proc.c

早期freebsd实现

/*-
 * Copyright (c) 1980, 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char sccsid[] = "@(#)proc.c	8.1 (Berkeley) 5/31/93";
#endif /* not lint */

#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#if __STDC__
# include <stdarg.h>
#else
# include <varargs.h>
#endif

#include "csh.h"
#include "dir.h"
#include "proc.h"
#include "extern.h"

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

static struct rusage zru;

static void	 pflushall __P((void));
static void	 pflush __P((struct process *));
static void	 pclrcurr __P((struct process *));
static void	 padd __P((struct command *));
static int	 pprint __P((struct process *, int));
static void	 ptprint __P((struct process *));
static void	 pads __P((Char *));
static void	 pkill __P((Char **v, int));
static struct	process
		*pgetcurr __P((struct process *));
static void	 okpcntl __P((void));

/*
 * 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!
 */
/* ARGUSED */
void
pchild(notused)
	int notused;
{
    register struct process *pp;
    register struct process *fp;
    register int pid;
    extern int insource;
    union wait w;
    int     jobflags;
    struct rusage ru;

loop:
    errno = 0;			/* reset, just in case */
    pid = wait3(&w.w_status,
       (setintr && (intty || insource) ? WNOHANG | WUNTRACED : WNOHANG), &ru);

    if (pid <= 0) {
	if (errno == EINTR) {
	    errno = 0;
	    goto loop;
	}
	pnoprocesses = pid == -1;
	return;
    }
    for (pp = proclist.p_next; pp != NULL; pp = pp->p_next)
	if (pid == pp->p_pid)
	    goto found;
    goto loop;
found:
    if (pid == atoi(short2str(value(STRchild))))
	unsetv(STRchild);
    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(STRtime))
	    (void) gettimeofday(&pp->p_etime, NULL);

	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(STRtime) &&
	    fp->p_rusage.ru_utime.tv_sec + fp->p_rusage.ru_stime.tv_sec
	    >= atoi(short2str(value(STRtime))))
	    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 */
	    }
	    /* PWP: print a newline after ^C */
	    else if (jobflags & PINTERRUPTED) {
		(void) vis_fputc('\r' | QUOTE, cshout);
		(void) fputc('\n', cshout);
	    }
	}
	else {
	    if (jobflags & PNOTIFY || adrof(STRnotify)) {
		(void) vis_fputc('\r' | QUOTE, cshout);
		(void) fputc('\n', cshout);
		(void) pprint(pp, NUMBER | NAME | REASON);
		if ((jobflags & PSTOPPED) == 0)
		    pflush(pp);
	    }
	    else {
		fp->p_flags |= PNEEDNOTE;
		neednote++;
	    }
	}
    }
    goto loop;
}

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

    neednote = 0;
    for (pp = proclist.p_next; pp != NULL; pp = pp->p_next) {
	if (pp->p_flags & PNEEDNOTE) {
	    omask = sigblock(sigmask(SIGCHLD));
	    pp->p_flags &= ~PNEEDNOTE;
	    flags = pprint(pp, NUMBER | NAME | REASON);
	    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.
 */
void
pwait()
{
    register struct process *fp, *pp;
    sigset_t omask;

    /*
     * Here's where dead procs get flushed.
     */
    omask = sigblock(sigmask(SIGCHLD));
    for (pp = (fp = &proclist)->p_next; pp != NULL; pp = (fp = pp)->p_next)
	if (pp->p_pid == 0) {
	    fp->p_next = pp->p_next;
	    xfree((ptr_t) 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((ptr_t) 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)
 */
void
pjwait(pp)
    register struct process *pp;
{
    register struct process *fp;
    int     jobflags, reason;
    sigset_t omask;

