
 }
diff --git a/gio/gpollableoutputstream.h b/gio/gpollableoutputstream.h
index abef0ede6..c5945ce33 100644
--- a/gio/gpollableoutputstream.h
+++ b/gio/gpollableoutputstream.h
@@ -18,6 +18,10 @@
  * Boston, MA 02111-1307, USA.
  */
 
+#if !defined (__GIO_GIO_H_INSIDE__) && !defined (GIO_COMPILATION)
+#error "Only <gio/gio.h> can be included directly."
+#endif
+
 #ifndef __G_POLLABLE_OUTPUT_STREAM_H__
 #define __G_POLLABLE_OUTPUT_STREAM_H__
 
@@ -73,7 +77,7 @@ struct _GPollableOutputStreamInterface
 				     GCancellable           *cancellable);
   gssize       (*write_nonblocking) (GPollableOutputStream  *stream,
 				     const void             *buffer,
-				     gsize                   size,
+				     gsize                   count,
 				     GError                **error);
 };
 
@@ -87,7 +91,7 @@ GSource *g_pollable_output_stream_create_source     (GPollableOutputStream  *str
 
 gssize   g_pollable_output_stream_write_nonblocking (GPollableOutputStream  *stream,
 						     const void             *buffer,
-						     gsize                   size,
+						     gsize                   count,
 						     GCancellable           *cancellable,
 						     GError                **error);