[PATCH v3 12/20] monitor: introduce monitor_cur_hmp() function

[Daniel P . Berrangé]

A number of callers use monitor_cur() followed by !monitor_cur_is_qmp().

This is undesirable because monitor_cur_is_qmp() will itself call
monitor_cur() again, and monitor_cur() must acquire locks and do
hash table lookups. Introducing a monitor_cur_hmp() helper will
combine the two operations into one reducing cost.

Signed-off-by: Daniel P. Berrangé <berra...@redhat.com>
---
 include/monitor/monitor.h      |  1 +
 monitor/monitor.c              | 14 ++++++++++++++
 stubs/monitor-core.c           |  5 +++++
 tests/unit/test-util-sockets.c |  1 +
 4 files changed, 21 insertions(+)

diff --git a/include/monitor/monitor.h b/include/monitor/monitor.h
index 296690e1f1..c3b79b960a 100644
--- a/include/monitor/monitor.h
+++ b/include/monitor/monitor.h
@@ -14,6 +14,7 @@ typedef struct MonitorOptions MonitorOptions;
 extern QemuOptsList qemu_mon_opts;
 
 Monitor *monitor_cur(void);
+Monitor *monitor_cur_hmp(void);
 Monitor *monitor_set_cur(Coroutine *co, Monitor *mon);
 bool monitor_cur_is_qmp(void);
 
diff --git a/monitor/monitor.c b/monitor/monitor.c
index e1e5dbfcbe..cff502c53e 100644
--- a/monitor/monitor.c
+++ b/monitor/monitor.c
@@ -84,6 +84,20 @@ Monitor *monitor_cur(void)
     return mon;
 }
 
+Monitor *monitor_cur_hmp(void)
+{
+    Monitor *mon;
+
+    qemu_mutex_lock(&monitor_lock);
+    mon = g_hash_table_lookup(coroutine_mon, qemu_coroutine_self());
+    if (mon && monitor_is_qmp(mon)) {
+        mon = NULL;
+    }
+    qemu_mutex_unlock(&monitor_lock);
+
+    return mon;
+}
+
 /**
  * Sets a new current monitor and returns the old one.
  *
diff --git a/stubs/monitor-core.c b/stubs/monitor-core.c
index b498a0f1af..1e0b11ec29 100644
--- a/stubs/monitor-core.c
+++ b/stubs/monitor-core.c
@@ -7,6 +7,11 @@ Monitor *monitor_cur(void)
     return NULL;
 }
 
+Monitor *monitor_cur_hmp(void)
+{
+    return NULL;
+}
+
 bool monitor_cur_is_qmp(void)
 {
     return false;
diff --git a/tests/unit/test-util-sockets.c b/tests/unit/test-util-sockets.c
index bd48731ea2..d40813c682 100644
--- a/tests/unit/test-util-sockets.c
+++ b/tests/unit/test-util-sockets.c
@@ -72,6 +72,7 @@ int monitor_get_fd(Monitor *mon, const char *fdname, Error 
**errp)
  * otherwise we get duplicate syms at link time.
  */
 Monitor *monitor_cur(void) { return cur_mon; }
+Monitor *monitor_cur_hmp(void) { return cur_mon; }
 bool monitor_cur_is_qmp(void) { return false; }
 Monitor *monitor_set_cur(Coroutine *co, Monitor *mon) { abort(); }
 int monitor_vprintf(Monitor *mon, const char *fmt, va_list ap) { abort(); }
-- 
2.50.1