altos: Keep telemetry and command output from interleaving

When monitoring telemetry, the frame needs to be sent together on one
line, not split with the output of a command (like 'a') mixed in.

Use a mutex for products with monitoring to keep command output and
telemetry output each on separate lines.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/kernel/ao_cmd.c b/src/kernel/ao_cmd.c
index 605a2f20..10716afd 100644
--- a/src/kernel/ao_cmd.c
+++ b/src/kernel/ao_cmd.c
@@ -394,11 +394,17 @@ ao_cmd(void)
 			if (func)
 				break;
 		}
+#if HAS_MONITOR
+		ao_mutex_get(&ao_monitoring_mutex);
+#endif
 		if (func)
 			(*func)();
 		else
 			ao_cmd_status = ao_cmd_syntax_error;
 		report();
+#if HAS_MONITOR
+		ao_mutex_put(&ao_monitoring_mutex);
+#endif
 	}
 }