jobs.h

操作系统源代码

/*-
 * Copyright (c) 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * 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.
 *
 *	@(#)jobs.h	5.1 (Berkeley) 3/7/91
 */

/* Mode argument to forkshell.  Don't change FORK_FG or FORK_BG. */
#define FORK_FG 0
#define FORK_BG 1
#define FORK_NOJOB 2


/*
 * A job structure contains information about a job.  A job is either a
 * single process or a set of processes contained in a pipeline.  In the
 * latter case, pidlist will be non-NULL, and will point to a -1 terminated
 * array of pids.
 */

struct procstat {
	short pid;		/* process id */
	short status;		/* status flags (defined above) */
	char *cmd;		/* text of command being run */
};


/* states */
#define JOBSTOPPED 1		/* all procs are stopped */
#define JOBDONE 2		/* all procs are completed */


struct job {
	struct procstat ps0;	/* status of process */
	struct procstat *ps;	/* status or processes when more than one */
	short nprocs;		/* number of processes */
	short pgrp;		/* process group of this job */
	char state;		/* true if job is finished */
	char used;		/* true if this entry is in used */
	char changed;		/* true if status has changed */
#if JOBS
	char jobctl;		/* job running under job control */
#endif
};

extern short backgndpid;	/* pid of last background process */


#ifdef __STDC__
void setjobctl(int);
void showjobs(int);
struct job *makejob(union node *, int);
int forkshell(struct job *, union node *, int);
int waitforjob(struct job *);
#else
void setjobctl();
void showjobs();
struct job *makejob();
int forkshell();
int waitforjob();
#endif

#if ! JOBS
#define setjobctl(on)	/* do nothing */
#endif