package picos_io

0.6.0

• Added a futex-like Awaitable abstraction as the picos_std.awaitable library (@polytypic)
• Changed the core Picos library to be internally built from a single .ml file (@polytypic)
• Optimized heap and stack usage of fibers and resource cleanup mechanisms and added workarounds for compiler generated space leaks due to closures (@polytypic)
• Added lastly as a safe alternative to Fun.protect (@polytypic)
• Workarounds for the Uri library not being threadsafe (@polytypic)
• Fixed to raise proper error when Picos_io_select has not been configured properly (@polytypic)

• Forbid cancelation propagation during release calls in the picos_std.finally library (@polytypic)

  • This is a change in behaviour and could be seen as a breaking change, but it should really be considered a bug fix.
• Renamed (Ivar|Stream).poison to (Ivar|Stream).poison_at and added (Ivar|Stream).poison with optional ?callstack:int (@polytypic)

0.5.0

• Major additions, changes, bug fixes, improvements, and restructuring (@polytypic, @c-cube)

  • Additions:

    • Minimalistic Cohttp implementation
    • Implicitly propagated Flock of fibers for structured concurrency
    • Option to terminate Bundle and Flock on return
    • Event abstraction

    • Synchronization and communication primitives:

      • Incremental variable or Ivar
      • Countdown Latch
      • Semaphore
      • Stream of events
    • Multi-producer, multi-consumer lock-free queue optimized for schedulers
    • Multithreaded (work-stealing) FIFO scheduler
    • Support quota for FIFO based schedulers
    • Transactional interface for atomically completing multiple Computations

  • Changes:

    • Redesigned resource management based on ('r -> 'a) -> 'a functions
    • Redesigned spawn interface allowing FLS entries to be populated before spawn
    • Introduced concept of fatal errors, which must terminate the scheduler or the whole program
    • Simplified FLS interface
    • Removed Exn_bt

  • Improvements:

    • Signficantly reduced per fiber memory usage of various sample schedulers

  • Picos has now been split into multiple packages and libraries:

    • pkg: picos

      • lib: picos
      • lib: picos.domain
      • lib: picos.thread

    • pkg: picos_aux

      • lib: picos_aux.htbl
      • lib: picos_aux.mpmcq
      • lib: picos_aux.mpscq
      • lib: picos_aux.rc

    • pkg: picos_lwt

      • lib: picos_lwt
      • lib: picos_lwt.unix
    • pkg: picos_meta (integration tests)

    • pkg: picos_mux

      • lib: picos_mux.fifo
      • lib: picos_mux.multififo
      • lib: picos_mux.random
      • lib: picos_mux.thread

    • pkg: picos_std

      • lib: picos_std.event
      • lib: picos_std.finally
      • lib: picos_std.structured
      • lib: picos_std.sync

    • pkg: picos_io

      • lib: picos_io
      • lib: picos_io.fd
      • lib: picos_io.select

    • pkg: picos_io_cohttp

      • lib: picos_io_cohttp

0.4.0

• Renamed Picos_mpsc_queue to Picos_mpscq. (@polytypic)

• Core API changes:

  • Added Computation.returned. (@polytypic)

• Lwt interop improvements:

  • Fixed Picos_lwt handling of Cancel_after to not raise in case of cancelation. (@polytypic)
  • Redesigned Picos_lwt to take a System module, which must implement a semi thread-safe trigger mechanism to allow unblocking Lwt promises on the main thread. (@polytypic)
  • Added Picos_lwt_unix interface to Lwt, which includes an internal System module implemented using Lwt_unix. (@polytypic)
  • Dropped thunking from Picos_lwt.await. (@polytypic)
• Added a randomized multicore scheduler Picos_randos for testing. (@polytypic)
• Changed Picos_select.check_configured to always (re)configure signal handling on the current thread. (@polytypic)

• Picos_structured:

  • Added a minimalistic Promise abstraction. (@polytypic)
  • Changed to more consistently not treat Terminate as an error. (@polytypic)
• Changed schedulers to take ~forbid as an optional argument. (@polytypic)
• Various minor additions, fixes, and documentation improvements. (@polytypic)

0.3.0

• Core API changes:

  • Added Fiber.set_computation, which represents a semantic change
  • Renamed Fiber.computation to Fiber.get_computation
  • Added Computation.attach_canceler
  • Added Fiber.sleep
  • Added Fiber.create_packed
  • Removed Fiber.try_attach
  • Removed Fiber.detach

  Most of the above changes were motivated by work on and requirements of the added structured concurrency library (@polytypic)

• Added a basic user level structured concurrent programming library Picos_structured (@polytypic)
• Added a functorized Picos_lwt providing direct style effects based interface to programming with Lwt (@polytypic)
• Added missing Picos_stdio.Unix.select (@polytypic)

0.2.0

• Documentation fixes and restructuring (@polytypic)
• Scheduler friendly waitpid, wait, and system in Picos_stdio.Unix for platforms other than Windows (@polytypic)
• Added Picos_select.configure to allow, and sometimes require, configuring Picos_select for co-operation with libraries that also deal with signals (@polytypic)
• Moved Picos_tls into Picos_thread.TLS (@polytypic)
• Enhanced sleep and sleepf in Picos_stdio.Unix to block in a scheduler friendly manner (@polytypic)

0.1.0

• First experimental release of Picos.

  Core:

  • picos — A framework for interoperable effects based concurrency.

  Sample schedulers:

  • picos.fifos — Basic single-threaded effects based Picos compatible scheduler for OCaml 5.
  • picos.threaded — Basic Thread based Picos compatible scheduler for OCaml 4.

  Scheduler agnostic libraries:

  • picos.sync — Basic communication and synchronization primitives for Picos.
  • picos.stdio — Basic IO facilities based on OCaml standard libraries for Picos.
  • picos.select — Basic Unix.select based IO event loop for Picos.

  Auxiliary libraries:

  • picos.domain — Minimalistic domain API available both on OCaml 5 and on OCaml 4.
  • picos.exn_bt — Wrapper for exceptions with backtraces.
  • picos.fd — Externally reference counted file descriptors.
  • picos.htbl — Lock-free hash table.
  • picos.mpsc_queue — Multi-producer, single-consumer queue.
  • picos.rc — External reference counting tables for disposable resources.
  • picos.tls — Thread-local storage.