问题
I'm trying to profile my JNI application. Is there something like "Get ticks since startup" that I can use to measure functions and/or systems? Anything with the precision of 1/10 of a millisecond will do.
Obviously, a fully native function would be nicer, I'd prefer not to call a Java function for every single thing I'm trying to profile, but if that's the only option, I'll take that too.
回答1:
clock_gettime(). You'll see sample code in android-ndk-r5b/samples/hello-neon/jni/helloneon.c and android-ndk-r5b/samples/native-plasma/jni/plasma.c.
You want to look for something like CLOCK_MONOTONIC to make sure you're getting ticks since startup, not the wall clock.
回答2:
Take a look at
System.currentTimeMillis();
and/or
System.nanoTime();
I don't think either of those are time since startup, but they are both millisecnond timestamps that you may be able to use.
来源：https://stackoverflow.com/questions/5054376/high-precision-timer-in-android-jni