resource philosopher
   import dining_server
body philosopher(i : int; dcap : cap dining_server; thinking, eating: int)
   printf("comment ")                                        # animator
   write("philosopher", i, "alive, max think eat delays", thinking, eating)

   procedure think()
      var napping : int
      napping := int(random(1000*thinking))
      printf("comment ")                                     # animator
      writes("age=",age(),", philosopher ",i," thinking for ",napping," ms\n")
      nap(napping)
   end think

   procedure eat()
      var napping : int
      napping := int(random(1000*eating))
      printf("comment ")                                     # animator
      writes("age=",age(),", philosopher ",i," eating for ",napping," ms\n")
      printf("color %d  blue\n", i)                          # animator
      printf("fill  %d solid\n", i)                          # animator
      nap(napping)
   end eat

   process phil
      do true ->
         think()
         printf("comment ")                                  # animator
         writes("age=", age(), ", philosopher ", i, " is hungry\n")
         printf("color %d green\n", i)                       # animator
         printf("fill  %d solid\n", i)                       # animator
         dcap.take_forks(i)
         printf("comment ")                                  # animator
         writes("age=", age(), ", philosopher ", i, " has taken forks\n")
         eat()
         dcap.put_forks(i)
         printf("comment ")                                  # animator
         writes("age=", age(), ", philosopher ", i, " has returned forks\n")
         printf("fill  %d outline\n", i)                     # animator
         printf("color %d   black\n", i)                     # animator
      od
   end phil
end philosopher

resource dining_server
   op take_forks(i : int), put_forks(i : int)
body dining_server(num_phil : int)
   printf("comment ")                                        # animator
   write("dining server for", num_phil, "philosophers is alive")
   sem mutex := 1
   type states = enum(thinking, hungry, eating)
   var state[1:num_phil] : states := ([num_phil] thinking)
   sem phil[1:num_phil] := ([num_phil] 0)

   procedure left(i : int) returns lft : int
      if i=1 -> lft := num_phil [] else -> lft := i-1 fi
   end left

   procedure right(i : int) returns rgh : int
      if i=num_phil -> rgh := 1 [] else -> rgh := i+1 fi
   end right

   procedure test(i : int)
      if state[i] = hungry and state[left(i)] ~= eating
            and state[right(i)] ~= eating ->
         state[i] := eating
         V(phil[i])
      fi
   end test

   proc take_forks(i)
      P(mutex)
      state[i] := hungry
      test(i)
      V(mutex)
      P(phil[i])
   end take_forks

   proc put_forks(i)
      P(mutex)
      state[i] := thinking
      test(left(i)); test(right(i))
      V(mutex)
   end put_forks
end dining_server

resource start()
   import philosopher, dining_server
   var num_phil : int := 5, run_time : int := 60
   getarg(1, num_phil); getarg(2, run_time)
   var max_think_delay[1:num_phil] : int := ([num_phil] 5)
   var max_eat_delay[1:num_phil] : int := ([num_phil] 2)
   fa i := 1 to num_phil ->
      getarg(2*i+1, max_think_delay[i]); getarg(2*i+2, max_eat_delay[i])
   af

   var dcap : cap dining_server
   printf("comment ")                                             # animator
   write(num_phil, "dining philosophers running", run_time, "seconds")
   printf("coords -1.5 -1.5 1.5 1.5\n")                           # animator
   printf("circle 1000  0.0  0.0 1.0  black outline\n")           # animator
   printf("circle 1001 -1.4 -1.0 0.05 black outline\n")           # animator
   printf("text   1002 -1.3 -1.025 0  black THINKING\n")          # animator
   printf("circle 1003 -1.4 -1.2 0.05 green solid\n")             # animator
   printf("text   1004 -1.3 -1.225 0  black HUNGRY\n")            # animator
   printf("circle 1005 -1.4 -1.4 0.05 blue  solid\n")             # animator
   printf("text   1006 -1.3 -1.425 0  black EATING\n")            # animator
   dcap := create dining_server(num_phil)
   const TWO_PI := 2.0*acos(-1.0)                                 # animator
   fa i := 1 to num_phil ->
      printf("circle %d %7.2f %7.2f 0.1 black outline\n",         # animator
         i, sin(i*(TWO_PI/num_phil)), cos(i*(TWO_PI/num_phil)))   # animator
      printf("text %d %7.2f %7.2f 1 black %d\n",                  # animator
         1010+i, sin(i*(TWO_PI/num_phil))+0.1,                    # animator
         cos(i*(TWO_PI/num_phil))+0.1, i)                         # animator
      create philosopher(i, dcap, max_think_delay[i], max_eat_delay[i])
   af
   nap(1000*run_time); printf("comment "); write("must stop now"); stop
end start

/* ............... Example compile and run(s)

