ref: de1eabd91024f360845dfe7382581e0acbc368e1
dir: /lib/std/wait+plan9.myr/
use sys use "alloc" use "chartype" use "die" use "extremum" use "hashfuncs" use "hasprefix" use "htab" use "intparse" use "option" use "strsplit" use "striter" use "syswrap" use "utf" use "sleq" use "fmt" use "threadhooks" pkg std = type waitstatus = union `Wsuccess `Wfailure `Wsignalled `Waiterror ;; const wait : (pid : pid -> waitstatus) const waitany : (-> (pid, waitstatus)) ;; var statusmap : htab(pid, waitstatus)# const __init__ = { statusmap = mkht() } const waitany = { var buf : byte[512] var ret, it lock(envlck) if htcount(statusmap) == 0 unlock(envlck) match sys.await(buf[:]) | -1: -> (-1, `Waiterror) | n: -> parsestatus(buf[:n]) ;; else it = std.byhtkeyvals(statusmap) __iternext__(&it, &ret) unlock(envlck) -> ret ;; } const wait = {pid var buf : byte[512] var xpid, status lock(envlck) match htget(statusmap, pid) | `None: | `Some st: unlock(envlck) htdel(statusmap, pid) -> st ;; unlock(envlck) while true match sys.await(buf[:]) | -1: -> `Waiterror | n: (xpid, status) = parsestatus(buf[:n]) ;; if xpid == pid -> status else lock(envlck) htput(statusmap, xpid, status) unlock(envlck) ;; ;; /* impossible */ -> `Waiterror } const parsestatus = {status -> (pid, waitstatus) var st : waitstatus var spbuf : byte[:][5] var xpid, sp sp = bstrsplit(spbuf[:], status, " ") if sp.len == 0 -> (-1, `Wfailure) ;; match intparse(sp[0]) | `Some pid: xpid = pid /* exits(nil) => sp[0] either not present or equal to '' */ if sp.len == 4 || (sp.len == 5 && sleq(sp[4], "''")) st = `Wsuccess elif sp.len == 5 st = `Wfailure else /* we have a malformed await message */ st = `Waiterror ;; | `None: xpid = -1 st = `Waiterror ;; -> (xpid, st) }