package rio

Changes

0.0.8

This is the largest Riot release yet, and we are splitting the package into 4 sub-packages:

• the Riot runtime+library
• Bytestring – efficient and ergonomic bytestring manipulation
• Gluon – a low-level, efficient async I/O engine
• Rio – composable I/O streams for vectored operations

Riot Runtime

• Improved performance and memory usage by creating 95% smaller processes, ensuring fibers are always properly discontinued to release their resources, and moving to Weak references for processes to ensure they get garbage collected timely.
• Introduce Process Priorities – the scheduler has been improved to support processes with different priorities (High, Normal, and Low). Thanks @LeedsJohn for the contribution! 👏
• Introduce receive Timeouts – you can now call receive ~after:10L () and if there are messages fetched in 10 microseconds receive will raise a Receive_timeout exception that you can match on.
• Introduce syscall Timeouts – any syscall being made now can specify a timeout for an answer. If the syscall isn't ready to retry within the timeout period, a Syscall_timeout exception will be raised.
• Improve Timer_wheel with support for clearing timers, iterating timers in the order in which they were created, and a MinHeap backend.

Riot Lib

• New Dynamic_supervisor to dynamically allocate pools of processes up to a maximum.
• New Runtime.Stats server can be started to periodically print out statistics about the runtime and the garbage collector.
• The Net.Socket module is now split into a Tcp_listener and a Tcp_stream, with their corresponding functions for listening, connecting, sending, and receiving. These also include support for timeouts.
• New File and File Descriptor operations for seeking. Thanks to @diogomqbm! 👏
• Introduce SSL module to turn sockets into SSL-backed Reader/Writer streams. This includes making a Net.Socket.stream_socket into a client or a server SSL-backed stream pair.
• Introduce Task to quickly spin up processes that we can await. This is the closest we have to a future. A Task is typed, executes a single function, and MUST be awaited with Task.await ?timeout task.
• Introduce Crypto.Random module with high-level utilities for creating random data of different types, including integers of different sizes, strings, bytestrings, bytes, characters, and ASCII strings.
• Introduce new named pid functions Process.where_is and Porcess.await_name to make it easier to find pids by name, and await a name to be registered.
• New Process.is_alive predicate to check if a process is alive
• Improve logging on most modules with namespaces
• Initializing the Riot runtime twice results in a runtime exception – thanks @julien-leclercq for the contribution! 👏
• Introduce Ref.cast to do type-safe type-casting based on runtime information of a Ref at its instantiation time.
• Introduce a Stream module that extends the stdlib Seq with a reduce_while combinator.
• Introduce inmemory key-value Store that works in a process-friendly fashion, similar to Erlang's ETS.

Bytestring

• First implementation of efficient immutable byte strings with cheap view and concat operations. Thanks to @felipecrv for contributing! 👏
• Iterators and Transient builders for efficiently examining, destructuring, and constructing byte strings from different sources.
• Preliminary Bytestrings syntax support (via a ppx) for constructions and efficient pattern matching using the %b sigil.

Gluon

• First implementation of an efficient, low-level async I/O engine inspired by Rust's Mio. Gluon uses an opaque Token based approach that lets you directly reference an OCaml value as part of the polled events from the underlying async engine. Thanks to @diogomqbm and @emilpriver for contributing! 👏
• Preliminary support for epoll on Linux and kqueue on macOS with conditional compilation via the config package.

Rio

• First implementation of composable I/O streams via a Read/Write interface inspired by Rust's Read/Write traits.

0.0.7

• Introduce IO module with low-level IO operations such as performing direct vectorized (or regular) reads/writes. New operations include:

  • read, write
  • single_read, single_write (vectorized)
  • await_readable, await_writeable, await
  • write_all
  • copy and copy_buffered
• Introduce Buffer module with support for converting from and to CStruct and String, including position tracking.
• Introduce Read/Reader interface for creating buffered and unbuffered readers of arbitrary sources.
• Introduce Write/Writer interfaces for creating unbuffered writers into arbitrary destinations/sinks.
• Introduce File module with Reader and Writer implementations
• Implment Reader and Writer interfaces for Net.Socket
• Dropped dependency on Bigstringaf and moved to Cstruct
• Fix max number of domains to always be under the recommended domain count
• Fix issue with tests where the runtime idled after the main would die. Now the main process finishing with an exception is considered reason enough to shutdown the system.
• Refactor tests to always output test_name: OK when everything is fine and all modules to end in _test.
• Add several IO tests.
• Fix log levels for writing to sockets
• Include proper license for C Stubs copied from lib_eio_posix for vectorized i/o.
• Split test suite into io/non-io so io tests are left outside opam ci
• Improved IO polling that removes heavy iterations over process/fds tables
• Rewrite Dashmap internals to use a Hashtbl

0.0.6

• Redo packaging to expose a single public library: riot
• Fix issue with schedulers busy-waiting
• Introduce separate IO Schedulers for polling
• Switch to poll to support kqueue on macOS
• Reuse read-buffers on Rio.read loops
• Broaden IO socket types to file descriptors
• Improved polling with shorter poll timeouts and safety checks
• Add Dashmap.iter to iterate over a collection
• Add net_test with an echo tcp server/client
• Fix bugs with syscall suspension that was introduced with reduction counting

0.0.5

• Add register name pid
• Add unregister name
• Add send_by_name ~name msg
• Fix timer wheel making it remove timers correctly
• Add better test for Timer.send_after

0.0.4

• Internally immediately suspend (bypassing reduction counts) when on a receive expression
• Fix reads from closed Unix sockets
• Fix writes to closed Unix sockets
• Ignore SIGPIPEs on setup
• Fix always mark connected sockets as nonblocking
• Fix GC i/o process table
• Surface pretty-printing of socket values

0.0.3

• Big namespace refactor. Riot.Runtime includes the lower-level runtime blocks, and everything else that is more user-friendly lives at the Riot.* level.
• Introduce reduction counting, so processes will run up to N iterations unless they finish, or they execute an unhandled effect.
• Introduce the Application interface for managing the lifecycle of the system
• Fix Riot.Logger to fit the Application interface
• Add a new Riot.Telemetry backend for doing async telemetry

0.0.2

• New Riot.random () API to expose current scheduler's random state
• Better logging in the Net module
• Fix a bug where Net.Socket operations where hanging on I/O polling when they could have been eager

0.0.1

First release, including:

• First working version of the scheduler
• Support for process spawning, message passing, monitoring, and linking
• Rudimentary supervisors
• Basic (and incomplete) GenServer
• Scheduling-aware I/O primitives
• Scheduling-aware Logger
• Timers