IssueTracker

Component used: androidx.tracing Version used: 1.1.0

Hi there, using the AndroidX tracing API requires matching the opening and closing spans like this:

androidx.tracing.Trace.beginSection("x");
x();
androidx.tracing.Trace.endSection();

Or, to be careful if x can throw:

androidx.tracing.Trace.beginSection("x");
try {
  x();
} finally {
  androidx.tracing.Trace.endSection();
}

This is a bit manual, tedious, error-prone, etc. Easy to mismatch. We've seen in our app many cases where sections don't get closed symmetrically.

We've had some success in our app with a java try-with-resources wrapper:

try (Section s = TraceHelper.section("x")) {
  x();
}

Now all our trace spans are automatically closed at the end of the brace.

I think this could be useful for other apps to alleviate some of the tedium of closing traces symmetrically, and would make a worthy addition to the androidx library.

To ensure we support old-ish versions of java, we should make sure Section implements java.io.Closeable rather than the new java8+ java.lang.AutoCloseable. In practice if you make the Section class final then the compiler understands the close() method can't throw IOException and doesn't make callers catch IOException.