Also a little test program to demo channels in action.
This commit is contained in:
parent
061e6a21a5
commit
42526cb15d
|
@ -0,0 +1,409 @@
|
|||
# .tlv file generated by https://github.com/akkartik/teliva
|
||||
# You may edit it if you are careful; however, you may see cryptic errors if you
|
||||
# violate Teliva's assumptions.
|
||||
#
|
||||
# .tlv files are representations of Teliva programs. Teliva programs consist of
|
||||
# sequences of definitions. Each definition is a table of key/value pairs. Keys
|
||||
# and values are both strings.
|
||||
#
|
||||
# Lines in .tlv files always follow exactly one of the following forms:
|
||||
# - comment lines at the top of the file starting with '#' at column 0
|
||||
# - beginnings of definitions starting with '- ' at column 0, followed by a
|
||||
# key/value pair
|
||||
# - key/value pairs consisting of ' ' at column 0, containing either a
|
||||
# spaceless value on the same line, or a multi-line value
|
||||
# - multiline values indented by more than 2 spaces, starting with a '>'
|
||||
#
|
||||
# If these constraints are violated, Teliva may unceremoniously crash. Please
|
||||
# report bugs at http://akkartik.name/contact
|
||||
- __teliva_timestamp: original
|
||||
str_helpers:
|
||||
>-- some string helpers from http://lua-users.org/wiki/StringIndexing
|
||||
>
|
||||
>-- index characters using []
|
||||
>getmetatable('').__index = function(str,i)
|
||||
> if type(i) == 'number' then
|
||||
> return string.sub(str,i,i)
|
||||
> else
|
||||
> return string[i]
|
||||
> end
|
||||
>end
|
||||
>
|
||||
>-- ranges using (), selected bytes using {}
|
||||
>getmetatable('').__call = function(str,i,j)
|
||||
> if type(i)~='table' then
|
||||
> return string.sub(str,i,j)
|
||||
> else
|
||||
> local t={}
|
||||
> for k,v in ipairs(i) do
|
||||
> t[k]=string.sub(str,v,v)
|
||||
> end
|
||||
> return table.concat(t)
|
||||
> end
|
||||
>end
|
||||
>
|
||||
>-- iterate over an ordered sequence
|
||||
>function q(x)
|
||||
> if type(x) == 'string' then
|
||||
> return x:gmatch('.')
|
||||
> else
|
||||
> return ipairs(x)
|
||||
> end
|
||||
>end
|
||||
>
|
||||
>-- insert within string
|
||||
>function string.insert(str1, str2, pos)
|
||||
> return str1:sub(1,pos)..str2..str1:sub(pos+1)
|
||||
>end
|
||||
>
|
||||
>function string.remove(s, pos)
|
||||
> return s:sub(1,pos-1)..s:sub(pos+1)
|
||||
>end
|
||||
>
|
||||
>-- TODO: backport utf-8 support from Lua 5.3
|
||||
- __teliva_timestamp: original
|
||||
debugy:
|
||||
>debugy = 5
|
||||
- __teliva_timestamp: original
|
||||
dbg:
|
||||
>-- helper for debug by print; overlay debug information towards the right
|
||||
>-- reset debugy every time you refresh screen
|
||||
>function dbg(window, s)
|
||||
> local oldy = 0
|
||||
> local oldx = 0
|
||||
> oldy, oldx = window:getyx()
|
||||
> window:mvaddstr(debugy, 60, s)
|
||||
> debugy = debugy+1
|
||||
> window:mvaddstr(oldy, oldx, '')
|
||||
>end
|
||||
- __teliva_timestamp: original
|
||||
check_eq:
|
||||
>function check_eq(x, expected, msg)
|
||||
> if eq(x, expected) then
|
||||
> curses.addch('.')
