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[Qemu-devel] [PATCH v7 13/23] monitor: let suspend/resume work even with
From: |
Peter Xu |
Subject: |
[Qemu-devel] [PATCH v7 13/23] monitor: let suspend/resume work even with QMPs |
Date: |
Wed, 24 Jan 2018 13:39:47 +0800 |
This patches allows QMP monitors to be suspended/resumed.
One thing to mention is that for QMPs that are using IOThreads, we need
an explicit kick for the IOThread in case it is sleeping.
Meanwhile, we need to take special care on non-interactive HMPs.
Currently only gdbserver is using that. For these monitors, we still
don't allow suspend/resume operations.
Since at it, add traces for the operations.
Signed-off-by: Peter Xu <address@hidden>
---
monitor.c | 45 ++++++++++++++++++++++++++++++++++++++++++---
trace-events | 1 +
2 files changed, 43 insertions(+), 3 deletions(-)
diff --git a/monitor.c b/monitor.c
index 60bcf67b3a..76137ba2a4 100644
--- a/monitor.c
+++ b/monitor.c
@@ -246,6 +246,21 @@ static inline bool monitor_is_qmp(const Monitor *mon)
return (mon->flags & MONITOR_USE_CONTROL);
}
+/**
+ * Whether @mon is using readline? Note: not all HMP monitors can are
+ * using readline, e.g., gdbserver has non-interactive HMP monitor, so
+ * readline is not used there.
+ */
+static inline bool monitor_uses_readline(const Monitor *mon)
+{
+ return mon->flags & MONITOR_USE_READLINE;
+}
+
+static inline bool monitor_is_hmp_non_interactive(const Monitor *mon)
+{
+ return !monitor_is_qmp(mon) && !monitor_uses_readline(mon);
+}
+
/**
* Is the current monitor, if any, a QMP monitor?
*/
@@ -3994,19 +4009,43 @@ static void monitor_command_cb(void *opaque, const char
*cmdline,
int monitor_suspend(Monitor *mon)
{
- if (!mon->rs)
+ if (monitor_is_hmp_non_interactive(mon)) {
return -ENOTTY;
+ }
+
+ if (monitor_is_qmp(mon)) {
+ /*
+ * Kick iothread to make sure this takes effect. It'll be
+ * evaluated again in prepare() of the watch object.
+ */
+ aio_notify(iothread_get_aio_context(mon_global.mon_iothread));
+ }
atomic_inc(&mon->suspend_cnt);
+ trace_monitor_suspend(mon, 1);
return 0;
}
void monitor_resume(Monitor *mon)
{
- if (!mon->rs)
+ if (monitor_is_hmp_non_interactive(mon)) {
return;
+ }
+
if (atomic_dec_fetch(&mon->suspend_cnt) == 0) {
- readline_show_prompt(mon->rs);
+ if (monitor_is_qmp(mon)) {
+ /*
+ * For QMP monitors that are running in IOThread, let's
+ * kick the thread in case it's sleeping.
+ */
+ if (mon->use_io_thr) {
+ aio_notify(iothread_get_aio_context(mon_global.mon_iothread));
+ }
+ } else {
+ assert(mon->rs);
+ readline_show_prompt(mon->rs);
+ }
}
+ trace_monitor_suspend(mon, -1);
}
static QObject *get_qmp_greeting(Monitor *mon)
diff --git a/trace-events b/trace-events
index ec95e67089..eecb68b1d5 100644
--- a/trace-events
+++ b/trace-events
@@ -47,6 +47,7 @@ monitor_protocol_event_emit(uint32_t event, void *data)
"event=%d data=%p"
monitor_protocol_event_queue(uint32_t event, void *qdict, uint64_t rate)
"event=%d data=%p rate=%" PRId64
handle_hmp_command(void *mon, const char *cmdline) "mon %p cmdline: %s"
handle_qmp_command(void *mon, const char *req) "mon %p req: %s"
+monitor_suspend(void *ptr, int cnt) "mon %p: %d"
# dma-helpers.c
dma_blk_io(void *dbs, void *bs, int64_t offset, bool to_dev) "dbs=%p bs=%p
offset=%" PRId64 " to_dev=%d"
--
2.14.3
- [Qemu-devel] [PATCH v7 03/23] qobject: introduce qobject_get_try_str(), (continued)
- [Qemu-devel] [PATCH v7 03/23] qobject: introduce qobject_get_try_str(), Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 04/23] qobject: let object_property_get_str() use new API, Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 05/23] monitor: move skip_flush into monitor_data_init, Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 06/23] monitor: move the cur_mon hack deeper for QMP, Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 07/23] monitor: unify global init, Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 08/23] monitor: let mon_list be tail queue, Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 09/23] monitor: allow using IO thread for parsing, Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 10/23] qmp: introduce QMPCapability, Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 11/23] monitor: introduce monitor_qmp_respond(), Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 12/23] monitor: let suspend_cnt be thread safe, Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 13/23] monitor: let suspend/resume work even with QMPs,
Peter Xu <=
- [Qemu-devel] [PATCH v7 14/23] monitor: separate QMP parser and dispatcher, Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 15/23] qmp: add new event "command-dropped", Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 16/23] monitor: send event when command queue full, Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 17/23] qapi: introduce new cmd option "allow-oob", Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 18/23] qmp: support out-of-band (oob) execution, Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 19/23] qmp: isolate responses into io thread, Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 20/23] monitor: enable IO thread for (qmp & !mux) typed, Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 21/23] qmp: add command "x-oob-test", Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 22/23] tests: qmp-test: verify command batching, Peter Xu, 2018/01/24
- [Qemu-devel] [PATCH v7 23/23] tests: qmp-test: add oob test, Peter Xu, 2018/01/24