sh.proc.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 1,167 行 · 第 1/2 页

#ifndef lint
static char *sccsid = "@(#)sh.proc.c	4.3  (ULTRIX)        11/13/90";
#endif
/************************************************************************
 *                                                                      *
 *                      Copyright (c) 1988 by                           *
 *              Digital Equipment Corporation, Maynard, MA              *
 *                      All rights reserved.                            *
 *                                                                      *
 *   This software is furnished under a license and may be used and     *
 *   copied  only  in accordance with the terms of such license and     *
 *   with the  inclusion  of  the  above  copyright  notice.   This     *
 *   software  or  any  other copies thereof may not be provided or     *
 *   otherwise made available to any other person.  No title to and     *
 *   ownership of the software is hereby transferred.                   *
 *                                                                      *
 *   The information in this software is subject to change  without     *
 *   notice  and should not be construed as a commitment by Digital     *
 *   Equipment Corporation.                                             *
 *                                                                      *
 *   Digital assumes no responsibility for the use  or  reliability     *
 *   of its software on equipment which is not supplied by Digital.     *
 *                                                                      *
 ************************************************************************/
/* ------------------------------------------------------------------ */
/* | Copyright Unpublished, MIPS Computer Systems, Inc.  All Rights | */
/* | Reserved.  This software contains proprietary and confidential | */
/* | information of MIPS and its suppliers.  Use, disclosure or     | */
/* | reproduction is prohibited without the prior express written   | */
/* | consent of MIPS.                                               | */
/* ------------------------------------------------------------------ */
/* $Header: sh.proc.c,v 1.4 87/04/06 21:00:16 dce Exp $ */

#include "sh.h"
#include "sh.dir.h"
#include "sh.proc.h"
#include <sys/wait.h>
#include <sys/ioctl.h>

/*
 * C Shell - functions that manage processes, handling hanging, termination
 * Modification History
 *
 * 005 - Bob Fontaine - Mon Oct 22 13:46:48 EDT 1990
 *    Fix typo from 003.  Must increment the pointer to the users input
 *    so that the % sign is not part of the job number.
 *
 * 004 - Bob Fontaine - Fri Jun 22 09:53:01 EDT 1990
 *	Changed call to internal printf routine to csh_printf to avoid
 *	 confusion with library routine.
 *
 * 003 - Bob Fontaine - Thu Jun 21 10:22:20 EDT 1990
 *	pstart routine used to just search for a job in the proc list
 *	that matched the second digit in the job number entered by the user.
 *	(ie job 11 would map to job 1).  Fix is to look at the entire 
 *	string the user entered.  QAR # 957
 *
 * 002 - Gary A. Gaudet - Tue Jan  2 11:56:15 EST 1990
 *	added retrun value checks fro ioctl()
 *	added some (castings)
 *
 * 01 Sat Aug 13 15:28:57 EDT 1988, Gary A. Gaudet
 *	merging mips & ultrix for 8 bit clean and bug fixes
 */

#define BIGINDEX	9	/* largest desirable job index */

/*
 * pchild - called at interrupt level by the SIGCHLD signal
 *	indicating that at least one child has terminated or stopped
 *	thus at least one wait system call will definitely return a
 *	childs status.  Top level routines (like pwait) must be sure
 *	to mask interrupts when playing with the proclist data structures!
 */
pchild()
{
	register struct process *pp;
	register struct process	*fp;
	register int pid;
	union wait w;
	int jobflags;
	struct rusage ru;

