projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| a1330e13 BJ |
1 | /* |
| 2 | * This file holds definitions relevent to the wait system call. | |
| 3 | * Some of the options here are available only through the ``wait3'' | |
| 4 | * entry point; the old entry point with one argument has more fixed | |
| 5 | * semantics, never returning status of unstopped children, hanging until | |
| 6 | * a process terminates if any are outstanding, and never returns | |
| 7 | * detailed information about process resource utilization (<vtimes.h>). | |
| 8 | */ | |
| 9 | ||
| 10 | /* | |
| 11 | * Structure of the information in the first word returned by both | |
| 12 | * wait and wait3. If w_stopval==WSTOPPED, then the second structure | |
| 13 | * describes the information returned, else the first. See WUNTRACED below. | |
| 14 | */ | |
| 15 | union wait { | |
| 16 | int w_status; /* used in syscall */ | |
| 17 | /* | |
| 18 | * Terminated process status. | |
| 19 | */ | |
| 20 | struct { | |
| 21 | unsigned short w_Termsig:7; /* termination signal */ | |
| 22 | unsigned short w_Coredump:1; /* core dump indicator */ | |
| 23 | unsigned short w_Retcode:8; /* exit code if w_termsig==0 */ | |
| 24 | } w_T; | |
| 25 | /* | |
| 26 | * Stopped process status. Returned | |
| 27 | * only for traced children unless requested | |
| 28 | * with the WUNTRACED option bit. | |
| 29 | */ | |
| 30 | struct { | |
| 31 | unsigned short w_Stopval:8; /* == W_STOPPED if stopped */ | |
| 32 | unsigned short w_Stopsig:8; /* signal that stopped us */ | |
| 33 | } w_S; | |
| 34 | }; | |
| 35 | #define w_termsig w_T.w_Termsig | |
| 36 | #define w_coredump w_T.w_Coredump | |
| 37 | #define w_retcode w_T.w_Retcode | |
| 38 | #define w_stopval w_S.w_Stopval | |
| 39 | #define w_stopsig w_S.w_Stopsig | |
| 40 | ||
| 41 | ||
| 42 | #define WSTOPPED 0177 /* value of s.stopval if process is stopped */ | |
| 43 | ||
| 44 | /* | |
| 45 | * Option bits for the second argument of wait3. WNOHANG causes the | |
| 46 | * wait to not hang if there are no stopped or terminated processes, rather | |
| 47 | * returning an error indication in this case (pid==0). WUNTRACED | |
| 48 | * indicates that the caller should receive status about untraced children | |
| 49 | * which stop due to signals. If children are stopped and a wait without | |
| 50 | * this option is done, it is as though they were still running... nothing | |
| 51 | * about them is returned. | |
| 52 | */ | |
| 53 | #define WNOHANG 1 /* dont hang in wait */ | |
| 54 | #define WUNTRACED 2 /* tell about stopped, untraced children */ | |
| 55 | ||
| 56 | #define WIFSTOPPED(x) ((x).w_stopval == WSTOPPED) | |
| 57 | #define WIFSIGNALED(x) ((x).w_stopval != WSTOPPED && (x).w_termsig != 0) | |
| 58 | #define WIFEXITED(x) ((x).w_stopval != WSTOPPED && (x).w_termsig == 0) |