tasync_cpp.nim « cpp « tests - Nim - This repository contains the Nim compiler, Nim's stdlib, tools, and documentation. (mirror)

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blob: 792f2938b96b1072297643bd80f3591b2e3d5ee3 (plain) (blame)

discard """
  cmd: "nim cpp $file"
  output: "hello"
"""

# bug #3299

import jester
import asyncdispatch, asyncnet

echo "hello"

ht .ow { color: #008800 } /* Operator.Word */ .highlight .w { color: #bbbbbb } /* Text.Whitespace */ .highlight .mb { color: #0000DD; font-weight: bold } /* Literal.Number.Bin */ .highlight .mf { color: #0000DD; font-weight: bold } /* Literal.Number.Float */ .highlight .mh { color: #0000DD; font-weight: bold } /* Literal.Number.Hex */ .highlight .mi { color: #0000DD; font-weight: bold } /* Literal.Number.Integer */ .highlight .mo { color: #0000DD; font-weight: bold } /* Literal.Number.Oct */ .highlight .sa { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Affix */ .highlight .sb { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Backtick */ .highlight .sc { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Char */ .highlight .dl { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Delimiter */ .highlight .sd { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Doc */ .highlight .s2 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Double */ .highlight .se { color: #0044dd; background-color: #fff0f0 } /* Literal.String.Escape */ .highlight .sh { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Heredoc */ .highlight .si { color: #3333bb; background-color: #fff0f0 } /* Literal.String.Interpol */ .highlight .sx { color: #22bb22; background-color: #f0fff0 } /* Literal.String.Other */ .highlight .sr { color: #008800; background-color: #fff0ff } /* Literal.String.Regex */ .highlight .s1 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Single */ .highlight .ss { color: #aa6600; background-color: #fff0f0 } /* Literal.String.Symbol */ .highlight .bp { color: #003388 } /* Name.Builtin.Pseudo */ .highlight .fm { color: #0066bb; font-weight: bold } /* Name.Function.Magic */ .highlight .vc { color: #336699 } /* Name.Variable.Class */ .highlight .vg { color: #dd7700 } /* Name.Variable.Global */ .highlight .vi { color: #3333bb } /* Name.Variable.Instance */ .highlight .vm { color: #336699 } /* Name.Variable.Magic */ .highlight .il { color: #0000DD; font-weight: bold } /* Literal.Number.Integer.Long */

#
#
#            Nim's Runtime Library
#        (c) Copyright 2015 Andreas Rumpf
#
#    See the file "copying.txt", included in this
#    distribution, for details about the copyright.
#

## This module implements a helper for a thread pool to determine whether
## creating a thread is a good idea.
##
## Unstable API.

when defined(windows):
  import winlean, os, strutils, math

  proc `-`(a, b: FILETIME): int64 = a.rdFileTime - b.rdFileTime
elif defined(linux):
  from cpuinfo import countProcessors

when defined(nimPreviewSlimSystem):
  import std/syncio

type
  ThreadPoolAdvice* = enum
    doNothing,
    doCreateThread,  # create additional thread for throughput
    doShutdownThread # too many threads are busy, shutdown one

  ThreadPoolState* = object
    when defined(windows):
      prevSysKernel, prevSysUser, prevProcKernel, prevProcUser: FILETIME
    calls*: int

proc advice*(s: var ThreadPoolState): ThreadPoolAdvice =
  when defined(windows):
    var
      sysIdle, sysKernel, sysUser,
        procCreation, procExit, procKernel, procUser: FILETIME
    if getSystemTimes(sysIdle, sysKernel, sysUser) == 0 or
        getProcessTimes(Handle(-1), procCreation, procExit,
                        procKernel, procUser) == 0:
      return doNothing
    if s.calls > 0:
      let
        sysKernelDiff = sysKernel - s.prevSysKernel
        sysUserDiff = sysUser - s.prevSysUser

        procKernelDiff = procKernel - s.prevProcKernel
        procUserDiff = procUser - s.prevProcUser

        sysTotal = sysKernelDiff + sysUserDiff
        procTotal = procKernelDiff + procUserDiff
      # total CPU usage < 85% --> create a new worker thread.
      # Measurements show that 100% and often even 90% is not reached even
      # if all my cores are busy.
      if sysTotal == 0 or procTotal.float / sysTotal.float < 0.85:
        result = doCreateThread
    s.prevSysKernel = sysKernel
    s.prevSysUser = sysUser
    s.prevProcKernel = procKernel
    s.prevProcUser = procUser
  elif defined(linux):
    proc fscanf(c: File, frmt: cstring) {.varargs, importc,
      header: "<stdio.h>".}

    var f: File
    if f.open("/proc/loadavg"):
      var b: float
      var busy, total: int
      fscanf(f,"%lf %lf %lf %ld/%ld",
            addr b, addr b, addr b, addr busy, addr total)
      f.close()
      let cpus = countProcessors()
      if busy-1 < cpus:
        result = doCreateThread
      elif busy-1 >= cpus*2:
        result = doShutdownThread
      else:
        result = doNothing
    else:
      result = doNothing
  else:
    # XXX implement this for other OSes
    result = doNothing
  inc s.calls

when not defined(testing) and isMainModule and not defined(nimdoc):
  import random

  proc busyLoop() =
    while true:
      discard rand(80)
      os.sleep(100)

  spawn busyLoop()
  spawn busyLoop()
  spawn busyLoop()
  spawn busyLoop()

  var s: ThreadPoolState

  for i in 1 .. 70:
    echo advice(s)
    os.sleep(1000)