loop:
	pid = wait3(&w, ((setintr && intty) ? WNOHANG|WUNTRACED:WNOHANG), &ru);
	if (pid <= 0) {
		if (errno == EINTR) {
			errno = 0;
			goto loop;
		}
		pnoprocesses = pid == -1;
		return;
	}
	for (pp = proclist.p_next; pp != PNULL; pp = pp->p_next)
		if (pid == pp->p_pid)
			goto found;
	goto loop;
found:
	if (pid == atoi(value("child")))
		unsetv("child");
	pp->p_flags &= ~(PRUNNING|PSTOPPED|PREPORTED);
	if (WIFSTOPPED(w)) {
		pp->p_flags |= PSTOPPED;
		pp->p_reason = w.w_stopsig;
	} else {
		if (pp->p_flags & (PTIME|PPTIME) || adrof("time"))
			(void) gettimeofday(&pp->p_etime, (struct timezone *)0);
		pp->p_rusage = ru;
		if (WIFSIGNALED(w)) {
			if (w.w_termsig == SIGINT)
				pp->p_flags |= PINTERRUPTED;
			else
				pp->p_flags |= PSIGNALED;
			if (w.w_coredump)
				pp->p_flags |= PDUMPED;
			pp->p_reason = w.w_termsig;
		} else {
			pp->p_reason = w.w_retcode;
			if (pp->p_reason != 0)
				pp->p_flags |= PAEXITED;
			else
				pp->p_flags |= PNEXITED;
		}
	}
	jobflags = 0;
	fp = pp;
	do {
		if ((fp->p_flags & (PPTIME|PRUNNING|PSTOPPED)) == 0 &&
		    !child && adrof("time") &&
		    fp->p_rusage.ru_utime.tv_sec+fp->p_rusage.ru_stime.tv_sec >=
		     atoi(value("time")))
			fp->p_flags |= PTIME;
		jobflags |= fp->p_flags;
	} while ((fp = fp->p_friends) != pp);
	pp->p_flags &= ~PFOREGND;
	if (pp == pp->p_friends && (pp->p_flags & PPTIME)) {
		pp->p_flags &= ~PPTIME;
		pp->p_flags |= PTIME;
	}
	if ((jobflags & (PRUNNING|PREPORTED)) == 0) {
		fp = pp;
		do {
			if (fp->p_flags&PSTOPPED)
				fp->p_flags |= PREPORTED;
		} while((fp = fp->p_friends) != pp);
		while(fp->p_pid != fp->p_jobid)
			fp = fp->p_friends;
		if (jobflags&PSTOPPED) {
			if (pcurrent && pcurrent != fp)
				pprevious = pcurrent;
			pcurrent = fp;
		} else
			pclrcurr(fp);
		if (jobflags&PFOREGND) {
			if (jobflags & (PSIGNALED|PSTOPPED|PPTIME) ||
#ifdef IIASA
			    jobflags & PAEXITED ||
#endif
			    !eq(dcwd->di_name, fp->p_cwd->di_name)) {
				;	/* print in pjwait */
			}
/*
		else if ((jobflags & (PTIME|PSTOPPED)) == PTIME)
				ptprint(fp);
*/
		} else {
			if (jobflags&PNOTIFY || adrof("notify")) {
				putchar ('\r' | QUOTE);
				putchar ('\n');
				(void) pprint(pp, NUMBER|NAME|REASON|NOISEOK);
				if ((jobflags&PSTOPPED) == 0)
					pflush(pp);
			} else {
				fp->p_flags |= PNEEDNOTE;
				neednote++;
			}
		}
	}
	goto loop;
}

pnote()
{
	register struct process *pp;
	int flags, omask;

	neednote = 0;
	for (pp = proclist.p_next; pp != PNULL; pp = pp->p_next) {
		if (pp->p_flags & PNEEDNOTE) {
			omask = sigblock(sigmask(SIGCHLD));
			pp->p_flags &= ~PNEEDNOTE;
			flags = pprint(pp, NUMBER|NAME|REASON|NOISEOK);
			if ((flags&(PRUNNING|PSTOPPED)) == 0)
				pflush(pp);
			(void) sigsetmask(omask);
		}
	}
}

/*
 * pwait - wait for current job to terminate, maintaining integrity
 *	of current and previous job indicators.
 */
pwait()
{
	register struct process *fp, *pp;
	int omask;

	/*
	 * Here's where dead procs get flushed.
	 */
	omask = sigblock(sigmask(SIGCHLD));
	for (pp = (fp = &proclist)->p_next; pp != PNULL; pp = (fp = pp)->p_next)
		if (pp->p_pid == 0) {
			fp->p_next = pp->p_next;
			xfree(pp->p_command);
			if (pp->p_cwd && --pp->p_cwd->di_count == 0)
				if (pp->p_cwd->di_next == 0)
					dfree(pp->p_cwd);
			xfree((char *)pp);
			pp = fp;
		}
	(void) sigsetmask(omask);
	pjwait(pcurrjob);
}

/*
 * pjwait - wait for a job to finish or become stopped
 *	It is assumed to be in the foreground state (PFOREGND)
 */
pjwait(pp)
	register struct process *pp;
{
	register struct process *fp;
	int jobflags, reason, omask;

