This commit eliminates unused boost header includes from the tree.
Removing these unnecessary includes reduces dependencies on the
external Boost.Adapters library, leading to faster compile times
and a slightly cleaner codebase.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#22857
Replace remaining uses of boost::adaptors::transformed with std::views::transform
to reduce Boost dependencies, following the migration pattern established in
bab12e3a. This change addresses recently merged code that reintroduced Boost
header dependencies through boost::adaptors::transformed usage.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#22365
Replace the reader concurrency semaphores for user reads and view
updates with the newly introduced reader concurrency semaphore group,
which assigns a semaphore for each service level.
Each group is statically assigned to some pool of memory on startup and
dynamically distribute this memory between the semaphores, relative to
the number of shares of the corresponding scheduling group.
The intent of having a separate reader concurrency semaphore for each
scheduling group is to prevent priority inversion issues due to reads
with different priorities waiting on the same semaphore, as well as make
memory allocation more fair between service levels due to the adjusted
number of shares.