% sr -o din_phil din_phil.sr
% ./din_phil 5 3
comment 5 dining philosophers running 3 seconds
coords -1.5 -1.5 1.5 1.5
circle 1000  0.0  0.0 1.0  black outline
circle 1001 -1.4 -1.0 0.05 black outline
text   1002 -1.3 -1.025 0  black THINKING
circle 1003 -1.4 -1.2 0.05 green solid
text   1004 -1.3 -1.225 0  black HUNGRY
circle 1005 -1.4 -1.4 0.05 blue  solid
text   1006 -1.3 -1.425 0  black EATING
comment dining server for 5 philosophers is alive
circle 1    0.95    0.31 0.1 black outline
text 1011    1.05    0.41 1 black 1
comment philosopher 1 alive, max think eat delays 5 2
comment age=70, philosopher 1 thinking for 4557 ms
circle 2    0.59   -0.81 0.1 black outline
text 1012    0.69   -0.71 1 black 2
comment philosopher 2 alive, max think eat delays 5 2
comment age=94, philosopher 2 thinking for 2019 ms
circle 3   -0.59   -0.81 0.1 black outline
text 1013   -0.49   -0.71 1 black 3
comment philosopher 3 alive, max think eat delays 5 2
comment age=117, philosopher 3 thinking for 758 ms
circle 4   -0.95    0.31 0.1 black outline
text 1014   -0.85    0.41 1 black 4
comment philosopher 4 alive, max think eat delays 5 2
comment age=141, philosopher 4 thinking for 4206 ms
circle 5   -0.00    1.00 0.1 black outline
text 1015    0.10    1.10 1 black 5
comment philosopher 5 alive, max think eat delays 5 2
comment age=165, philosopher 5 thinking for 4084 ms
comment age=887, philosopher 3 is hungry
color 3 green
fill  3 solid
comment age=899, philosopher 3 has taken forks
comment age=903, philosopher 3 eating for 1603 ms
color 3  blue
fill  3 solid
comment age=2127, philosopher 2 is hungry
color 2 green
fill  2 solid
comment age=2518, philosopher 3 has returned forks
fill  3 outline
color 3   black
comment age=2527, philosopher 3 thinking for 2381 ms
comment age=2532, philosopher 2 has taken forks
comment age=2537, philosopher 2 eating for 1954 ms
color 2  blue
fill  2 solid
comment must stop now
% ./din_phil 5 10 | animator
Press RUN ANIMATION button to begin

XTANGO Version 1.52

 5 dining philosophers running 10 seconds
 dining server for 5 philosophers is alive
 philosopher 1 alive, max think eat delays 5 2
 age=40, philosopher 1 thinking for 1708 ms
 philosopher 2 alive, max think eat delays 5 2
 age=51, philosopher 2 thinking for 4904 ms
 philosopher 3 alive, max think eat delays 5 2
 age=82, philosopher 3 thinking for 3533 ms
 philosopher 4 alive, max think eat delays 5 2
 age=93, philosopher 4 thinking for 832 ms
 philosopher 5 alive, max think eat delays 5 2
 age=134, philosopher 5 thinking for 836 ms
 age=942, philosopher 4 is hungry
 age=944, philosopher 4 has taken forks
 age=945, philosopher 4 eating for 1506 ms
 age=976, philosopher 5 is hungry
 age=1757, philosopher 1 is hungry
 age=1760, philosopher 1 has taken forks
 age=1761, philosopher 1 eating for 687 ms
 age=2457, philosopher 1 has returned forks
 age=2459, philosopher 1 thinking for 96 ms
 age=2463, philosopher 4 has returned forks
 age=2465, philosopher 4 thinking for 2294 ms
 age=2466, philosopher 5 has taken forks
 age=2470, philosopher 5 eating for 656 ms
 age=2559, philosopher 1 is hungry
 age=3138, philosopher 5 has returned forks
 age=3140, philosopher 5 thinking for 4016 ms
 age=3141, philosopher 1 has taken forks
 age=3142, philosopher 1 eating for 551 ms
 age=3620, philosopher 3 is hungry
 age=3622, philosopher 3 has taken forks
 age=3623, philosopher 3 eating for 221 ms
 age=3697, philosopher 1 has returned forks
 age=3699, philosopher 1 thinking for 1524 ms
 age=3849, philosopher 3 has returned forks
 age=3851, philosopher 3 thinking for 1049 ms
 age=4781, philosopher 4 is hungry
 age=4797, philosopher 4 has taken forks
 age=4798, philosopher 4 eating for 1215 ms
 age=4945, philosopher 3 is hungry
 age=4957, philosopher 2 is hungry
 age=4959, philosopher 2 has taken forks
 age=4960, philosopher 2 eating for 1169 ms
 age=5227, philosopher 1 is hungry
 age=6027, philosopher 4 has returned forks
 age=6029, philosopher 4 thinking for 4183 ms
 age=6141, philosopher 2 has returned forks
 age=6149, philosopher 2 thinking for 2860 ms
 age=6150, philosopher 3 has taken forks
 age=6151, philosopher 3 eating for 1200 ms
 age=6153, philosopher 1 has taken forks
 age=6154, philosopher 1 eating for 1822 ms
 age=7197, philosopher 5 is hungry
 age=7365, philosopher 3 has returned forks
 age=7377, philosopher 3 thinking for 3983 ms
 age=7992, philosopher 1 has returned forks
 age=8009, philosopher 1 thinking for 2440 ms
 age=8010, philosopher 5 has taken forks
 age=8011, philosopher 5 eating for 1558 ms
 age=9011, philosopher 2 is hungry
 age=9013, philosopher 2 has taken forks
 age=9014, philosopher 2 eating for 298 ms
 age=9318, philosopher 2 has returned forks
 age=9320, philosopher 2 thinking for 1550 ms
 age=9588, philosopher 5 has returned forks
 age=9590, philosopher 5 thinking for 2647 ms
 must stop now
                                              */