|
||||
> else
|
||||
> print('F - '..msg)
|
||||
> print(' expected '..str(expected)..' but got '..str(x))
|
||||
> teliva_num_test_failures = teliva_num_test_failures + 1
|
||||
> -- overlay first test failure on editors
|
||||
> if teliva_first_failure == nil then
|
||||
> teliva_first_failure = msg
|
||||
> end
|
||||
> end
|
||||
>end
|
||||
- __teliva_timestamp: original
|
||||
eq:
|
||||
>function eq(a, b)
|
||||
> if type(a) ~= type(b) then return false end
|
||||
> if type(a) == 'table' then
|
||||
> if #a ~= #b then return false end
|
||||
> for k, v in pairs(a) do
|
||||
> if b[k] ~= v then
|
||||
> return false
|
||||
> end
|
||||
> return true
|
||||
> end
|
||||
> end
|
||||
> return a == b
|
||||
>end
|
||||
- __teliva_timestamp: original
|
||||
str:
|
||||
>-- smarter tostring
|
||||
>-- slow; used only for debugging
|
||||
>function str(x)
|
||||
> if type(x) == 'table' then
|
||||
> local result = ''
|
||||
> result = result..#x..'{'
|
||||
> for k, v in pairs(x) do
|
||||
> result = result..str(k)..'='..str(v)..', '
|
||||
> end
|
||||
> result = result..'}'
|
||||
> return result
|
||||
> end
|
||||
> return tostring(x)
|
||||
>end
|
||||
- __teliva_timestamp: original
|
||||
map:
|
||||
>-- only for arrays
|
||||
>function map(l, f)
|
||||
> result = {}
|
||||
> for _, x in ipairs(l) do
|
||||
> table.insert(result, f(x))
|
||||
> end
|
||||
> return result
|
||||
>end
|
||||
- __teliva_timestamp: original
|
||||
reduce:
|
||||
>-- only for arrays
|
||||
>function reduce(l, f, init)
|
||||
> result = init
|
||||
> for _, x in ipairs(l) do
|
||||
> result = f(result, x)
|
||||
> end
|
||||
> return result
|
||||
>end
|
||||
- __teliva_timestamp: original
|
||||
filter:
|
||||
>-- only for arrays
|
||||
>function filter(l, f)
|
||||
> result = {}
|
||||
> for _, x in ipairs(l) do
|
||||
> if f(x) then
|
||||
> table.insert(result, x)
|
||||
> end
|
||||
> end
|
||||
> return result
|
||||
>end
|
||||
- __teliva_timestamp: original
|
||||
find_index:
|
||||
>function find_index(arr, x)
|
||||
> for n, y in ipairs(arr) do
|
||||
> if x == y then
|
||||
> return n
|
||||
> end
|
||||
> end
|
||||
>end
|
||||
- __teliva_timestamp: original
|
||||
trim:
|
||||
>function trim(s)
|
||||
> return s:gsub('^%s*', ''):gsub('%s*$', '')
|
||||
>end
|
||||
- __teliva_timestamp: original
|
||||
split:
|
||||
>function split(s, d)
|
||||
> result = {}
|
||||
> for match in (s..d):gmatch("(.-)"..d) do
|
||||
> table.insert(result, match);
|
||||
> end
|
||||
> return result
|
||||
>end
|
||||
- __teliva_timestamp:
|
||||
>Mon Feb 21 17:45:04 2022
|
||||
sort_string:
|
||||
>function sort_string(s)
|
||||
> tmp = {}
|
||||
> for i=1,#s do
|
||||
> table.insert(tmp, s[i])
|
||||
> end
|
||||
> table.sort(tmp)
|
||||
> local result = ''
|
||||
> for _, c in pairs(tmp) do
|
||||
> result = result..c
|
||||
> end
|
||||
> return result
|
||||
>end
|
||||
>
|
||||
>function test_sort_string(s)
|
||||
> check_eq(sort_string(''), '', 'test_sort_string: empty')
|
||||
> check_eq(sort_string('ba'), 'ab', 'test_sort_string: non-empty')
|
||||
> check_eq(sort_string('abba'), 'aabb', 'test_sort_string: duplicates')
|
||||
>end
|
||||
- __teliva_timestamp: original
|
||||
append:
|
||||
>-- concatenate list 'elems' into 'l', modifying 'l' in the process
|
||||
>function append(l, elems)
|
||||
> for i=1,#elems do
|
||||
> l[#l+1] = elems[i]
|
||||
> end
|
||||
>end
|
||||
- __teliva_timestamp: original
|
||||
window:
|
||||
>window = curses.stdscr()
|
||||
- __teliva_timestamp: original
|
||||
render:
|
||||
>function render(window)
|
||||
> window:clear()
|
||||
> -- draw stuff to screen here
|
||||
> window:attron(curses.A_BOLD)
|
||||
> window:mvaddstr(1, 5, "example app")
|
||||
> window:attrset(curses.A_NORMAL)
|
||||
> for i=0,15 do
|
||||
> window:attrset(curses.color_pair(i))
|
||||
> window:mvaddstr(3+i, 5, "========================")
|
||||
> end
|
||||
> curses.refresh()
|
||||
>end
|
||||
- __teliva_timestamp: original
|
||||
menu:
|
||||
>-- To show app-specific hotkeys in the menu bar, add hotkey/command
|
||||
>-- arrays of strings to the menu array.
|
||||
>menu = {}
|
||||
- __teliva_timestamp: original
|
||||
update:
|
||||
>function update(window)
|
||||
> local key = curses.getch()
|
||||
> -- process key here
|
||||
>end
|
||||
- __teliva_timestamp: original
|
||||
init_colors:
|
||||
>function init_colors()
|
||||
> for i=0,7 do
|
||||
> curses.init_pair(i, i, -1)
|
||||
> end
|
||||
> curses.init_pair(8, 7, 0)
|
||||
> curses.init_pair(9, 7, 1)
|
||||
> curses.init_pair(10, 7, 2)
|
||||
> curses.init_pair(11, 7, 3)
|
||||
> curses.init_pair(12, 7, 4)
|
||||
> curses.init_pair(13, 7, 5)
|
||||
> curses.init_pair(14, 7, 6)
|
||||
> curses.init_pair(15, -1, 15)
|
||||
>end
|
||||
- __teliva_timestamp: original
|
||||
main:
|
||||
>function main()
|
||||
> init_colors()
|
||||
>
|
||||
> while true do
|
||||
> render(window)
|
||||
> update(window)
|
||||
> end
|
||||
>end
|
||||
- __teliva_timestamp: original
|
||||
doc:blurb:
|
||||
>To show a brief description of the app on the 'big picture' screen, put the text in a special buffer called 'doc:blurb'.
