This CL introduces new embedding APIs for supporting heap sample
profiling. A registered sampling callback is invoked approximately every
N bytes based on an exponential distribution, providing information
about the isolate group the allocation occurred in, the user visible
name of the allocated object type, a weak persistent handle to the
allocated object, and the size of the allocation.
Sampling is triggered using artificial TLAB boundaries to cause
allocations to be sampled to take the allocation slow path where the
registered callback can be invoked with the allocation information.
Only new space allocations are currently traced, with old space
allocation support to be added in a future CL.
TEST=Dart_HeapSampling
Change-Id: I22bcdeec6e823bc1ab44898d4c596fbed7169fa1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/264520
Commit-Queue: Ben Konyi <bkonyi@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Ben Konyi
8caeaf7a6c