[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH 3/3] qga: set file descriptor in qmp_guest_file_open
From: |
Denis V. Lunev |
Subject: |
[Qemu-devel] [PATCH 3/3] qga: set file descriptor in qmp_guest_file_open non-blocking on Win32 |
Date: |
Wed, 28 Oct 2015 18:13:57 +0300 |
From: Olga Krishtal <address@hidden>
Set fd non-blocking to avoid common use cases (like reading from a
named pipe) from hanging the agent. This was missed in the original
code.
The patch introduces qemu_set_handle_nonoblocking, the local analog
of qemu_set_nonblock for HANDLES.
The usage of handles in qemu_set_non/block is impossible, because for
win32 there is a difference between file discriptors and file handles,
and all file ops are made via Win32 api.
Signed-off-by: Olga Krishtal <address@hidden>
Signed-off-by: Denis V. Lunev <address@hidden>
CC: Michael Roth <address@hidden>
CC: Stefan Weil <address@hidden>
---
qga/commands-win32.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/qga/commands-win32.c b/qga/commands-win32.c
index 97f19d5..a5306e7 100644
--- a/qga/commands-win32.c
+++ b/qga/commands-win32.c
@@ -128,6 +128,28 @@ static GuestFileHandle *guest_file_handle_find(int64_t id,
Error **errp)
return NULL;
}
+static void handle_set_nonblocking(HANDLE fh)
+{
+ DWORD file_type, pipe_state;
+ file_type = GetFileType(fh);
+ if (file_type != FILE_TYPE_PIPE) {
+ return;
+ }
+ /* If file_type == FILE_TYPE_PIPE, according to MSDN
+ * the specified file is socket or named pipe */
+ if (!GetNamedPipeHandleState(fh, &pipe_state, NULL,
+ NULL, NULL, NULL, 0)) {
+ return;
+ }
+ /* The fd is named pipe fd */
+ if (pipe_state & PIPE_NOWAIT) {
+ return;
+ }
+
+ pipe_state |= PIPE_NOWAIT;
+ SetNamedPipeHandleState(fh, &pipe_state, NULL, NULL);
+}
+
int64_t qmp_guest_file_open(const char *path, bool has_mode,
const char *mode, Error **errp)
{
@@ -158,6 +180,11 @@ int64_t qmp_guest_file_open(const char *path, bool
has_mode,
return -1;
}
+ /* set fd non-blocking to avoid common use cases (like reading from a
+ * named pipe) from hanging the agent
+ */
+ handle_set_nonblocking(fh);
+
fd = guest_file_handle_add(fh, errp);
if (fd < 0) {
CloseHandle(fh);
--
2.1.4