|
||||
>
|
||||
>You can also override the default big picture screen entirely by creating a buffer called 'doc:main'.
|
||||
- __teliva_timestamp:
|
||||
>Sat Feb 26 21:49:00 2022
|
||||
main:
|
||||
>function main()
|
||||
> task.spawn(main_task)
|
||||
> task.scheduler()
|
||||
> print('out of scheduler')
|
||||
> curses.getch()
|
||||
>end
|
||||
- __teliva_timestamp:
|
||||
>Sat Feb 26 21:50:11 2022
|
||||
main_task:
|
||||
>function main_task()
|
||||
> local c = task.Channel:new()
|
||||
> task.spawn(counter, c)
|
||||
> for i=1,10 do
|
||||
> print(c:recv())
|
||||
> end
|
||||
>end
|
||||
- __teliva_timestamp:
|
||||
>Sat Feb 26 21:50:11 2022
|
||||
__teliva_note:
|
||||
>a simple counter
|
||||
counter:
|
||||
>function counter(c)
|
||||
> local i = 2
|
||||
> while true do
|
||||
> c:send(i)
|
||||
> i = i+1
|
||||
> end
|
||||
>end
|
||||
- __teliva_timestamp:
|
||||
>Sat Feb 26 21:54:53 2022
|
||||
filter_task:
|
||||
>function filter_task(p, cin, cout)
|
||||
> while true do
|
||||
> local i = cin:recv()
|
||||
> if i%p ~= 0 then
|
||||
> cout:send(i)
|
||||
> end
|
||||
> end
|
||||
>end
|
||||
- __teliva_timestamp:
|
||||
>Sat Feb 26 21:55:46 2022
|
||||
main_task:
|
||||
>function main_task()
|
||||
> local primes = task.Channel:new()
|
||||
> task.spawn(sieve, primes)
|
||||
> for i=1,10 do
|
||||
> print(primes:recv())
|
||||
> end
|
||||
>end
|
||||
- __teliva_timestamp:
|
||||
>Sat Feb 26 21:59:37 2022
|
||||
__teliva_note:
|
||||
>filter out multiples of a single number
|
||||
sieve:
|
||||
>function sieve(ch)
|
||||
> local iota = task.Channel:new()
|
||||
> task.spawn(counter, iota)
|
||||
> task.spawn(filter_task, 2, iota, ch)
|
||||
>end
|
||||
- __teliva_timestamp:
|
||||
>Sat Feb 26 22:08:07 2022
|
||||
__teliva_note:
|
||||
>implement the complete sieve algorithm
|
||||
sieve:
|
||||
>-- Set up a Sieve of Eratosthenes (https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes)
|
||||
>-- for computing prime numbers by chaining tasks, one per prime.
|
||||
>-- Each task is responsible for filtering out all multiples of its prime.
|
||||
>function sieve(primes_ch)
|
||||
> local c = task.Channel:new()
|
||||
> task.spawn(counter, c)
|
||||
> while true do
|
||||
> local p, newc = c:recv(), task.Channel:new()
|
||||
> primes_ch:send(p)
|
||||
> task.spawn(filter_task, p, c, newc)
|
||||
> c = newc
|
||||
> end
|
||||
>end
|
||||
- __teliva_timestamp:
|
||||
>Sat Feb 26 22:09:47 2022
|
||||
main_task:
|
||||
>function main_task(window)
|
||||
> local primes = task.Channel:new()
|
||||
> task.spawn(sieve, primes)
|
||||
> while true do
|
||||
> window:addstr(primes:recv())
|
||||
> window:addstr(' ')
|
||||
> window:refresh()
|
||||
> end
|
||||
>end
|
||||
- __teliva_timestamp:
|
||||
>Sat Feb 26 22:08:52 2022
|
||||
__teliva_note:
|
||||
>infinite primes
|
||||
main:
|
||||
>function main()
|
||||
> window:nodelay(true)
|
||||
> window:clear()
|
||||
> task.spawn(main_task, window)
|
||||
> task.scheduler()
|
||||
> print('key pressed; done')
|
||||
> window:nodelay(false)
|
||||
> curses.getch()
|
||||
>end
|
||||
- __teliva_timestamp:
|
||||
>Sat Feb 26 22:09:47 2022
|
||||
__teliva_note:
|
||||
>clear screen when it fills up; pause on keypress
|
||||
>
|
||||
>In Teliva getch() implicitly refreshes the screen.
