/* -----------------------------------------------------------------------------
Copyright 2021 Kevin P. Barry

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
----------------------------------------------------------------------------- */

// Author: Kevin P. Barry [ta0kira@gmail.com]

testcase "EnumeratedBarrier tests" {
  success
}

unittest correctCount {
  ReadAt<BarrierWait> barriers <- EnumeratedBarrier.new(13)
  \ Testing.checkEquals<?>(barriers.size(),13)
}

unittest waitForOneThread {
  ReadAt<BarrierWait> barriers <- EnumeratedBarrier.new(1)
  \ barriers.readAt(0).wait()
}

unittest zeroAllowed {
  ReadAt<BarrierWait> barriers <- EnumeratedBarrier.new(0)
  \ Testing.checkEquals<?>(barriers.size(),0)
}

unittest waitForMultipleThreads {
  Value value <- Value.create()
  Mutex mutex <- SimpleMutex.new()
  ReadAt<BarrierWait> barriers <- EnumeratedBarrier.new(3)

  Thread thread1 <- ProcessThread.from(WaitAndIncrement.create(2,value,mutex,barriers.readAt(1))).start()
  Thread thread2 <- ProcessThread.from(WaitAndIncrement.create(2,value,mutex,barriers.readAt(2))).start()

  \ barriers.readAt(0).wait()
  \ Testing.checkEquals<?>(value.get(),2)

  \ barriers.readAt(0).wait()
  \ Testing.checkEquals<?>(value.get(),4)

  \ thread1.join()
  \ thread2.join()
}

concrete WaitAndIncrement {
  refines Routine

  @type create (Int,Value,Mutex,BarrierWait) -> (WaitAndIncrement)
}

define WaitAndIncrement {
  @value Int count
  @value Value value
  @value Mutex mutex
  @value BarrierWait barrier

  create (count,value,mutex,barrier) {
    return WaitAndIncrement{ count, value, mutex, barrier }
  }

  run () {
    scoped {
      Int i <- 0
    } in while (i < count) {
      $Hidden[i,count]$
      scoped {
        MutexLock lock <- MutexLock.lock(mutex)
      } cleanup {
        \ lock.freeResource()
      } in {
        \ value.increment()
      }
      \ barrier.wait()
      // Gives the main thread time to read the value.
      \ Realtime.sleepSeconds(0.01)
    } update {
      i <- i+1
    }
  }
}


testcase "EnumeratedBarrier crashes with negative count" {
  crash
  require "-4"
}

unittest test {
  ReadAt<BarrierWait> barriers <- EnumeratedBarrier.new(-4)
}


testcase "wait() crashes when references are lost" {
  crash
  require "BarrierWait.*destroyed"
}

unittest test {
  scoped {
    ReadAt<BarrierWait> barriers <- EnumeratedBarrier.new(2)
  } in BarrierWait barrier <- barriers.readAt(0)
  \ barrier.wait()
}


testcase "references lost during wait() causes crash" {
  crash
  require "BarrierWait.*waiting"
}

unittest test {
  scoped {
    ReadAt<BarrierWait> barriers <- EnumeratedBarrier.new(2)
  } in {
    Thread thread <- ProcessThread.from(WaitAndExit.create(barriers.readAt(0))).start()
    // Give the thread time to start.
    \ Realtime.sleepSeconds(0.1)
  }
}

concrete WaitAndExit {
  refines Routine

  @type create (BarrierWait) -> (WaitAndExit)
}

define WaitAndExit {
  @value BarrierWait barrier

  create (barrier) {
    return WaitAndExit{ barrier }
  }

  run () {
    \ barrier.wait()
  }
}


testcase "wait() crashes when two threads use same BarrierWait" {
  crash
  require "BarrierWait.*in use"
}

unittest test {
  ReadAt<BarrierWait> barriers <- EnumeratedBarrier.new(2)
  Thread thread <- ProcessThread.from(WaitAndExit.create(barriers.readAt(0))).start()
  \ barriers.readAt(0).wait()
}

concrete WaitAndExit {
  refines Routine

  @type create (BarrierWait) -> (WaitAndExit)
}

define WaitAndExit {
  @value BarrierWait barrier

  create (barrier) {
    return WaitAndExit{ barrier }
  }

  run () {
    \ barrier.wait()
  }
}