First: ugh.
Second: allow tracer global variables to be registered and then parsed out of a configuration environment variable.
Expose TSI trace config variable directly to ease this a little.
- Renaming default credentials -> google default credentials.
- Various other things in cpp:
- Adding Cpp wrapping for JWT Tokens.
- Renaming ComposeCredentials -> CompositeCredentials.
- Tested with new tool (print_default_creds_token) on:
- workstation for env var and well known place.
- GCE for compute engine default creds.
- I'd prefer the grpc_default_credentials_create() API to remain
synchronous even though there may be an async call for gce detection
on which we block.
We have many assumptions about languages baked into the test system, and we want this test harness to trigger when testing C++ stuff, so it needs to be written in C++.
This is a multipoller based on epoll rather than poll.
Note that this implementation is aimed at correctness rather than
performance, although it should immediately have better scalability to
large numbers of FDs, both due to epoll's O(1) sized API and due to not
needing to wake up polling threads to do interest set changes.
One notable difference here is that we directly attach a wakeup fd
rather than using the freelisting kick mechanism that the poll() based
implementations use, because modifying the epoll set to use a different
kick fd each time isn't free.