|
||||
main_task:
|
||||
>function main_task(window)
|
||||
> local primes = task.Channel:new()
|
||||
> task.spawn(sieve, primes)
|
||||
> local h, w = window:getmaxyx()
|
||||
> while true do
|
||||
> window:addstr(primes:recv())
|
||||
> window:addstr(' ')
|
||||
> local c = curses.getch()
|
||||
> if c then break end -- key pressed
|
||||
> local y, x = window:getyx()
|
||||
> if y > h-1 then
|
||||
> window:clear()
|
||||
> end
|
||||
> end
|
||||
>end
|
||||
- __teliva_timestamp:
|
||||
>Sat Feb 26 22:27:25 2022
|
||||
doc:blurb:
|
||||
>Sieve of Eratosthenes
|
||||
>https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes
|
||||
>
|
||||
>A demonstration of tasks and channels, the primitives for (cooperative) concurrency in Teliva.
|
||||
>
|
||||
>We string together a cascade of tasks connected by channels. Every prime number gets a new task that prints the first incoming number, and then filters out multiples of it from the incoming channel.
|
||||
>
|
||||
>This approach has the advantage that we don't need to create an array of n numbers to compute primes less than n.
|
||||
>
|
||||
>However, we still need to create p tasks and p channels if there are p primes less than n. Probably not worth it, given tasks and channels are much larger than numbers. This is just a demo.
|
||||
>
|
||||
>The noticeable periodic pauses are perhaps due to garbage collection.
|
|
@ -234,6 +234,8 @@ static int pmain (lua_State *L) {
|
|||
if (status != 0) return 0;
|
||||
status = dorequire(L, "src/json.lua", "json");
|
||||
if (status != 0) return 0;
|
||||
status = dorequire(L, "src/task.lua", "task");
|
||||
if (status != 0) return 0;
|
||||
lua_gc(L, LUA_GCRESTART, 0);
|
||||
s->status = handle_luainit(L);
|
||||
if (s->status != 0) return 0;
|
||||
|
|
|
@ -0,0 +1,632 @@
|
|||
----------------------------------------------------------------------------
|
||||
-- Go style Channels for Lua
|
||||
-- https://github.com/majek/lua-channels
|
||||
--
|
||||
-- This code is derived from libtask library by Russ Cox, mainly from
|
||||
-- channel.c. Semantically channels as implemented here are quite
|
||||
-- similar to channels from the Go language.
|
||||
--
|
||||
-- Usage (we're using unbuffered channel here):
|
||||
--
|
||||
-- local task = require('task')
|
||||
--
|
||||
-- local function counter(channel)
|
||||
-- local i = 1
|
||||
-- while true do
|
||||
-- channel:send(i)
|
||||
-- i = i + 1
|
||||
-- end
|
||||
-- end
|
||||
--
|
||||
-- local function main()
|
||||
-- local channel = task.Channel:new()
|
||||
-- task.spawn(counter, channel)
|
||||
-- assert(channel:recv() == 1)
|
||||
-- assert(channel:recv() == 2)
|
||||
-- assert(channel:recv() == 3)
|
||||
-- end
|
||||
--
|
||||
-- task.spawn(main)
|
||||
-- task.scheduler()
|
||||
--
|
||||
--
|
||||
-- This module exposes:
|
||||
--
|
||||
-- task.spawn(fun, [...]) - run fun as a coroutine with given
|
||||
-- parameters. You should use this instead of
|
||||
-- coroutine.create()
|
||||
--
|
||||
-- task.scheduler() - can be run only from the main thread, executes
|
||||
-- all the stuff, resumes the coroutines that are
|
||||
-- blocked on channels that became available. You
|
||||
-- can only do non-blocking sends / receives from
|
||||
-- the main thread.
|
||||
--
|
||||
-- task.Channel:new([buffer size]) - create a new channel with given size
|
||||
--
|
||||
-- task.chanalt(alts, can_block) - run alt / select / multiplex over
|
||||
-- the alts structure. For example:
|
||||
--
|
||||
-- task.chanalt({{c = channel_1, op = task.RECV},
|
||||
-- {c = channel_2, op = task.SEND, p = "hello"}}, true)
|
||||
--
|
||||
-- This will block current coroutine until it's possible to receive
|
||||
-- from channel_1 or send to channel_2. chanalt returns a number of
|
||||
-- statement from alts that succeeded (1 or 2 here) and a received
|
||||
-- value if executed statement was RECV.
|
||||
--
|
||||
-- Finally, if two alt statements can be fulfilled at the same time,
|
||||
-- we use math.random() to decide which one should go first. So it
|
||||
-- makes sense to initialize seed with something random. If you don't
|
||||
-- have access to an entropy source you can do:
|
||||
-- math.randomseed(os.time())
|
||||
-- but beware, the results of random() will predictable to a attacker.
