perf ui: Serialize screen updates
The ui operations so far were used by just one thread, but 'perf top
--tui' now has two threads updating the screen, so we need to use a
mutex to avoid garbling the screen.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/ui/helpline.c b/tools/perf/util/ui/helpline.c
index 8d79daa..f36d2ff5 100644
--- a/tools/perf/util/ui/helpline.c
+++ b/tools/perf/util/ui/helpline.c
@@ -5,6 +5,7 @@
#include "../debug.h"
#include "helpline.h"
+#include "ui.h"
void ui_helpline__pop(void)
{
@@ -55,7 +56,8 @@
int ret;
static int backlog;
- ret = vsnprintf(ui_helpline__last_msg + backlog,
+ pthread_mutex_lock(&ui__lock);
+ ret = vsnprintf(ui_helpline__last_msg + backlog,
sizeof(ui_helpline__last_msg) - backlog, format, ap);
backlog += ret;
@@ -64,6 +66,7 @@
newtRefresh();
backlog = 0;
}
+ pthread_mutex_unlock(&ui__lock);
return ret;
}