This PR contains:
1. An ALTS context exposed for users to use, and a GetAltsContextFromAuthContext() function to get ALTS context from an AuthContext. Functionality-wise this part is similar with a previous PR https://github.com/grpc/grpc/pull/21536, but in this PR, we adjusted the code structure and made some minor changes to better suit function clientAuthzCheck()
2. A clientAuthzCheck() function for users to check if the server is authorized
Some e2e tests were disabled on iOS because they hit the Apple CFStream bug.
This commit enables e2e tests and works around the Apple bug by disabling CFStream.
- Define grpc_iomgr_run_in_background in iomgr_posix_cfstream.cc
- Use *_IF_SUPPORTED() for death tests
- Move global test init, teardown to SetUpTestCase, TearDownTestCase as GTMGoogleTestRun doesn't run main()
This is to use `grpc_core::RefCount` to improve performnace.
This commit also replaces explicit C vtables, with C++ vtable
with its own compile time assertions and performance benefits.
It also makes use of `RefCountedPtr` wherever possible.
src/core. exec_ctx is now a thread_local pointer of type ExecCtx instead of
grpc_exec_ctx which is initialized whenever ExecCtx is instantiated. ExecCtx
also keeps track of the previous exec_ctx so that nesting of exec_ctx is
allowed. This means that there is only one exec_ctx being used at any
time. Also, grpc_exec_ctx_finish is called in the destructor of the
object, and the previous exec_ctx is restored to avoid breaking current
functionality. The code still explicitly calls grpc_exec_ctx_finish
because removing all such instances causes the code to break.