|
||||
----------------------------------------------------------------------------
|
||||
|
||||
local _M = {}
|
||||
|
||||
-- Constants
|
||||
local RECV = 0x1
|
||||
local SEND = 0x2
|
||||
local NOP = 0x3
|
||||
|
||||
-- Global objects for scheduler
|
||||
local tasks_runnable = {} -- list of coroutines ready to be resumed
|
||||
|
||||
|
||||
----------------------------------------------------------------------------
|
||||
--- Helpers
|
||||
|
||||
local function random_choice(arr)
|
||||
if #arr > 1 then
|
||||
return arr[math.random(#arr)]
|
||||
else
|
||||
return arr[1]
|
||||
end
|
||||
end
|
||||
|
||||
-- Specialised Set data structure (with random element selection)
|
||||
local Set = {
|
||||
new = function(self)
|
||||
local o = {a = {}, l = {}}; setmetatable(o, self); self.__index = self
|
||||
return o
|
||||
end,
|
||||
|
||||
add = function(self, v)
|
||||
local a, l = self.a, self.l
|
||||
if a[v] == nil then
|
||||
table.insert(l, v)
|
||||
a[v] = #l
|
||||
return true
|
||||
end
|
||||
end,
|
||||
|
||||
remove = function(self, v)
|
||||
local a, l = self.a, self.l
|
||||
local i = a[v]
|
||||
if i > 0 then
|
||||
local t = l[#l]
|
||||
a[t], l[i] = i, t
|
||||
a[i], l[#l] = nil, nil
|
||||
return true
|
||||
end
|
||||
end,
|
||||
|
||||
random = function(self, v)
|
||||
return random_choice(self.l)
|
||||
end,
|
||||
|
||||
len = function(self)
|
||||
return #self.l
|
||||
end,
|
||||
}
|
||||
|
||||
-- Circular Buffer data structure
|
||||
local CircularBuffer = {
|
||||
new = function(self, size)
|
||||
local o = {b = {}, slots = size + 1, size = size, l = 0, r = 0}
|
||||
setmetatable(o, self); self.__index = self
|
||||
return o
|
||||
end,
|
||||
|
||||
len = function(self)
|
||||
return (self.r - self.l) % self.slots
|
||||
end,
|
||||
|
||||
pop = function(self)
|
||||
assert(self.l ~= self.r)
|
||||
local v = self.b[self.l]
|
||||
self.l = (self.l + 1) % self.slots
|
||||
return v
|
||||
end,
|
||||
|
||||
push = function(self, v)
|
||||
self.b[self.r] = v
|
||||
self.r = (self.r + 1) % self.slots
|
||||
assert(self.l ~= self.r)
|
||||
end,
|
||||
}
|
||||
|
||||
----------------------------------------------------------------------------
|
||||
-- Scheduling
|
||||
--
|
||||
-- Tasks ready to be run are placed on a stack and it's possible to
|
||||
-- starve a coroutine.
|
||||
local function scheduler()
|
||||
local self_coro, is_main = coroutine.running()
|
||||
|
||||
-- We actually don't care if scheduler is run from the main
|
||||
-- coroutine. But we do need to make sure that user doesn't do
|
||||
-- blocking operation from it, as it can't yield.
|
||||
|
||||
-- Be compatible with 5.1 and 5.2
|
||||
assert(not(self_coro ~= nil and is_main ~= true),
|
||||
"Scheduler must be run from the main coroutine.")
|
||||
|
||||
local i = 0
|
||||
while #tasks_runnable > 0 do
|
||||
local co = table.remove(tasks_runnable)
|
||||
local okay, emsg = coroutine.resume(co)
|
||||
if not okay then
|
||||
error(emsg)
|
||||
end
|
||||
i = i + 1
|
||||
end
|
||||
return i
|
||||
end
|
||||
|
||||
local function task_ready(co)
|
||||
table.insert(tasks_runnable, co)
|
||||
end
|
||||
|
||||
local function spawn(fun, ...)
|
||||
local args = {...}
|
||||
|
||||
local f = function()
|
||||
fun(unpack(args))
|
||||
end
|
||||
local co = coroutine.create(f)
|
||||
task_ready(co)
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------------
|
||||
-- Channels - chanalt and helpers
|
||||
|
||||
-- Given two Alts from a single channel exchange data between
|
||||
-- them. It's implied that one is RECV and another is SEND. Channel
|
||||
-- may be buffered.
|
||||
local function altcopy(a, b)
|
||||
local r, s, c = a, b, a.c
|
||||
if r.op == SEND then
|
||||
r, s = s, r
|
||||
end
|
||||
|
||||
assert(s == nil or s.op == SEND)
|
||||
assert(r == nil or r.op == RECV)
|
||||
|
||||
-- Channel is empty or unbuffered, copy directly
|
||||
if s ~= nil and r and c._buf:len() == 0 then
|
||||
r.alt_array.value = s.p
|
||||
return
|
||||
end
|
||||
|
||||
-- Otherwise it's always okay to receive and then send.
|
||||
if r ~= nil then
|
||||
r.alt_array.value = c._buf:pop()
|
||||
end
|
||||
if s ~= nil then
|
||||
c._buf:push(s.p)
|
||||
end
|
||||
end
|
||||
|
||||
-- Given enqueued alt_array from a chanalt statement remove all alts
|
||||
-- from the associated channels.
