v20.1 - 2021-10-05:
Tracing service and probes:
* Fixed standalone Windows build. Updated the llvm-win toolchain.
v20.0 - 2021-10-03:
Tracing service and probes:
* Removed DCHECK that would cause crashes when a debug build of the service
is used with a producer built with -DNDEBUG.
* Changed the service-side field-level filtering configuration protobuf
field number, because the feature had a bug. This is effectively
equivalent to deprecating the feature and reintroducing it under a
different name.
* Added support for boot tracing on Android. Early kernel tracing (prior to
the point when /data is mounted) is not yet supported. For instructions
see /docs/case-studies/android-boot-tracing.md .
Trace Processor:
* Added reqiurement of separating queries by semi-colon (;) followed by
new-line when specifying a query file with -q to trace processor shell.
* Added "ancestor_slice_by_stack" and "descendant_slice_by_stack" table
functions to walk up and down the slice stacks.
* Overhauled windowed sorting to be based on packet ordering and
lifecycle events inside the trace instead of time-based ordering.
* Removed |SortingMode::kForceFlushPeriodWindowedSort| due to changes to the
sorting algorithm, which is now based on Flush events rather than time.
Embedders should switch to |SortingMode::kDefaultHeuristics|. Other
SortingMode enum values are no-ops and will be removed in future versions.
UI:
* Added initial flamegraph support for traced_perf callstack samples.
* Added initial Pivot table for aggregation of userspace slices. The feature
is disabled by default for and requires manual enabling via
https://ui.perfetto.dev/#!/flags .
SDK:
* Changed DCHECK and DLOGs to be always disabled in SDK builds, regardless
of NDEBUG.
