1 /* 2 * Copyright (c) 1982 Regents of the University of California. 3 * All rights reserved. The Berkeley software License Agreement 4 * specifies the terms and conditions for redistribution. 5 * 6 * @(#)wait.h 6.2 (Berkeley) 06/08/85 7 */ 8 9 /* 10 * This file holds definitions relevent to the wait system call. 11 * Some of the options here are available only through the ``wait3'' 12 * entry point; the old entry point with one argument has more fixed 13 * semantics, never returning status of unstopped children, hanging until 14 * a process terminates if any are outstanding, and never returns 15 * detailed information about process resource utilization (<vtimes.h>). 16 */ 17 18 /* 19 * Structure of the information in the first word returned by both 20 * wait and wait3. If w_stopval==WSTOPPED, then the second structure 21 * describes the information returned, else the first. See WUNTRACED below. 22 */ 23 union wait { 24 int w_status; /* used in syscall */ 25 /* 26 * Terminated process status. 27 */ 28 struct { 29 unsigned short w_Termsig:7; /* termination signal */ 30 unsigned short w_Coredump:1; /* core dump indicator */ 31 unsigned short w_Retcode:8; /* exit code if w_termsig==0 */ 32 } w_T; 33 /* 34 * Stopped process status. Returned 35 * only for traced children unless requested 36 * with the WUNTRACED option bit. 37 */ 38 struct { 39 unsigned short w_Stopval:8; /* == W_STOPPED if stopped */ 40 unsigned short w_Stopsig:8; /* signal that stopped us */ 41 } w_S; 42 }; 43 #define w_termsig w_T.w_Termsig 44 #define w_coredump w_T.w_Coredump 45 #define w_retcode w_T.w_Retcode 46 #define w_stopval w_S.w_Stopval 47 #define w_stopsig w_S.w_Stopsig 48 49 50 #define WSTOPPED 0177 /* value of s.stopval if process is stopped */ 51 52 /* 53 * Option bits for the second argument of wait3. WNOHANG causes the 54 * wait to not hang if there are no stopped or terminated processes, rather 55 * returning an error indication in this case (pid==0). WUNTRACED 56 * indicates that the caller should receive status about untraced children 57 * which stop due to signals. If children are stopped and a wait without 58 * this option is done, it is as though they were still running... nothing 59 * about them is returned. 60 */ 61 #define WNOHANG 1 /* dont hang in wait */ 62 #define WUNTRACED 2 /* tell about stopped, untraced children */ 63 64 #define WIFSTOPPED(x) ((x).w_stopval == WSTOPPED) 65 #define WIFSIGNALED(x) ((x).w_stopval != WSTOPPED && (x).w_termsig != 0) 66 #define WIFEXITED(x) ((x).w_stopval != WSTOPPED && (x).w_termsig == 0) 67