diff --git a/gio/gioprivate.h b/gio/gioprivate.h
index a917510b9..2bc54e49b 100644
--- a/gio/gioprivate.h
+++ b/gio/gioprivate.h
@@ -35,6 +35,23 @@ gboolean g_output_stream_async_close_is_via_threads (GOutputStream *stream);
void g_socket_connection_set_cached_remote_address (GSocketConnection *connection,
GSocketAddress *address);
+/* POSIX defines IOV_MAX/UIO_MAXIOV as the maximum number of iovecs that can
+ * be sent in one go. We define our own version of it here as there are two
+ * possible names, and also define a fall-back value if none of the constants
+ * are defined */
+#if defined(IOV_MAX)
+#define G_IOV_MAX IOV_MAX
+#elif defined(UIO_MAXIOV)
+#define G_IOV_MAX UIO_MAXIOV
+#else
+/* 16 is the minimum value required by POSIX */
+#define G_IOV_MAX 16
+#endif
+
+/* The various functions taking iovecs as parameter use a plain int
+ * for the number of vectors. Limit it to G_MAXINT for this reason.
+ */
+G_STATIC_ASSERT (G_IOV_MAX <= G_MAXINT);
G_END_DECLS
diff --git a/gio/glocalfileoutputstream.c b/gio/glocalfileoutputstream.c
index 6d44989bf..a3dd62172 100644
--- a/gio/glocalfileoutputstream.c
+++ b/gio/glocalfileoutputstream.c
@@ -42,6 +42,7 @@
#endif
#include "glib-private.h"
+#include "gioprivate.h"
#ifdef G_OS_WIN32
#include <io.h>
@@ -243,11 +244,11 @@ g_local_file_output_stream_writev (GOutputStream *stream,
if (bytes_written)
*bytes_written = 0;
- /* Clamp to G_MAXINT as writev() takes an integer for the number of vectors.
- * We handle this like a short write in this case
+ /* Clamp the number of vectors if more given than we can write in one go.
+ * The caller has to handle short writes anyway.
*/
- if (n_vectors > G_MAXINT)
- n_vectors = G_MAXINT;
+ if (n_vectors > G_IOV_MAX)
+ n_vectors = G_IOV_MAX;
file = G_LOCAL_FILE_OUTPUT_STREAM (stream);
diff --git a/gio/gsocket.c b/gio/gsocket.c
index 06514d102..3cdce1053 100644
--- a/gio/gsocket.c
+++ b/gio/gsocket.c
@@ -74,6 +74,7 @@
#include "gcredentials.h"
#include "gcredentialsprivate.h"
#include "glibintl.h"
+#include "gioprivate.h"
#ifdef G_OS_WIN32
/* For Windows XP runtime compatibility, but use the system's if_nametoindex() if available */
@@ -4960,14 +4961,11 @@ g_socket_send_messages_with_timeout (GSocket *socket,
struct mmsghdr *msgvec;
gint i, num_sent;
-#ifdef UIO_MAXIOV
-#define MAX_NUM_MESSAGES UIO_MAXIOV
-#else
-#define MAX_NUM_MESSAGES 1024
-#endif
-
- if (num_messages > MAX_NUM_MESSAGES)
- num_messages = MAX_NUM_MESSAGES;
+ /* Clamp the number of vectors if more given than we can write in one go.
+ * The caller has to handle short writes anyway.
+ */
+ if (num_messages > G_IOV_MAX)
+ num_messages = G_IOV_MAX;
msgvec = g_newa (struct mmsghdr, num_messages);
@@ -5482,14 +5480,11 @@ g_socket_receive_messages_with_timeout (GSocket *socket,
struct mmsghdr *msgvec;
guint i, num_received;
-#ifdef UIO_MAXIOV
-#define MAX_NUM_MESSAGES UIO_MAXIOV
-#else
-#define MAX_NUM_MESSAGES 1024
-#endif
-
- if (num_messages > MAX_NUM_MESSAGES)
- num_messages = MAX_NUM_MESSAGES;
+ /* Clamp the number of vectors if more given than we can write in one go.
+ * The caller has to handle short writes anyway.
+ */
+ if (num_messages > G_IOV_MAX)
+ num_messages = G_IOV_MAX;
msgvec = g_newa (struct mmsghdr, num_messages);
diff --git a/gio/gsocketoutputstream.c b/gio/gsocketoutputstream.c
index fcca56efc..482ee39b9 100644
--- a/gio/gsocketoutputstream.c
+++ b/gio/gsocketoutputstream.c
@@ -33,6 +33,7 @@
#include "gioerror.h"
#include "glibintl.h"
#include "gfiledescriptorbased.h"
+#include "gioprivate.h"
struct _GSocketOutputStreamPrivate
{
@@ -146,8 +147,8 @@ g_socket_output_stream_writev (GOutputStream *stream,
/* Clamp the number of vectors if more given than we can write in one go.
* The caller has to handle short writes anyway.
*/
- if (n_vectors > G_MAXINT)
- n_vectors = G_MAXINT;
+ if (n_vectors > G_IOV_MAX)
+ n_vectors = G_IOV_MAX;
res = g_socket_send_message_with_timeout (output_stream->priv->socket, NULL,
vectors, n_vectors,
@@ -194,8 +195,8 @@ g_socket_output_stream_pollable_writev_nonblocking (GPollableOutputStream *poll
/* Clamp the number of vectors if more given than we can write in one go.
* The caller has to handle short writes anyway.
*/
- if (n_vectors > G_MAXINT)
- n_vectors = G_MAXINT;
+ if (n_vectors > G_IOV_MAX)
+ n_vectors = G_IOV_MAX;
return g_socket_send_message_with_timeout (output_stream->priv->socket,
NULL, vectors, n_vectors,
diff --git a/gio/gunixoutputstream.c b/gio/gunixoutputstream.c
index 5536e00b4..506e09a8c 100644
--- a/gio/gunixoutputstream.c
+++ b/gio/gunixoutputstream.c
@@ -37,6 +37,7 @@
#include "gasynchelper.h"
#include "gfiledescriptorbased.h"
#include "glibintl.h"
+#include "gioprivate.h"
/**
@@ -425,11 +426,11 @@ g_unix_output_stream_writev (GOutputStream *stream,
if (bytes_written)
*bytes_written = 0;
- /* Clamp to G_MAXINT as writev() takes an integer for the number of vectors.
- * We handle this like a short write in this case
+ /* Clamp the number of vectors if more given than we can write in one go.
+ * The caller has to handle short writes anyway.
*/
- if (n_vectors > G_MAXINT)
- n_vectors = G_MAXINT;
+ if (n_vectors > G_IOV_MAX)
+ n_vectors = G_IOV_MAX;
unix_stream = G_UNIX_OUTPUT_STREAM (stream);
@@ -635,11 +636,11 @@ g_unix_output_stream_pollable_writev_nonblocking (GPollableOutputStream *stream
return G_POLLABLE_RETURN_WOULD_BLOCK;
}
- /* Clamp to G_MAXINT as writev() takes an integer for the number of vectors.
- * We handle this like a short write in this case
+ /* Clamp the number of vectors if more given than we can write in one go.
+ * The caller has to handle short writes anyway.
*/
- if (n_vectors > G_MAXINT)
- n_vectors = G_MAXINT;
+ if (n_vectors > G_IOV_MAX)
+ n_vectors = G_IOV_MAX;
if (G_OUTPUT_VECTOR_IS_IOVEC)
{