code / tomo-coroutines

   1 # This is a coroutine library that uses libaco (https://libaco.org)
   2 #
   3 # Lua programmers will recognize this as similar to Lua's stackful coroutines.
   4 #
   5 # Async/Await programmers will weep at its beauty and gnash their teeth and
   6 # rend their garments in despair at what they could have had.
   7 
   8 use ./aco.h
   9 use ./aco.c
  10 use ./acoyield.S
  11 
  12 func main()
  13     say("Example usage")
  14     co := Coroutine(func()
  15         say("I'm in the coroutine!")
  16         yield()
  17         say("I'm back in the coroutine!")
  18     )
  19     >> co
  20     say("I'm in the main func")
  21     >> co.resume()
  22     say("I'm back in the main func")
  23     >> co.resume()
  24     say("I'm back in the main func again")
  25     >> co.resume()
  26 
  27 _main_co : @Memory? = none
  28 _shared_stack : @Memory? = none
  29 
  30 struct Coroutine(co:@Memory)
  31     convert(fn:func() -> Coroutine)
  32         if not _main_co
  33             _init()
  34 
  35         main_co := _main_co
  36         shared_stack := _shared_stack
  37         aco_ptr := C_code:@Memory`
  38             aco_create(@main_co, @shared_stack, 0, (void*)@fn.fn, @fn.userdata)
  39         `
  40         return Coroutine(aco_ptr)
  41 
  42     func is_finished(co:Coroutine->Bool; inline)
  43         return C_code:Bool`((aco_t*)@(co.co))->is_finished`
  44 
  45     func resume(co:Coroutine->Bool)
  46         if co.is_finished()
  47             return no
  48         C_code `aco_resume(@co.co);`
  49         return yes
  50 
  51 func _init()
  52     C_code `
  53         aco_set_allocator(GC_malloc, NULL);
  54         aco_thread_init(aco_exit_fn);
  55     `
  56     _main_co = C_code:@Memory`aco_create(NULL, NULL, 0, NULL, NULL)`
  57 
  58     _shared_stack = C_code:@Memory`aco_shared_stack_new(0)`
  59 
  60 func yield(; inline)
  61     C_code `
  62         aco_yield();
  63     `
  64