liminix/pkgs/anoia/process.fnl

85 lines
2.5 KiB
Fennel

(local ll (require :lualinux))
(local { : find-executable } (require :anoia.fs))
(import-macros { : define-tests : expect : expect= } :anoia.assert)
(macro errno-check [x]
`(match ,x
val# val#
(nil errno#) (assert nil (.. "system call failed, errno=" errno#))
))
(fn popen2 [pname argv envp]
(case (ll.pipe2)
(cin-s cin-d)
(match (ll.pipe2)
(cout-s cout-d)
(let [(pid err) (ll.fork)]
(if (not pid) (error (.. "error: " err))
(= pid 0)
(do
(ll.close cin-d)
(ll.close cout-s)
(ll.dup2 cin-s 0)
(ll.dup2 cout-d 1)
(ll.dup2 cout-d 2)
(ll.execve pname argv envp)
(error "execve failed"))
(> pid 0)
(do
(ll.close cin-s)
(ll.close cout-d)))
(values pid cin-d cout-s))
(nil err) (error (.. "popen pipe out: " err)))
(nil err) (error (.. "popen pipe in: " err))))
(fn spawn [pname argv envp callback]
(let [(pid in out) (popen2 pname argv envp)
pollfds [
(bor (lshift in 32) (lshift 4 16))
(bor (lshift out 32) (lshift 1 16))
]]
(while (or (> (. pollfds 1) 0) (> (. pollfds 2) 0))
(ll.poll pollfds)
(if
(> (band (. pollfds 2) 0x11) 0) ; POLLIN | POLLHUP
(if (not (callback :out out)) (tset pollfds 2 (lshift -1 32)))
(> (band (. pollfds 1) 4) 0) ; POLLOUT
(if (not (callback :in in)) (tset pollfds 1 (lshift -1 32)))
))
(match (ll.waitpid pid)
(0 status) false
(pid status) (rshift (band status 0xff00) 8)
(nil errno) (error (.. "waitpid: " errno)))))
(define-tests
(var buf "4 * 6\n") ;; spawn bc to multiply two numbers
(let [out []
p (spawn
(assert (find-executable "bc" (os.getenv "PATH")))
["bc"]
(ll.environ)
(fn [stream fd]
(match stream
:out (let [b (ll.read fd)]
(table.insert out b)
(> (# b) 0))
:in (if (> (# buf) 0)
(let [bytes (ll.write fd buf)]
(set buf (string.sub buf (+ bytes 1) -1))
true)
(do
(ll.close fd)
false))
:err (assert nil (ll.read fd)))))]
(expect= (table.concat out) "24\n"))
)
{
: popen2
: spawn
}