src/posix/generic/Dsw/Mod/HostProcs.cp

   1 MODULE DswHostProcs;
   2
   3   IMPORT SYSTEM, Log, DswProcs, HostLang, unistd := PosixCunistd, stdlib := PosixCstdlib,
   4     signal := PosixCsignal, sys_wait := PosixCsys_wait, macro := PosixCmacro,
   5     errno := PosixCerrno;
   6
   7   TYPE
   8     Directory = POINTER TO RECORD (DswProcs.Directory) END;
   9
  10     String = POINTER TO ARRAY OF SHORTCHAR;
  11     SString = POINTER TO ARRAY OF String;
  12
  13     Process = POINTER TO RECORD (DswProcs.Process)
  14       argv: SString;
  15       pid: unistd.pid_t;
  16       code: unistd.int;
  17     END;
  18
  19   PROCEDURE (d: Directory) New* (): Process;
  20     VAR p: Process;
  21   BEGIN
  22     NEW(p); p.argv := NIL; p.pid := -1; p.code := 0;
  23     RETURN p
  24   END New;
  25
  26   PROCEDURE ToHost (IN s: ARRAY OF CHAR): String;
  27     VAR ss: String; res: INTEGER;
  28   BEGIN
  29     NEW(ss, LEN(s$) * 3 + 1);
  30     ASSERT(ss # NIL, 100);
  31     HostLang.StringToHost(s, ss, HostLang.pep383x, res);
  32     ASSERT(res = 0, 101);
  33     RETURN ss
  34   END ToHost;
  35
  36   PROCEDURE (p: Process) Program* (IN exe: ARRAY OF CHAR);
  37     VAR argv: SString;
  38   BEGIN
  39     ASSERT(p.pid = -1, 20);
  40     NEW(argv, 1); argv[0] := ToHost(exe);
  41     p.argv := argv
  42   END Program;
  43
  44   PROCEDURE (p: Process) PutParam* (IN par: ARRAY OF CHAR);
  45     VAR i: INTEGER; argv: SString;
  46   BEGIN
  47     ASSERT(p.pid = -1, 20);
  48     ASSERT(p.argv # NIL, 21);
  49     NEW(argv, LEN(p.argv) + 1);
  50     FOR i := 0 TO LEN(p.argv) - 1 DO
  51       argv[i] := p.argv[i]
  52     END;
  53     argv[i] := ToHost(par);
  54     p.argv := argv
  55   END PutParam;
  56
  57   PROCEDURE (p: Process) Execute* (OUT ok: BOOLEAN);
  58     TYPE
  59       UString = POINTER [untagged] TO ARRAY [untagged] OF SHORTCHAR;
  60       SUString = POINTER TO ARRAY OF UString;
  61     VAR
  62       i, j: INTEGER; pid: unistd.pid_t; res: unistd.int; argv: SUString;
  63   BEGIN
  64     ASSERT(p.pid = -1, 20);
  65     ASSERT(p.argv # NIL, 21);
  66     NEW(argv, LEN(p.argv) + 1);
  67     FOR i := 0 TO LEN(p.argv) - 1 DO
  68       argv[i] := SYSTEM.VAL(UString, SYSTEM.ADR(p.argv[i, 0]))
  69     END;
  70     pid := unistd.fork();
  71     IF pid = 0 THEN
  72       res := unistd.execv(argv[0], argv);
  73       unistd._exit(127); (* system() and most utils exit with 126/127 *)
  74       ok := FALSE
  75     ELSIF pid = -1 THEN
  76       ok := FALSE
  77     ELSE
  78       p.argv := NIL; (* or save it for debugging and reuse? *)
  79       p.pid := pid;
  80       ok := TRUE
  81     END
  82   END Execute;
  83
  84   PROCEDURE (p: Process) Terminate* (OUT ok: BOOLEAN);
  85     VAR res, e: signal.int;
  86   BEGIN
  87     ASSERT(p.pid > 0, 20);
  88     res := signal.kill(p.pid, signal.SIGTERM);
  89     IF res = 0 THEN p.Wait; ok := TRUE
  90     ELSIF res = -1 THEN
  91       e := macro.errno();
  92       CASE e OF
  93       | errno.EINVAL: HALT(100) (* wat *)
  94       | errno.EPERM: ok := FALSE (* process can not be killed *)
  95       | errno.ESRCH: p.code := 0; p.pid := -1; ok := TRUE (* process already killed *)
  96       END
  97     ELSE HALT(101) (* wat *)
  98     END
  99   END Terminate;
 100
 101   PROCEDURE (p: Process) IsTerminated* (): BOOLEAN;
 102     VAR pid: unistd.pid_t; e: unistd.int;
 103   BEGIN
 104     IF p.pid # -1 THEN
 105       ASSERT(p.pid > 0, 100); (* wat *)
 106       pid := sys_wait.waitpid(p.pid, p.code, sys_wait.WNOHANG);
 107       IF pid = 0 THEN (* process still executes *)
 108       ELSIF pid = p.pid THEN p.pid := -1 (* process returns code *)
 109       ELSIF pid = -1 THEN
 110         e := macro.errno();
 111         CASE e OF
 112         | errno.ECHILD: p.code := 0; p.pid := -1 (* process was killed externally *)
 113         | errno.EINVAL: HALT(101) (* wat *)
 114         | errno.EINTR: (* assume that process still executes *)
 115         END
 116       ELSE HALT(102) (* wat *)
 117       END
 118     END;
 119     RETURN p.pid = -1
 120   END IsTerminated;
 121
 122   PROCEDURE (p: Process) Wait*;
 123     VAR pid: unistd.pid_t; e: unistd.int;
 124   BEGIN
 125     ASSERT(p.pid > 0, 20);
 126     REPEAT
 127       pid := sys_wait.waitpid(p.pid, p.code, 0);
 128       IF pid = p.pid THEN p.pid := -1 (* was terminated *)
 129       ELSIF pid = -1 THEN
 130         e := macro.errno();
 131         CASE e OF
 132         | errno.ECHILD: p.code := 0; p.pid := -1 (* process was killed externally *)
 133         | errno.EINVAL: HALT(100) (* wat *)
 134         | errno.EINTR: (* continue wait for process termination *)
 135         END
 136       ELSE HALT(101) (* wat *)
 137       END
 138     UNTIL p.pid = -1
 139   END Wait;
 140
 141   PROCEDURE (p: Process) Result (): INTEGER;
 142   BEGIN
 143     IF p.pid # -1 THEN p.Wait END;
 144     (* RETURN SYSTEM.CONV(INTEGER, sys_wait.WEXITSTATUS(p.code)) *) (* !!! *)
 145     RETURN SYSTEM.VAL(INTEGER, p.code) DIV 256 MOD 128
 146   END Result;
 147
 148   PROCEDURE Init;
 149     VAR d: Directory;
 150   BEGIN
 151     NEW(d); DswProcs.SetDir(d)
 152   END Init;
 153
 154 BEGIN
 155   Init
 156 END DswHostProcs.