ref: 30c662571c4f64f72171cca0efc7bedc59bd53fa
dir: /lib/thread/spawn+openbsd.myr/
use std use sys pkg thread = type tid = uint64 const spawn : (fn : (-> void) -> std.result(tid, byte[:])) ;; const Stacksz = 8*std.MiB extern const exit : (-> void) const spawn = {fn; -> spawnstk(fn, Stacksz) } const spawnstk = {fn, sz var stk, szp, fp, tos, tfp, env, envsz var ret stk = getstk(sz) if stk == sys.Mapbad -> `std.Err "couldn't get stack" ;; /* store size */ tos = (stk : std.intptr) tos -= sizeof(int64) szp = (tos : sys.size#) szp# = Stacksz /* store func */ envsz = std.fnenvsz(fn) tos -= (envsz : std.intptr) env = tos tos -= sizeof((->void)) fp = (tos : (->void)#) fp# = std.fnbdup(fn, (env : byte#)[:envsz]) tfp = [ .tcb = (0 : void#), .tid = &ret, .stk = (tos : byte#), ] if sys.__tfork_thread(&tfp, \ sizeof(sys.tforkparams), \ (startthread : void#), \ (0 : void#)) < 0 -> `std.Err "couldn't spawn thread" ;; -> `std.Ok (ret : tid) } const getstk = {sz var p, m p = sys.mmap((0 : byte#), sz, sys.Mprotrw, sys.Mpriv | sys.Manon, -1, 0) if p == sys.Mapbad -> p ;; /* stack starts at the top of memory and grows down. */ m = (p : std.intptr) m += (sz : std.intptr) -> (m : byte#) } const startthread = {fn : (-> void) fn() exit() }