1. 03 Dec, 2021 3 commits
  2. 02 Dec, 2021 2 commits
  3. 29 Nov, 2021 1 commit
  4. 24 Nov, 2021 2 commits
  5. 23 Nov, 2021 2 commits
    • Florian Fischer's avatar
    • Florian Fischer's avatar
      add concurrent BPS test · 65a593bc
      Florian Fischer authored
      The test introduces multiple cycles of Semaphores and
      a Fiber for each semaphore blocking and signaling the next.
      Through work-stealing the fibers from a cycle should be spread
      across different workers and thus test concurrent use of
      Cycle of length 3: Sem A -> Sem B -> Sem C -> Sem A -> ...
      	if isFirstInCycle
      		signal next
      	if not isFirstInCycle
      		signal next
  6. 15 Nov, 2021 2 commits
    • Florian Schmaus's avatar
      Merge branch 'fix_pipe_sleep_notifyFromAnywhere' into 'master' · cc63bd70
      Florian Schmaus authored
      [PipeSleepStrategy] fix notifyFromAnywhere
      See merge request !277
    • Florian Fischer's avatar
      [PipeSleepStrategy] fix notifyFromAnywhere · d31442ad
      Florian Fischer authored
      Don't decrease the sleeper count in the CAS loop further than
      -count, which is the threshold we need to ensure that the notification
      will be observed.
      Decreasing it further than our threshold is not faulty it just results
      in unnecessary skipped sleeps.
      Don't call writeNotifications with a negative count.
      Which will be interpreted as an unsigned value and thus results
      in writing way to much hints to the pipe, jamming it.
      If the original value before a successfully CAS is already negative
      we called writeNotifications with this negative value.
      This is fixed by using max(toWakeup, 0).
  7. 11 Nov, 2021 1 commit
  8. 10 Nov, 2021 5 commits
  9. 29 Oct, 2021 1 commit
  10. 28 Oct, 2021 6 commits
  11. 13 Oct, 2021 4 commits
  12. 12 Oct, 2021 1 commit
  13. 11 Oct, 2021 10 commits
    • Florian Fischer's avatar
      [IoContext] document and fix possible scenario resulting in lost wakeup · 1e647338
      Florian Fischer authored
      This is fixed by using a normal lock instead of the try lock in the OWNER
    • Florian Fischer's avatar
      [IoContext] implement lockless CQ reaping · d9d350d9
      Florian Fischer authored
      TODO: think about stats and possible ring buffer pointers overflow and ABA.
    • Florian Fischer's avatar
      implement IO stealing · 0abc29ad
      Florian Fischer authored
      IO stealing is analog to work-stealing and means that worker thread
      without work will try to steal IO completions (CQEs) from other worker's
      IoContexts. The work stealing algorithm is modified to check a victims
      CQ after findig their work queue empty.
      This approach in combination with future additions (global notifications
      on IO completions, and lock free CQE consumption) are a realistic candidate
      to replace the completer thread without loosing its benefits.
      To allow IO stealing the CQ must be synchronized which is already the
      case with the IoContext::cq_lock.
      Currently stealing workers always try to pop a single CQE (this could
      be configurable).
      Steal attempts are recorded in the IoContext's Stats object and
      successfully stolen IO continuations in the AbstractWorkStealingWorkerStats.
      I moved the code transforming CQEs into continuation Fibers from
      reapCompletions into a seperate function to make the rather complicated
      function more readable and thus easier to understand.
      Remove the default CallerEnvironment template arguments to make
      the code more explicit and prevent easy errors (not propagating
      the caller environment or forgetting the function takes a caller environment).
      io::Stats now need to use atomics because multiple thread may increment
      them in parallel from EMPER and the OWNER.
      And since using std::atomic<T*> in std::map is not easily possible we
      use the compiler __atomic_* builtins.
      Add, adjust and fix some comments.
    • Florian Fischer's avatar
      [CallerEnvironment] Add a new OWNER caller environment · 69e73b98
      Florian Fischer authored
      The OWNER caller environment can be used when the executed algorithm
      should be different if the current worker owns the objects it touches.
      For example a worker reaping completions on a foreign IoContext may
      use the EMPER callerEnvironment and the worker of the IoContext OWNER.
      Also implement the stream operator to print caller environments.
    • Florian Schmaus's avatar
      Merge branch 'write-stats-to-file' into 'master' · e677b305
      Florian Schmaus authored
      print runtime stats to the environment variable EMPER_STATS_FILE
      See merge request !269
    • Florian Fischer's avatar
      print runtime stats to the environment variable EMPER_STATS_FILE · a757eb0e
      Florian Fischer authored
      * Make all stats print methods accept a std::ostream as output.
      * Move the printing of runtime component stats into Runtime::printStats.
      * Use Runtime::printStats instead of Runtime::printLastRuntimeStats in
        ~Runtime, because we are already in a runtime which may differ from
      * Write the stats in ~Runtime to a possible file passed in the
        environment variable EMPER_STATS_FILE
    • Florian Schmaus's avatar
      Merge branch 'remove-useless-private-stats-members' into 'master' · 8160f360
      Florian Schmaus authored
      [sleep_strategy/Stats] remove old obsolete stats member
      See merge request !270
    • Florian Schmaus's avatar
      Merge branch 'fix-cache-line-exclusive-macro' into 'master' · 8c6aceca
      Florian Schmaus authored
      [Common.hpp] fix CACHE_LINE_EXCLUSIVE macro
      See merge request !268
    • Florian Schmaus's avatar
      Merge branch 'use-scheduler-hint-stats' into 'master' · 1b7295a9
      Florian Schmaus authored
      [AbstractWorkStealingStats] actually use hint stats
      See merge request !267
    • Florian Schmaus's avatar
      Merge branch 'fix-throttle-wakeup' into 'master' · 267e9876
      Florian Schmaus authored
      [WakeupStrategy] fix the throttle algorithm for notifiaction from anywhere
      Closes #26
      See merge request !266