Open Mash Cross Reference
mash/tcl/net/rlm-misc.tcl

   # rlm-misc.tcl --
   #
   #       FIXME: This file needs a description here.
   #
   # Copyright (c) 1996-2002 The Regents of the University of California.
   # All rights reserved.
   #
   # Redistribution and use in source and binary forms, with or without
   # modification, are permitted provided that the following conditions are met:
  #
  # A. Redistributions of source code must retain the above copyright notice,
  #    this list of conditions and the following disclaimer.
  # B. Redistributions in binary form must reproduce the above copyright notice,
  #    this list of conditions and the following disclaimer in the documentation
  #    and/or other materials provided with the distribution.
  # C. Neither the names of the copyright holders nor the names of its
  #    contributors may be used to endorse or promote products derived from this
  #    software without specific prior written permission.
  #
  # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS''
  # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  # ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
  # ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  # SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  #
  # @(#) $Header: /usr/mash/src/repository/mash/mash-1/tcl/net/rlm-misc.tcl,v 1.5 2002/02/03 04:28:06 lim Exp $
  
  
  #FIXME
  #proc randomize v {
  #       return [expr 0.5 * $v + double([ns-random] % 10000000) / 1e7 * $v]
  #
  #}
  
  proc uniform01 {} {
      return [expr double(([random] % 10000000) + 1) / 1e7]
  }
  
  proc uniform { a b } {
          return [expr ($b - $a) * [uniform01] + $a]
  }
  
  proc exponential mean {
          return [expr - $mean * log([uniform01])]
  }
  
  proc trunc_exponential lambda {
          while 1 {
                  set u [exponential $lambda]
                  if { $u < [expr 4 * $lambda] } {
                          return $u
                  }
          }
  }
  
  #FIXME make this a class?
  proc sched { delay proc } {
          set delay [expr int($delay * 1000)]
          return [after $delay $proc]
  }
  
  proc set_timer { which mmg delay } {
          global rlm_tid
          set v $which:$mmg
          if [info exists rlm_tid($v)] {
                  puts "timer botched ($v)"
                  exit -1
          }
          set rlm_tid($v) [sched $delay "trigger_timer $which $mmg"]
  }
  
  proc trigger_timer { which mmg } {
          global rlm_tid
          unset rlm_tid($which:$mmg)
          $mmg trigger_$which
  }
  
  #
  # cancel s-timer on flow $mmg
  # e.g., because we experienced loss
  #
  proc cancel_timer { which mmg } {
          global rlm_tid
          set v $which:$mmg
          if [info exists rlm_tid($v)] {
                  after cancel $rlm_tid($v)
                  unset rlm_tid($v)
          }
  }