	while (pp->p_pid != pp->p_jobid)
		pp = pp->p_friends;
	fp = pp;
	do {
		if ((fp->p_flags&(PFOREGND|PRUNNING)) == PRUNNING)
			csh_printf("BUG: waiting for background job!\n"); /* 004 RNF */
	} while ((fp = fp->p_friends) != pp);
	/*
	 * Now keep pausing as long as we are not interrupted (SIGINT),
	 * and the target process, or any of its friends, are running
	 */
	fp = pp;
	omask = sigblock(sigmask(SIGCHLD));
	for (;;) {
		jobflags = 0;
		do
			jobflags |= fp->p_flags;
		while ((fp = (fp->p_friends)) != pp);
		if ((jobflags & PRUNNING) == 0)
			break;
		sigpause(sigblock(0) &~ sigmask(SIGCHLD));
	}
	(void) sigsetmask(omask);
	if (tpgrp > 0)			/* get tty back */
		if (ioctl(FSHTTY, TIOCSPGRP, (char *)&tpgrp)) {	/* 002 - GAG */
			Perror ("ioctl");
		}
	if ((jobflags&(PSIGNALED|PSTOPPED|PTIME)) ||
	     !eq(dcwd->di_name, fp->p_cwd->di_name)) {
		if (jobflags&PSTOPPED)
			csh_printf("\n");			/* 004 RNF */
		(void) pprint(pp, AREASON|SHELLDIR);
	}
	if ((jobflags&(PINTERRUPTED|PSTOPPED)) && setintr &&
	    (!gointr || !eq(gointr, "-"))) {
		if ((jobflags & PSTOPPED) == 0)
			pflush(pp);
		pintr1(0);
		/*NOTREACHED*/
	}
	reason = 0;
	fp = pp;
	do {
		if (fp->p_reason)
			reason = fp->p_flags & (PSIGNALED|PINTERRUPTED) ?
				fp->p_reason | QUOTE : fp->p_reason;
	} while ((fp = fp->p_friends) != pp);
	set("status", putn(reason));
	if (reason && exiterr)
		exitstat();
	pflush(pp);
}

/*
 * dowait - wait for all processes to finish
 */
dowait()
{
	register struct process *pp;
	int omask;

	pjobs++;
	omask = sigblock(sigmask(SIGCHLD));
loop:
	for (pp = proclist.p_next; pp; pp = pp->p_next)
		if (pp->p_pid && /* pp->p_pid == pp->p_jobid && */
		    pp->p_flags&PRUNNING) {
			sigpause(0);
			goto loop;
		}
	(void) sigsetmask(omask);
	pjobs = 0;
}

/*
 * pflushall - flush all jobs from list (e.g. at fork())
 */
pflushall()
{
	register struct process	*pp;

	for (pp = proclist.p_next; pp != PNULL; pp = pp->p_next)
		if (pp->p_pid)
			pflush(pp);
}

/*
 * pflush - flag all process structures in the same job as the
 *	the argument process for deletion.  The actual free of the
 *	space is not done here since pflush is called at interrupt level.
 */
pflush(pp)
	register struct process	*pp;
{
	register struct process *np;
	register int index;

	if (pp->p_pid == 0) {
		csh_printf("BUG: process flushed twice");	/* 004 RNF */
		return;
	}
	while (pp->p_pid != pp->p_jobid)
		pp = pp->p_friends;
	pclrcurr(pp);
	if (pp == pcurrjob)
		pcurrjob = 0;
	index = pp->p_index;
	np = pp;
	do {
		np->p_index = np->p_pid = 0;
		np->p_flags &= ~PNEEDNOTE;
	} while ((np = np->p_friends) != pp);
	if (index == pmaxindex) {
		for (np = proclist.p_next, index = 0; np; np = np->p_next)
			if (np->p_index > index)
				index = np->p_index;
		pmaxindex = index;
	}
}

/*
 * pclrcurr - make sure the given job is not the current or previous job;
 *	pp MUST be the job leader
 */
pclrcurr(pp)
	register struct process *pp;
{

	if (pp == pcurrent)
		if (pprevious != PNULL) {
			pcurrent = pprevious;
			pprevious = pgetcurr(pp);
		} else {
			pcurrent = pgetcurr(pp);
			pprevious = pgetcurr(pp);
		}
	else if (pp == pprevious)
		pprevious = pgetcurr(pp);
}

/* +4 here is 1 for '\0', 1 ea for << >& >> */
char	command[PMAXLEN+4];
int	cmdlen;
char	*cmdp;
/*
 * palloc - allocate a process structure and fill it up.
 *	an important assumption is made that the process is running.
 */
palloc(pid, t)
	int pid;
	register struct command *t;
{
	register struct process	*pp;
	int i;

