Add callback hack to find out when to reload system properties.
Every IBinder object can accept a new transaction to tell it that
it might want to reload system properties, and in the process
anyone can register a callback to be executed when this happens.
Use this to reload the trace property.
This is very much ONLY for debugging.
Change-Id: I55c67c46f8f3fa9073bef0dfaab4577ed1d47eb4
diff --git a/libs/utils/Trace.cpp b/libs/utils/Trace.cpp
index f3ec485..5cd5731 100644
--- a/libs/utils/Trace.cpp
+++ b/libs/utils/Trace.cpp
@@ -19,6 +19,7 @@
#include <cutils/properties.h>
#include <utils/Log.h>
#include <utils/Trace.h>
+#include <utils/misc.h>
namespace android {
@@ -27,10 +28,19 @@
uint64_t Tracer::sEnabledTags = 0;
Mutex Tracer::sMutex;
+void Tracer::changeCallback() {
+ Mutex::Autolock lock(sMutex);
+ if (sIsReady && sTraceFD >= 0) {
+ loadSystemProperty();
+ }
+}
+
void Tracer::init() {
Mutex::Autolock lock(sMutex);
if (!sIsReady) {
+ add_sysprop_change_callback(changeCallback, 0);
+
const char* const traceFileName =
"/sys/kernel/debug/tracing/trace_marker";
sTraceFD = open(traceFileName, O_WRONLY);
@@ -38,14 +48,18 @@
ALOGE("error opening trace file: %s (%d)", strerror(errno), errno);
// sEnabledTags remains zero indicating that no tracing can occur
} else {
- char value[PROPERTY_VALUE_MAX];
- property_get("debug.atrace.tags.enableflags", value, "0");
- sEnabledTags = (strtoll(value, NULL, 0) & ATRACE_TAG_VALID_MASK)
- | ATRACE_TAG_ALWAYS;
+ loadSystemProperty();
}
android_atomic_release_store(1, &sIsReady);
}
}
+void Tracer::loadSystemProperty() {
+ char value[PROPERTY_VALUE_MAX];
+ property_get("debug.atrace.tags.enableflags", value, "0");
+ sEnabledTags = (strtoll(value, NULL, 0) & ATRACE_TAG_VALID_MASK)
+ | ATRACE_TAG_ALWAYS;
+}
+
} // namespace andoid