diff options
Diffstat (limited to 'bin/sh/jobs.c')
| -rw-r--r-- | bin/sh/jobs.c | 61 |
1 files changed, 0 insertions, 61 deletions
diff --git a/bin/sh/jobs.c b/bin/sh/jobs.c index 990b5b9..1cab468 100644 --- a/bin/sh/jobs.c +++ b/bin/sh/jobs.c @@ -49,12 +49,10 @@ __FBSDID("$FreeBSD$"); #include <unistd.h> #include <stdlib.h> #include <sys/param.h> -#ifdef BSD #include <sys/wait.h> #include <sys/time.h> #include <sys/resource.h> #include <paths.h> -#endif #include <sys/ioctl.h> #include "shell.h" @@ -96,9 +94,6 @@ STATIC void restartjob(struct job *); STATIC void freejob(struct job *); STATIC struct job *getjob(char *); STATIC pid_t dowait(int, struct job *); -#if SYSV -STATIC int onsigchild(void); -#endif STATIC pid_t waitproc(int, int *); STATIC void cmdtxt(union node *); STATIC void cmdputs(char *); @@ -112,10 +107,6 @@ STATIC void showjob(struct job *, pid_t, int, int); /* * Turn job control on and off. - * - * Note: This code assumes that the third arg to ioctl is a character - * pointer, which is true on Berkeley systems but not System V. Since - * System V doesn't have job control yet, this isn't a problem now. */ MKINIT int jobctl; @@ -1005,44 +996,10 @@ dowait(int block, struct job *job) * Do a wait system call. If job control is compiled in, we accept * stopped processes. If block is zero, we return a value of zero * rather than blocking. - * - * System V doesn't have a non-blocking wait system call. It does - * have a SIGCLD signal that is sent to a process when one of it's - * children dies. The obvious way to use SIGCLD would be to install - * a handler for SIGCLD which simply bumped a counter when a SIGCLD - * was received, and have waitproc bump another counter when it got - * the status of a process. Waitproc would then know that a wait - * system call would not block if the two counters were different. - * This approach doesn't work because if a process has children that - * have not been waited for, System V will send it a SIGCLD when it - * installs a signal handler for SIGCLD. What this means is that when - * a child exits, the shell will be sent SIGCLD signals continuously - * until is runs out of stack space, unless it does a wait call before - * restoring the signal handler. The code below takes advantage of - * this (mis)feature by installing a signal handler for SIGCLD and - * then checking to see whether it was called. If there are any - * children to be waited for, it will be. - * - * If neither SYSV nor BSD is defined, we don't implement nonblocking - * waits at all. In this case, the user will not be informed when - * a background process until the next time she runs a real program - * (as opposed to running a builtin command or just typing return), - * and the jobs command may give out of date information. */ - -#ifdef SYSV -STATIC sig_atomic_t gotsigchild; - -STATIC int onsigchild() { - gotsigchild = 1; -} -#endif - - STATIC pid_t waitproc(int block, int *status) { -#ifdef BSD int flags; #if JOBS @@ -1053,24 +1010,6 @@ waitproc(int block, int *status) if (block == 0) flags |= WNOHANG; return wait3(status, flags, (struct rusage *)NULL); -#else -#ifdef SYSV - int (*save)(); - - if (block == 0) { - gotsigchild = 0; - save = signal(SIGCLD, onsigchild); - signal(SIGCLD, save); - if (gotsigchild == 0) - return 0; - } - return wait(status); -#else - if (block == 0) - return 0; - return wait(status); -#endif -#endif } /* |
