| # Android Version Notes | |
| This page documents all the caveats of using Perfetto on older versions of | |
| Android. Because of the yearly release cycle, it's often the case that a | |
| feature is shipped but we later discover a bug/problem which makes the feature | |
| not usable or needs to be used in a very specific way. | |
| ## U- | |
| ### New features | |
| * The CLONE_SNAPSHOT trigger mode was introduced. | |
| * String field filtering in traces was introduced. | |
| ### Caveats | |
| * On the CLONE_SNAPSHOT codepath, the trace UUID gets rewritten when the session | |
| is clone but a statsd atom linking the two is not emitted. This means we | |
| should be careful to exclude any "clone-only" sessions as being "failed" | |
| sessions. | |
| ## T- | |
| ### New features | |
| * Reporting traces through the framework was introduced. | |
| ### Caveats | |
| * CLONE_SNAPSHOT does not exist in T- but there is a subtle edge case | |
| (b/274931668) which means it's quite dangerous to specify CLONE_SNAPSHOT on | |
| configs being sent to T- devices. | |
| ## P | |
| ### New features | |
| * Perfetto was included in the system image! | |
| ### Caveats | |
| * --txt option is not supported so configs must be binary encoded. |