Annotation of 42BSD/sys/h/wait.h, revision 1.1.1.1

1.1       root        1: /*     wait.h  6.1     83/07/29        */
                      2: 
                      3: /*
                      4:  * This file holds definitions relevent to the wait system call.
                      5:  * Some of the options here are available only through the ``wait3''
                      6:  * entry point; the old entry point with one argument has more fixed
                      7:  * semantics, never returning status of unstopped children, hanging until
                      8:  * a process terminates if any are outstanding, and never returns
                      9:  * detailed information about process resource utilization (<vtimes.h>).
                     10:  */
                     11: 
                     12: /*
                     13:  * Structure of the information in the first word returned by both
                     14:  * wait and wait3.  If w_stopval==WSTOPPED, then the second structure
                     15:  * describes the information returned, else the first.  See WUNTRACED below.
                     16:  */
                     17: union wait     {
                     18:        int     w_status;               /* used in syscall */
                     19:        /*
                     20:         * Terminated process status.
                     21:         */
                     22:        struct {
                     23:                unsigned short  w_Termsig:7;    /* termination signal */
                     24:                unsigned short  w_Coredump:1;   /* core dump indicator */
                     25:                unsigned short  w_Retcode:8;    /* exit code if w_termsig==0 */
                     26:        } w_T;
                     27:        /*
                     28:         * Stopped process status.  Returned
                     29:         * only for traced children unless requested
                     30:         * with the WUNTRACED option bit.
                     31:         */
                     32:        struct {
                     33:                unsigned short  w_Stopval:8;    /* == W_STOPPED if stopped */
                     34:                unsigned short  w_Stopsig:8;    /* signal that stopped us */
                     35:        } w_S;
                     36: };
                     37: #define        w_termsig       w_T.w_Termsig
                     38: #define w_coredump     w_T.w_Coredump
                     39: #define w_retcode      w_T.w_Retcode
                     40: #define w_stopval      w_S.w_Stopval
                     41: #define w_stopsig      w_S.w_Stopsig
                     42: 
                     43: 
                     44: #define        WSTOPPED        0177    /* value of s.stopval if process is stopped */
                     45: 
                     46: /*
                     47:  * Option bits for the second argument of wait3.  WNOHANG causes the
                     48:  * wait to not hang if there are no stopped or terminated processes, rather
                     49:  * returning an error indication in this case (pid==0).  WUNTRACED
                     50:  * indicates that the caller should receive status about untraced children
                     51:  * which stop due to signals.  If children are stopped and a wait without
                     52:  * this option is done, it is as though they were still running... nothing
                     53:  * about them is returned.
                     54:  */
                     55: #define WNOHANG                1       /* dont hang in wait */
                     56: #define WUNTRACED      2       /* tell about stopped, untraced children */
                     57: 
                     58: #define WIFSTOPPED(x)  ((x).w_stopval == WSTOPPED)
                     59: #define WIFSIGNALED(x) ((x).w_stopval != WSTOPPED && (x).w_termsig != 0)
                     60: #define WIFEXITED(x)   ((x).w_stopval != WSTOPPED && (x).w_termsig == 0)

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