cutils: trace: add atrace_update_tags()
Adds a function to read the current trace system property value, and
sets the trace tags to it, do be used as a sysprop change callback.
Change-Id: Ia6336652173aa5b07188898736c2c795a69fe79a
diff --git a/libcutils/trace.c b/libcutils/trace.c
index 15c8a98..152ea61 100644
--- a/libcutils/trace.c
+++ b/libcutils/trace.c
@@ -33,6 +33,7 @@
int atrace_marker_fd = -1;
uint64_t atrace_enabled_tags = ATRACE_TAG_NOT_READY;
static pthread_once_t atrace_once_control = PTHREAD_ONCE_INIT;
+static pthread_mutex_t atrace_tags_mutex = PTHREAD_MUTEX_INITIALIZER;
// Read the sysprop and return the value tags should be set to
static uint64_t atrace_get_property()
@@ -54,6 +55,18 @@
return (tags | ATRACE_TAG_ALWAYS) & ATRACE_TAG_VALID_MASK;
}
+// Update tags if tracing is ready. Useful as a sysprop change callback.
+void atrace_update_tags()
+{
+ uint64_t tags;
+ if (CC_UNLIKELY(android_atomic_acquire_load(&atrace_is_ready))) {
+ tags = atrace_get_property();
+ pthread_mutex_lock(&atrace_tags_mutex);
+ atrace_enabled_tags = tags;
+ pthread_mutex_unlock(&atrace_tags_mutex);
+ }
+}
+
static void atrace_init_once()
{
atrace_marker_fd = open("/sys/kernel/debug/tracing/trace_marker", O_WRONLY);