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[Qemu-devel] [RFC v5 18/26] monitor: send event when request queue full
From: |
Peter Xu |
Subject: |
[Qemu-devel] [RFC v5 18/26] monitor: send event when request queue full |
Date: |
Tue, 5 Dec 2017 13:51:52 +0800 |
Set maximum QMP request queue length to 8. If queue full, instead of
queue the command, we directly return a "request-dropped" event, telling
client that specific command is dropped.
Note that this flow control mechanism is only valid if OOB is enabled.
If it's not, the effective queue length will always be 1, which strictly
follows original behavior of QMP command handling (which never drop
messages).
Signed-off-by: Peter Xu <address@hidden>
---
monitor.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/monitor.c b/monitor.c
index c20e659740..f7923c4590 100644
--- a/monitor.c
+++ b/monitor.c
@@ -4029,6 +4029,8 @@ static void monitor_qmp_bh_dispatcher(void *data)
}
}
+#define QMP_REQ_QUEUE_LEN_MAX (8)
+
static void handle_qmp_command(JSONMessageParser *parser, GQueue *tokens,
void *opaque)
{
@@ -4061,6 +4063,19 @@ static void handle_qmp_command(JSONMessageParser
*parser, GQueue *tokens,
req_obj->id = id;
req_obj->req = req;
+ if (qmp_oob_enabled(mon)) {
+ /* Drop the request if queue is full. */
+ if (mon->qmp.qmp_requests->length >= QMP_REQ_QUEUE_LEN_MAX) {
+ qapi_event_send_request_dropped(id,
+ REQUEST_DROP_REASON_QUEUE_FULL,
+ NULL);
+ qobject_decref(id);
+ qobject_decref(req);
+ g_free(req_obj);
+ return;
+ }
+ }
+
/*
* Put the request to the end of queue so that requests will be
* handled in time order. Ownership for req_obj, req, id,
--
2.14.3
- Re: [Qemu-devel] [RFC v5 16/26] monitor: separate QMP parser and dispatcher, (continued)
- Re: [Qemu-devel] [RFC v5 16/26] monitor: separate QMP parser and dispatcher, Peter Xu, 2017/12/16
- Re: [Qemu-devel] [RFC v5 16/26] monitor: separate QMP parser and dispatcher, Peter Xu, 2017/12/16
- Re: [Qemu-devel] [RFC v5 16/26] monitor: separate QMP parser and dispatcher, Stefan Hajnoczi, 2017/12/16
- Re: [Qemu-devel] [RFC v5 16/26] monitor: separate QMP parser and dispatcher, Peter Xu, 2017/12/18
- Re: [Qemu-devel] [RFC v5 16/26] monitor: separate QMP parser and dispatcher, Stefan Hajnoczi, 2017/12/18
- Re: [Qemu-devel] [RFC v5 16/26] monitor: separate QMP parser and dispatcher, Peter Xu, 2017/12/18
[Qemu-devel] [RFC v5 17/26] qmp: add new event "request-dropped", Peter Xu, 2017/12/05
[Qemu-devel] [RFC v5 18/26] monitor: send event when request queue full,
Peter Xu <=
[Qemu-devel] [RFC v5 19/26] qapi: introduce new cmd option "allow-oob", Peter Xu, 2017/12/05
[Qemu-devel] [RFC v5 20/26] qmp: support out-of-band (oob) execution, Peter Xu, 2017/12/05