问题
I am amending an Android C++ system executable (healthd), which runs as root.
I want the amended healthd to be able to receive some form of signal from an unprivileged Android Java app.
A few hundred ms of latency is fine, as is polling from healthd, rather than an actual "event".
I only need to send an indication that something has happened - there's no requirement to transport data.
What's the simplest form of communication I can use?
来源：https://stackoverflow.com/questions/57199825/signalling-a-root-c-executabke-from-a-non-privileged-java-android-app