|
||||
local function altalldequeue(alt_array)
|
||||
for i = 1, #alt_array do
|
||||
local a = alt_array[i]
|
||||
if a.op == RECV or a.op == SEND then
|
||||
a.c:_get_alts(a.op):remove(a)
|
||||
end
|
||||
end
|
||||
end
|
||||
|
||||
-- Can this Alt be execed without blocking?
|
||||
local function altcanexec(a)
|
||||
local c, op = a.c, a.op
|
||||
if c._buf.size == 0 then
|
||||
if op ~= NOP then
|
||||
return c:_get_other_alts(op):len() > 0
|
||||
end
|
||||
else
|
||||
if op == SEND then
|
||||
return c._buf:len() < c._buf.size
|
||||
elseif op == RECV then
|
||||
return c._buf:len() > 0
|
||||
end
|
||||
end
|
||||
end
|
||||
|
||||
-- Alt can be execed so find a counterpart Alt and exec it!
|
||||
local function altexec(a)
|
||||
local c, op = a.c, a.op
|
||||
local other_alts = c:_get_other_alts(op)
|
||||
local other_a = other_alts:random()
|
||||
-- other_a may be nil
|
||||
altcopy(a, other_a)
|
||||
if other_a ~= nil then
|
||||
-- Disengage from channels used by the other Alt and make it ready.
|
||||
altalldequeue(other_a.alt_array)
|
||||
other_a.alt_array.resolved = other_a.alt_index
|
||||
task_ready(other_a.alt_array.task)
|
||||
end
|
||||
end
|
||||
|
||||
-- The main entry point. Call it `alt` or `select` or just a
|
||||
-- multiplexing statement. This is user facing function so make sure
|
||||
-- the parameters passed are sane.
|
||||
local function chanalt(alt_array, canblock)
|
||||
assert(#alt_array)
|
||||
|
||||
local list_of_canexec_i = {}
|
||||
for i = 1, #alt_array do
|
||||
local a = alt_array[i]
|
||||
a.alt_array = alt_array
|
||||
a.alt_index = i
|
||||
assert(type(a.op) == "number" and
|
||||
(a.op == RECV or a.op == SEND or a.op == NOP),
|
||||
"op field must be RECV, SEND or NOP in alt")
|
||||
assert(type(a.c) == "table" and a.c.__index == _M.Channel,
|
||||
"pass valid channel to a c field of alt")
|
||||
if altcanexec(a) == true then
|
||||
table.insert(list_of_canexec_i, i)
|
||||
end
|
||||
end
|
||||
|
||||
if #list_of_canexec_i > 0 then
|
||||
local i = random_choice(list_of_canexec_i)
|
||||
altexec(alt_array[i])
|
||||
return i, alt_array.value
|
||||
end
|
||||
|
||||
if canblock ~= true then
|
||||
return nil
|
||||
end
|
||||
|
||||
local self_coro, is_main = coroutine.running()
|
||||
alt_array.task = self_coro
|
||||
assert(self_coro ~= nil and is_main ~= true,
|
||||
"Unable to block from the main thread, run scheduler.")
|
||||
|
||||
for i = 1, #alt_array do
|
||||
local a = alt_array[i]
|
||||
if a.op ~= NOP then
|
||||
a.c:_get_alts(a.op):add(a)
|
||||
end
|
||||
end
|
||||
|
||||
-- Make sure we're not woken by someone who is not the scheduler.
|
||||
alt_array.resolved = nil
|
||||
coroutine.yield()
|
||||
assert(alt_array.resolved > 0)
|
||||
|
||||
local r = alt_array.resolved
|
||||
return r, alt_array.value
|
||||
end
|
||||
|
||||
|
||||
----------------------------------------------------------------------------
|
||||
-- Channel object
|
||||
|
||||
local Channel = {
|
||||
new = function(self, buf_size)
|
||||
local o = {}; setmetatable(o, self); self.__index = self
|
||||
o._buf = CircularBuffer:new(buf_size or 0)
|
||||
o._recv_alts, o._send_alts = Set:new(), Set:new()
|
||||
return o
|
||||
end,
|
||||
|
||||
send = function(self, msg)
|
||||
assert(chanalt({{c = self, op = SEND, p = msg}}, true) == 1)
|
||||
return true
|
||||
end,
|
||||
|
||||
recv = function(self)
|
||||
local alts = {{c = self, op = RECV}}
|
||||
local s, msg = chanalt(alts, true)
|
||||
assert(s == 1)
|
||||
return msg
|
||||
end,
|
||||
|
||||
nbsend = function(self, msg)
|
||||
local s = chanalt({{c = self, op = SEND, p = msg}}, false)
|
||||
return s == 1
|
||||
end,
|
||||
|
||||
nbrecv = function(self)
|
||||
local s, msg = chanalt({{c = self, op = RECV}}, false)
|
||||
return s == 1, msg
|
||||
end,
|
||||
|
||||
_get_alts = function(self, op)