	pp = (struct process *)calloc((unsigned)1, (unsigned)sizeof(struct process));
	pp->p_pid = pid;
	pp->p_flags = t->t_dflg & FAND ? PRUNNING : PRUNNING|PFOREGND;
	if (t->t_dflg & FTIME)
		pp->p_flags |= PPTIME;
	cmdp = command;
	cmdlen = 0;
	padd(t);
	*cmdp++ = 0;
	if (t->t_dflg & FPOU) {
		pp->p_flags |= PPOU;
		if (t->t_dflg & FDIAG)
			pp->p_flags |= PDIAG;
	}
	pp->p_command = savestr(command);
	if (pcurrjob) {
		struct process *fp;
		/* careful here with interrupt level */
		pp->p_cwd = 0;
		pp->p_index = pcurrjob->p_index;
		pp->p_friends = pcurrjob;
		pp->p_jobid = pcurrjob->p_pid;
		for (fp = pcurrjob; fp->p_friends != pcurrjob; fp = fp->p_friends)
			;
		fp->p_friends = pp;
	} else {
		pcurrjob = pp;
		pp->p_jobid = pid;
		pp->p_friends = pp;
		pp->p_cwd = dcwd;
		dcwd->di_count++;
		if (pmaxindex < BIGINDEX)
			pp->p_index = ++pmaxindex;
		else {
			struct process *np;

			for (i = 1; ; i++) {
				for (np = proclist.p_next; np; np = np->p_next)
					if (np->p_index == i)
						goto tryagain;
				pp->p_index = i;
				if (i > pmaxindex)
					pmaxindex = i;
				break;			
			tryagain:;
			}
		}
		if (pcurrent == PNULL)
			pcurrent = pp;
		else if (pprevious == PNULL)
			pprevious = pp;
	}
	pp->p_next = proclist.p_next;
	proclist.p_next = pp;
	(void) gettimeofday(&pp->p_btime, (struct timezone *)0);
}

padd(t)
	register struct command *t;
{
	char **argp;

	if (t == 0)
		return;
	switch (t->t_dtyp) {

	case TPAR:
		pads("( ");
		padd(t->t_dspr);
		pads(" )");
		break;

	case TCOM:
		for (argp = t->t_dcom; *argp; argp++) {
			pads(*argp);
			if (argp[1])
				pads(" ");
		}
		break;

	case TOR:
	case TAND:
	case TFIL:
	case TLST:
		padd(t->t_dcar);
		switch (t->t_dtyp) {
		case TOR:
			pads(" || ");
			break;
		case TAND:
			pads(" && ");
			break;
		case TFIL:
			pads(" | ");
			break;
		case TLST:
			pads("; ");
			break;
		}
		padd(t->t_dcdr);
		return;
	}
	if ((t->t_dflg & FPIN) == 0 && t->t_dlef) {
		pads((t->t_dflg & FHERE) ? " << " : " < ");
		pads(t->t_dlef);
	}
	if ((t->t_dflg & FPOU) == 0 && t->t_drit) {
		pads((t->t_dflg & FCAT) ? " >>" : " >");
		if (t->t_dflg & FDIAG)
			pads("&");
		pads(" ");
		pads(t->t_drit);
	}
}

pads(cp)
	char *cp;
{
	register int i = strlen(cp);

	if (cmdlen >= PMAXLEN)
		return;
	if (cmdlen + i >= PMAXLEN) {
		(void) strcpy(cmdp, " ...");
		cmdlen = PMAXLEN;
		cmdp += 4;
		return;
	}
	(void) strcpy(cmdp, cp);
	cmdp += i;
	cmdlen += i;
}

/*
 * psavejob - temporarily save the current job on a one level stack
 *	so another job can be created.  Used for { } in exp6
 *	and `` in globbing.
 */
psavejob()
{

	pholdjob = pcurrjob;
	pcurrjob = PNULL;
}

/*
 * prestjob - opposite of psavejob.  This may be missed if we are interrupted
 *	somewhere, but pendjob cleans up anyway.
 */
prestjob()
{

	pcurrjob = pholdjob;
	pholdjob = PNULL;
}

/*
 * pendjob - indicate that a job (set of commands) has been completed
 *	or is about to begin.
 */
pendjob()
{
	register struct process *pp, *tp;

	if (pcurrjob && (pcurrjob->p_flags&(PFOREGND|PSTOPPED)) == 0) {
		pp = pcurrjob;
		while (pp->p_pid != pp->p_jobid)
			pp = pp->p_friends;
		csh_printf("[%d]", pp->p_index);		/* 004 RNF */
		tp = pp;
		do {
			csh_printf(" %d", pp->p_pid);		/* 004 RNF */
			pp = pp->p_friends;
		} while (pp != tp);
		csh_printf("\n");				/* 004 RNF */
	}
	pholdjob = pcurrjob = 0;
}

/*
 * pprint - print a job
 */
pprint(pp, flag)
	register struct process	*pp;
{
	register status, reason;
	struct process *tp;
	extern char *linp, linbuf[];
	int jobflags, pstatus;
	char *format;

	while (pp->p_pid != pp->p_jobid)
		pp = pp->p_friends;