[Qemu-devel] [PATCH v7 06/42] Add wrapper for setting blocking status on a QEMUFile

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <address@hidden>

Add a wrapper to change the blocking status on a QEMUFile
rather than having to use qemu_set_block(qemu_get_fd(f));
it seems best to avoid exposing the fd since not all QEMUFile's
really have one.  With this wrapper we could move the implementation
down to be different on different transports.

Signed-off-by: Dr. David Alan Gilbert <address@hidden>
Reviewed-by: Amit Shah <address@hidden>
---
 include/migration/qemu-file.h |  1 +
 migration/qemu-file.c         | 15 +++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h
index 29a9d69..d43c835 100644
--- a/include/migration/qemu-file.h
+++ b/include/migration/qemu-file.h
@@ -193,6 +193,7 @@ int qemu_file_get_error(QEMUFile *f);
 void qemu_file_set_error(QEMUFile *f, int ret);
 int qemu_file_shutdown(QEMUFile *f);
 void qemu_fflush(QEMUFile *f);
+void qemu_file_change_blocking(QEMUFile *f, bool block);
 
 static inline void qemu_put_be64s(QEMUFile *f, const uint64_t *pv)
 {
diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index c111a6b..c746129 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -651,3 +651,18 @@ size_t qemu_get_counted_string(QEMUFile *f, char buf[256])
 
     return res == len ? res : 0;
 }
+
+/*
+ * Change the blocking state of the QEMUFile.
+ * Note: On some transports the OS only keeps a single blocking state for
+ *       both directions, and thus changing the blocking on the main
+ *       QEMUFile can also affect the return path.
+ */
+void qemu_file_change_blocking(QEMUFile *f, bool block)
+{
+    if (block) {
+        qemu_set_block(qemu_get_fd(f));
+    } else {
+        qemu_set_nonblock(qemu_get_fd(f));
+    }
+}
-- 
2.4.3