|
||||
return (op == RECV) and self._recv_alts or self._send_alts
|
||||
end,
|
||||
|
||||
_get_other_alts = function(self, op)
|
||||
return (op == SEND) and self._recv_alts or self._send_alts
|
||||
end,
|
||||
|
||||
__tostring = function(self)
|
||||
return string.format("<Channel size=%i/%i send_alt=%i recv_alt=%i>",
|
||||
self._buf:len(), self._buf.size, self._send_alts:len(),
|
||||
self._recv_alts:len())
|
||||
end,
|
||||
|
||||
__call = function(self)
|
||||
local function f(s, v)
|
||||
return true, self:recv()
|
||||
end
|
||||
return f, nil, nil
|
||||
end,
|
||||
}
|
||||
|
||||
----------------------------------------------------------------------------
|
||||
-- Public interface
|
||||
|
||||
_M.scheduler = scheduler
|
||||
_M.spawn = spawn
|
||||
_M.Channel = Channel
|
||||
_M.chanalt = chanalt
|
||||
_M.RECV = RECV
|
||||
_M.SEND = SEND
|
||||
_M.NOP = NOP
|
||||
|
||||
----------------------------------------------------------------------------
|
||||
----------------------------------------------------------------------------
|
||||
-- Tests
|
||||
--
|
||||
-- To run:
|
||||
-- $ lua task.lua
|
||||
|
||||
local task = _M
|
||||
|
||||
local tests = {
|
||||
counter = function ()
|
||||
local done
|
||||
local function counter(c)
|
||||
local i = 1
|
||||
while true do
|
||||
c:send(i)
|
||||
i = i + 1
|
||||
end
|
||||
end
|
||||
local function main()
|
||||
local c = task.Channel:new()
|
||||
task.spawn(counter, c)
|
||||
assert(c:recv() == 1)
|
||||
assert(c:recv() == 2)
|
||||
assert(c:recv() == 3)
|
||||
assert(c:recv() == 4)
|
||||
assert(c:recv() == 5)
|
||||
done = true
|
||||
end
|
||||
task.spawn(main)
|
||||
task.scheduler()
|
||||
assert(done)
|
||||
end,
|
||||
|
||||
nonblocking_channel = function()
|
||||
local done
|
||||
local function main()
|
||||
local b = task.Channel:new()
|
||||
assert(b:nbsend(1) == false)
|
||||
assert(b:nbrecv() == false)
|
||||
|
||||
local c = task.Channel:new(1)
|
||||
assert(c:nbrecv() == false)
|
||||
assert(c:nbsend(1) == true)
|
||||
assert(c:nbsend(1) == false)
|
||||
local r, v = c:nbrecv()
|
||||
assert(r == true)
|
||||
assert(v == 1)
|
||||
assert(c:nbrecv() == false)
|
||||
done = true
|
||||
end
|
||||
task.spawn(main)
|
||||
task.scheduler()
|
||||
assert(done)
|
||||
end,
|
||||
|
||||
concurrent_send_and_recv = function()
|
||||
local l = {}
|
||||
local function a(c, name)
|
||||
-- Blocking send and recv from the same process
|
||||
local alt = {{c = c, op = task.SEND, p = 1},
|
||||
{c = c, op = task.RECV}}
|
||||
local i, v = task.chanalt(alt, true)
|
||||
local k = string.format('%s %s', name, i == 1 and "send" or "recv")
|
||||
l[k] = (l[k] or 0) + 1
|
||||
end
|
||||
|
||||
for i = 0, 1000 do
|
||||
-- On Mac OS X in lua 5.1 initializing seed with a
|
||||
-- predictable value makes no sense. For all seeds from 1 to
|
||||
-- 1000 the result of math.random(1,3) is _exactly_ the same!
|
||||
-- So beware, when seeding!
|
||||
-- math.randomseed(i)
|
||||
local c = task.Channel:new()
|
||||
task.spawn(a, c, "a")
|
||||
task.spawn(a, c, "b")
|
||||
task.scheduler()
|
||||
end
|
||||
|
||||
-- Make sure we have randomness, that is: events occur in both
|
||||
-- orders in 1000 runs
|
||||
assert(l['a recv'] > 0)
|
||||
assert(l['a send'] > 0)
|
||||
assert(l['b recv'] > 0)
|
||||
assert(l['b send'] > 0)
|
||||
end,
|
||||
|
||||
channels_from_a_coroutine = function()
|
||||
local done
|
||||
local c = task.Channel:new()
|
||||
local function a()
|
||||
for i = 1, 100 do
|
||||
c:send(i)
|
||||
end
|
||||
end
|
||||
local function b()
|
||||
assert(c:recv() == 1)
|
||||
assert(c:recv() == 2)
|
||||
assert(c:recv() == 3)
|
||||
assert(c:recv() == 4)
|
||||
assert(c:recv() == 5)
|
||||
done = true
|
||||
end
|
||||
local a_co = coroutine.create(a)
|
||||
local b_co = coroutine.create(b)
|
||||
coroutine.resume(a_co)