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

    do {
	if ((fp->p_flags & (PFOREGND | PRUNNING)) == PRUNNING)
	    (void) fprintf(csherr, "BUG: waiting for background job!\n");
    } 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 (;;) {
	(void) sigblock(sigmask(SIGCHLD));
	jobflags = 0;
	do
	    jobflags |= fp->p_flags;
	while ((fp = (fp->p_friends)) != pp);
	if ((jobflags & PRUNNING) == 0)
	    break;
#ifdef JOBDEBUG
	(void) fprintf(csherr, "starting to sigpause for  SIGCHLD on %d\n",
		       fp->p_pid);
#endif				/* JOBDEBUG */
	(void) sigpause(omask & ~sigmask(SIGCHLD));
    }
    (void) sigsetmask(omask);
    if (tpgrp > 0)		/* get tty back */
	(void) tcsetpgrp(FSHTTY, tpgrp);
    if ((jobflags & (PSIGNALED | PSTOPPED | PTIME)) ||
	!eq(dcwd->di_name, fp->p_cwd->di_name)) {
	if (jobflags & PSTOPPED) {
	    (void) fputc('\n', cshout);
	    if (adrof(STRlistjobs)) {
		Char   *jobcommand[3];

		jobcommand[0] = STRjobs;
		if (eq(value(STRlistjobs), STRlong))
		    jobcommand[1] = STRml;
		else
		    jobcommand[1] = NULL;
		jobcommand[2] = NULL;

		dojobs(jobcommand, NULL);
		(void) pprint(pp, SHELLDIR);
	    }
	    else
		(void) pprint(pp, AREASON | SHELLDIR);
	}
	else
	    (void) pprint(pp, AREASON | SHELLDIR);
    }
    if ((jobflags & (PINTERRUPTED | PSTOPPED)) && setintr &&
	(!gointr || !eq(gointr, STRminus))) {
	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 | META : fp->p_reason;
    } while ((fp = fp->p_friends) != pp);
    if ((reason != 0) && (adrof(STRprintexitvalue))) {
	(void) fprintf(cshout, "Exit %d\n", reason);
    }
    set(STRstatus, putn(reason));
    if (reason && exiterr)
	exitstat();
    pflush(pp);
}

/*
 * dowait - wait for all processes to finish
 */
void
/*ARGSUSED*/
dowait(v, t)
    Char **v;
    struct command *t;
{
    register struct process *pp;
    sigset_t 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) {
	    (void) sigpause((sigset_t) 0);
	    goto loop;
	}
    (void) sigsetmask(omask);
    pjobs = 0;
}

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

    for (pp = proclist.p_next; pp != NULL; 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.
 */
static void
pflush(pp)
    register struct process *pp;
{
    register struct process *np;
    register int idx;

    if (pp->p_pid == 0) {
	(void) fprintf(csherr, "BUG: process flushed twice");
	return;
    }
    while (pp->p_pid != pp->p_jobid)
	pp = pp->p_friends;
    pclrcurr(pp);
    if (pp == pcurrjob)
	pcurrjob = 0;
    idx = pp->p_index;
    np = pp;
    do {
	np->p_index = np->p_pid = 0;
	np->p_flags &= ~PNEEDNOTE;
    } while ((np = np->p_friends) != pp);
    if (idx == pmaxindex) {
	for (np = proclist.p_next, idx = 0; np; np = np->p_next)
	    if (np->p_index > idx)
		idx = np->p_index;
	pmaxindex = idx;
    }
}

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

    if (pp == pcurrent)
	if (pprevious != NULL) {
	    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 << >& >> */
static Char command[PMAXLEN + 4];
static int cmdlen;
static Char *cmdp;

/*
 * palloc - allocate a process structure and fill it up.
 *	an important assumption is made that the process is running.
 */
void
palloc(pid, t)
    int     pid;
    register struct command *t;
{
    register struct process *pp;
    int     i;

    pp = (struct process *) xcalloc(1, (size_t) sizeof(struct process));
    pp->p_pid = pid;
    pp->p_flags = t->t_dflg & F_AMPERSAND ? PRUNNING : PRUNNING | PFOREGND;
    if (t->t_dflg & F_TIME)
	pp->p_flags |= PPTIME;