MediaUtils: Use delayed / lazy library loading
Postpone loading libutilscallstack until needed
to save memory.
Test: atest library_tests
Test: adb shell 'showmap $(pgrep mediametrics)'
Bug: 227536784
Change-Id: I3d4c9e9b6d854b013185e18fc20d4bec320df14e
diff --git a/media/utils/MediaUtilsDelayedLibrary.h b/media/utils/MediaUtilsDelayedLibrary.h
new file mode 100644
index 0000000..3d72a3a
--- /dev/null
+++ b/media/utils/MediaUtilsDelayedLibrary.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <string>
+#include <unistd.h>
+
+// This should not be directly included by clients.
+// Use MediaUtilsDelayed.h instead.
+
+namespace android::mediautils::delayed_library {
+
+// Use a dispatch table to return methods from the delayed library
+struct DelayedDispatchTable {
+ std::string (*getCallStackStringForTid)(pid_t tid);
+};
+
+// Match with Android.bp and MediaUtilsDelayed.cpp.
+#define MEDIAUTILS_DELAYED_LIBRARY_NAME "libmediautils_delayed.so"
+
+// Match with MediaUtilsDelayed.cpp and MediaUtilsDelayedLibrary.cpp
+#define MEDIAUTILS_DELAYED_DISPATCH_TABLE_SYMBOL_NAME "gDelayedDispatchTable"
+
+} // namespace android::mediautils::delayed_library