|
||||
coroutine.resume(b_co)
|
||||
task.scheduler()
|
||||
assert(done)
|
||||
end,
|
||||
|
||||
fibonacci = function()
|
||||
local done
|
||||
local function fib(c)
|
||||
local x, y = 0, 1
|
||||
while true do
|
||||
c:send(x)
|
||||
x, y = y, x + y
|
||||
end
|
||||
end
|
||||
local function main(c)
|
||||
assert(c:recv() == 0)
|
||||
assert(c:recv() == 1)
|
||||
assert(c:recv() == 1)
|
||||
assert(c:recv() == 2)
|
||||
assert(c:recv() == 3)
|
||||
assert(c:recv() == 5)
|
||||
assert(c:recv() == 8)
|
||||
assert(c:recv() == 13)
|
||||
assert(c:recv() == 21)
|
||||
assert(c:recv() == 34)
|
||||
done = true
|
||||
end
|
||||
|
||||
local c = task.Channel:new()
|
||||
task.spawn(fib, c)
|
||||
task.spawn(main, c)
|
||||
task.scheduler()
|
||||
assert(done)
|
||||
end,
|
||||
|
||||
non_blocking_chanalt = function()
|
||||
local done
|
||||
local function main()
|
||||
local c = task.Channel:new()
|
||||
local alts = {{c = c, op = task.RECV},
|
||||
{c = c, op = task.NOP},
|
||||
{c = c, op = task.SEND, p = 1}}
|
||||
assert(task.chanalt(alts, false) == nil)
|
||||
|
||||
local c = task.Channel:new(1)
|
||||
local alts = {{c = c, op = task.RECV},
|
||||
{c = c, op = task.NOP},
|
||||
{c = c, op = task.SEND, p = 1}}
|
||||
assert(task.chanalt(alts, false) == 3)
|
||||
assert(task.chanalt(alts, false) == 1)
|
||||
|
||||
local alts = {{c = c, op = task.NOP}}
|
||||
assert(task.chanalt(alts, false) == nil)
|
||||
|
||||
done = true
|
||||
end
|
||||
task.spawn(main)
|
||||
task.scheduler()
|
||||
assert(done)
|
||||
end,
|
||||
|
||||
-- Apparently it's not really a Sieve of Eratosthenes:
|
||||
-- http://www.cs.hmc.edu/~oneill/papers/Sieve-JFP.pdf
|
||||
eratosthenes_sieve = function()
|
||||
local done
|
||||
local function counter(c)
|
||||
local i = 2
|
||||
while true do
|
||||
c:send(i)
|
||||
i = i + 1
|
||||
end
|
||||
end
|
||||
|
||||
local function filter(p, recv_ch, send_ch)
|
||||
while true do
|
||||
local i = recv_ch:recv()
|
||||
if i % p ~= 0 then
|
||||
send_ch:send(i)
|
||||
end
|
||||
end
|
||||
end
|
||||
|
||||
local function sieve(primes_ch)
|
||||
local c = task.Channel:new()
|
||||
task.spawn(counter, c)
|
||||
while true do
|
||||
local p, newc = c:recv(), task.Channel:new()
|
||||
primes_ch:send(p)
|
||||
task.spawn(filter, p, c, newc)
|
||||
c = newc
|
||||
end
|
||||
end
|
||||
|
||||
local function main()
|
||||
local primes = task.Channel:new()
|
||||
task.spawn(sieve, primes)
|
||||
assert(primes:recv() == 2)
|
||||
assert(primes:recv() == 3)
|
||||
assert(primes:recv() == 5)
|
||||
assert(primes:recv() == 7)
|
||||
assert(primes:recv() == 11)
|
||||
assert(primes:recv() == 13)
|
||||
done = true
|
||||
end
|
||||
|
||||
task.spawn(main)
|
||||
task.scheduler()
|
||||
assert(done)
|
||||
end,
|
||||
|
||||
channel_as_iterator = function()
|
||||
local done
|
||||
local function counter(c)
|
||||
local i = 2
|
||||
while true do
|
||||
c:send(i)
|
||||
i = i + 1
|
||||
end
|
||||
end
|
||||
|
||||
local function main()
|
||||
local numbers = task.Channel:new()
|
||||
task.spawn(counter, numbers)
|
||||
for _, j in numbers() do
|
||||
if j == 100 then
|
||||
break
|
||||
end
|
||||
done = true
|
||||
end
|
||||
end
|
||||
if _VERSION == "Lua 5.1" then
|
||||
-- sorry, this doesn't work in 5.1
|
||||
print('skipping... (5.1 unsupported)')
|
||||
done = true
|
||||
else
|
||||
task.spawn(main)
|
||||
task.scheduler()
|
||||
end
|
||||
assert(done)
|
||||
end,
|
||||
|
||||
}
|
||||
|
||||
return _M
|
|
@ -259,8 +259,7 @@
|
|||
> update(window)
|
||||
> end
|
||||
>end
|
||||
- __teliva_timestamp:
|
||||
>Thu Feb 17 20:10:02 2022
|
||||
- __teliva_timestamp: original
|
||||
doc:blurb:
|
||||
>To show a brief description of the app on the 'big picture' screen, put the text in a special buffer called 'doc:blurb'.
|
||||
>
|
||||
|
|
Loading…
Reference in New Issue