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hmp: human-monitor-command: stop using the Memory chardev driver

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The Memory chardev driver was added because, as the Monitor's output
buffer was static, we needed a way to accumulate the output of an
HMP commmand when ran by human-monitor-command.

However, the Monitor's output buffer is now dynamic, so it's possible
for the human-monitor-command to use it instead of the Memory chardev
driver.

This commit does that change, but there are two important
observations about it:

 1. We need a way to signal to the Monitor that it shouldn't call
    chardev functions when flushing its output. This is done
    by adding a new flag to the Monitor object called skip_flush
	(which is set to true by qmp_human_monitor_command())

 2. The current code has buffered semantics: QMP clients will
    only see a command's output if it flushes its output with
	a new-line character. This commit changes this to unbuffered,
	which means that QMP clients will see a command's output
	whenever the command prints anything.

	I don't think this will matter in practice though, as I believe
	all HMP commands print the new-line character anyway.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Luiz Capitulino 2013-04-02 15:07:33 -04:00
parent e1f2641b59
commit 48c043d0d1
1 changed files with 8 additions and 9 deletions
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17
monitor.c
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@ -188,6 +188,7 @@ struct Monitor {
int reset_seen;
int flags;
int suspend_cnt;
bool skip_flush;
QString *outbuf;
ReadLineState *rs;
MonitorControl *mc;
@ -273,6 +274,10 @@ void monitor_flush(Monitor *mon)
size_t len;
const char *buf;
if (mon->skip_flush) {
return;
}
buf = qstring_get_str(mon->outbuf);
len = qstring_get_length(mon->outbuf);
@ -675,13 +680,10 @@ char *qmp_human_monitor_command(const char *command_line, bool has_cpu_index,
{
char *output = NULL;
Monitor *old_mon, hmp;
CharDriverState mchar;
memset(&hmp, 0, sizeof(hmp));
hmp.outbuf = qstring_new();
qemu_chr_init_mem(&mchar);
hmp.chr = &mchar;
hmp.skip_flush = true;
old_mon = cur_mon;
cur_mon = &hmp;
@ -699,17 +701,14 @@ char *qmp_human_monitor_command(const char *command_line, bool has_cpu_index,
handle_user_command(&hmp, command_line);
cur_mon = old_mon;
if (qemu_chr_mem_osize(hmp.chr) > 0) {
QString *str = qemu_chr_mem_to_qs(hmp.chr);
output = g_strdup(qstring_get_str(str));
QDECREF(str);
if (qstring_get_length(hmp.outbuf) > 0) {
output = g_strdup(qstring_get_str(hmp.outbuf));
} else {
output = g_strdup("");
}
out:
QDECREF(hmp.outbuf);
qemu_chr_close_mem(hmp.chr);
return output;
}