[Qemu-devel] [PATCH 2/2] qemu-io: check registered fds in command_loop()

[MORITA Kazutaka]

Some block drivers use an aio handler and do I/O completion routines
in it.  However, the handler is not invoked if we only do
aio_read/write, because registered fds are not checked at all.

This patch registers a command processing function as a fd handler to
STDIO, and calls qemu_aio_wait() in command_loop().  Any other
handlers can be invoked when user input is idle.

Signed-off-by: MORITA Kazutaka <address@hidden>
---
 cmd.c |   53 +++++++++++++++++++++++++++++++++++++++--------------
 1 files changed, 39 insertions(+), 14 deletions(-)

diff --git a/cmd.c b/cmd.c
index 460df92..2b66e24 100644
--- a/cmd.c
+++ b/cmd.c
@@ -24,6 +24,7 @@
 #include <getopt.h>
 
 #include "cmd.h"
+#include "qemu-aio.h"
 
 #define _(x)   x       /* not gettext support yet */
 
@@ -149,6 +150,37 @@ add_args_command(
        args_func = af;
 }
 
+static char *get_prompt(void);
+
+static void do_command(void *opaque)
+{
+       int             c;
+       int *done = opaque;
+       char            *input;
+       char            **v;
+       const cmdinfo_t *ct;
+
+       if ((input = fetchline()) == NULL) {
+               *done = 1;
+               return;
+       }
+       v = breakline(input, &c);
+       if (c) {
+               ct = find_command(v[0]);
+               if (ct)
+                       *done = command(ct, c, v);
+               else
+                       fprintf(stderr, _("command \"%s\" not found\n"),
+                               v[0]);
+       }
+       doneline(input, v);
+
+       if (*done == 0) {
+               printf("%s", get_prompt());
+               fflush(stdout);
+       }
+}
+
 void
 command_loop(void)
 {
@@ -186,20 +218,15 @@ command_loop(void)
                free(cmdline);
                return;
        }
+
+       printf("%s", get_prompt());
+       fflush(stdout);
+
+       qemu_aio_set_fd_handler(STDIN_FILENO, do_command, NULL, NULL, NULL, 
&done);
        while (!done) {
-               if ((input = fetchline()) == NULL)
-                       break;
-               v = breakline(input, &c);
-               if (c) {
-                       ct = find_command(v[0]);
-                       if (ct)
-                               done = command(ct, c, v);
-                       else
-                               fprintf(stderr, _("command \"%s\" not found\n"),
-                                       v[0]);
-               }
-               doneline(input, v);
+               qemu_aio_wait();
        }
+       qemu_aio_set_fd_handler(STDIN_FILENO, NULL, NULL, NULL, NULL, NULL);
 }
 
 /* from libxcmd/input.c */
@@ -270,8 +297,6 @@ fetchline(void)
 
        if (!line)
                return NULL;
-       printf("%s", get_prompt());
-       fflush(stdout);
 again:
        if (!fgets(line, MAXREADLINESZ, stdin)) {
                if (errno == EINTR)
-- 
1.5.6.5